diff --git "a/raw_rss_feeds/https___arxiv_org_rss_physics.xml" "b/raw_rss_feeds/https___arxiv_org_rss_physics.xml" --- "a/raw_rss_feeds/https___arxiv_org_rss_physics.xml" +++ "b/raw_rss_feeds/https___arxiv_org_rss_physics.xml" @@ -7,4098 +7,2212 @@ http://www.rssboard.org/rss-specification en-us - Tue, 09 Dec 2025 05:00:07 +0000 + Wed, 10 Dec 2025 05:00:03 +0000 rss-help@arxiv.org - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 Saturday Sunday - The rationality of radical pair mechanism in real biological systems - https://arxiv.org/abs/2512.05974 - arXiv:2512.05974v1 Announce Type: new -Abstract: The radical pair mechanism (RPM) in the chemical magnetic compass model is considered to be one of the most promising candidates for the avian magnetic navigation, and quantum needle phenomenon further boosts the navigation precision to a new high level. It is well known that there are also a variety of methods in the field of magnetic field sensing in laboratory, e.g. Ramsey protocol of NV centers in diamond. Here, we compare the RPM model and Ramsey-like model under laboratory conditions and under in vivo conditions respectively. The results are both surprising and reasonable. Under laboratory conditions, if we have precise control over time and a reasonably accurate prior knowledge of the magnetic field direction, the Ramsey-like model will outperform the RPM model. However, when such information is unavailable, as under in vivo conditions, the RPM model stands out. The RPM model achieves greater practicality at the cost of reduced accuracy. - oai:arXiv.org:2512.05974v1 - physics.bio-ph - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Xiaoyu Chen, Haibin Liu, Jianming Cai - - - Physics Enhanced Deep Surrogates for the Phonon Boltzmann Transport Equation - https://arxiv.org/abs/2512.05976 - arXiv:2512.05976v1 Announce Type: new -Abstract: Designing materials with controlled heat flow at the nano-scale is central to advances in microelectronics, thermoelectrics, and energy-conversion technologies. At these scales, phonon transport follows the Boltzmann Transport Equation (BTE), which captures non-diffusive (ballistic) effects but is too costly to solve repeatedly in inverse-design loops. Existing surrogate approaches trade speed for accuracy: fast macroscopic solvers can overestimate conductivities by hundreds of percent, while recent data-driven operator learners often require thousands of high-fidelity simulations. This creates a need for a fast, data-efficient surrogate that remains reliable across ballistic and diffusive regimes. We introduce a Physics-Enhanced Deep Surrogate (PEDS) that combines a differentiable Fourier solver with a neural generator and couples it with uncertainty-driven active learning. The Fourier solver acts as a physical inductive bias, while the network learns geometry-dependent corrections and a mixing coefficient that interpolates between macroscopic and nano-scale behavior. PEDS reduces training-data requirements by up to 70% compared with purely data-driven baselines, achieves roughly 5% fractional error with only 300 high-fidelity BTE simulations, and enables efficient design of porous geometries spanning 12-85 W m$^{-1}$ K$^{-1}$ with average design errors of 4%. The learned mixing parameter recovers the ballistic-diffusive transition and improves out of distribution robustness. These results show that embedding simple, differentiable low-fidelity physics can dramatically increase surrogate data-efficiency and interpretability, making repeated PDE-constrained optimization practical for nano-scale thermal-materials design. - oai:arXiv.org:2512.05976v1 - physics.comp-ph - cs.LG - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Antonio Varagnolo, Giuseppe Romano, Rapha\"el Pestourie - - - Autoencoder-based time series anomaly detection for ATLAS Liquid Argon calorimeter data quality monitoring - https://arxiv.org/abs/2512.05977 - arXiv:2512.05977v1 Announce Type: new -Abstract: The ATLAS experiment at the LHC employs comprehensive data quality monitoring procedures to ensure high-quality physics data. This contribution presents a long short-term memory autoencoder-based algorithm for detecting anomalies in ATLAS Liquid Argon calorimeter data, represented as multidimensional time series of statistical moments of energy cluster properties. Trained on good-quality data, the model identifies anomalous intervals. Validation is performed using a known short-term issue of noise bursts, and the potential for broader application to transient calorimeter issues is discussed. - oai:arXiv.org:2512.05977v1 - physics.ins-det - hep-ex - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Vilius \v{C}epaitis (on behalf of the ATLAS collaboration) - - - Data-Driven Model for Elastomers under Simultaneous Thermal and Radiation Exposure - https://arxiv.org/abs/2512.05978 - arXiv:2512.05978v1 Announce Type: new -Abstract: We present a physics-informed neural network framework for predicting the mechanical performance of elastomers exposed to concurrent thermal and gamma-radiation exposure, such as elastomers in nuclear cables or space electronics. Our demonstrated approach integrates the dual-network hypothesis with the microsphere concept to represent soft and brittle sub-networks, while embedding physical laws directly into the machine learning process. - Hard constraints, e.g., incompressibility, bounded network fractions are enforced through network architecture, and soft constraints e.g., monotonicity, polyconvexity, and fading effects are imposed through the loss function. This integration reduces the effective search space, guiding the optimization toward physically admissible solutions and enhancing robustness under sparse data. Validation against published datasets on silicone rubber, ethylene propylene diene monomer, and silica-reinforced silicone foam shows accurate predictions of stress-strain behavior and elongation-at-break at exposure times not used for training. Results confirm that physics-informed constraints improve extrapolation, capture synergistic thermal-radiation effects, and provide a reliable tool for lifetime assessment of nuclear cable insulation and other radiation-exposed elastomers. - oai:arXiv.org:2512.05978v1 - physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Pouyan Nasiri, Leonard S. Fifield, Hadis Nouri, Roozbeh Dargazany - - - Accelerating Materials Discovery: Learning a Universal Representation of Chemical Processes for Cross-Domain Property Prediction - https://arxiv.org/abs/2512.05979 - arXiv:2512.05979v1 Announce Type: new -Abstract: Experimental validation of chemical processes is slow and costly, limiting exploration in materials discovery. Machine learning can prioritize promising candidates, but existing data in patents and literature is heterogeneous and difficult to use. We introduce a universal directed-tree process-graph representation that unifies unstructured text, molecular structures, and numeric measurements into a single machine-readable format. To learn from this structured data, we developed a multi-modal graph neural network with a property-conditioned attention mechanism. Trained on approximately 700,000 process graphs from nearly 9,000 diverse documents, our model learns semantically rich embeddings that generalize across domains. When fine-tuned on compact, domain-specific datasets, the pretrained model achieves strong performance, demonstrating that universal process representations learned at scale transfer effectively to specialized prediction tasks with minimal additional data. - oai:arXiv.org:2512.05979v1 - physics.chem-ph - cs.AI - cs.DM - cs.LG - Tue, 09 Dec 2025 00:00:00 -0500 + Normal form computation of nonlinear dispersion relationship for locally resonant metamaterial + https://arxiv.org/abs/2512.07861 + arXiv:2512.07861v1 Announce Type: new +Abstract: This article is devoted to the application of the parametrisation method for invariant manifold with a complex normal form style (CNF), for the derivation of high-order approximations of underdamped nonlinear dispersion relationships for periodic structures, more specifically by considering the case of a locally resonant metamaterial chain incorporating damping and various nonlinear stiffnesses. Two different strategies are proposed to solve the problem. In the first one, Bloch's assumption is first applied to the equations of motion, and then the nonlinear change of coordinates provided by the complex normal form style in the parametrisation method is applied. This direct procedure, which applies first the wave dependency to the original physical coordinates of the problem, is referred to as CNF-BP (for CNF applied with Bloch's assumption on physical coordinates). In the second strategy, the nonlinear change of coordinates provided by the parametrisation method, which relates the physical coordinates to the so-called normal coordinates, is first applied. Then the periodic assumption is used, thus imposing a Bloch wave ansatz on the normal coordinates. This method will be referred to as CNF-PN (for CNF with a periodic assumption on normal coordinates). In the conservative case, the CNF-PN strategy exhibits superior capability in capturing complex wave propagation phenomena, whereas the CNF-BP strategy encounters limitations in handling non-fundamental harmonics and the nonlinear interactions between host oscillators. For underdamped systems, the CNF-PN is rigorously validated and systematically compared against numerical techniques, a classical analytical perturbation technique (the method of multiple scales), and direct numerical time integration of annular chain structures. + oai:arXiv.org:2512.07861v1 + physics.optics + math.DS + physics.app-ph + physics.class-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Mikhail Tsitsvero, Atsuyuki Nakao, Hisaki Ikebata - - - Quenching factors for Na recoils as a function of Tl dopant concentrations in NaI(Tl) crystals - https://arxiv.org/abs/2512.05980 - arXiv:2512.05980v1 Announce Type: new -Abstract: Thallium-doped sodium iodide (NaI(Tl)) scintillation detectors play an important role in the field of direct dark matter (DM) searches. The DAMA/LIBRA experiment stands out for its reported observation of an annually modulating DM-like signal, which is in direct contrast with other results. To accurately calibrate the energies of nuclear recoil signals with electron recoils, precise measurements of the quenching factor of the NaI(Tl) crystals are essential, as the two processes have different scintillation light yield. In this article, we present results of a systematic study carried out by the COSINUS collaboration and Duke University to measure the quenching factor of sodium (Na) recoils as a function of nuclear recoil energy and for differing Thallium (Tl) dopant concentrations in the bulk crystal. Five ultrapure NaI(Tl) crystals, manufactured by the Shanghai Institute for Ceramics, were irradiated with a quasi-monoenergetic neutron beam at the Triangle Universities Nuclear Laboratory, North Carolina, USA. The quenching factor for low nuclear recoil energies of 5-26keV$_{nr}$ was extracted for all 5 crystals. A Tl-dependence could be deduced with a proportional response calibration schema using a $^{241}$Am source. However, this effect was not observed when using a low-energy calibration line from $^{133}$Ba. - oai:arXiv.org:2512.05980v1 - physics.ins-det - astro-ph.CO - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - G. Angloher, M. R. Bharadwaj, A. B\"ohmer, M. Cababie, I. Colantoni, I. Dafinei, N. Di Marco, C. Dittmar, L. Einfalt, F. Ferrella, F. Ferroni, S. Fichtinger, A. Filipponi, T. Frank, M. Friedl, M. Gapp, L. Gai, Z. Ge, M. Heikinheimo, M. N. Hughes, K. Huitu, M. Kellermann, R. Maji, M. Mancuso, L. Pagnanini, F. Petricca, S. Pirro, F. Pr\"obst, G. Profeta, A. Puiu, F. Reindl, K. Sch\"affner, J. Schieck, P. Schreiner, C. Schwertner, K. Shera, M. Stahlberg, A. Stendahl, M. Stukel, C. Tresca, F. Wagner, S. Yue, V. Zema, Y. Zhu, P. S. Barbeau, S. C. Hedges, C. Awe, J. Runge, T. Johnson, D. M. Markoff, P. An, C. G. Prior, A. Bracho, S. Alawabdeh + Tao Wang, Cyril Touz\'e, Haiqin Li, Qian Ding - FlockVote: LLM-Empowered Agent-Based Modeling for Simulating U.S. Presidential Elections - https://arxiv.org/abs/2512.05982 - arXiv:2512.05982v1 Announce Type: new -Abstract: Modeling complex human behavior, such as voter decisions in national elections, is a long-standing challenge for computational social science. Traditional agent-based models (ABMs) are limited by oversimplified rules, while large-scale statistical models often lack interpretability. We introduce FlockVote, a novel framework that uses Large Language Models (LLMs) to build a "computational laboratory" of LLM agents for political simulation. Each agent is instantiated with a high-fidelity demographic profile and dynamic contextual information (e.g. candidate policies), enabling it to perform nuanced, generative reasoning to simulate a voting decision. We deploy this framework as a testbed on the 2024 U.S. Presidential Election, focusing on seven key swing states. Our simulation's macro-level results successfully replicate the real-world outcome, demonstrating the high fidelity of our "virtual society". The primary contribution is not only the prediction, but also the framework's utility as an interpretable research tool. FlockVote moves beyond black-box outputs, allowing researchers to probe agent-level rationale and analyze the stability and sensitivity of LLM-driven social simulations. - oai:arXiv.org:2512.05982v1 - physics.soc-ph + Referenceless Proton Resonance Frequency Thermometry Using Deep Learning with Self-Attention + https://arxiv.org/abs/2512.07882 + arXiv:2512.07882v1 Announce Type: new +Abstract: Background: Accurate proton resonance frequency (PRF) MR thermometry is essential for monitoring temperature rise during thermal ablation with high intensity focused ultrasound (FUS). Conventional referenceless methods such as complex field estimation (CFE) and phase finite difference (PFD) tend to exhibit errors when susceptibility-induced phase discontinuities occur at tissue interfaces. + oai:arXiv.org:2512.07882v1 + physics.med-ph cs.AI - cs.MA - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Lingfeng Zhou, Yi Xu, Zhenyu Wang, Dequan Wang + Yueran Zhao, Chang-Sheng Mei, Nathan J. McDannold, Shenyan Zong, Guofeng Shen - Dual-moon forced dynamics and nonlinear aggregation in Saturn's F ring: From quasi-periodicity to modulated oscillations - https://arxiv.org/abs/2512.05984 - arXiv:2512.05984v1 Announce Type: new -Abstract: We develop a minimal nonlinear model to investigate the oscillatory dynamics of Saturn's F ring under dual-moon forcing from Prometheus and Pandora. The model extends classical predator--prey dynamics by incorporating both a nonlinear mass aggregation term $kM^n$ and explicit dual-frequency forcing, capturing how higher-order coagulation physics interacts with multi-moon perturbations. Through extensive numerical integration and dynamical systems analysis, including time-series, spectral, stroboscopic mapping, and rotation number diagnostics, we identify distinct dynamical regimes controlled by the parameters $n$ and $k$. - For moderate nonlinearity $(n=1.28, k=0.54)$, the system exhibits regular quasi-periodic motion on a two-torus, characterized by smooth amplitude modulation and discrete spectral lines. As nonlinearity increases $(n=1.30, k=0.62)$, the dynamics transition to strongly modulated oscillations with intermittent phase slips, broadened Poincar\'e bands, and sideband-rich spectra. A rotation number heatmap reveals organized structures in parameter space, with smooth quasi-periodic regions bounded by near-locking bands analogous to Arnold tongues. - Our results demonstrate that the F ring's complex morphology can emerge from deterministic multi-frequency dynamics rather than stochastic processes, with the system operating near critical boundaries where small parameter variations can trigger macroscopic reorganization. The model provides a framework for understanding pattern formation in other driven granular systems while offering testable predictions for ring observations. - oai:arXiv.org:2512.05984v1 - physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Idealized Cumulus Cloud-Scale Motions and the Dynamics of Isolated and Coupled Flows + https://arxiv.org/abs/2512.07889 + arXiv:2512.07889v1 Announce Type: new +Abstract: Developing an understandable theory for the dynamic evolution of the morphology of clouds remains intractable. To break this deadlock, we introduce a new conceptual model for cloud-scale motions named the Kinematics Representation of Non-rotating Updraft Tori (KRoNUT) model, where non-rotating reflects the absence of motion in the azimuthal direction. Using this model, we conduct a series of relaxation experiments whereby we ``turn off'' the baroclinic term associated with a pre-existing cloud-scale circulation. We then implement a moment reduction technique to generate a system of differential equations named the Dynamics of Non-rotating Updraft Tori (DoNUT) equations, which describe the temporal evolution of a cloudy circulation under various combinations of forcings, namely turbulent diffusion, self-advection, and cross-advection from a neighboring cloud-scale flow. The solutions of the DoNUT equations show that all single KRoNUT configurations either start at or evolve toward a specific steady state circulation. The cloud-scale motions represented by the current KRoNUT model always grow vertically but may narrow, due to advection, or widen, due to diffusion. Meanwhile, invigoration or enervation of the vertical velocity may result from advection or diffusion processes, with short, wide KRoNUTs more likely to invigorate and tall, narrow KRoNUTs likely to enervate. Our study of the coupled KRoNUTs provides insight into clouds' tendencies to attract or repel one another. Important results of the coupled KRoNUT analysis include a scaled metric for interaction, ranges of specific height ratios that induce the most meaningful interaction, and circulation parameters that alter the location and stability of a steady KRoNUT. + oai:arXiv.org:2512.07889v1 + physics.flu-dyn + physics.ao-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Omar El Deeb + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Dario P. Falcone, Matthew R. Igel, Joseph A. Biello - Stochastic Quantum Gravity - https://arxiv.org/abs/2512.05985 - arXiv:2512.05985v1 Announce Type: new -Abstract: This work explores the possibility of applying stochastic quantum mechanics to curved spacetimes, with an emphasis on the Schwarzschild black hole. After reviewing the fundamental concepts of this approach, the quantum stochastic equations are extended to curved spacetime using a fully covariant treatment. Subsequently, the Klein-Gordon equation is solved for scalar perturbations, and the resulting stochastic trajectories are analyzed by varying parameters such as angular momentum, particle frequency, and computational integration time. In conclusion, we find that the trajectories are influenced by gravitational fluctuations in spacetime and that, depending on the variation of the fundamental parameters, different types of stochastic trajectories are obtained. - oai:arXiv.org:2512.05985v1 - physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 + The effects of H blistering and ELMs on the thermal fatigue cracking of W by strikepoint sweeping + https://arxiv.org/abs/2512.07891 + arXiv:2512.07891v1 Announce Type: new +Abstract: Cyclic thermal loads imposed on a W divertor by strikepoint sweeping may induce low-cycle thermal fatigue cracking of its plasma-facing surfaces. This cracking may be accelerated by plasma-material interactions such as H implantation, blistering, fuzz and void formation. Fatigue cracking may also synergise with ELM cracking. To explore these novel forms of environmentally assisted fatigue, FEA modelling was used to design a uniaxial fatigue experiment for Magnum-PSI that represents strikepoint sweeping at 1 Hz across a 100 mm span of a divertor target. Magnum-PSI was used to combine cyclic thermal loading of W with H implantation and two forms of ELM like pre-cracking. Quantitative SEM analysis of fatigue-cracked W revealed that H implantation significantly delayed crack initiation, with preimplanted targets requiring 450-600 cycles before failure compared to 150 cycles for non-implanted samples. This was attributed to hydrogen-induced dislocation pinning, which produces a case-hardening effect that inhibits persistent slip band formation. ELM-like pre-cracking combined with strikepoint sweeping was found to give rise to localised melting and the formation of 30 micromete diameter droplets, caused by thermal isolation of W regions by fatigue cracks. The implications for the fatigue lifetime of tokamak divertors are also discussed. + oai:arXiv.org:2512.07891v1 + physics.plasm-ph + cond-mat.mtrl-sci + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Juan S. Jerez- Rodr\'iguez, Eric S. Escobar-Aguilar, Tonatiuh Matos + http://creativecommons.org/licenses/by-sa/4.0/ + J. Hargreaves, J. Vernimmen, J. Scholten, T. W Morgan - Detuning-insensitive wide-field imaging of vector microwave fields with diamond sensors - https://arxiv.org/abs/2512.05986 - arXiv:2512.05986v1 Announce Type: new -Abstract: Nitrogen vacancy (NV) centers in diamond have precipitated profound advances in microwave detection, manifesting themselves both in spatial resolution and sensitivity. However, typical methods based on Rabi oscillations are subject to detunings due to thermal and magnetic fluctuations and/or gradients, which introduce systematic errors and render the measurements susceptible to environmental perturbations. Here, we propose and demonstrate a novel approach for determining both the magnitude and direction of microwaves, by exploiting the spectral line broadening effect in the optically detected magnetic resonance of NV centers. This method eliminates the requirement of aligning the MW frequency to the spin transitions and is therefore immune to variations and inhomogeneities of the magnetic field and temperature, providing an optimal tool for fast imaging applications. With this method, we achieved wide-field imaging of near field microwaves generated with a microscale $\rm{\Omega}$-pattern antenna with a resolution of 800\,nm. Combining with the vector detection using multi-axis NVs, a full reconstruction of the vector microwave fields is obtained. Besides, our scheme also exhibits excellent linearity over a broad range of MW amplitudes, and the scale is theoretically calculated to be more than four orders. Our results augment the applicability of diamond-based microwave devices in applications under complex scenarios, especially where large dynamic range, fast test speed, and high spatial resolution are demanded. - oai:arXiv.org:2512.05986v1 - physics.ins-det - cond-mat.mes-hall - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Kinetic Alfv\'en waves in the temperature anisotropic space plasma with a kappa-Maxwellian distribution + https://arxiv.org/abs/2512.07893 + arXiv:2512.07893v1 Announce Type: new +Abstract: The dispersion and damping rate of kinetic Alfv\'en waves are studied in temperature anisotropic space plasma with kappa-Maxwellian distribution. Employing a kinetic approach, the wave frequency and damping rate of kinetic Alfv\'en waves and the modified ion acoustic waves are derived in a low \b{eta} plasma, which both depend on the parameters \k{appa} and . The numerical analyses show that the wave frequency of kinetic Alfv\'en waves is larger in kappa-Maxwellian plasma than that in Maxwellian case. The wave frequency of the modified ion acoustic waves in kappa-Maxwellian plasma is larger in the short-wave region but smaller in the long-wave region than that in Maxwellian case. Again, we found that the damping rate of kinetic Alfv\'en waves in kappa-Maxwellian plasma is stronger than that in Maxwellian case. The damping rate of modified ion acoustic waves in kappa-Maxwellian plasma is stronger in the short-wave region but weaker in the long-wave region than that in Maxwellian case. The impact of the parameter on the two modes is relatively small because we consider the low \b{eta} case. These results are helpful for us to understand better the characteristics of kinetic Alfv\'en waves in space plasma. + oai:arXiv.org:2512.07893v1 + physics.plasm-ph + physics.space-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Xiu-Qi Chen, Rui-Zhi Zhang, Gang-Qin Liu, Huijie Zheng + http://creativecommons.org/licenses/by/4.0/ + Chin. J. Phys. 90 (2024) 199 + Rui Huo, Jiulin Du, Ran Guo - Kirchhoff`s Forgotten Contributions to Electromagnetism: Continuity Equation versus Displacement Currents - https://arxiv.org/abs/2512.05997 - arXiv:2512.05997v1 Announce Type: new -Abstract: In 1857, Kirchhoff published two seminal papers on the motion of electricity in wires. In that work, he was the first to derive what we now call the telegrapher`s equations, which describes the propagation of electromagnetic signals along a cable at the speed of light, in some conditions. How was Kirchhoff able to describe electromagnetic propagation as early as 1857, when the notion of displacement current which is believed to be the essential ingredient for the propagation of electric and magnetic fields was not introduced by Maxwell until 1861 and fully explained later in 1865? In this paper, we show that Kirchhoff was the first, in his 1857 paper, to introduce the continuity equation when discussing electromagnetic propagation. We argue that the continuity equation used by Kirchhoff is a more fundamental concept now as it was in 1865 than displacement current. In our view, the dynamics of charged particles can be formulated without invoking fields, but the dynamics of fields cannot be formulated without a continuity equation describing the properties of matter. - oai:arXiv.org:2512.05997v1 - physics.hist-ph - physics.class-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Firehose instability in the space plasma with anisotropic Cairns-distribution electrons + https://arxiv.org/abs/2512.07894 + arXiv:2512.07894v1 Announce Type: new +Abstract: We study the electron firehose mode propagating parallel to the ambient magnetic field in the space plasma with anisotropic Cairns-distribution electrons. The dispersion relation, the wave frequency and the growth rate of electron firehose mode are derived, and the condition for onset of the firehose instability is obtained. We show that the wave frequency and the growth rate both depend significantly on the parameters, such as the parallel electron beta , the nonthermal parameter {\Lambda} and the electron temperature anisotropy Ae , and the anisotropic Cairns-distribution electrons change the instability condition. The numerical analyses show that the wave frequency and the growth rate of the electron firehose mode increase with increase of the parameters. The results may be helpful for understanding the firehose instability in space plasma environments. + oai:arXiv.org:2512.07894v1 + physics.plasm-ph + physics.space-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Xavier Oriols, Robert Eisenberg, David K. Ferry + http://creativecommons.org/licenses/by/4.0/ + Eur. Phys. J. Plus. 139 (2024) 604 + Rui Huo, Jiulin Du - Exact solution of three-dimensional (3D) spinless fermions - https://arxiv.org/abs/2512.06000 - arXiv:2512.06000v1 Announce Type: new -Abstract: The three-dimensional (3D) Ising model is mapped into a 3D spinless fermionic model by the Jordan-Wigner transformation. The exact solution of the 3D model for spinless fermions is derived analytically by performing a diagonalization process consisting of the Clifford algebraic approach, the Fourier transformation and the Bogoliubov transformation. The Clifford algebraic approach is the same as that developed for the 3D Ising model, using a time average within the Jordan-von Neumann-Wigner framework, a linearization procedure and a local gauge transformation. The formulas for eigenvalues, partition function, subsequent thermodynamic properties and critical behaviors are presented. The dimensionality and the topological phases are investigated. The present results for many spinless fermions in a 3D lattice are applicable for studying the mechanisms of magnetism, superfluid, superconductors and topological materials. - oai:arXiv.org:2512.06000v1 - physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Ion-acoustic shock and solitary waves in magnetized plasma with Cairns-Gurevich distribution electrons + https://arxiv.org/abs/2512.07895 + arXiv:2512.07895v1 Announce Type: new +Abstract: The propagation properties of ion-acoustic solitary and shock waves in the magnetized viscous plasma with nonthermal trapped electrons are investigated. The Cairns-Gurevich distribution as the electron distribution is considered to describe the plasma nonthermality and particle trapping. By adopting the reductive perturbation technique, we derived the nonlinear Schamel-Korteweg-de Vries-Burgers (SKdVB) equation, and then obtained the ion-acoustic shock and solitary wave solutions of the SKdVB equation for different limiting cases. It is found that the impact of nonthermal parameter {\alpha}, external magnetic field {\Omega}, obliqueness lz, wave speed U0, and the ion kinematic viscosity {\eta}0 can significantly change the characteristics of the shock and solitary waves. These results may be useful for better understanding the propagation of nonlinear structures in space (i.e. Earth's magnetosphere and ionosphere, auroral regions) and laboratory plasma with nonthermal trapped electrons. + oai:arXiv.org:2512.07895v1 + physics.plasm-ph + physics.space-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Zhidong Zhang + Commun. Theor. Phys. 77 (2025) 065501 + Rui Huo, Jiulin Du - Small Language Models Reshape Higher Education: Courses, Textbooks, and Teaching - https://arxiv.org/abs/2512.06001 - arXiv:2512.06001v1 Announce Type: new -Abstract: While large language models (LLMs) have introduced novel paradigms in science and education, their adoption in higher education is constrained by inherent limitations. These include a tendency to produce inaccuracies and high computational requirements, which compromise the strict demands for accurate and reliable knowledge essential in higher education. Small language models (MiniLMs), by contrast, offer distinct advantages in professional education due to their lightweight nature and precise retrieval capabilities. This research takes "Atmospheric Physics" as an example. We established a specialized corpus and image repository by gathering over 550,000 full-text PDFs from over 130 international well-respected journals in Earth and environmental science. From this collection, we extracted over 100 million high-quality sentence-level corpus and more than 3 million high-resolution academic images. Using MiniLMs, these resources were organized into a high-dimensional vector library for precise retrieval and efficient utilization of extensive educational content. Consequently, we systematically redesigned the courses, textbooks, and teaching strategies for "Atmospheric Physics" based on MiniLMs. The course is designed as a "interdisciplinary-frontier" system, breaking down traditional boundaries between atmospheric science, space science, hydrology, and remote sensing. Teaching materials are transformed from static, lagging text formats into a dynamic digital resource library powered by MiniLM. For teaching methods, we have designed a question-based learning pathway. This paradigm promotes a shift from passive knowledge transfer to active cognitive development. Consequently, this MiniLM-driven "Atmospheric Physics" course demonstrates a specific avenue for "AI for education". - oai:arXiv.org:2512.06001v1 - physics.ed-ph - cs.CL - Tue, 09 Dec 2025 00:00:00 -0500 + Analysis of the Sybil defense of Duniter-based cryptocurrencies + https://arxiv.org/abs/2512.07897 + arXiv:2512.07897v1 Announce Type: new +Abstract: Duniter-based cryptocurrencies, which are providing a kind of universal basic income, are using a system called "Web of Trust" based on a social network whose evolution is subject to graph theoretical rules, time constraints and a licence in order to avoid large Sybil attacks. We investigate in this article the largest size of a Sybil attack that a simplified version of the graph theoretical rules of a Web of Trust can undergo depending on the number of attackers and on the parameters of the system. We show that even if in theory, without considering social and time constraints, this system cannot in general prevent huge attacks, in the real-world case of a Duniter-based cryptocurrency (with thousands of users), the system can prevent attacks of large size with only graph theoretical rules. + oai:arXiv.org:2512.07897v1 + physics.soc-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Jian Zhang, Jia Shao + Lucas Isenmann - Comparison between Idealized and Realized Accessibility Measures in GIScience - https://arxiv.org/abs/2512.06007 - arXiv:2512.06007v1 Announce Type: new -Abstract: Measures of access, defined as the ease with which people can reach opportunities or services, are often based on proximity. Proximity measures of access are often unrealistic or idealized, ignoring many of the real barriers to access including social and economic barriers. There is a need to develop GIS measures of access that incorporate all aspects of access, which we term realized access. Our goal is to develop a conceptual framework of realized accessibility in active transportation, and compare idealized and realized measures of access to bicycling. We apply the framework to measure realized accessibility in a case study focusing on bicycling access in Santa Barbara County, and compare idealized and realized measures of access for four cities in Santa Barbara County in California (Santa Maria, Lompoc, Santa Barbara, and Goleta). Differences in measures from idealized access to realized access are greatly increased in cities with lower median household income and a higher proportion of people identifying as Hispanic. Studies aiming to understand equity and access can benefit from more nuanced and realized access measures, as idealized access measures may overestimate accessibility in underserved communities. In GIScience, especially as new data on mobility become more widely available, nuanced measures of accessibility should be the standards in analysis. - oai:arXiv.org:2512.06007v1 - physics.soc-ph - Tue, 09 Dec 2025 00:00:00 -0500 + A one-dimensional reduced plasma model for the electrical treeing + https://arxiv.org/abs/2512.07900 + arXiv:2512.07900v1 Announce Type: new +Abstract: Plasma models, consisting of advection-diffusion Partial Differential Equations coupled with chemical reactions, are widely adopted to describe corona, streamers and dielectric barrier discharges. However, the complex geometry of the electrical treeing represents an obstacle for numerical simulations. We develop a reduced one-dimensional formulation of a plasma model for the electrical treeing, describing the evolution of charge concentrations under the effect of an electric field. The reduced system consists of weakly coupled advection-diffusion-reaction equations for charge concentrations inside the treeing and on the dielectric surface, coupled with production-destruction Ordinary Differential Equations for the dipole moment. A numerical scheme based on Finite Volumes and Patankar-type methods allows efficient simulations, while preserving key physical properties. The model is tested on increasingly complex geometries, from a straight line to a realistic electrical treeing. + oai:arXiv.org:2512.07900v1 + physics.plasm-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yuyan Che, Trisalyn A. Nelson, Somayeh Dodge, Peter Kedron + http://creativecommons.org/licenses/by/4.0/ + Beatrice Crippa, Anna Scotti, Andrea Villa - Baryogenesis constraints and parameter bounds in $f(T,T_{G})$ modified gravity - https://arxiv.org/abs/2512.06009 - arXiv:2512.06009v1 Announce Type: new -Abstract: We investigate the generation of the observed baryon asymmetry of the Universe within the framework of $f(T,T_{G})$ gravity, where $T$ is the torsion scalar and $T_{G}$ denotes its teleparallel Gauss--Bonnet counterpart. Two illustrative models, $f(T,T_{G})=\alpha T+\beta \sqrt{T_{G}}$ and $f(T,T_{G})=-T+\delta\, T_{G}\ln(T_{G})$, are examined in a power-law background $a(t)=a_{0} t^{m}$. For both models, we derive analytic expressions for the baryon-to-entropy ratio $\eta_{B}/s$ using the standard and generalized baryogenesis formalisms, adopting high-energy decoupling conditions with $g_{b}=1$, $g_{s}=106$, $T_{D}=2\times10^{16}\,\mathrm{GeV}$, and $M_{\star}=2\times10^{12}\,\mathrm{GeV}$. Consistency of the cosmological dynamics requires $m>1$, and the observed value $\eta_{B}/s \simeq 9.42\times10^{-11}$ is obtained for constrained intervals of the parameters $\alpha$, $\beta$, $\delta$, and $m$. Numerical results confirm that both models reproduce the measured baryon asymmetry without invoking extra fields or exotic matter sources. These findings indicate that teleparallel gravity with a Gauss--Bonnet torsion term provides a natural and viable mechanism for baryogenesis, offering a compelling alternative to curvature-based descriptions of the early Universe. - oai:arXiv.org:2512.06009v1 + Schr\"odinger and Klein-Gordon oscillators in Eddington-inspired Born-Infeld gravity: Degree-one Confluent Heun polynomial correspondence + https://arxiv.org/abs/2512.07904 + arXiv:2512.07904v1 Announce Type: new +Abstract: We investigate Schr\"odinger and Klein-Gordon (KG) oscillators in the spacetime of a global monopole (GM) within Eddington inspired Born-Infeld (EiBI) gravity, including, in the relativistic sector, the coupling to a Wu-Yang magnetic monopole (WYMM). By reducing the radial equations to the confluent Heun form and enforcing termination of the Heun series, we obtain conditionally exact solutions in which the radial eigenfunctions truncate to polynomials of degree $(n+1)\geq 1$. This truncation imposes algebraic constraints that quantize the oscillator frequency and restrict the values allowed for the orbital angular momenta $\ell$. In the lowest nontrivial case $n=0$, the degree-one Heun polynomial yields a closed analytic expression for the frequency and determines a finite upper bound on $\ell$, dictated jointly by the EiBI deformation and the GM deficit. The resulting parametric correlations reveal a sharp geometric control of the spectrum: EiBI nonlinearities and the angular deficit fix the admissible bound states through polynomial truncation conditions. The confluent Heun correspondence is made explicit, providing a rigorous and reproducible framework for extracting analytical solutions from otherwise non-polynomial Heun structures. Applying the same method to the KG oscillator with a WYMM, we derive conditionally exact particle and antiparticle energies in a closed form. The relativistic spectrum exhibits perfect charge symmetry and a precise dependence on the WYMM strength, the EiBI parameter and the angular momentum constraint. To the best of our knowledge, this constitutes the first unified and fully consistent treatment of conditionally exact Schr\"odinger and Klein-Gordon oscillators in EiBI gravity based on a degree-one confluent Heun polynomial. + oai:arXiv.org:2512.07904v1 physics.gen-ph - gr-qc - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Amit Samaddar, S. Surendra Singh + http://creativecommons.org/licenses/by/4.0/ + Omar Mustafa, Abdullah Guvendi - A few ideas to promote inclusion - https://arxiv.org/abs/2512.06011 - arXiv:2512.06011v1 Announce Type: new -Abstract: Promoting diversity, equity, inclusion and accessibility (DEIA) is both a legal and professional responsibility in French research institutions. This paper presents practical strategies to foster inclusive work environments within French research units. We summarize the regulatory context, key findings from the INSU-AA prospective on discrimination, and fundamental principles for promoting equity. We discuss approaches to mitigate implicit biases across all career stages, from early education to retirement, and outline strategies for equitable recruitment and career advancement. Concrete initiatives in one of our units (LESIA/LIRA) are described, including internal communications, exhibitions, and accessible pedagogical activities. The creation of a dedicated commission within the unit council ensures coordinated DEIA efforts, legitimized by institutional support and methodical planning. By sharing these experiences, we provide actionable guidance for research units seeking to advance DEIA in science. - oai:arXiv.org:2512.06011v1 + Renewable Energies in the Agricultural Sector: A Perspective Analysis of the Last Three Years + https://arxiv.org/abs/2512.07905 + arXiv:2512.07905v1 Announce Type: new +Abstract: Over the last three years, research on the application of renewable energies in the agricultural sector has grown significantly. In this study, we conducted a bibliometric analysis of global scientific production from 2019 to 2021 to identify trends, leading contributors, and emerging research areas. Based on 1378 documents retrieved from Scopus, we observed a clear upward trend in publications, with a peak in 2021. India, China, the United States, Italy, and the United Kingdom were the most productive countries, while key institutions from China, Iran, and the Netherlands led the research output. Our results reveal five major thematic clusters: renewable energy technologies in agriculture, bioenergy, sustainable agriculture, biomass energy, and the environmental impact of agricultural activities. Notable advances include agrovoltaic systems, the use of agricultural and livestock waste for biogas production, and the development of agricultural robots powered by renewable energy sources. Additionally, there is increasing interest in examining the links among agriculture, renewable energy use, and greenhouse gas emissions, aligned with global sustainability goals. This analysis highlights the evolution of the field, international collaboration patterns, and the most influential research lines, offering valuable insights to guide future scientific developments in integrating renewable energies within the agricultural sector. + oai:arXiv.org:2512.07905v1 physics.soc-ph - astro-ph.IM - physics.ed-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-sa/4.0/ - SF2A-2025: Proceedings of the Annual meeting of the French Society of Astronomy and Astrophysics, pp.377-382, https://sf2a.eu/proceedings/2025/2025sf2a.conf.377P.pdf - Thibaut Paumard, Aur\'elie Guilbert-Lepoutre, Ma\"ica Clavel, Florence Cornu, Ludovic Petitdemange, Fran\c{c}ois Dulieu, L\'ea Griton, Rhita-Maria Ouazzani + http://creativecommons.org/licenses/by/4.0/ + 10.3390/en16010345 + Energies 2023, 16(1), 345 + Quetzalcoatl Hernandez-Escobedo, David Mu\~noz-Rodr\'iguez, Alejandro Vargas-Casillas, Jos\'e Manuel Ju\'arez Lopez, Pilar Aparicio-Mart\'inez, Mar\'ia Pilar Mart\'inez-Jim\'enez, Alberto-Jesus Perea-Moreno - The Clock Paradox in Chukchi Myth and the Teaching of Special Relativity - https://arxiv.org/abs/2512.06015 - arXiv:2512.06015v1 Announce Type: new -Abstract: The teaching of special relativity still follows Einstein's original two-postulate approach and thus recreates the relativistic revolution in the minds of students again and again, with all its attendant shocking and mysterious aspects. As Hermann Bondi long ago noted, such an approach, which emphasizes the revolutionary aspects of a theory rather than its continuity with earlier thought, "is hardly conducive to easy teaching and good understanding". But what could be a better alternative? In 1923, the distinguished Russian ethnographer, linguist, and anthropologist Tan-Bogoraz described the striking similarities between the special theory of relativity and the mythology of Chukchi shamans. Inspired by this surprising observation, I assume that the basic concepts of relativity are not at all alien to our innate perception of time and space, and I propose an approach to the foundations of relativity that emphasizes absolute concepts such as proper time and causal cones rather than relative ones. - oai:arXiv.org:2512.06015v1 + Formal developments in curved momentum space: the quantum field theory roadmap + https://arxiv.org/abs/2512.07913 + arXiv:2512.07913v1 Announce Type: new +Abstract: We advocate that the dual picture of spacetime noncommutativity , i.e. the existence of a curved momentum space, could be a way out to solve some of the open conceptual problems in the field, such as the basis dependence of observables. In this framework, we show how to build deformed Klein--Gordon and Dirac equations. In addition, we give an outlook of how one could define quantum field theories, both free and interacting ones. + oai:arXiv.org:2512.07913v1 physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zurab K. Silagadze + 10.1088/1742-6596/2667/1/012069 + J.Phys.Conf.Ser. 2667 (2023) 1, 012069 + S. A. Franchino-Vi\~nas - Natural Convection Heat Transfer from an Inclined Cylinder - https://arxiv.org/abs/2512.06019 - arXiv:2512.06019v1 Announce Type: new -Abstract: This investigation derives a novel formula predicting the natural convective heat transfer from an inclined cylinder given its length, diameter, inclination angle, Rayleigh number, and the fluid's Prandtl number and thermal conductivity. - The present formula was tested with 93 inclined cylinder measurements having length-to-diameter ratios between 1.48 and 104 in nine data-sets from three peer-reviewed studies, yielding (data-set) root-mean-squared relative error values between 1.6% and 4.7%. - oai:arXiv.org:2512.06019v1 + Hydroacoustic Absorption and Amplification by Turbulence + https://arxiv.org/abs/2512.07920 + arXiv:2512.07920v1 Announce Type: new +Abstract: Acoustic waves propagating through fluid media are significantly influenced by turbulence. This paper experimentally investigates the influence of underwater turbulence on the propagation characteristics of acoustic waves, revealing that acoustic waves can be absorbed or amplified at frequencies far exceeding the turbulent fluctuation frequency. The maximum observed attenuation or amplification of received signals exceeds 60%, with no spectral broadening. The study covers two flow conditions: pipe flow and free jet, driven by either a pump or hydraulic head difference. Hydroacoustic transducers with frequencies ranging from 60 kHz to 4.4 MHz are used, while the wave propagation directions both parallel and perpendicular to the mean flow are considered. The variation trend and magnitude of received signals depend on wave frequency, amplitude and flow conditions. For each case, the amplitudes of all frequency components simultaneously decreases or increases under turbulence, with no new spectral components appearing. After closing the flow control valve, the receiver signal requires a finite time to stabilize to its quiescent-state value. In contrast, suction near the pipe outlet shows that laminar flow has no effect on acoustic signals, confirming that the primary cause of signal variation is turbulent fluctuations rather than mean flow. Comparison with conventional theories and experiments indicates that mechanisms such as bubbles, resonance, scattering, or viscous dissipation cannot explain the observed phenomena. This suggests the existence of a previously unknown interaction mechanism between turbulence and acoustic waves. + oai:arXiv.org:2512.07920v1 physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Aubrey G. Jaffer, Martin S. Jaffer - - - Investigating the effect of adaptive optimal control function in epidemic dynamics: predictions and strategy evolution based on SIR/V game theoretic framework - https://arxiv.org/abs/2512.06021 - arXiv:2512.06021v1 Announce Type: new -Abstract: In this paper, we consider an adaptive optimal control problem for an SIR/V epidemic model with human behavioral effects.We develop a model where effective management of infectious diseases are monitored by the means of non pharmaceutical interventions.This study develops an adaptive optimal control function within an SIR/V framework embedding a non cooperative game theoretic mechanism to capture the dynamic interplay between individual vaccination behavior and population level transmission. We derive analytical expression for the optimal control trajectory under resource constrain and heterogeneous susceptibility and we validate our model using numerical simulations,calibrated with the real world epidemic parameters. We find that for the adaptive optimal policy for a generally known SIR/V model depending on the game theoretic epidemic state leads to substantial reduction in expenses compared to non adaptive policies. Moreover, our results demonstrate that, adaptive strategies significantly outperform the static policies by achieving lower peak infections and faster epidemic extinctions while evolutionary game dynamics identify critical behavioral thresholds that drive strategy evolution and inform timely policy adaptation - oai:arXiv.org:2512.06021v1 - physics.soc-ph - math.DS - q-bio.PE - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Nuruzzaman Rahat, Abid Hossain, Muntasir Alam + Kai-Xin Hu, Yue-Jin Hu - Extending Integrated Assessment Model scenarios until 2150 using an emulation approach - https://arxiv.org/abs/2512.06026 - arXiv:2512.06026v1 Announce Type: new -Abstract: Whereas there is growing interest in exploring longer-term climate, including tipping elements, beyond 2100, most Integrated Assessment Models (IAMs) generate emissions scenarios only till 2100. Here we propose a framework to extend scenarios until 2150 using an emulator of IAMs. Our framework offers a potential interim solution for developing very long-term scenarios, such as the Scenario Model Intercomparison Project (ScenarioMIP), circumventing the challenges of fully simulating IAMs beyond 2100. - oai:arXiv.org:2512.06026v1 - physics.soc-ph - physics.ao-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Measuring the group velocity dispersion in near resonant hot atomic vapors + https://arxiv.org/abs/2512.07954 + arXiv:2512.07954v1 Announce Type: new +Abstract: Group velocity dispersion (GVD) in near-resonant hot atomic vapors is difficult to measure with standard pulse broadening or interferometric techniques, as absorption, pulse distortion and nonlinearities strongly affect the probe and reduce the signal-to-noise ratio. We introduce a simpler method using a continuous-wave laser with weak phase modulation and a slow photodetector, directly inspired by Bragg-like spectroscopy in fluids of light. During propagation, the red and blue-detuned sidebands accumulate different dispersive phase shifts, leading to oscillations in the transmitted modulation contrast as the modulation frequency is scanned. Vanishing contrast at well-defined frequencies directly yields the GVD. We apply this technique to hot rubidium vapors and observe the strong frequency dependence of the GVD across a broad detuning range of the D2 line at different temperatures. + oai:arXiv.org:2512.07954v1 + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Weiwei Xiong, Katsumasa Tanaka - - - The program Simourg for simulating the response functions of gamma detectors with simple geometries - https://arxiv.org/abs/2512.06030 - arXiv:2512.06030v1 Announce Type: new -Abstract: The program Simourg (Simulator of Usually Requested Geometries) is based on the Geant4 toolkit and created for Monte Carlo simulation of gamma-ray spectrometric nuclear detectors with a simple axial symmetric geometry, which is typical for many tasks of studying the decay of long-lived nuclei and measuring the radioactivity of natural objects. The program is designed for quick estimation of the effectiveness and the response function of the detector to monoenergetic gamma quanta in the energy range from keV to several MeV. - oai:arXiv.org:2512.06030v1 - physics.ins-det - nucl-ex - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-sa/4.0/ - 10.15407/jnpae2011.03.301 - Nucl. Physics and Atomic Energy. 2011, Vol. 12, no. 3, p. 301-306 - V. V. Kobychev + Alix Merolle, Quentin Glorieux - Multi-resolution Physics-Aware Recurrent Convolutional Neural Network for Complex Flows - https://arxiv.org/abs/2512.06031 - arXiv:2512.06031v1 Announce Type: new -Abstract: We present MRPARCv2, Multi-resolution Physics-Aware Recurrent Convolutional Neural Network, designed to model complex flows by embedding the structure of advection-diffusion-reaction equations and leveraging a multi-resolution architecture. MRPARCv2 introduces hierarchical discretization and cross-resolution feature communication to improve the accuracy and efficiency of flow simulations. We evaluate the model on a challenging 2D turbulent radiative layer dataset from The Well multi-physics benchmark repository and demonstrate significant improvements when compared to the single resolution baseline model, in both Variance Scaled Root Mean Squared Error and physics-driven metrics, including turbulent kinetic energy spectra and mass-temperature distributions. Despite having 30% fewer trainable parameters, MRPARCv2 outperforms its predecessor by up to 50% in roll-out prediction error and 86% in spectral error. A preliminary study on uncertainty quantification was performed, and we also analyzed the model's performance under different levels of abstractions of the flow, specifically on sampling subsets of field variables. We find that the absence of physical constraints on the equation of state (EOS) in the network architecture leads to degraded accuracy. A variable substitution experiment confirms that this issue persists regardless of which physical quantity is predicted directly. Our findings highlight the advantages of multi-resolution inductive bias for capturing multi-scale flow dynamics and suggest the need for future PIML models to embed EOS knowledge to enhance physical fidelity. - oai:arXiv.org:2512.06031v1 - physics.flu-dyn - cs.LG - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Watt-level second harmonic generation in periodically poled thin-film lithium tantalate + https://arxiv.org/abs/2512.07968 + arXiv:2512.07968v1 Announce Type: new +Abstract: Second-harmonic generation (SHG) is a fundamental tool in modern laser technology, enabling coherent frequency conversion to remote optical bands, serving as the basis for self-referenced femtosecond lasers and quadrature-squeezed light sources. State-of-the-art SHG relies on bulk crystals and ridge waveguides, although continuous-wave (CW) SH efficiency in bulk crystals is limited by short interaction lengths and large mode areas. Ridge waveguides offer better performance with lower pump power requirements, yet must span several centimeters to deliver high output power, complicating fabrication and narrowing the bandwidth. Recently, SHG in periodically poled thin-film lithium niobate integrated photonic circuits has attracted significant interest, offering orders-of-magnitude improvement in SHG under CW pumping due to the stronger optical mode confinement. However, lithium niobate has a low optical damage threshold, even in MgO-doped substrates, which limits SH power output to well below the watt level. Here, we overcome this challenge and demonstrate 7 mm-long periodically poled thin-film lithium tantalate (PPLT) waveguides that achieve high SH output in the CW regime, with generated power exceeding 1 W and off-chip output above 0.5 W at 775 nm under 4.5 W pump power. PPLT offers a higher optical damage threshold than PPLN and supports watt-level operation. By optimizing electrode geometry and poling conditions, we obtain reproducible poling despite lithium tantalate's coercive field being nearly four times higher than that of MgO-doped lithium niobate. Although its effective nonlinearity is more than five times lower, we achieve watt-level CW output with a short waveguide, demonstrating the potential of PPLT circuits for high-power applications in integrated lasers, quantum photonics, AMO physics, optical clocks, and frequency metrology. + oai:arXiv.org:2512.07968v1 + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ - 10.1063/5.0295883 - APL Mach. Learn. 3, 046110 (2025) - Xinlun Cheng, Joseph Choi, H. S. Udaykumar, Stephen Baek + Nikolai Kuznetsov, Zihan Li, Tobias J. Kippenberg - PoliFi Tokens and the Trump Effect - https://arxiv.org/abs/2512.06036 - arXiv:2512.06036v1 Announce Type: new -Abstract: Cryptoassets launched by political figures, e.g., political finance (PoliFi) tokens, have recently attracted attention. Chief among them are the eponymous tokens backed by the 47th president and first lady of the United States, TRUMPandMELANIA. We empirically analyze both, and study their impact on the broad decentralized finance (DeFi) ecosystem. Via a comparative longitudinal study, we uncover a "Trump Effect": the behavior of these tokens correlates positively with presidential approval ratings, whereas the same tight coupling does not extend to other cryptoassets and administrations. We additionally quantify the ecosystemic impact, finding that the fervor surrounding the two assets was accompanied by capital flows towards associated platforms like the Solana blockchain, which also enjoyed record volumes and fee expenditure. - oai:arXiv.org:2512.06036v1 + On the accuracy of population level approximation of network processes + https://arxiv.org/abs/2512.07995 + arXiv:2512.07995v1 Announce Type: new +Abstract: The individual-based model of simple contagion processes is considered on regular graphs. This model explicitly incorporates the adjacency matrix of the network enabling us to study the effect of network structure on the dynamic of the propagation process. While the asymptotic behaviour of the model is well known, the transient behaviour has been less studied. Our goal in this paper is to give a theoretical estimate on the accuracy of the one-dimensional population-level approximation. This is carried out for arbitrary simple contagion processes and regular Tur\'an graphs. Numerical evidence is shown that the theoretical estimate is rather sharp for dense graphs. + oai:arXiv.org:2512.07995v1 physics.soc-ph - econ.GN - q-fin.EC - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Ignacy Nieweglowski, Aviv Yaish, Fahad Saleh, Fan Zhang - - - From Time Series Expansion to Proper Generalized Decomposition via Graph-Theoretical Connection: Stabilized Simulation of Fluids Flow - https://arxiv.org/abs/2512.06047 - arXiv:2512.06047v1 Announce Type: new -Abstract: In this paper, we employ graph theory to establish a connection between the Time Series Expansion (TSE) and Proper Generalized Decomposition (PGD) methods. Using the concept of a directed graph, we demonstrate how one can transition from the computation of space modes in the TSE--first illustrated for the diffusion equation--to those of space modes in PGD, in which an inhomogeneous Volterra-type convolution recurrence relation, weighted by time-dependent coefficients, appears. This recurrence relation is simplified through graph-based analysis into a compact form using a simple path traversal, reducing the computational complexity. Moreover, the compact formulation reveals a natural stabilization process in the computation of space modes, where stabilized coefficients are automatically derived and can be used in the Stabilized-TSE (STSE) framework. To explicitly construct these coefficients, we consider a Simplified PGD (SPGD) formulation in which the time modes are chosen to be the time polynomial basis $t^n$. This choice yields a one-level Volterra-type recurrence relation that is similarly simplified using a simple path representation, demonstrating a connection in the computation of space modes from TSE, through STSE and SPGD, to PGD. This graph-based connection is exhibited in the case of inviscid flow to check how crucial the addition of an artificial diffusion is in stabilizing the recurrence formula of TSE. Finally, we extend the approach to the incompressible, dimensionless Navier-Stokes (NS) equations and build stabilization coefficients that depend on the Reynolds number Re, the space mode rank, and the simulation time step. Both the STSE and SPGD approaches are tested to simulate the wake behind a bluff body at Re = 5 000. - oai:arXiv.org:2512.06047v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 + math.DS + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ - Ahmad Deeb, Vladimir Parezanovic, Denys Dutykh + No\'emi Nagy, S\'andor Horv\'ath, Bal\'azs Maga, P\'eter L. Simon - A formalism of Gravitation based on a Physical Field Strength - https://arxiv.org/abs/2512.06050 - arXiv:2512.06050v1 Announce Type: new -Abstract: We propose a reformulation of gravitation in which the gravitational interaction is treated as a genuine force rather than an inertial effect arising from spacetime geometry. Within this framework, the difference between the affine connection and a flat reference connection defines a tensor $\mathrm{K}^\mu{}_{\alpha\beta}$, identified as the gravitational field strength. This object cannot be eliminated by coordinate transformations, demonstrating that gravity possesses true physical degrees of freedom. The formalism introduces vector fields $\xi_a{}^\mu$ that extend the notion of infinitesimal translations to curved spacetime and naturally yield a gauge-invariant field strength $\mathfrak{F}^{\xi a}{}_{\mu\nu}$. The dynamics of the gravitational field are governed by a Lagrangian of Yang--Mills type with an additional scalar degree of freedom $\phi^{2}$, corresponding to the Newtonian potential. In the limit of vanishing gravitational coupling $\mathfrak{g}\to0$, the theory reduces to General Relativity, while for nonzero $\mathfrak{g}$ it constitutes an $\mathrm{SU(2)\times U(1)}$ gauge theory of gravity. The framework provides a unified description in which dark energy emerges as the self-interaction energy of the $\phi$ field, and dark-matter-like effects arise from the extended gravitational degrees of freedom. This formulation offers a consistent bridge between classical and quantum descriptions of gravity and clarifies the conceptual foundations of the gravitational interaction. - oai:arXiv.org:2512.06050v1 - physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 + ALS Storage Ring RF Control System Upgrade Plan and Status + https://arxiv.org/abs/2512.07996 + arXiv:2512.07996v1 Announce Type: new +Abstract: The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory, a third-generation synchrotron light source operational since 1992, is undergoing a comprehensive upgrade of its storage ring RF control system. The legacy Horner PLC controllers and remote I/O modules, now at end-of-life, are being replaced with an Allen-Bradley PLC platform to improve maintainability, reliability, and long-term support. This paper presents the planning, design, and current status of the upgrade project. + oai:arXiv.org:2512.07996v1 + physics.acc-ph + cs.SY + eess.SY + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/publicdomain/zero/1.0/ - L. Horoto, F. G. Scholtz + http://creativecommons.org/licenses/by/4.0/ + 10.18429/jacow-icalepcs2025-tupd030 + ICALEPCS 2025 + Najm Us Saqib, Angel Jurado, Esteban Andrade, Qiang Du, Jeong Han Lee, Miroslaw Dach, Benjamin Flugstad - Quantum, Diplomacy, and Geopolitics - https://arxiv.org/abs/2512.06052 - arXiv:2512.06052v1 Announce Type: new -Abstract: Quantum technologies -- spanning communication, sensing, computing, and cryptography -- are rapidly emerging as critical paths of geopolitical competition and strategic defence innovation. Unlike traditional technological advances, quantum introduces novel capabilities that fundamentally disrupt established norms of security, intelligence, and diplomatic engagement. This strategic analysis explores the evolving quantum landscape through the dual lenses of diplomacy and geopolitics, with specific implications for defence leaders, policymakers, and industry stakeholders. The benefits and challenges of quantum technologies are examined from a diplomatic and geopolitical perspective to help leaders make informed strategic decisions. Leading powers now recognise quantum as a domain where technological leadership directly translates to geopolitical influence, compelling an intense race for dominance alongside new forms of multilateral diplomacy aimed at managing both risks and opportunities. Quantum technologies do not all have the same operational maturity, but technological progress is accelerating. Post-quantum cryptography demands immediate action -- every encrypted communication created today may be harvested and decrypted within the decade by adversaries equipped with quantum capabilities. - oai:arXiv.org:2512.06052v1 - physics.soc-ph - cs.CY - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Robust External-Beam Calibration of Plastic Scintillation Detectors for In-Vivo Dosimetry in HDR Brachytherapy + https://arxiv.org/abs/2512.08014 + arXiv:2512.08014v1 Announce Type: new +Abstract: Purpose: HDR brachytherapy is a widely adopted modality for cancer treatment. However, it is not free from error and uncertainty. In-vivo dosimetry (IVD) is the only technique that can confirm correct dose delivery. This study details and validates a calibration method for Plastic Scintillation Detector (PSD), bypassing dose gradient and positioning issues in brachytherapy calibration. Methods: The PRB-0057 PSD (Medscint, Canada) was calibrated, 1x1 mm scintillating fiber coupled to a 20 m Eska GH-4001 clear optical fiber (Mitsubishi Rayon, Japan). The fiber is connected to the Hyperscint-RP200 research platform for signal collection. Hyperspectral calibration was performed at a LINAC with a 6 MV beam, enabling removal of stem effects before brachytherapy measurements. For validation, an Iridium-192 Flexisource (Elekta Brachy, The Netherlands), Sk=29447U, was used in a motorized IBA-Blue-Phantom2 water tank (48x48x41cm3). Dose rates were measured at 10 Hz along the source z-axis at a fixed transverse distance of 1.2+/-0.05 cm in 0.2 cm steps. Relative difference (RD) between measured and TG-43U1 dose rates was assessed. A detailed uncertainty budget was associated with brachytherapy measurements. Results: Comparison shows good agreement with RD around 2.5 $\%$ at 1.2 cm, corresponding to positional uncertainties of <0.15 mm. At greater depths up to 8 cm, RDs increase to about 5 $\%$, mainly due to reduced light yield. Uncertainties depend on the source-detector distance, ranging from 3.81 to 6.39 $\%$ (k=1) over the explored range. Conclusions: Results confirm the PSD calibration effectiveness using a 6MV external beam with hyperspectral technique. Uncertainties close to the source align with positional errors and are dominated by reduced PSD sensitivity at larger distances. The study underlined the intrinsic limitation of IVD in the face of known uncertainties. + oai:arXiv.org:2512.08014v1 + physics.med-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Axel Ferrazzini + Chahrazed Ghannoudi, Marie-Claude Lavallee, Benjamin Cote, Luc Beaulieu - GPU acceleration of optical photon propagation in low photon yield applications: Opticks for the Electron Ion Collider - https://arxiv.org/abs/2512.06061 - arXiv:2512.06061v1 Announce Type: new -Abstract: The bulk of time spent in the simulation of Cherenkov and other scintillation detectors is spent on optical-photon transport, i.e. ray tracing, a task that GPUs are uniquely qualified to perform. We present EIC-Opticks, a fork of Opticks, which uses event aggregation to drastically accelerate photon transport simulation for low-to-moderate photon yield experiments. During the full Geant4 Monte Carlo simulation of a given detector, optical photon simulation is performed on GPU(s) using the NVIDIA OptiX framework. We validate this approach using the ePIC pfRICH detector. We find GPU and CPU simulations in excellent agreement. For $5\times 10^4$ electrons with a momentum of $p=5~\mathrm{MeV}/c$ in the test case of the pfRICH detector, EIC-Opticks shows an order-of-magnitude speedup over multi-threaded Geant4, and a factor of up to 161$\pm$3 over single-threaded execution. In the case of low-to-moderate applications event aggregation reduces the per-photon simulation time from $\sim60\,\mu\mathrm{s}$ for single events to $\sim20\,\mathrm{ns}$ with batching, a factor of $\sim3000$. In order to make EIC-Opticks easily installable, we authored a Spack package that makes it possible to install it with a single command. Additionally, a Docker container is provided for users with EIC-Opticks installed. EIC-Opticks provides guardrails for common pitfalls (e.g. nested volume conversion, ray tracing setting optimization). - oai:arXiv.org:2512.06061v1 - physics.ins-det - hep-ex - nucl-ex - physics.acc-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Overview of the Helios Design: A Practical Planar Coil Stellarator Fusion Power Plant + https://arxiv.org/abs/2512.08027 + arXiv:2512.08027v1 Announce Type: new +Abstract: Thea Energy, Inc. has developed the preconceptual design for "Helios," a fusion power plant based on the planar coil stellarator architecture. In this overview paper, the design is summarized and the reader is referred to the other papers for more detail. The Helios design is based around a two-field-period quasi-axisymmetric ("QA") stellarator equilibrium with aspect ratio 4.5 and a novel tokamak-like X-point divertor. The natural stability, low recirculating power, and steady-state capability of the stellarator are leveraged. Stability and transport are calculated using state-of-the-art, high-fidelity codes and grounded in measured performance of existing experiments. The electromagnetic coil set is high-temperature superconducting ("HTS") and consists of 12 large, plasma-encircling coils like the toroidal field coils of a tokamak, and 324 smaller, field-shaping coils. All coils are planar and convex. A maximum of 20 T on-coil is enforced, a value which has been achieved in existing large-bore HTS coils. There is a minimum of 1.2 m between plasma and coils, leaving space for tritium breeding blanket and neutron shielding. Because of this thick shielding, all coils have a minimum 40-year operational lifetime, the same minimum lifetime of the power plant system. 1.1 GW of thermal power and 390 MW of net electric power are produced. The shaping coils are individually controllable, enabling a uniquely configurable magnetic field for relaxed manufacturing and assembly tolerances and plasma control. A practical maintenance architecture is a primary driver of the design; maintenance is performed on entire toroidal sectors that are removed from between the encircling coils. A biennial maintenance cycle is estimated to take approximately 84 days, resulting in an 88% capacity factor. Rigorous engineering constraints such as temperature and stress limits are enforced. + oai:arXiv.org:2512.08027v1 + physics.plasm-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Gabor Galgoczi, Kolja Kauder, Maxim Potekhin, Sakib Rahman, Dmitri Smirnov, Torre Wenaus + C. P. S. Swanson, S. T. A. Kumar, D. W. Dudt, E. R. Flom, W. B. Kalb, T. G. Kruger, M. F. Martin, J. R. Olatunji, S. Pasmann, L. Z. Tang, J. von der Linden, J. Wasserman, M. Avida, A. S. Basurto, M. Dickerson, N. de Boer, M. J. Donovan, A. H. Doudn Cate, D. Fort, W. Harris, U. Khera, A. Koen, J. A. Labbate, N. Maitra, A. Ottaviano, R. K. Parmar, E. J. Paul, B. Reydel, A. van Riel, P. K. Romano, M. Savastianov, S. Saxena, S. Seethalla, S. Srinivasan, R. H. Wu, D. Nash, J. Priebe, M. Slepchenkov, S. Walsh, B. Berzin, D. A. Gates, the Thea Energy team - Single-particle incoherent diffractive imaging and amplified spontaneous emission in copper nanocubes - https://arxiv.org/abs/2512.06110 - arXiv:2512.06110v1 Announce Type: new -Abstract: We demonstrate element-specific incoherent diffractive imaging (IDI) of single copper nanocubes using intensity correlations of K$\alpha$ fluorescence at a hard X-ray free-electron laser. Combining single particle diffraction classification with IDI, we retrieve the form factor of 88 nm cubes with 20 nm resolution, extending IDI to the destructive single-particle regime with a large gain in resolution. IDI visibility drops sharply above a fluence of $10^2$ J/cm$^2$, consistent with the assumption of amplified spontaneous emission. Our results reveal fundamental limits for high-fluence nanoimaging towards future single-particle X-ray imaging. - oai:arXiv.org:2512.06110v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 + Metabolic rate beyond the 3/4 law + https://arxiv.org/abs/2512.08031 + arXiv:2512.08031v1 Announce Type: new +Abstract: This work presents a discrete theoretical model in which basal metabolic rate \(B\) is described as a dynamic function of an organism's ontogenetic stage \(n\). Instead of treating \(B\) only as a static function of body mass \(M\), we adopt the form \(B(n) = B_0 \, M^{\,b(n)}\), in which the effective scaling exponent \(b(n)\) varies systematically throughout development. In contrast to classical approaches, such as Kleiber's empirical law (\(B \propto M^{3/4}\)) and the continuous fractal model of West--Brown--Enquist (WBE), which assume a constant exponent, the present framework emphasizes how the metabolic scaling relationship itself can evolve over the life cycle of a single individual. The model is inspired by a Fibonacci-based description of growth in discrete stages, leading to analytic expressions for \(b(n)\) that connect ontogenetic progression to changes in the scaling between metabolism and mass. In this setting, Kleiber's constant \(B_0 \approx 70\) kcal/day is reinterpreted as a \emph{metabolic anchoring point}, linking the classical law \(B \approx 70\,M^{3/4}\) to a developmentally explicit formulation. We show that the resulting trajectory \(B(n)\) captures, at a conceptual level, how metabolic scaling can shift from strongly sublinear behavior at early stages towards an almost linear regime as \(n\) increases, and that the predicted basal rates remain compatible, in order of magnitude, with values reported for mammals of different sizes. In this way, the work offers a unified framework that connects the evolution of \(B(n)\) across ontogeny to the recursive organization of biological growth. + oai:arXiv.org:2512.08031v1 + physics.bio-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Tamme Wollweber, Sarodi Jonak Dutta, Zhou Shen, Johan Bielecki, Carl Caleman, Sebastian Cardoch, Armando D. Estillore, Lukas V. Haas, Sebastian Karl, Faisal H. M. Koua, Abhishek Mall, Parichita Mazumder, Diogo Melo, Mauro Prasciolu, Omkar V. Rambadey, Amit Kumar Samanta, Abhisakh Sarma, Tokushi Sato, Egor Sobolev, Fabian Trost, Sa\v{s}a Bajt, Richard Bean, Jochen K\"upper, Nicusor Timneanu, Ralf Rohlsberger, Joachim von Zanthier, Florian Schulz, Henry N. Chapman, Kartik Ayyer + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Dorilson Silva Cambui - A Method for Solving Linearized Vlasov Equation for Low-Frequency Long-Wavelength Electromagnetic Modes in Inhomogeneous Plasmas - https://arxiv.org/abs/2512.06114 - arXiv:2512.06114v1 Announce Type: new -Abstract: A method for solving linearized Vlasov equation for low-frequency, long-wavelength electromagnetic modes in magnetically confined inhomogeneous plasmas is described. The relevant non-local solution that includes the lowest-significant-order effects of inhomogeneities is obtained from the solutions of three simple equations by means of elementary algebra. The method appears to be more convenient than the commonly used method of integration along the unperturbed particle orbits and should be of interest to students of theoretical plasma physics. - oai:arXiv.org:2512.06114v1 - physics.plasm-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Ab initio study of highly charged ion-induced Coulomb explosion imaging + https://arxiv.org/abs/2512.08102 + arXiv:2512.08102v1 Announce Type: new +Abstract: We present a theoretical investigation of ion-induced Coulomb explosion imaging (CEI) of pyridazine molecules driven by energetic C$^{5+}$ projectiles, using time-dependent density-functional theory (TDDFT) with Ehrenfest nuclear dynamics. By systematically varying the projectile's impact point and orientation relative to the molecular plane, we compare orthogonal and in-plane trajectories and quantify their effects on fragment momenta, electron-density response, and atom-resolved ionization. Newton plots and time-resolved density snapshots show that trajectories avoiding direct atomic collisions yield the most faithful structural reconstructions, whereas direct impacts impart large, highly localized momenta that distort the recovered geometry. Planar trajectories generate substantially greater ionization and broader momentum distributions than orthogonal ones due to deeper traversal through the molecular electron cloud. Quantitative analysis of electron removal at 10~fs confirms that projectile proximity and orientation strongly modulate both local and global ionization. These findings clarify how impact geometry governs the fidelity of ion-induced CEI structural recovery and help explain the variability and noise observed in experimental CEI measurements. More broadly, the results highlight both the strengths and the intrinsic limitations of ion-induced CEI and identify key considerations for interpreting experiments. + oai:arXiv.org:2512.08102v1 + physics.chem-ph + quant-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Bamandas Basu + Misa Viveiros, Samuel S. Taylor, Cody Covington, K\'alm\'an Varga - Nonlinear phenomena in X-ray fluorescence from single nanoparticles under extreme conditions - https://arxiv.org/abs/2512.06118 - arXiv:2512.06118v1 Announce Type: new -Abstract: Materials exposed to intense femtosecond X-ray pulses with energies above their K-shell absorption edge can enter an extremely ionized state, which could give rise to nonlinear phenomena, such as saturable absorption and reverse saturable absorption. In this work, we investigate these effects on single copper nanoparticles irradiated by an X-ray free-electron laser pulse. We study the properties of the K$\alpha$ fluorescence for two different short pulse durations and three X-ray incident energies below and above the K-shell absorption edge, and correlate these with incident fluence estimates based on coherent diffraction. We observe that the incident fluence of the pulse and not its duration, is the main factor that modulates the non-linear response, which leads to an effective shortening of the fluorescence emission. Our findings have implications for fluorescence-based methods for imaging single particles using transiently coherent fluorescence, or diffractive imaging through transient resonances. - oai:arXiv.org:2512.06118v1 + Applicability of Metalenses for Generalizable Computer Vision + https://arxiv.org/abs/2512.08109 + arXiv:2512.08109v1 Announce Type: new +Abstract: Optical neural networks (ONNs) are gaining increasing attention to accelerate machine learning tasks. In particular, static meta-optical encoders designed for task-specific pre-processing demonstrated orders of magnitude smaller energy consumption over purely digital counterpart, albeit at the cost of slight degradation in classification accuracy. However, a lack of generalizability poses serious challenges for wide deployment of static meta-optical front-ends. Here, we investigate the utility of a metalens for generalized computer vision. Specifically, we show that a metalens optimized for full-color imaging can achieve image classification accuracy comparable to high-end, sensor-limited optics and consistently outperforms a hyperboloid metalens across a wide range of sensor pixel sizes. We further design an end-to-end single aperture metasurface for ImageNet classification and find that the optimized metasurface tends to balance the modulation transfer function (MTF) for each wavelength. Together, these findings highlight that the preservation of spatial frequency-domain information is an essential interpretable factor underlying ONN performance. Our work provides both an interpretable understanding of task-driven optical optimization and practical guidance for designing high-performance ONNs and meta-optical encoders for generalizable computer vision. + oai:arXiv.org:2512.08109v1 physics.optics - physics.atm-clus - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Sebastian Cardoch, Tamme Wollweber, Sarodi Jonak Dutta, Zhou Shen, Johan Bielecki, Fabian Trost, Armando D. Estillore, Lukas V. Haas, Sebastian Karl, Faisal H. M. Koua, Abhishek Mall, Parichita Mazumder, Diogo Melo, Mauro Prasciolu, Omkar V. Rambadey, Amit Kumar Samanta, Abhisakh Sarma, Tokushi Sato, Egor Sobolev, Sa\v{s}a Bajt, Richard Bean, Carl Caleman, Jochen K\"upper, Ralf R\"ohlsberger, Joachim von Zanthier, Florian Schulz, Henry N. Chapman, Kartik Ayyer, Nicusor Timneanu + http://creativecommons.org/licenses/by/4.0/ + Yubo Zhang, Johannes Fr\"och, Jinlin Xiang, Shane Colburn, Myunghoo Lee, Zhihao Zhou, Minho Choi, Eli Shlizerman, Arka Majumdar - Tunable Narrowband Terahertz Radiation from van der Waals Ferroelectrics - https://arxiv.org/abs/2512.06139 - arXiv:2512.06139v1 Announce Type: new -Abstract: The terahertz (THz) spectral range is central to high-speed communication, precision metrology, sensing technologies, and a range of fundamental scientific investigations. Achieving these capabilities in practical systems increasingly demands chip-scale integration of THz photonic components that are typically bulky. In this context, van der Waals (vdW) materials provide a unique platform for integrated nonlinear photonics in the visible and near-infrared regimes, and extending this framework into the THz domain would constitute a significant advance. Here, we report tunable, intense, and narrowband THz radiation from ferroelectric niobium oxyhalides. Through halogen substitution and alloying, we achieve continuous and precise control over the emission frequency from 3.1 to 5.8 THz. We show that the narrowband THz radiation is driven by phonons associated with the ferroelectric polarization. We further demonstrate dynamic and nonvolatile control of the polarity of the coherent THz wave with external electric field. This work demonstrates efficient narrowband THz emission from vdW ferroeletrics and provides microscopic insight into its origin, paving the way for on-chip THz technology for a broad range of applications. - oai:arXiv.org:2512.06139v1 + FRINGE: a protocol for self-referenced quantum state estimation via photon-number-resolved interferometry + https://arxiv.org/abs/2512.08127 + arXiv:2512.08127v1 Announce Type: new +Abstract: We introduce a self-referenced method for quantum-state tomography of light based on photon-number-resolved double-slit interferometry. Two identical copies of the unknown quantum field illuminate laterally displaced slits, guaranteeing perfect spatiotemporal mode matching without a separate local oscillator. In the far-field, detection at transverse position $x$ is associated with a relative slit phase $\phi(x)$, and an $N$-photon event projects the detected quantum field onto a state $|N;\phi(x)\rangle$. The resulting distribution $P(N,\phi)$ is the quantum analogue of a Frequency Resolved Optical Gating (FROG) trace: whereas FROG reconstructs the classical complex spectral field $E(\omega)$ from a spectrally resolved second harmonic of a pulse with its delayed self, our measurement reconstructs the Fock-space wavefunction or density matrix from binomially weighted self-interference. The scheme requires no known or mode-matched reference and is compatible with commercially available photon-number-resolving cameras. Beyond conceptual simplicity and automatic mode matching, the FROG analogy permits direct transfer of mature ultrafast-optics methodologies (e.g., mixed-state, ptychographic, and vectorial extensions) into quantum optics, offering a versatile route to tomography of quantum photon states. + oai:arXiv.org:2512.08127v1 physics.optics - cond-mat.other - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Chun-Ying Huang, Taketo Handa, Daniel G. Chica, Zhihao Cui, Ding Xu, Jeongheon Choe, Yiliu Li, Margalit L. Feuer, Milan E. Delor, Michael Fechner, David R. Reichman, Xavier Roy, Xiaoyang Zhu + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Matan Even Tzur - Synergistic Computational Approaches for Accelerated Drug Discovery: Integrating Quantum Mechanics, Statistical Thermodynamics, and Quantum Computing - https://arxiv.org/abs/2512.06141 - arXiv:2512.06141v1 Announce Type: new -Abstract: Accurately predicting protein-ligand binding free energies (BFEs) remains a central challenge in drug discovery, particularly because the most reliable methods, such as free energy perturbation (FEP), are computationally intensive and difficult to scale. Here, we introduce a hybrid quantum-classical framework that combines Mining Minima sampling with quantum mechanically refined ligand partial charges, QM/MM interaction evaluation, and variational quantum eigensolver (VQE)-based electronic energy correction. This design enables explicit treatment of polarization, charge redistribution, and electronic correlation effects that are often underestimated in purely classical scoring schemes, while retaining computational efficiency. Across 23 protein targets and 543 ligands, the method achieves a mean absolute error of about 1.10 kcal/mol with strong rank-order fidelity (Pearson R = 0.75, Spearman rho = 0.76, Kendall tau = 0.57), consistent with the performance of contemporary FEP protocols. Notably, the workflow requires only about 25 minutes per ligand on standard compute resources, resulting in an approximate 20-fold reduction in computational cost relative to alchemical free energy approaches. This level of accuracy and efficiency makes the method well-suited for high-throughput lead optimization and iterative design cycles in pharmaceutical discovery. The framework also provides a natural foundation for future integration with machine learning models to enable predictive, large-scale, and adaptive screening strategies. - oai:arXiv.org:2512.06141v1 - physics.chem-ph - q-bio.QM - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Single-step laser patterning and thinning of biocompatible MEMS flow sensor + https://arxiv.org/abs/2512.08128 + arXiv:2512.08128v1 Announce Type: new +Abstract: Micro-electro mechanical systems (MEMS) thermal flow sensors are increasingly used for compact, low-power flow monitoring in biomedical applications. However, silicon-based method for sensor fabrication is limited by high cost, rigidity, and multi-step cleanroom processes. This study presents a single-step fiber laser micromachining method for fabricating biocompatible, free-standing MEMS thermal flow sensors from ultrathin titanium foil. The process combines patterning and localized thinning in single-step process, with titanium serving as resistive sensing element. A dual-matrix optimization approach consisting of a Threshold Mapping Matrix (TMM) and Energy Density Matrix (EDM) was used to determine optimized parameters without repeated trial-and-error. For localized thinning, sequential R-T scans with cooling intervals reduced redeposition from the Gaussian beam profile and produced uniform thickness reduction from 50 {\mu}m to 20--30 {\mu}m. The fabricated sensors were evaluated through thermal coefficient resistance (TCR) measurement, Infrared (IR) thermography, and airflow tests under steady and cyclic conditions controlled by artificial ventilation system. The fabricated devices showed a stable TCR of 3278 ppm {\deg}C$^{-1}$, a linear relationship calibration curve between velocity and resistance with $R^2$=0.986 and a 54% improvement in thermal response was achieved with the free-standing structure design compared to substrate-fixed designs. This fabrication approach removes the need for photolithography, wet/dry etching, and wafer bonding, enabling faster and lower-cost production of flexible, biocompatible flow sensors. The method can be applied to other MEMS devices that require compact size, flexibility, localized thinning and free-standing structures. + oai:arXiv.org:2512.08128v1 + physics.ins-det + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Farzad Molani, Art E. Cho + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Mohammad Nizar Mohamed Zukri, Muhammad Salman Al Farisi, Yoshihiro Hasegawa, Mitsuhiro Shikida - Direct Radiative Impacts of Stratospheric Aerosols on the Tropical Troposphere: Clouds, Precipitation, and Circulation in Convection-Resolving and Global Simulations - https://arxiv.org/abs/2512.06163 - arXiv:2512.06163v1 Announce Type: new -Abstract: A concern for stratospheric aerosol injection (SAI) is that stratospheric aerosols could inadvertently alter rain and winds through mechanisms independent of the intended surface cooling. We here use a multi-model framework to investigate how the tropical troposphere responds to SAI when sea surface temperatures are held fixed. By performing convection-resolving simulations in small-domains and in mock-Walker setups, and contrasting these with global climate model simulations, we trace how stratospheric aerosols radiatively heat the troposphere, and in turn alter convection, clouds, and rainfall. Our simulations show an SAI-induced reduction in tropical mean precipitation, yet decreased cloud radiative heating moderates this effect and complicates its predictability. Regional rainfall anomalies within the tropics can be substantial. However, surface-temperature-independent effects on tropical circulation are found to be negligible, indicating that stratospheric aerosols do not inherently alter the tropical overturning circulation as previously suggested. These results clarify the mechanisms governing SAI hydroclimate impacts and show that key uncertainties arise from cloud processes that models are unable to constrain. Consequently, near-term SAI deployment would carry the risk of being implemented without the ability to reliably predict its hydroclimate impacts. - oai:arXiv.org:2512.06163v1 - physics.ao-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Laser-assisted deposition of carbon nanotubes in optical fibers with multiparameter control + https://arxiv.org/abs/2512.08154 + arXiv:2512.08154v1 Announce Type: new +Abstract: We demonstrate a new method to deposit carbon nanotubes (CNT) on optical fibers based on a syringe-loaded CNT solution axially aligned to the fiber tip. A laser generates an optical tweezer in a water-based CNT solution, depositing nanotubes over the fiber cross-section. The parameters are adjusted, resulting in two deposited CNT layers with distinct thicknesses. This setup employs smaller solution volumes than those commonly used in beckers, providing high confinement, protection, and interaction of nanotubes, laser, and fiber, offering a promising alternative for real-time monitoring, which are significant to the development of industrial fiber lasers and biomedical optoacoustic devices. + oai:arXiv.org:2512.08154v1 + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Zachary McGraw, Lorenzo M. Polvani + 10.1109/SBFotonIOPC66433.2025.11218439 + R. E. da Silva and C. M. B. Cordeiro, "Laser-Assisted Deposition of Carbon Nanotubes in Optical Fibers with Multiparameter Control," SBFoton International Optics and Photonics Conference, Sao Pedro SP, Brazil, 2025, pp. 1-3 + Ricardo E. da Silva, Cristiano M. B. Cordeiro - MaxwellLink: A unified framework for self-consistent light-matter simulations - https://arxiv.org/abs/2512.06173 - arXiv:2512.06173v1 Announce Type: new -Abstract: A major challenge in light-matter simulations is bridging the disparate time and length scales of electrodynamics and molecular dynamics. Current computational approaches often rely on heuristic approximations of either the electromagnetic (EM) or material component, hindering the exploration of complex light-matter systems. Herein, MaxwellLink -- a modular, open-source Python framework -- is developed for the massively parallel, self-consistent propagation of classical EM fields interacting with a large heterogeneous molecular ensemble. The package utilizes a robust TCP/UNIX socket interface to couple EM solvers with a wide range of external molecular drivers. This decoupled architecture allows users to seamlessly switch between levels of theory of either the EM solver or molecules without modifying the counterpart. Crucially, MaxwellLink supports EM solvers spanning from single-mode cavities to full-feature three-dimensional finite-difference time-domain (FDTD) engines, and molecules described by multilevel open quantum systems, force-field and first-principles molecular dynamics, and nonadiabatic real-time Ehrenfest dynamics. Benefiting from the socket-based design, the EM engine and molecular drivers scale independently across multiple high-performance computing (HPC) nodes, facilitating large-scale simulations previously inaccessible to existing numerical schemes. The versatility and accuracy of this code are demonstrated through applications including superradiance, radiative energy transfer, vibrational strong coupling in Bragg resonators, and plasmonic heating of molecular gases. By providing a unified, extensible engine, MaxwellLink potentially offers a powerful platform for exploring emerging phenomena across the research fronts of spectroscopy, quantum optics, plasmonics, and polaritonics. - oai:arXiv.org:2512.06173v1 + Seasonal thermal stress analysis of defective mass concrete sidewalls based on the average forming temperature method + https://arxiv.org/abs/2512.08158 + arXiv:2512.08158v1 Announce Type: new +Abstract: Thermal cracking in urban underground sidewalls is frequently observed when structures are cast in summer and enter service in winter, as seasonal temperature gradients act under structural restraint. To quantify the local stress field associated with pre-existing cracks, an orthogonal finite-element simulation matrix of 16 combinations is constructed. Distributions of maximum principal stress () at the surface crack tip and along the upper half of the crack bottom are evaluated using steady-state thermal loading and a linear-elastic constitutive model. Across all cases, pronounced tensile stress concentration occurs at both locations: the maximum ranges from 19.2 to 34.1 MPa at the crack surface end and from 17.2 to 29.4 MPa at the crack bottom. These concentrated values are consistently higher than the stress level at the same locations in an otherwise identical uncracked wall, clarifying how seasonal temperature gradients under restraint amplify local stresses around existing defects. The quantitative ranges reported here provide a basis for risk screening and for formulating practical mitigation measures (e.g., joint spacing and insulation strategies) in the design and operation of urban underground enclosure walls. In addition, three-dimensional simulations of randomly distributed internal voids show that adopting average forming temperature increases the peak tensile stress on void surfaces from 3.42 to 4.40 MPa at 10 deg C and from 5.98 to 6.96 MPa at -5 deg C, further highlighting the risk amplification effect of AFT under cold service conditions. + oai:arXiv.org:2512.08158v1 physics.comp-ph - physics.chem-ph - physics.optics - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Xinwei Ji, Andres Felipe Bocanegra Vargas, Gang Meng, Tao E. Li + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Ziyan Zhao, Ting Peng, Peng Wu, Chaojun Hu, Qilin Yi, Chuangrui Huang, Junjie Niu, Xiaoxue Xu, Tao Li, Yuan Li - Why are diffuse atomic orbitals needed for accurate electronic wave functions of even neutral molecules? - https://arxiv.org/abs/2512.06184 - arXiv:2512.06184v1 Announce Type: new -Abstract: An accurate description of electron correlation energies in molecules requires either basis set extrapolation or the use of explicitly-correlated wave functions that address the deficiencies of standard determinantal expansions at short interelectronic distances. Practical and robust explicitly-correlated F12 methods require the use of standard or specialized atomic orbital (AO) basis sets that include diffuse AOs, even for neutral species. Although modern reduced-scaling formulations of explicitly-correlated many-body methods have become routinely applicable to molecules with hundreds of atoms, application of F12 methods to large molecular systems can be severely hampered due to the onset of ill-conditioning spurred by the presence of diffuse AOs in the F12-appropriate orbital basis sets. Here we re-examine why diffuse AOs are necessary for application of F12 methods. To help such an investigation, we developed a dual-basis formulation of traditional and F12 coupled-cluster singles and doubles (CCSD) methods in which the reference (occupied) and correlating (virtual) orbitals are expanded in separate AO basis sets. Our conclusion is that diffuse AOs are fundamentally important for the traditional (non-F12) description of dynamical correlation; the necessity of diffuse AOs in F12 calculations arises indirectly due to the dramatic reduction of the basis set error by the F12 terms such that the error due to the lack of diffuse AOs becomes comparable to the residual basis set incompleteness. The dual-basis CC methods are suggested as an important candidate formalism for accurate (in particular, F12) reduced-scaling many-body methods in extended systems. - oai:arXiv.org:2512.06184v1 - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Efficient simulation framework for modeling collective emission in ensembles of inhomogeneous solid-state emitters + https://arxiv.org/abs/2512.08174 + arXiv:2512.08174v1 Announce Type: new +Abstract: An efficient simulation framework is proposed to model collective emission in disordered ensembles of quantum emitters. Using a cumulant expansion approach, the computational complexity scales polynomially as opposed to exponentially with the number of emitters, enabling Monte Carlo sampling over a large number of realizations. The framework is applied to model negatively charged silicon-vacancy (SiV$^{-}$) centers inside diamond. Incorporating spatial disorder and inhomogeneous broadening, we obtain statistically averaged responses over hundreds of SiV$^{-}$ clusters. These simulations reveal two signatures of collective behavior. First, dynamics of fully inverted clusters show that superradiant emission occurs only with sufficiently large emitter number and high quantum efficiency. Unlike ideal Dicke superradiance, the burst is substantially suppressed by strong near-field dipole-dipole interaction, consistent with existing theoretical predictions. Second, under continuous-wave excitation we compute photoluminescence-excitation spectra, which exhibit interaction-induced broadening in the distribution of resonance peaks. The corresponding density of states also displays a non-zero skewness. Overall, by incorporating realistic inhomogeneities in emitter clusters, our framework is able to predict statistics for disordered ensembles that can be compared to experiments directly. Our approach generalizes to other types of emitters, including atoms, molecules, and quantum dots, thus providing a practical tool for analyzing collective behavior in realistic quantum systems. + oai:arXiv.org:2512.08174v1 + physics.optics + physics.app-ph + physics.comp-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Samuel R. Powell, Edward F. Valeev + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Qingyi Zhou, Wenxin Wu, Maryam Zahedian, Zongfu Yu, Jennifer T. Choy - On the Effect of Missing Transmission Chain Information in Agent-Based Models: Outcomes of Superspreading Events and Workplace Transmission - https://arxiv.org/abs/2512.06189 - arXiv:2512.06189v1 Announce Type: new -Abstract: Agent-based models (ABMs) have emerged as distinguished tools for epidemic modeling due to their ability to capture detailed human contact patterns. ABMs can support decision-makers in times of outbreaks and epidemics substantially. However, as a result of missing correspondingly resolved data transmission events are often modeled based on simplified assumptions. In this article, we present a framework to assess the impact of these simplifications on epidemic prediction outcomes, considering superspreading and workplace transmission events. We couple the VADERE microsimulation model with the large-scale MEmilio-ABM and compare the outcomes of four outbreak events after 10 days of simulation in a synthetic city district generated from German census data. In a restaurant superspreading event, where up to four households share tables, we observe 17.2~\% more infections on day 10 after the outbreak. The difference increases to 46.0 % more infections when using the simplified initialization in a setting where only two households share tables. We observe similar outcomes (41.3 % vs. 9.3 % more infections) for two workplace settings with different mixing patterns between teams at work. In addition to the aggregated difference, we show differences in spatial dynamics and transmission trees obtained with complete or reduced outbreak information. We observe differences between simplified and fully detailed initializations that become more pronounced when the subnetworks in the outbreak setting are mixing less. In consequence and aside from classical calibration of models, the significant outcome differences should drive us to develop a more profound understanding of how and where simplified assumptions about transmission events are adequate. - oai:arXiv.org:2512.06189v1 + Restoring Network Evolution from Static Structure + https://arxiv.org/abs/2512.08209 + arXiv:2512.08209v1 Announce Type: new +Abstract: The dynamical evolution of complex networks underpins the structure-function relationships in natural and artificial systems. Yet, restoring a network's formation from a single static snapshot remains challenging. Here, we present a transferable machine learning framework that infers network evolutionary trajectories solely from present topology. By integrating graph neural networks with transformers, our approach unlocks a latent temporal dimension directly from the static topology. Evaluated across diverse domains, the framework achieves high transfer accuracy of up to 95.3%, demonstrating its robustness and transferability. Applied to the Drosophila brain connectome, it restores the formation times of over 2.6 million neural connections, revealing that early-forming links support essential behaviors such as mating and foraging, whereas later-forming connections underpin complex sensory and social functions. These results demonstrate that a substantial fraction of evolutionary information is encoded within static network architecture, offering a powerful, general tool for elucidating the hidden temporal dynamics of complex systems. + oai:arXiv.org:2512.08209v1 physics.soc-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Sascha Korf, Sophia Johanna Wagner, Gerta K\"oster, Martin J. K\"uhn + Jiu Zhang, Zhanwei Du, Hongwei Hu, Ke Wu, Tongchao Li, Chuan Shi, Xiaohui Huang, Yamir Moreno, Yanqing Hu - Dispersion Engineering of Planar Sub-millimeter Wave Waveguides and Resonators with Low Radiation Loss - https://arxiv.org/abs/2512.06199 - arXiv:2512.06199v1 Announce Type: new -Abstract: Mm-wave and THz superconducting circuits find numerous applications in areas ranging from quantum information and sensing to high-energy physics. Planar THz transmission lines and resonators are fabrication-friendly, compact, and scalable, and they can be efficiently interfaced with external signals and controls. However, planar circuits radiate strongly at high frequencies, which precludes their use in loss-sensitive applications. Here, we present the design and characterization of planar dispersion-engineered transmission lines that effectively suppress radiation leakage in desired mm-wave bands. We extend this concept to design planar resonators with extremely low radiation leakage, resulting in radiation Q-factors above 106 at 553 GHz. Low-loss planar THz circuitry will impact many application domains, including broadband communications, quantum information, radio astronomy, and cosmology. - oai:arXiv.org:2512.06199v1 - physics.optics - physics.app-ph - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Frequency Locking to Environmental Forcing Suppresses Oscillatory Extinction in Phage-Bacteria Interactions + https://arxiv.org/abs/2512.08224 + arXiv:2512.08224v1 Announce Type: new +Abstract: Bacteriophage-bacteria interactions are central to microbial ecology, influencing evolution, biogeochemical cycles, and pathogen behavior. Most theoretical models assume static environments and passive bacterial hosts, neglecting the joint effects of bacterial traits and environmental fluctuations on coexistence dynamics. This limitation hinders the prediction of microbial persistence in dynamic ecosystems such as soils and oceans.Using a minimal ordinary differential equation framework, we show that the bacterial growth rate and the phage adsorption rate collectively determine three possible ecological outcomes: phage extinction, stable coexistence, or oscillation-induced extinction. Specifically, we demonstrate that environmental fluctuations can suppress destructive oscillations through resonance, promoting coexistence where static models otherwise predict collapse. Counterintuitively, we find that lower bacterial growth rates are helpful in enhancing survival under high infection pressure, elucidating the observed post-infection growth reduction.Our studies reframe bacterial hosts as active builders of ecological dynamics and environmental variation as a potential stabilizing force. Our findings thus bridge a key theory-experiment gap and provide a foundational framework for predicting microbial responses to environmental stress, which might have potential implications for phage therapy, microbiome management, and climate-impacted community resilience. + oai:arXiv.org:2512.08224v1 + physics.bio-ph + nlin.CD + q-bio.PE + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Furkan Sahbaz, Simeon I. Bogdanov + Hao-Neng Luo, Zhi-Xi Wu, Jian-Yue Guan - Lensless and Lossless HoloVAM - https://arxiv.org/abs/2512.06209 - arXiv:2512.06209v1 Announce Type: new -Abstract: We report the first successful fabrication of three-dimensional models using our fully lensless holographic volumetric additive manufacturing (HoloVAM) platform. In this configuration, tomographic light fields are generated directly from a phase-only spatial light modulator (SLM) and delivered into a rotating vial of photopolymer without any imaging optics, relays, or index-matching bath. Building on the HoloTile framework for tiled Fourier holography and point-spread function (PSF) shaping, the system creates volumetric dose distributions with high photon efficiency and well-controlled axial propagation. Using a simple acrylate resin formulation and a minimalized optical train, we demonstrate reproducible fabrication of complex geometries. These results establish lensless HoloVAM as a practical and mechanically minimal route to volumetric fabrication, opening a new pathway toward compact and application-flexible VAM devices. - oai:arXiv.org:2512.06209v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 + Ion-beam driven dust-cyclotron and dust-lower-hybrid instabilities in nonthermal dusty magnetoplasmas with dust-charge fluctuation + https://arxiv.org/abs/2512.08259 + arXiv:2512.08259v1 Announce Type: new +Abstract: We reveal a new dispersive dust-lower-hybrid (DLH)-like mode that can couple to modified dust-cyclotron (DC) waves in a dusty magnetoplasma by the influence of a streaming ion beam. Previous studies have overlooked such hybrid modes and the coupling in the study of resonant cyclotron instabilities in dusty magnetoplasmas. Using two-fluid models for positive ion beams and charged dust grains, nonthermal $\kappa$-density distributions for electrons and positive ions, and orbital motion limited (OML) models for dust-charge fluctuations, we derive a general linear dispersion relation for the coupled DLH and DC modes in the limit of when the hydrodynamic time scale is much longer than the dust-charging time scale. The hybrid mode propagates with a frequency lower than the typical dust-lower-hybrid frequency, $\widetilde{\omega}_{\rm{dl}}\equiv\omega_{\rm{pd}}\Omega_d/\sqrt{\omega^2_{\rm{pd}}+\Omega^2_d}$, where $\omega_{\rm{pd}}$ is the dust-plasma oscillation frequency and $\Omega_d$ is the dust-cyclotron frequency. We obtain the growth rates of instabilities due to Cerenkov and cyclotron interactions and analyze them, taking into account the influences of the static magnetic field, ion-to-electron temperature ratio, electron-to-dust number density ratio, dust-charge fluctuation, and superthermal electrons and ions. We find that the maximum growth rates tend to increase but reach steady states as the wave number increases. The instabilities reported here could be relevant to various plasma environments, including space plasmas (e.g., Earth's magnetosphere) and laboratory dusty plasma experiments. + oai:arXiv.org:2512.08259v1 + physics.plasm-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Andreas Erik Gejl Madsen, Jesper Gl\"uckstad + http://creativecommons.org/licenses/by-nc-nd/4.0/ + 10.1088/1402-4896/ae296d + A. P. Misra, N. P. Acharya, S. Basnet, R. Khanal - Filters and Redundancies: An Exploration of Novel Coherent Noise Filters for High Energy Physics - https://arxiv.org/abs/2512.06217 - arXiv:2512.06217v1 Announce Type: new -Abstract: This work presents radiation-tolerant implementations for the SALSA front-end readout ASIC through redundancy methods applied to two median-finding algorithms designed for coherent noise suppression. Bit-wise Median Finder (BWMF) and Combinatorial Sum Median Finder (CSMF) were implemented in TSMC \SI{65}{\nano\meter} and evaluated in terms of area, power, and latency. Three redundancy techniques were applied in this work to compare their impact: simple TMR, full TMR, and temporal TMR (TTMR). The simple and full TMR approach was applied in both algorithms to establish comparisons and TTMR was applied to CSMF as an improvement. The results indicate that the BWMF achieves efficient performance in terms of area and power under the simple TMR scheme, but exhibits significantly higher power consumption when using the more robust full TMR approach. The TTMR technique, in turn, offers reliable fault tolerance while maintaining a feasible balance between area and power. - oai:arXiv.org:2512.06217v1 - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 + Self-Reinforced Deep Priors for Reparameterized Full Waveform Inversion + https://arxiv.org/abs/2512.08284 + arXiv:2512.08284v1 Announce Type: new +Abstract: Full waveform inversion (FWI) has become a widely adopted technique for high-resolution subsurface imaging. However, its inherent strong nonlinearity often results in convergence toward local minima. Recently, deep image prior-based reparameterized FWI (DIP-FWI) has been proposed to alleviate the dependence on massive training data. By exploiting the spectral bias and implicit regularization in the neural network architecture, DIP-FWI can effectively avoid local minima and reconstruct more geologically plausible velocity models. Nevertheless, existing DIP-FWI typically use a fixed random input throughout the inversion process, which fails to utilize the mapping and correlation between the input and output of the network. Moreover, under complex geological conditions, the lack of informative prior in the input can exacerbate the ill-posedness of the inverse problem, leading to artifacts and unstable reconstructions. To address these limitations, we propose a self-reinforced DIP-FWI (SRDIP-FWI) framework, in which a steering algorithm alternately updates both the network parameters and the input at each iteration using feedback from the current network output. This design allows adaptive structural enhancement and improved regularization, thereby effectively mitigating the ill-posedness in FWI. Additionally, we analyze the spectral bias of the network in SRDIP-FWI and quantify its role in multiscale velocity model building. Synthetic tests and field land data application demonstrate that SRDIP-FWI achieves superior resolution, improved accuracy and greater depth penetration compared to multiscale FWI. More importantly, SRDIP-FWI eliminates the need for manual frequency-band selection and time-window picking, substantially simplifying the inversion workflow. Overall, the proposed method provides a novel, adaptive and robust framework for accurate subsurface velocity model reconstruction. + oai:arXiv.org:2512.08284v1 + physics.geo-ph + cs.CV + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Felipe Costa, Nicolas Guimar\~aes, Guilherme Milani, Bruno Sanches, Irakli Mandjavidze, Damien Neyret, Wilhelmus Van Noije + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Guangyuan Zou, Junlun Li, Feng Liu, Xuejing Zheng, Jianjian Xie, Guoyi Chen - 3D PIC Simulations on Hall Thruster Electron Drift Instability: Influence of Magnetic Field on Electron Transport - https://arxiv.org/abs/2512.06222 - arXiv:2512.06222v1 Announce Type: new -Abstract: Three-dimensional particle-in-cell simulations are employed to investigate electron transport characteristics in Hall thrusters, with particular focus on how magnetic field configuration affects the electron transport due to electron drift instabilities. Comparing analytic and realistic magnetic field models reveals significant differences in electron transport patterns, where radial variations in field strength lead to asymmetric transport enhanced in low-field regions. The derived effective electron mobility shows agreement with direct simulation diagnoses, and the obtained two-dimensional transport profiles provide a foundation for developing more accurate reduced-dimensional models. - oai:arXiv.org:2512.06222v1 - physics.plasm-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Rigid body kinematics in an intuitive group-theoretic approach, as completely as possible: Part I Rotational phenomena + https://arxiv.org/abs/2512.08285 + arXiv:2512.08285v1 Announce Type: new +Abstract: This paper focuses on rotational phenomena of rigid body kinematics. It discusses them in a group-theoretic approach as completely as possible, using methods and notations as intuitive as possible. With a review of current literature, this article also covers some original parts that remain largely unexplored. + oai:arXiv.org:2512.08285v1 + physics.class-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Yinjian Zhao, Kunpeng Zhong + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Ziyuan Wang - Curation and Dissemination of Complex Multi-modal Data Sets for Radiation Detection, Localization, and Tracking - https://arxiv.org/abs/2512.06225 - arXiv:2512.06225v1 Announce Type: new -Abstract: The PANDAWN sensor network in Chicago, IL, is a state-of-the-art test-bed for networked, multi-modal sensing. It integrates AI/data science methods into its operation, from data acquisition to automated data labeling and curation workflows. The curation and dissemination of diverse multi-modal data sets will enable the development of new radiological/nuclear (R/N) detection, localization, and tracking algorithms, and methods relevant across the nonproliferation mission space. This paper first introduces the PANDAWN sensor network and the features that make it stand out from previous multi-modal data acquisition efforts. We then review the various data streams acquired on the PANDAWN nodes, and present the implementation of an automated data curation pipeline that includes the labeling of radiation and contextual data streams. We finally provide a short overview of different studies that leveraged the curated data sets. - oai:arXiv.org:2512.06225v1 - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Photon Phase-Space Dynamics in a Plasma Wakefield Accelerator + https://arxiv.org/abs/2512.08295 + arXiv:2512.08295v1 Announce Type: new +Abstract: Frequency up-shifting of laser light in a beam-driven plasma wakefield has the potential to provide high-intensity sources of short wavelength radiation. Simulations have demonstrated that a laser pulse can undergo large frequency shifts, limited only by the drive beam energy, when the plasma density is tailored to match the accelerating phase of the wake to the group velocity of the pulse. Here, we study the dynamical evolution of photons in the phase-space vicinity of the plasma wake- phase matching condition. Numerical calculations using a photon kinetic model are validated by direct comparison with full electromagnetic particle-in-cell simulations. These calculations form the basis of a linear theory of the photon dynamics which reveals several important results, including scalings for the properties of the witness pulse and a self-similar solution for the photon phase-space dynamics. One prediction of the theory is that the pulse can be compressed indefinitely with no lower bound on the duration. This predication suggests that photon acceleration can provide a novel source of sub-femtosecond, short wavelength radiation. + oai:arXiv.org:2512.08295v1 + physics.plasm-ph + math-ph + math.MP + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Nicolas Abgrall, Mark S. Bandstra, Reynold J. Cooper, Marco Salathe, Brian J. Quiter, Rajesh Sankaran, Yongho Kim, Sean Shahkarami + Neil Beri, John Palastro, Qian Qian, Kyle Miller, Brandon Russell, Alexander Thomas - Physics-based Full-band GaN HEMT Simulation Suggests Upper Bound of LO Phonon Lifetime - https://arxiv.org/abs/2512.06226 - arXiv:2512.06226v1 Announce Type: new -Abstract: Intrinsic limits to device performance arise from fundamental material properties that define the best achievable operation, independent of engineering constraints. In GaN high electron mobility transistors (HEMTs), hot longitudinal optical (LO) phonons can act as an intrinsic performance bottleneck by reducing electron saturation velocity, output current, and transconductance, which are key device metrics. While bulk GaN studies report LO phonon lifetimes of approximately 1 ps, leading to strong nonequilibrium phonon populations, ungated heterostructures show much shorter lifetimes of only tens of femtoseconds. Because direct measurement inside a HEMT channel is challenging, the true impact of hot phonons remains uncertain. Using full-band transport simulations of a fabricated GaN HEMT, we show that LO phonon lifetimes must be less than about 40 fs to reproduce measured I-V characteristics, consistent with ultrafast decay observed in GaN heterostructures. We further demonstrate that even these ultrafast lifetimes are not sufficient to eliminate hot phonon effects: the residual nonequilibrium LO population continues to limit the current density at high bias. Moreover, when the LO phonon lifetime exceeds a few tens of femtoseconds, a pronounced hot phonon bottleneck emerges, leading to substantial current-density suppression that is inconsistent with experiment. - oai:arXiv.org:2512.06226v1 - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Optics experiments as a tool for developing critical thinking in physics education + https://arxiv.org/abs/2512.08297 + arXiv:2512.08297v1 Announce Type: new +Abstract: Experimental activities are an essential part of physics education. In addition to conveying scientific knowledge, they play a significant role in developing scientific literacy, inquiry skills, and critical thinking. In today's world, where students are exposed to vast amounts of information of varying quality, the ability to analyse, evaluate, and interpret information correctly has become increasingly important. This paper presents a series of physics experiments in the field of optics, specifically designed to foster critical thinking at various stages of the inquiry process. The topic of optics was chosen deliberately, as many optical phenomena occur naturally in everyday life, are familiar to students, and stimulate their curiosity. At the same time, they provide space for formulating hypotheses, designing experiments, interpreting data, and evaluating alternative explanations. Each experiment begins with a real-life problem situation that students are expected to explore and resolve through their own investigative work. The tasks are structured to encourage discussion, require argumentation, and promote reflection on both the process and the outcomes. The proposed experiments are suitable for students at both primary and secondary school levels and can be implemented in formal as well as non-formal educational settings. The aim of this contribution is to demonstrate how well-designed and pedagogically grounded experiments can not only enhance the understanding of physical concepts but also systematically develop critical thinking skills - one of the key competencies of 21st-century education. + oai:arXiv.org:2512.08297v1 + physics.ed-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ - Ankan Ghosh Dastider, Matt Grupen, Ashwin Tunga, Shaloo Rakheja - - - Fast and Robust T1 Mapping Based on a 3D Dual-Echo UTE Sequence (PETALUTE) for SPION Biodistribution Assessment - https://arxiv.org/abs/2512.06237 - arXiv:2512.06237v1 Announce Type: new -Abstract: Superparamagnetic iron oxide nanoparticles (SPIONs) such as ferumoxytol are promising theranostic agents detectable with MRI. Relaxation time mapping offers reproducible, quantitative biomarkers of SPION distribution, but conventional methods suffer from susceptibility artifacts, long echo times, and extended scan durations, limiting accurate quantification. This study developed a fast, B1-corrected T1-mapping protocol using PETALUTE, a 3D dual-echo ultrashort-echo MRI sequence with a rosette k-space trajectory and variable flip-angle acquisition for quantitative ferumoxytol imaging. Agarose phantoms containing 0-5000 ppm ferumoxytol were scanned at 7T with PETALUTE and vendor-supplied RARE-VTR. PETALUTE T1 maps were derived from two flip angles (4 deg and 20 deg), and mean R1 values were correlated with ferumoxytol concentration. For in vivo feasibility, mice bearing 4T1 mammary and flank tumors were scanned 24 h post-injection (ferumoxytol: n=2, 40 mg/kg; control: n=1). Regions of interest in muscle and tumors were analyzed to compare T1 and R1 values obtained with both methods. PETALUTE produced positive contrast for all phantom concentrations except 5000 ppm, whereas RARE-VTR did not. PETALUTE demonstrated a significant linear correlation between R1 and ferumoxytol concentration (R=0.975, p<0.01), in contrast to RARE-VTR (R=0.672, p=0.144). In vivo, PETALUTE enabled high-resolution, whole-abdominal imaging in 4 min 19 s. Ferumoxytol-injected mice showed T1 shortening in flank tumors, consistent with iron uptake, and PETALUTE revealed elevated T1 value with preserved T2*-weighted signal in one mammary tumor. PETALUTE-based T1 mapping provides fast, quantitative, positive-contrast ferumoxytol imaging with greater spatial coverage and a wider usable concentration range than conventional RARE-VTR. - oai:arXiv.org:2512.06237v1 - physics.med-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zhen Jiang, Stephen Sawiak, Alexandra Lipka, Xin Shen, Uzay Emir, Ali \"Ozen, Mark Chiew, Justin Geise, Joseph Speth, Deng-Yuan Chang, Jessica Veenstra, Mitchell Gabalski, Luis Solorio, Gregory Tamer Jr., Matthew Scarpelli + 10.1088/1742-6596/3155/1/012017 + J. Phys.: Conf. Ser. 3155 012017 (2025) + Miriam Spodniakov\'a Pfefferov\'a, Martin Plesch - How Conflict Aversion Can Enable Authoritarianism: An Evolutionary Dynamics Approach - https://arxiv.org/abs/2512.06245 - arXiv:2512.06245v1 Announce Type: new -Abstract: We use evolutionary game theory to examine how conflict-averse centrism can unintentionally facilitate authoritarian success in polarized political conflicts. Many such conflicts are asymmetric: authoritarian actors can employ norm-breaking or coercive tactics, while democratic resistance faces stronger constraints on what counts as normatively acceptable behavior. Yet formal models typically treat opposing sides symmetrically and rarely examine conflict-averse behavior. Drawing on empirical research on protest backlash, civility norms, and authoritarian resilience, we model these dynamics as a three-strategy evolutionary game in which resistance, authoritarianism, and conflict-averse centrism interact under replicator dynamics. This framework yields two distinct outcomes -- cyclic resurgence of authoritarian strength through a heteroclinic cycle and a stable centrist-authoritarian coalition that excludes resistance -- depending on how actors respond to confrontation. The analysis shows how payoff differences can reorganize long-run dynamics in asymmetric conflicts. Our contribution is to demonstrate how an established dynamical framework, combined with empirically grounded behavioral assumptions, clarifies the strategic conditions under which conflict aversion can diminish the effectiveness of democratic resistance. - oai:arXiv.org:2512.06245v1 + Critical Thresholds in Non-Pharmaceutical Interventions for Epidemic Control + https://arxiv.org/abs/2512.08339 + arXiv:2512.08339v1 Announce Type: new +Abstract: Non-pharmaceutical interventions, such as contact tracing and social distancing, are critical for controlling epidemic outbreaks, yet their dynamic interactions remain underexplored. We introduce a probabilistic framework to analyze the synergy between contact tracing speed, quantified by the contact tracing period $\tau$, and the average number of close contacts, $\bar{k}_+$, reflecting social distancing measures. We identify critical thresholds ($R=1$) that separate pandemic and contained phases in the $\bar{k}_{+}-\tau$ plane, validated using high-resolution data from Shenzhen's 2022 Omicron outbreak (1,187 cases, 86,451 contacts). Our findings show that contact tracing alone can contain diseases with $R_0 < 2.12$ (95% CI 2.07-2.16), covering 43.33% of major infectious diseases, while combining with social distancing extends control to $R_0 < 7.82$ (95% CI 7.70-7.93), encompassing 86.67% of pathogens. These results, supported by empirical data, highlight the efficacy of rapid tracing and targeted social distancing as alternatives to mass PCR testing. Our framework offers actionable insights for optimizing NPI strategies, though challenges in scaling to regions with higher tracing miss rates or weaker infrastructure underscore the need for adaptive, data-driven policies. + oai:arXiv.org:2512.08339v1 physics.soc-ph - nlin.AO - q-bio.PE - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Chad M. Topaz + Jinghui Wang, Yutian Zeng, Cong Xu, Xiyun Zhang, Zhanwei Du, Jiarong Xie, Jiu Zhang, Sen Pei, Zijian Feng, Yanqing Hu - A Wideband Tri-Band Shared-Aperture Antenna Array for 5G and 6G Applications - https://arxiv.org/abs/2512.06264 - arXiv:2512.06264v1 Announce Type: new -Abstract: This work presents a wideband tri-band shared-aperture antenna array covering the 5G mid-band and 6G centimetric band. The challenge of scattering and coupling suppression is holistically addressed across the wide bands. Guided by characteristic mode analysis (CMA), a segmented spiral radiator is developed to mitigate high-frequency scattering and coupling while maintaining low-frequency radiation performance. Compared with a conventional tube radiator, the proposed spiral achieves a reduced radar cross-section (RCS) over 4.7-21.5 GHz (128.2%). With the aid of serial resonators, the segmented-spiral dipole achieves impedance matching in the low band (LB, 3.05-4.68 GHz, 42.2%), covering the 5G band (3.3-4.2 GHz), while additional suppressors further reduce cross-band coupling. The middle band (MB) and high band (HB) antennas operate at 6.2-10.0 GHz (46.9%) and 10.0-15.6 GHz (43.8%), respectively, collectively covering the anticipated 5G-Advanced and 6G bands (6.425-15.35 GHz). Both the MB and HB antennas employ a planar magnetoelectric (ME) dipole structure to avoid common-mode resonances within the LB and MB and to minimize cross-band scattering in the HB. The proposed array maintains undistorted radiation patterns and better than 20 dB port isolation between any two ports across all three bands. - oai:arXiv.org:2512.06264v1 - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Enzyme-driven phase separation + https://arxiv.org/abs/2512.08356 + arXiv:2512.08356v1 Announce Type: new +Abstract: The formation of polarized signaling domains on cell membranes is a fundamental example of biological pattern formation. While such patterns resemble structures from equilibrium phase separation, they are intrinsically non-equilibrium, driven by energy-consuming enzymatic cycles that switch molecules like phosphoinositides or small GTPases between distinct states. Here, we develop a minimal model of this enzyme-driven phase ordering process. Starting from microscopic reaction kinetics, we derive a mesoscopic theory that belongs to the class of active Model A with a global constraint. This framework yields an explicit mean-field phase diagram and closed-form expressions for key observables, such as interfacial tension, domain fractions, and phase coexistence boundaries, in terms of kinetic rates. In this context, phase coexistence is controlled by non-equilibrium parameters like catalytic rates and enzymatic asymmetry, rather than equilibrium parameters such as saturation concentrations. The resulting phase-separated domains rapidly exchange material with their surroundings. Their maintenance requires a continuous power input determined by enzymatic kinetics. The predicted phenomenology is consistent with experimental observations on reconstituted systems of phosphoinositide and Rab5 membrane patterning. We further study how metastable uniform states decay via nucleation of minority-phase domains and subsequent coarsening, driven by an effective interfacial tension. Using large deviation theory, we derive the critical nucleation radius under the action of the intrinsic, multiplicative chemical noise. The analytical results are quantitatively confirmed by stochastic simulations of the process. Our work provides a theoretical framework identifying key biochemical parameters controlling active phase separation on membrane scaffolds, offering testable predictions for experiments. + oai:arXiv.org:2512.08356v1 + physics.bio-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Shang-Yi Sun, Can Ding, Hai-Han Sun, Alessio Monti, Y. Jay Guo + Damiano Andreghetti, Alfredo Braunstein, Luca Dall'Asta, Andrea Gamba - Frequency modulated enhancement of microwave resonator sensing - https://arxiv.org/abs/2512.06289 - arXiv:2512.06289v1 Announce Type: new -Abstract: We use the Pound-Drever-Hall (PDH) technique to characterize the frequency stability of a microwave-frequency surface acoustic wave (SAW) resonator-based sensor. The multi-mode acoustic resonator is integrated in a notch geometry with a transmission line, all fabricated on Y-cut lithium niobate. We measure the amplitude and phase of the resonator transfer function and the PDH signal across the resonator full spectral range. We use these measurements to emphasize the differences between the PDH measurement and a standard Phase-Locked Loop (PLL) technique. As compared to a PLL, we demonstrate that PDH is insensitive to phase error and exhibits a reduced Allan deviation of the center frequency measurement, in each case by up to an order of magnitude. The method rejects spurious effects and background frequency drift, demonstrating the enhancements possible with PDH-based measurements, which can be realized in a wide range of microwave-frequency resonator-based sensors and devices. - oai:arXiv.org:2512.06289v1 - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Dielectric permittivity tensor dynamics of in-plane hyperbolic van der Waals MoOCl2 and emergent chiral photonic applications + https://arxiv.org/abs/2512.08383 + arXiv:2512.08383v1 Announce Type: new +Abstract: Van der Waals (vdW) crystals offer unique opportunities for modern nanophotonic applications owing to their intrinsic anisotropic nature. While most of them exhibit uniaxial anisotropy arising from weak out-of-plane vdW interaction, some of their representative families also exhibit an in-plane biaxial anisotropy. Among the latter, outstand vdW oxochlorides with in-plane axes of a different physical character (metallic or dielectric). Here, we present an accurate dynamics of dielectric permittivity tensor components of vdW MoOCl2 in the ultraviolet (UV) to visible (Vis) spectral region partly covering near-infrared (NIR). Addressing its enormously anisotropic optical constants, we focus on another hyperbolicity window of vdW MoOCl2 emerging in the UV spectral region that may potentially unlock rich light-matter interaction effects. Furthermore, we propose an approach towards designing nanoscale handedness preserved Vis light circular polarizers based on twisted helical vdW MoOCl2 heterostructures. Our findings display that vdW MoOCl2 provides a highly promising platform not only for hyperbolic, but also for chiral nanophotonic applications. + oai:arXiv.org:2512.08383v1 + physics.optics + cond-mat.mtrl-sci + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Pranaya Kishore Rath, James D. Philips, Taekwan Yoon, Kent R. Shirer, Arash Fereidouni, Johannes Pollanen + Artsruni Margaryan, Maksim Sargsyan, Meri Hayrapetyan, David Karakhanyan, Kostya S. Novoselov, Davit A. Ghazaryan - Solitons in Quasi-Neutral non-Equilibrated Plasmas - https://arxiv.org/abs/2512.06291 - arXiv:2512.06291v1 Announce Type: new -Abstract: In an experiment performed in November 2022 at the one-petawatt (PW) laser facility Vega III in Salamanca, Spain, we studied the production of several radioisotopes using the Target Normal Sheath Acceleration (TNSA) method (M. Rodrigues et al. [1], K. Batani et al. [12]). Using the experimental proton energy distribution recorded on a shot-by-shot basis and confirmed on average in a follow-up experiment, we derive the number of nuclear reactions on different targets for a single shot. From this single-shot analysis, we obtain an effective plasma temperature per shot from the yield ratio 11C/7Be. This gives strong limits to the yields of the reaction p + 11B -> 3 alpha, which may reach (1.6 +/- 0.5) x 10^9 as in 2pi. From the fluctuations of the proton spectra and the fusion yields, we derive the TNSA Equation of State (EOS). The deviation of this EOS from the classical ideal gas limit indicates that the plasma is non-neutral and well described by the Korteweg-de Vries equation. Solitons drive the system toward charge neutrality. We derive an effective soliton mass of ms = (26 +/- 1) meV and a soliton speed on the order of vs/c ~ 0.06. Understanding the soliton dynamics is crucial for applications and basic science. - oai:arXiv.org:2512.06291v1 - physics.plasm-ph - nlin.PS - nucl-ex - Tue, 09 Dec 2025 00:00:00 -0500 + Development & first Performance evaluation of multielement monolithic HPGe detector for spectroscopy applications + https://arxiv.org/abs/2512.08389 + arXiv:2512.08389v1 Announce Type: new +Abstract: We present the first operational prototype of a high-purity Germanium (HPGe) detector developed within the framework of the European LEAPS-INNOV project. This prototype features a monolithic, multi-element sensor optimized for high-resolution X-ray spectroscopy in the hard X-ray regime. The study includes a comprehensive laboratory-based characterization of the detector's spectral and spatial performance, and an on-beam evaluation at the BM05 beamline of the ESRF synchrotron facility using monochromatic X-rays in the 20-50 keV energy range. Detailed characterization results are reported, including sensor performance metrics such as energy resolution, count rate, and spatial response uniformity. + oai:arXiv.org:2512.08389v1 + physics.ins-det + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Zhe Zhu, A. Bonasera, M. R. D. Rodrigues, J. A. P\'erez-Hern\'andez, M. Ehret, E. Filippov, H. Larreur, D. Molloy, G. G. Rapisarda, D. Lattuada, G. L. Guardo, C. Verona, Fe. Consoli, G. Petringa, A. McNamee, M. La Cognata, S. Palmerini, R. De Angelis, G. A. P. Cirrone, V. Istokskaia, D. Batani, K. Batani, R. Lera, L. Volpe, D. Giulietti, S. Agarwal, M. Krupka, S. Singh, Jun Xu + N. Goyal, F. J. Iguaz, S. Aplin, A. Balerna, P. Bell, J. Casas, M. Cascella, S. Chatterji, C. Cohen, E. Collet, E. N. Gimenez, H. Graafsma, H. Hiresmann, K. Klementiev, T. Kolodziej, T. Martin, R. H. Menk, C. Menneglier, C. Meraihia, J. R. Murias, M. Porro, M. Quispe, B. Schmitt, S. Scully, M. Turcato, C. Ward, E. Welter - In-series Multimode Interference Sensors and Fabry-Perot Interferometers for Enhanced Wavelength Shift Resolving Capabilities - https://arxiv.org/abs/2512.06305 - arXiv:2512.06305v1 Announce Type: new -Abstract: We report on the development of a refractive index sensor obtained by using a singlemode-multimode-singlemode (SMS) structure and a Fabry-Perot interferometer (FPI) set into an in-series configuration. Due to the self-imaging phenomenon, the SMS structure - formed by splicing a no-core fiber between two singlemode fibers -, provides a broad spectral peak whose central wavelength position is sensitive to variations in the refractive index of the medium surrounding the fiber. In turn, thanks to the in-series SMS-FPI configuration, the sensor's reflection spectrum exhibits the SMS spectral signature modulated by FPI fringes. This readily allows for reducing the width of the spectral features monitored during the sensing measurements, thus enhancing the capabilities of adequately resolving the corresponding spectral shifts. The FPIs reported in this investigation have been fabricated by using two different methods, namely by forming an air-gap FPI between the cleaved ends of two singlemode optical fibers, and by casting a polymeric film onto a connectorized fiber end tip. In the first configuration, the distance between the two cleaved fiber ends could be varied to tune the FPI's free spectral range, hence allowing for tailoring the widths of the spectral oscillations to be monitored during the sensing measurements. Alternatively, the second configuration, while avoiding the use of motorized translation stages, provides a more versatile option for applications. Thus, we understand that our work expands the application of multimode interference and FPIs in sensing scenarios, providing new opportunities for probing physical and chemical parameters by exploring their combined response. - oai:arXiv.org:2512.06305v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 + A cold beam of BaOH molecules using a water-vapour seeded neon gas + https://arxiv.org/abs/2512.08402 + arXiv:2512.08402v1 Announce Type: new +Abstract: In this paper we report on the production and characterization of a cold beam of BaOH molecules using a cryogenic buffer-gas beam source. BaOH is a highly suitable molecule for studies of the violation of fundamental symmetries, such as the search for the electron's electric dipole moment. BaOH molecules are synthesised inside the cold source through laser ablation of a barium metal target while water vapor is seeded into the neon buffer gas. The BaOH flux is significantly enhanced ($\sim$11 times) when laser-exciting the barium atoms inside the buffer-gas cell on the $^1\mathrm S_0 - ^3\mathrm P_1$ transition. A similar enhancement has been reported for other alkaline-earth(-like) monohydroxides. For typical source conditions, the molecular beam has an average velocity of $\approx180$ m/s and an intensity of $\sim 10^{9}$ molecules s$^{-1}$ in $N=1$, which is comparable to that of cryogenic BaF beams. + oai:arXiv.org:2512.08402v1 + physics.atom-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Jo\~ao G. M. de Carvalho, Luiz D. C. Silva, Flavio A. M. Marques, Alexandre A. C. Cotta, Jefferson E. Tsuchida, Julio C. Ugucioni, Sil\'esia C. da Silva, Leomar S. Marques, Diego C. Fuzatto, Alexandre Bessa dos Santos, Cristiano M. B. Cordeiro, Limin Xiao, Jonas H. Os\'orio + Ties Hendrik Fikkers, Nithesh Balasubramanian, Joost W. F. van Hofslot, Maarten C. Mooij, Hendrick L. Bethlem, Steven Hoekstra - Dual-comb correlation spectroscopy reveals laser dynamics - https://arxiv.org/abs/2512.06320 - arXiv:2512.06320v1 Announce Type: new -Abstract: Laser dynamics underpin a broad range of modern photonic technologies and continue to reveal rich nonlinear behaviors. However, existing spectroscopic tools, most notably time-stretched dispersive Fourier transform spectroscopy (TS-DFT), remain limited in spectral resolution, accuracy, and their ability to capture continuous waveforms and complex field dynamics. Here, we introduce dual-comb correlation spectroscopy (DCCS) as a powerful approach for resolving fast and intricate laser behaviors that are inaccessible to TS-DFT and conventional spectrometers. By correlating two sequences of heterodyne spectra produced by mixing a test laser with a pair of optical combs, DCCS enables rapid (e.g., 1 us) and high-resolution (0.08 pm) spectral retrieval over broad optical bandwidths. Leveraging these capabilities, we reveal mode-hopping and mode-competition dynamics in continuous-wave lasers, as well as the buildup process of a mode-locked laser. These results establish DCCS as a versatile and complementary tool to TS-DFT for exploring transient, broadband, and previously unresolvable behaviors in lasers and other time-evolving optical systems. - oai:arXiv.org:2512.06320v1 - physics.optics - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Dynamics of an internally actuated weakly elastic sphere in a general quadratic flow + https://arxiv.org/abs/2512.08408 + arXiv:2512.08408v1 Announce Type: new +Abstract: Internally actuated elastic particles are widely used in biomedical applications. It is imperative to understand the dynamics of such particles in pressure-driven microfluidic devices to manipulate their motion. We analytically examine the dynamics of an internally actuated elastic particle translating in a general unbounded quadratic flow in the inertialess limit. We consider the particle as a compressible weakly elastic sphere, and its motion is controlled by applying an external point force and a point torque at the centre of its undeformed shape. The fluid and the particle are modelled using the Stokes and the Navier elasticity equations, respectively. We use the domain perturbation method to capture the particle deformation. The point force and the point torque are obtained until \textit{O}($\alpha^2$), assuming $\alpha\ll 1$. Here, $\alpha$ is the measure of the particle elastic strain induced due to the fluid viscous stress. We present the results for the particle motion in a general unbounded quadratic flow. The results are simplified further for the motion along the centreline in the quadratic component of three Poiseuille flows: 1) elliptical Poiseuille, 2) plane Poiseuille, and 3) Hagen-Poiseuille flows. In the general quadratic flow, the point force at \textit{O}($\alpha$) is aligned with the particle velocity, while the force at \textit{O}($\alpha^2$) acts at an angle to the velocity. Furthermore, the torque is non-zero due to elastic effects at \textit{O}($\alpha$) and \textit{O}($\alpha^2$). For all the three Poiseuille flows, the point force until \textit{O}($\alpha^2$) is aligned with the particle velocity, while the torque comes as zero. + oai:arXiv.org:2512.08408v1 + physics.flu-dyn + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Xiuxiu Zhang, Zhuoren Wan, Yuling Sheng, Ming Yan, Yuan Chen, Zijian Wang, Zhaoyang Wen, Min Li, Heping Zeng + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Shashikant Verma, Navaneeth K. Marath - Alterations of brain tissue structural complexity and disorder in Parkinson disease (PD): Fractal, multifractal, fractal transformation, and disorder strength analyses - https://arxiv.org/abs/2512.06326 - arXiv:2512.06326v1 Announce Type: new -Abstract: Parkinson disease (PD) is marked by progressive neurodegeneration, yet early and subtle structural alterations in brain tissue remain difficult to detect with conventional imaging and analytical methods. Fractal and multifractal frameworks offer a principled way to quantify complex biological architecture, but their diagnostic utility in PD has been largely unexplored. In this study, we investigated the fractal and multifractal characteristics of human brain tissues to identify structural alterations associated with PD. Alongside conventional fractal and multifractal analysis, we employed a recently developed fractal functional distribution method that transforms distributions into a Gaussian form, thereby enhancing quantification. Using this combined approach, we found notable deviations across multiple distribution metrics in PD samples, offering potential for quantitative staging and diagnostic applications. The multifractal analysis revealed threshold-dependent variations in intensity-based measures, which are linked to the sparsity and heterogeneity of neural tissue and suggestive of potential biomarker value. Additionally, we applied inverse participation ratio (IPR) analysis to assess structural disorder, demonstrating that larger IPR pixel sizes correlate with increased structural complexity during disease progression. These complementary analyses outline a multi-layered quantitative profile of PD-related tissue disruption, offering a foundation for earlier, objective assessment of disease-associated microstructural change. - oai:arXiv.org:2512.06326v1 - physics.med-ph - nlin.CD - physics.bio-ph - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 + Trans-Arctic route feasibility on a pan-Arctic grid under bathymetric and sea-ice constraints + https://arxiv.org/abs/2512.08434 + arXiv:2512.08434v1 Announce Type: new +Abstract: Climate driven reductions in Arctic sea ice have renewed interest in trans Arctic shipping, but adoption remains limited by basic questions of route feasibility, safety and excess distance. Existing studies mostly compare idealised great circle shortcuts or use full weather routing systems, leaving a gap for simple basin scale diagnostics on realistic bathymetry and sea ice. We develop an offline graph based framework on a 0.5 degree pan Arctic grid that combines GEBCO 2024 bathymetry with a summer 2018 Arctic sea ice reanalysis from the Copernicus Marine Environment Monitoring Service (CMEMS). An A* pathfinding algorithm is applied to a canonical Europe Asia origin destination pair to quantify route availability and route length inflation relative to a great circle. Enforcing sea only feasibility increases route length by about 10 percent before depth and ice constraints are applied. Depth thresholds representative of under keel clearance (hmin = 20-50 m) remove up to roughly 15 percent of the sea mask but preserve a trans Arctic connection for hmin = 20 m. Summer sea ice exerts a strong seasonal control: continuous ice safe routes emerge only from mid August, with distances inflated by roughly 20-25 percent even in late summer. When depth and ice constraints are imposed jointly, only about 75 percent of sea cells remain safe and no continuous joint safe trans Arctic route exists in the tested season. The framework provides a basin scale screening tool for Arctic shipping and a baseline for forecast driven, multi objective routing studies. + oai:arXiv.org:2512.08434v1 + physics.geo-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Santanu Maity, Mousa Alrubayan, Mohammad Moshahid Khan, Prabhakar Pradhan + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Abdella Mohamed, Xiangyu Hu - High-Efficiency Isolator-Free Magnetron Power Combining Method Based on H-Plane Tee Coupling and Peer-to-Peer Locking - https://arxiv.org/abs/2512.06338 - arXiv:2512.06338v1 Announce Type: new -Abstract: Magnetrons are widely used as high-performance microwave sources in microwave heating, microwave chemistry, and microwave power transmission due to their high efficiency, low cost, and compact size advantages. However, the output power of a single magnetron is limited by its resonant cavities, posing a physical constraint. High-efficiency coherent power combining based on the injection-locking technique effectively overcomes this limitation and meets the demand for higher output power. Nevertheless, using isolators, such as circulators, introduces significant insertion loss, and the injection signal sources and phase shifters increase the system size, cost, and complexity in a conventional magnetron power combining (MPC) system. A novel method is proposed to utilize the coupling between two ports of an H-plane tee to achieve peer-to-peer injection locking magnetrons. Meanwhile, an asymmetric phase compensation is realized using a section of waveguide to adjust the magnetron output characteristics. Theoretical and numerical analyses provided qualitative insight into the system output behavior. Subsequently, an experimental system was developed for verification. In the experiments, the system achieved maximum microwave power combining efficiencies 90.2%, 93.6%, and 93.6% at electrical waveguide lengths corresponding to 90, 135, and 225, with output powers of 1650, 1260, and 1610 W, respectively, without the use of any isolators or external injection sources. The experimental results show good agreement with numerical calculations. This method offers the advantages of low cost, compact size, and low loss, providing a new approach for developing high-performance MPC systems in the future. - oai:arXiv.org:2512.06338v1 - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Scalable CFD Simulations in Multi-Billion Voxel Micro-CT Images of Porous Materials Using OpenFOAM on ARCHER2 + https://arxiv.org/abs/2512.08438 + arXiv:2512.08438v1 Announce Type: new +Abstract: This study investigates the use of High-Performance Computing (HPC) to simulate flow and transport in ultra-large micro-CT images of porous materials using Computational Fluid Dynamics (CFD). Two distinct rock samples, representative of two different rock formations - Bentheimer sandstone and Estaillades carbonate - are investigated. The Bentheimer sandstone image, with dimensions 1,950x1,950x10,800 voxels at 6 micron resolution, comprising 41 billion voxels, represents a largely homogeneous structure, while the Estaillades carbonate image, at 1,144x1,144x6,000 voxels and 3.9676 micron resolution, amounting to 8 billion voxels, features greater heterogeneity, including micro-porous regions. These images are used for direct CFD simulations with GeoChemFoam, our OpenFOAM-based numerical solver, leveraging the computational resources of the UK supercomputer ARCHER2. One of the key aspects of the study is the use of the Darcy-Brinkman-Stokes approach, for which the solid surface is represented using a volumetric indicator function, rather than a complex mesh. This enables the use of simple Cartesian meshes that can be generated in parallel in an efficient and scalable manner. The study explores both weak and strong scaling through subvolume decomposition, demonstrating that, due to the strong scalability and the computational power of ARCHER2, full-resolution CFD simulations can be carried out without the need for image size reduction. This work illustrates the potential of HPC to perform detailed, full-scale simulations on large, high-resolution micro-CT data. The approach relies on a meshing strategy that leverages simple, parallelisable Cartesian grids derived from volumetric indicator functions, eliminating the need for complex surface-conforming meshes and allowing scalable simulation of flow and transport in geological and engineering applications. + oai:arXiv.org:2512.08438v1 + physics.flu-dyn + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.1109/TMTT.2025.3598872 - IEEE Transactions on Microwave Theory and Techniques, vol. 73, no. 11, pp. 9429-9441, Nov. 2025 - Shaoyue Wang, Xu Zhu, Xiaojie Chen, Da He, Zhongqi He, Liping Yan, Changjun Liu + J. Maes, Gavin J. Pringle, Hannah P. Menke - Reynolds effects on transition to turbulence for hypersonic expansion and compression corner flows - https://arxiv.org/abs/2512.06384 - arXiv:2512.06384v1 Announce Type: new -Abstract: This experimental and numerical study examines transition to turbulence for a Cone-Cylinder-Flare geometry at Mach 7 and across a broad Reynolds number range. The focus is set on both attached boundary layers and separated shock-boundary layer interactions. The campaign is conducted in the R2Ch facility. Unsteady wall pressure fluctuations and high-speed schlieren images are analysed using data-driven techniques and compared with base flow computations and global linear stability analysis. The results distinguish two transition regimes. At high Reynolds numbers, transition is dominated by the second Mack mode and its non-linear interactions on the cone. High-frequency wall pressure measurements and schlieren imaging permit the capture of both fundamental waves and their non-linear harmonics. Non-linear interaction regions are resolved with unprecedented detail, clarifying the boundary-layer state before rapid breakdown at reattachment. At lower Reynolds numbers, the transition scenario is more intricate, marked by the coexistence of low- and high-frequency modes. A complex coupling between separated flow and convective instabilities is revealed, with trapped acoustic waves inside the recirculation region measured experimentally for the first time. Their linear origin is demonstrated through global stability analysis, and a simple acoustic duct model is provided to predict their frequencies. These waves offer a new interpretation of low-frequency pressure signatures and suggest a mechanism for energy transfer from high to low frequencies, ultimately driving transition on the flare. The findings advance understanding of hypersonic boundary-layer transition and its dependence on Reynolds number and flow separation. - oai:arXiv.org:2512.06384v1 + Transition in elastic Dean flow: the centre-mode versus hoop-stress pathways + https://arxiv.org/abs/2512.08456 + arXiv:2512.08456v1 Announce Type: new +Abstract: We analyse the stability of viscoelastic Dean flow (flow of an elastic fluid through a curved two-dimensional channel, driven by an azimuthal pressure gradient) in the absence of fluid inertia. This configuration is well known to exhibit a hoop-stress-driven `purely elastic' instability (referred to henceforth as the hoop-stress mode -- `HSM') on account of the base-flow streamline curvature. The objective of this study is to demonstrate the existence and importance of a distinct elastic instability in this flow configuration, which is not driven by hoop-stresses, but instead is a continuation of a novel `centre-mode' (CM) instability recently identified in rectilinear shear flows. We use both the Oldroyd-B and FENE-P models to map out parameter regimes in the $W\!i$--$\epsilon$--$\beta$ space where the aforementioned instabilities are present. Here, $W\!i$ is a suitably defined Weissenberg number that characterizes fluid elasticity, $\beta$ is the ratio of solvent to total solution viscosity, and $\epsilon$ is the ratio of the gap (channel) width to the radius of curvature. For FENE-P model, decreasing the finite extensibility parameter $L$ has opposing effects on the HSM and CM instabilities -- stabilising the former, but destabilising the latter. In the dilute solution regime ($\beta > 0.95$), and for realistic values of $L \sim O(100)$, corresponding to polymer molecular weights of $O(10^{5-6})$g/mol, the CM remains the most unstable mode for $\epsilon \leq 0.25$, rendering it potentially relevant to the onset of elastic turbulence in the flow of such polymer solutions through curved channels. + oai:arXiv.org:2512.08456v1 physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 + cond-mat.soft + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Cl\'ement Caillaud, Mathieu Lugrin, Nicolas Severac, S\'ebastien Esquieu + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + P. S. D. Surya Phani Tej, Ganesh Subramanian, V. Shankar - Demographic Dependence of Vaccine Adoption under Opinion Persuasion - https://arxiv.org/abs/2512.06385 - arXiv:2512.06385v1 Announce Type: new -Abstract: Inspired by contagion models of social belief formation, we develop an epistemically-informed modeling framework, SIS-Vo, in which vaccine-related information propagates on a signed opinion network. Our model allows for heterogeneous treatment effects of policy messages across subpopulations through demographic-specific responses. We derive fixed-point characterizations of the healthy (disease-free) and endemic equilibria of this model, and obtain conditions for local stability of the healthy state in terms of the contact network and opinion-dependent vaccination capacities. Using numerical simulations, we illustrate how suitably targeted policy interventions, acting through opinion dynamics, can stabilize the epidemic process by moving the system towards the healthy regime. The SIS-Vo framework thus provides a natural basis for control-theoretic analysis of vaccination policies that remain robust even when misinformation targets specific subgroups. - oai:arXiv.org:2512.06385v1 - physics.soc-ph - cs.SY - eess.SY - Tue, 09 Dec 2025 00:00:00 -0500 + Angular emission of scintillators for nuclear fusion diagnostics + https://arxiv.org/abs/2512.08501 + arXiv:2512.08501v1 Announce Type: new +Abstract: Accurate characterization of fast-ion behavior is essential for the safe and efficient operation of nuclear fusion plasmas, as energetic particle losses can degrade plasma performance and damage reactor components. Scintillator-based detectors are widely employed to monitor fast ions; however, existing studies often assume isotropic light emission, neglecting potential angular dependencies that can compromise the determination of ion fluxes. In this work, we investigate the angular emission properties of two commercial scintillators, TG-Green and b-SiAlON, under irradiation with 3.5 MeV He++ and 1 MeV D+ beams, representative of conditions in future fusion devices such as ITER. A novel experimental setup, combining precise optical alignment, angular scanning, and rigorous calibration, was developed to measure the detection efficiency as a function of observation angle. Prior to the characterization, stability tests demonstrated negligible radiation-induced degradation under the applied fluences, and transmission losses due to optical fiber bending were found to be below 1.5%. The results reveal a pronounced angular anisotropy in scintillation emission for both materials, with intensity decreasing as the detection angle increases, well described by an empirical cosine-based model. Additionally, the normalized response shows minimal dependence on ion species or energy. These findings improve scintillator-based diagnostics, allowing more accurate measurement of fast-ion fluxes in fusion plasmas. + oai:arXiv.org:2512.08501v1 + physics.ins-det + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Alessandro Casu, Camilla Quaresmini, Robin Delabays, Lewis Mitchell, Philip E. Par\'e + http://creativecommons.org/licenses/by-nc-nd/4.0/ + M. Rodr\'iguez-Ramos, J. Garc\'ia-L\'opeza, M. Videla-Trevina, J. Gonz\'alez-Martinc, P. Alvarez-Fraub, M. Kocan - Bayesian Earthquake Location with a Neural Travel-Time Surrogate: Fast, Robust, and Fully Probabilistic Inference in 3-D Media - https://arxiv.org/abs/2512.06407 - arXiv:2512.06407v1 Announce Type: new -Abstract: We present a Bayesian earthquake location framework that couples a Deep Learning Surrogate with Gibbs sampling to enable uncertainty-aware hypocenter estimation. The surrogate model is trained to reproduce the three-dimensional first-arrival travel-time field by enforcing the Eikonal equation, thereby removing the need for computationally intensive ray tracing. Within a fully probabilistic formulation, Gibbs sampling is used to explore the posterior distribution of source parameters, yielding comprehensive uncertainty quantification. Application to the 2021 Luding aftershock sequence shows that the proposed approach attains location accuracy comparable to that of NonLinLoc while reducing computational cost by more than an order of magnitude. In addition, it produces detailed posterior probability maps that explicitly characterize spatial uncertainty. This integration of physics-informed learning and Bayesian inference provides a scalable, physically consistent, and computationally efficient solution for real-time earthquake location in complex velocity structures. - oai:arXiv.org:2512.06407v1 - physics.geo-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Data-Efficient Learning of Anomalous Diffusion with Wavelet Representations: Enabling Direct Learning from Experimental Trajectories + https://arxiv.org/abs/2512.08510 + arXiv:2512.08510v1 Announce Type: new +Abstract: Machine learning (ML) has become a versatile tool for analyzing anomalous diffusion trajectories, yet most existing pipelines are trained on large collections of simulated data. In contrast, experimental trajectories, such as those from single-particle tracking (SPT), are typically scarce and may differ substantially from the idealized models used for simulation, leading to degradation or even breakdown of performance when ML methods are applied to real data. To address this mismatch, we introduce a wavelet-based representation of anomalous diffusion that enables data-efficient learning directly from experimental recordings. This representation is constructed by applying six complementary wavelet families to each trajectory and combining the resulting wavelet modulus scalograms. We first evaluate the wavelet representation on simulated trajectories from the andi-datasets benchmark, where it clearly outperforms both feature-based and trajectory-based methods with as few as 1000 training trajectories and still retains an advantage on large training sets. We then use this representation to learn directly from experimental SPT trajectories of fluorescent beads diffusing in F-actin networks, where the wavelet representation remains superior to existing alternatives for both diffusion-exponent regression and mesh-size classification. In particular, when predicting the diffusion exponents of experimental trajectories, a model trained on 1200 experimental tracks using the wavelet representation achieves significantly lower errors than state-of-the-art deep learning models trained purely on $10^6$ simulated trajectories. We associate this data efficiency with the emergence of distinct scale fingerprints disentangling underlying diffusion mechanisms in the wavelet spectra. + oai:arXiv.org:2512.08510v1 + physics.bio-ph + cond-mat.soft + cs.LG + physics.data-an + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Jinqing Sun, Ziye Yu, Zemin Liu, Lu Li, Chunyu Liu, Wei Yang, Yuqi Cai - - - Model of incompressible turbulent flows via a kinetic theory - https://arxiv.org/abs/2512.06433 - arXiv:2512.06433v1 Announce Type: new -Abstract: Kinetic theory offers a promising alternative to conventional turbulence modelling by providing a mesoscopic perspective that naturally captures non-equilibrium physics such as non-Newtonian effects. In this work, we present an extension and theoretical analysis of the recent kinetic model for incompressible turbulent flows developed by Chen et al. (Atmos. 14(7), 1109, 2023), constructed for unbounded flows. The first extension is to reselect a relaxation time such that the turbulent transport coefficients are obtained more consistently and better align with well-established turbulence theory. The Chapman-Enskog (CE) analysis of the kinetic model reproduces the traditional linear eddy viscosity and gradient diffusion models for Reynolds stress and turbulent kinetic energy flux at the first order, and yields nonlinear eddy viscosity and closure models at the second order. Particularly, a previously unreported CE solution for turbulent kinetic energy flux is obtained. The second extension is to enable the model for wall-bounded turbulent flows with preserved near-wall asymptotic behaviours. This involves developing a low-Reynolds number kinetic model incorporating wall damping effects and viscous diffusion, with boundary conditions enabling both viscous sublayer resolution and wall function application. Comprehensive validation against experimental and DNS data for turbulent plane Couette flow demonstrates excellent agreement in predicting mean velocity profiles, skin friction coefficients, and Reynolds stress distributions. It reveals that an averaged turbulent flow behaves similarly to a rarefied gas flow at a finite Knudsen number, capturing non-Newtonian effects inaccessible to linear eddy viscosity models. This kinetic model provides a physics-based foundation for turbulence modelling with reduced empirical dependence. - oai:arXiv.org:2512.06433v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Ziyang Xin, Zhaoli Guo, Hudong Chen + Gongyi Wang, Yu Zhang, Zihan Huang - Characteristic Bending in Incompressible Flows - https://arxiv.org/abs/2512.06455 - arXiv:2512.06455v1 Announce Type: new -Abstract: We present the Characteristic Bending (CB) method, a general framework for advecting quantities under incompressible velocity fields. The method builds on standard semi-Lagrangian advection by interpreting the backward-in-time characteristic reconstruction as the construction of a reference map, a diffeomorphism between the current and initial geometries of the advected space. From this viewpoint, the CB method applies a volume-preserving projection to the map, systematically removing spurious compressible errors arising from time integration, interpolation, or from velocity fields that are only approximately divergence-free. This projection bends the characteristics toward the divergence-free space, preserving mass and geometric features of the advected fields, even in the presence of significant error. We demonstrate the method in both two and three dimensions using benchmark problems and for multiphase flows governed by the incompressible Navier-Stokes equations. The results show that the CB method serves as a drop-in replacement for traditional semi-Lagrangian schemes and as an augmentation of reference map formulations, offering improved robustness and accuracy in incompressible flow simulations. - oai:arXiv.org:2512.06455v1 - physics.flu-dyn - cs.NA - math.NA - Tue, 09 Dec 2025 00:00:00 -0500 + Laser-pumped drilling carbon nanotube vortex shock waves in optical fibers + https://arxiv.org/abs/2512.08538 + arXiv:2512.08538v1 Announce Type: new +Abstract: We experimentally demonstrate laser-induced vortex shock waves formed by carbon nanotubes drilling optical fibers for the first time. Three samples of standard single-mode optical fibers (SMF) are sequentially inserted in a syringe loaded with a 1 mL solution of single-walled carbon nanotubes (CNT) and methanol, and a high-power laser is injected into the fibers for 5 (SMF 1), 10 (SMF 2), and 20 (SMF 3) minutes. The CNT solution thermally expands and generates vortex acoustic flows, which are confined in the syringe cavity, significantly increasing the velocity and impact of nanotubes at the fiber tip. The resulting shock waves achieve estimated hypersonic velocities (5742 m/s) and high pressures (6.7 GPa), overcoming the silica tensile strength and ablating structured vortices in the fibers. The material, geometry, and depth profile of the vortices are characterized, providing details of mixing carbon and silica layers, increasing radially from the fiber core center and in thickness to the cladding for longer laser periods (850 nm to 10 micron thickness). The cross-sections of the measured vortices are compared to analytical simulations, revealing unprecedented Fibonacci helices drilling holes in the fiber core with a 5 micron maximum depth, while depositing nanoscale CNT-silica layers following Fibonacci spirals. These achievements point out a new route for laser-controlled deposition of nanoparticles and fabrication of vortex devices on fiber tips, which is promising for all-fiber vortex spatial phase modulators in optical communications, fiber sensors, high-power pulsed fiber lasers, and biomedical ultrasonic neurotransmitters. + oai:arXiv.org:2512.08538v1 + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Matthew Blomquist, St\'ephane Gaudreault, Maxime Theillard + Ricardo E. da Silva, Marcos A. R. Franco - A Coupled CFD Framework for Combustor Turbine Interaction in a Research Aeroengine - https://arxiv.org/abs/2512.06460 - arXiv:2512.06460v1 Announce Type: new -Abstract: This work presents a fully coupled combustor turbine simulation framework applied to the MYTHOS aeroengine, developed within the Horizon Europe project MYTHOS, aimed at assessing the impact of Sustainable Aviation Fuels (SAFs) and hydrogen on next generation propulsion systems. The numerical setup features a dynamic, bidirectional coupling between a pressure-based solver with detailed finite rate chemistry, deployed in the combustor, and a density-based turbomachinery solver employing tabulated thermochemistry for efficiency, used for the turbine. The coupling is realised through a flux-averaging methodology that ensures conservative exchange of flow quantities and allows flow in arbitrary directions across the interface. Previous validation steps of presented methodology have shown the viability of the approach and are also shortly reviewd. The paper focuses on the chemistry handling strategy that guarantees thermochemical consistency between the two solvers. Coupled reacting simulations at cruise operating conditions demonstrate the capability of the framework to capture combustor generated hot streaks transport and their influence on turbine aerothermal loading. Comparison with segregated simulations of the two components shows that coupling captures the highly unsteady temperature and flow distributions at the turbine inlet and across the blade rows. Whilst mean aerodynamic loading are essentially unchanged, a realistic circumferential variability in blade thermal loading can be observed in the coupled simulations, thus establishing a consistent foundation for future studies on the effects of alternative fuels on core engine components. - oai:arXiv.org:2512.06460v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 + Polarization Dependent Enhancement of Magnetic Dipolar Emission with Silicon Nanodimers + https://arxiv.org/abs/2512.08546 + arXiv:2512.08546v1 Announce Type: new +Abstract: Eu(TTA)3 complexes are used as an emission source in the presence of high refrac- tive index dielectric nanostructures. These nanostructures support Mie-type resonances that modify the local density of optical states. Specifically, the silicon dimer provides polarization-dependent electric and magnetic field enhancement in the dimer gap to modify the electric dipolar and magnetic dipolar emissions of the Eu3+ at 610 nm and 590 nm, respectively. Finite element method simulations are used to determine the opti- mal parameters for the sample and to demonstrate the polarization-dependent emission enhancement of dipolar emitters in the gap. A two-step electron beam lithography pro- cess is used to fabricate the hybrid nanoscopic structures, with a Eu3+ doped electron beam resist located only in the center of the dimer. The results demonstrate the po- tential of these nanostructures to selectively tailor the emission of the two distinct dipolar transitions by engineering the resonant nanostructures. Our work highlights the potential of magnetic light-matter interactions as a novel degree of freedom. + oai:arXiv.org:2512.08546v1 + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Federico Lo Presti, Pierre Vauquelin, Jan Donndorf, Francesca di Mare, Xue-Song Bai, Christer Fureby + Marijn Rikers, Ayesheh Bashiri, Aleksandr Vaskin, \'Angela Barreda, Duk-Yong Choi, Michael Steinert, Thomas Pertsch, Isabelle Staude - Earth radius from a single sunrise image: a classroom-ready activity - https://arxiv.org/abs/2512.06474 - arXiv:2512.06474v1 Announce Type: new -Abstract: Using a photograph of the shadow of Mont Blanc taken from Geneva at sunrise, we derive an upper limit for the Earth radius. After presenting the observational context and the model underlying assumptions, we determine the direction of the solar rays relative to the local vertical. This direction constrains the Earth maximum diameter which -- once corrected for atmospheric refraction -- amounts to roughly 1.7 times its presently accepted value. This work illustrates a pedagogical approach to scientific inquiry, showing how simple observations, combined with reasoning and elementary mathematical and geometrical tools, can yield meaningful physical estimates. - oai:arXiv.org:2512.06474v1 - physics.ed-ph - physics.geo-ph - Tue, 09 Dec 2025 00:00:00 -0500 + A journey to ITACA + https://arxiv.org/abs/2512.08549 + arXiv:2512.08549v1 Announce Type: new +Abstract: A unique feature of gas xenon electroluminescent time projection chambers (GXeEL TPCs) in $0\nu\beta\beta$ searches is their ability to reconstruct event topology, in particular to distinguish "single-electron" from "double-electron" tracks, the latter being the signature of a $0\nu\beta\beta$ decay near the decay endpoint $Q_{\beta\beta}$. Together with excellent energy resolution and the t$_0$ provided by primary scintillation, this topological information is key to suppressing backgrounds. Preserving EL, however, requires operating in pure xenon (with helium as the only benign additive), and in pure xenon the diffusion of drifting electrons is large. As a result, the fidelity of reconstructed tracks is limited both by diffusion and by the intrinsic blurring of EL amplification. + We propose augmenting the detector with the ability to image not only the electron track but also the corresponding mirror ion track. Introducing trace amounts of NH$_3$ ($\sim$100 ppb) converts Xe$^+$ ions into NH$_4^+$ while leaving EL unaffected. For events in the region-of-interest, an ion sensor positioned near the cathode at the projected barycenter captures the NH$_4^+$ ions. Electrons drift rapidly to the anode, producing the standard EL image, whereas the NH$_4^+$ ions drift slowly toward the cathode. Their slow drift provides time to determine the event energy and barycenter. Laser interrogation of the sensor's molecular layer then reveals an ion-track image with sub-millimeter diffusion and no EL-induced smearing. + The combined electron-ion imaging substantially strengthens topological discrimination, improving background rejection by about an order of magnitude and significantly extending the discovery potential of GXeEL TPCs for very long $0\nu\beta\beta$ lifetimes. + oai:arXiv.org:2512.08549v1 + physics.ins-det + hep-ex + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Florian Dubath, Maria Alice Gasparini + http://creativecommons.org/licenses/by/4.0/ + J. J. G\'omez-Cadenas, L. Arazi, M. Elorza, Z. Freixa, F. Monrabal, A. Pazos, J. Renner, S. R. Soleti, S. Torelli - Study on Improving Microwave Heating Uniformity Based on Phase-Frequency Simultaneous Modulation Technique - https://arxiv.org/abs/2512.06482 - arXiv:2512.06482v1 Announce Type: new -Abstract: Conventional microwave heating techniques are limited due to inherent thermal point residency effects and inadequate control over the heating process. A novel method is proposed to enhance microwave heating uniformity using the injection-pulling technique. In this method, the injection-pulling technique is used to achieve simultaneous modulation of both the output phase and frequency of the magnetron, thereby extending the locking bandwidth of the injection-locking technique. The output characteristics of the injection-pulled magnetron were validated through numerical calculations and experiments. Microwave heating experiments were conducted under both a five-cup water load and an absorbent paper load. Compared with conventional injection-locking frequency sweeping, the proposed method not only expands the sweeping bandwidth from 8 to 18 MHz but also further improves heating uniformity, offering more options for magnetron applications in microwave heating. - oai:arXiv.org:2512.06482v1 - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Matrix-free algorithms for fast ab initio calculations on distributed CPU architectures using finite-element discretization + https://arxiv.org/abs/2512.08571 + arXiv:2512.08571v1 Announce Type: new +Abstract: Finite-element (FE) discretisations have emerged as a powerful real-space alternative to large-scale Kohn-Sham density functional theory (DFT) calculations, offering systematic convergence, excellent parallel scalability, while accommodating generic boundary conditions. However, the dominant computational bottleneck in FE-based DFT arises from the repeated application of the discretised sparse Hamiltonian to large blocks of trial vectors during iterations in an iterative eigensolver. Traditional sparse matrix-vector multiplications and FE cell-matrix approaches encounter memory limitations and high data-movement overheads, particularly at higher polynomial orders, typically used in DFT calculations. To overcome these challenges, this work develops matrix-free algorithms for FE-discretised DFT that substantially accelerate these products by doing on-the-fly operations that utilize structured tensor contractions over 1D basis functions and quadrature data. A unified multilevel batched data layout that handles both real and complex-valued operators is introduced to maximise cache reuse and SIMD utilisation on Frontier (AVX2), Param Pravega (AVX512) and Fugaku (SVE). We also combine terms for optimal cache reuse, even-odd decomposition to reduce FLOP, and mixed-precision intrinsics. Extensive benchmarks show that for large multivector pseudopotential DFT calculations, the matrix-free kernels deliver 1.5-4x speedups over the state-of-the-art cell-matrix approach baselines. For all-electron DFT calculations, the matrix-free operator achieves gains of up to 5.8x due to its efficient implementation and superior arithmetic intensity. When integrated with an error-tolerant Chebyshev-filtered subspace iteration eigensolver, the matrix-free formalism yields substantial reductions in end-to-end time-to-solution using FE meshes that deliver desired accuracies in ground-state properties. + oai:arXiv.org:2512.08571v1 + physics.comp-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - 10.1109/LMWT.2025.3591716 - IEEE Microwave and Wireless Technology Letters, vol. 35, no. 11, pp. 1871-1874, Nov. 2025 - Xu Zhu, Shaoyue Wang, Da He, Liping Yan, Jianan Hu, Changjun Liu + http://creativecommons.org/publicdomain/zero/1.0/ + Phani Motamarri, Gourab Panigrahi - Giant optical anisotropy and visible-frequency epsilon-near-zero in hyperbolic van der Waals MoOCl2 - https://arxiv.org/abs/2512.06495 - arXiv:2512.06495v1 Announce Type: new -Abstract: The realization of extreme optical anisotropy is foundational to nanoscale light manipulation. Van der Waals (vdW) crystal MoOCl2 has emerged as a promising candidate for this quest, hosting hyperbolic plasmon polaritons in the visible and near-infrared wavelengths. However, the fundamental anisotropic dielectric tensor governing this behavior has remained elusive. Here, we resolve this problem by providing the first experimental determination of the full dielectric tensor of hyperbolic vdW MoOCl2. Via spectroscopic ellipsometry, Mueller matrix, and reflectance measurements, we quantify the material's optical duality: a metallic optical response ({\epsilon}_1 < 0) along the crystallographic a-axis and a dielectric response ({\epsilon}_1 > 0) along the orthogonal directions. This dichotomy drives an epsilon-near-zero (ENZ) condition at \approx 512 nm and results in giant in-plane birefringence of \delta n \approx 2.2 for MoOCl2. As a result, our work provides the critical missing experimental parameters for MoOCl2, establishing it as a benchmark hyperbolic and ENZ material. - oai:arXiv.org:2512.06495v1 - physics.optics - cond-mat.mtrl-sci - Tue, 09 Dec 2025 00:00:00 -0500 + Study of a small-scale gamma-ray detection system employing Compton scattering with a monolithic CeBr3 crystal and segmented photodetector array + https://arxiv.org/abs/2512.08593 + arXiv:2512.08593v1 Announce Type: new +Abstract: Study of high energy cosmic events in the MeV range requires detector with high efficiency and energy resolution to be constructed. The present setup consisting of scintillator crystals CeBr3 with different thickness, each coupled with 12 x 12 segmented SiPM-based photodetector in a multichannel system represents an initial exploration of a gamma imaging system based on Compton scattering principles. A Monte Carlo simulation was conducted to evaluate the energy deposit and detection efficiency using the 137Cs gamma line. The study reveals a correlation between the relative distance between detector planes and the energy deposition efficiency, providing valuable insights into optimizing the telescope design. + oai:arXiv.org:2512.08593v1 + physics.ins-det + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Georgy Ermolaev, Adilet Toksumakov, Aleksandr Slavich, Anton Minnekhanov, Gleb Tselikov, Arslan Mazitov, Ivan Kruglov, Gleb Tikhonowski, Mikhail Mironov, Ilya Radko, Dmitriy Grudinin, Andrey Vyshnevyy, Zden\v{e}k Sofer, Aleksey Arsenin, Kostya S. Novoselov, Valentyn Volkov + 10.1088/1742-6596/3116/1/012007 + Journal of Physics: Conference Series 3116 (2025) 012007 + Veronika Asova, Galin Bistrev, Simeon Ivanov - Observation of two nuclear recoil peaks induced by neutron capture on Al2O3 - https://arxiv.org/abs/2512.06507 - arXiv:2512.06507v1 Announce Type: new -Abstract: We report the observation of two nuclear recoil peaks induced by neutron capture on aluminum in a cryogenic Al$_2$O$_3$ detector developed by the NUCLEUS collaboration for the detection of reactor neutrinos via coherent elastic neutrino-nucleus (CEvNS) process. Data collected at the Technical University of Munich in 2024 with a $^{252}$Cf source reveal a main recoil line at 1145 eV from single-$\gamma$ de-excitation of $^{28}$Al and a newly observed structure near 575 eV originating from several two-$\gamma$ cascades. The latter constitutes the first direct measurement of a nuclear recoil line induced by multi-$\gamma$ cascades. It is predicted by our simulations when the recoiling nucleus has time to stop before the emission of the next $\gamma$-ray in the cascade. These results demonstrate the potential performance of the CRAB (Calibration Recoil for Accurate Bolometry) method for in situ nuclear recoil calibration and highlight the importance of accurately modeling recoil stopping and nuclear de-excitation times in cryogenic detectors of CEvNS and dark matter interactions. - oai:arXiv.org:2512.06507v1 + Pulse Shape Discrimination for Germanium Detectors using Variational Quantum Circuits + https://arxiv.org/abs/2512.08603 + arXiv:2512.08603v1 Announce Type: new +Abstract: Pulse shape discrimination (PSD) is a critical component in background rejection for neutrinoless double-beta decay and dark matter searches using Broad Energy Germanium (BEGe) detectors. To date, advanced discrimination has relied on Deep Learning approaches employing e.g. Denoising Autoencoders (DAE) and Convolutional Neural Networks (CNN). While effective, these models require tens of thousands of parameters and heavy pre-processing. In this work, we present, to the best of our knowledge, the first application of Quantum Machine Learning (QML) to real, experimental pulse waveforms from a germanium detector. We propose a quantum-classical hybrid approach using Variational Quantum Circuits (VQC) with amplitude encoding. By mapping the 1024-sample waveforms directly into a 10-qubit Hilbert space, we demonstrate that a VQC with only 302 trainable parameters achieves a receiver operating characteristic (ROC) area under the curve (AUC) of 0.98 and a global accuracy of 97.1%. This result demonstrates that even in the current Noisy Intermediate-Scale Quantum (NISQ) era, quantum models can match the performance of state-of-the-art classical baselines while reducing model complexity by over two orders of magnitude. Furthermore, we envision a scenario where future quantum sensors transmit quantum states directly to such processing units, exploiting the exponentially large Hilbert space in a natively quantum pipeline. + oai:arXiv.org:2512.08603v1 physics.ins-det + hep-ex nucl-ex - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - H. Abele, P. Ajello, B. Arnold, E. Bossio, J. Burkhart, F. Cappella, N. Casali, R. Cerulli, J-P. Crocombette, G. del Castello, M. del Gallo Roccagiovine, P. de Marcillac, S. Dorer, C. Doutre, A. Erhart, S. Fichtinger, M. Friedl, C. Goupy, D. Hauff, E. Jericha, M. Kaznacheeva, H. Kluck, T. Lasserre, D. Lhuillier, O. Litaize, S. Marnieros, R. Martin, E. Namuth, T. Ortmann, L. Peters, D. V. Poda, F. Reindl, W. Reindl, J. Rothe, N. Schermer, J. Schieck, S. Sch\"onert, C. Schwertner, G. Soum-Sidikov, R. Strauss, R. Thalmeier, L. Thulliez, M. Vignati, M. Vivier, P. Wasser, A. Wex + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Fabrizio Napolitano - Laser-written reconfigurable photonic integrated circuit directly coupled to a single-photon avalanche diode array - https://arxiv.org/abs/2512.06528 - arXiv:2512.06528v1 Announce Type: new -Abstract: To date, most integrated quantum photonics experiments rely on single-photon detectors operating at cryogenic temperatures coupled to photonic integrated circuits (PICs) through single-mode optical fibers. This approach presents significant challenges due to the detection complexity, as cryogenic conditions hinder the development of scalable systems. In addition, going towards fully-integrated devices or, at least, removing the optical fibers would be also advantageous to develop compact and cost-efficient solutions featuring a high number of optical modes. This work reports on the direct coupling of a PIC, fabricated by femtosecond laser writing (FLW), and a silicon single-photon avalanche diode (SPAD) array, fabricated in a custom planar technology and compatible with the operation at room temperature. The effectiveness of this solution is shown by achieving perfect coupling and a system detection efficiency as high as 41.0% at a wavelength of 561 nm, which is the highest value reported to date among both heterogeneous/hybrid integrated and directly coupled systems. We also show the robustness of the coupling to misalignments, demonstrating that costly alignment procedures are not needed. Finally, we exploit the SPAD array to characterize a reconfigurable Mach-Zehnder interferometer, i.e., the basic building block of multimode reconfigurable PICs. This solution provides a new avenue to the design and implementation of quantum photonics experiments, especially effective when compact and cost-efficient systems are needed. - oai:arXiv.org:2512.06528v1 - physics.optics - physics.ins-det - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Modeling of van-der-Meer scan at NICA + https://arxiv.org/abs/2512.08605 + arXiv:2512.08605v1 Announce Type: new +Abstract: Van-der-Meer method is used in hadron colliders for absolute luminosity calibration. In the letter the applicability of the method is discussed when particles desnsity is distorted by hour-glass effect next to interaction point. The study is motivated by close commisioning of Nuclotron based Ion Collider fAcility where hour-glass effected is significant by design. The theoretical van-der-Meer formalism is revised for this case. Importance of hour-glass effect for luminosity measurements and calibration is demonstrated. Also, the general approach to the estimation of van-der-Meer method bias when it is used for non-factorizable beams is proposed. + oai:arXiv.org:2512.08605v1 + physics.acc-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.1038/s41377-025-01854-6 - Light: Science & Applications 14.1 (2025): 199 - Giulio Gualandi, Simone Atzeni, Marco Gardina, Antonino Caime, Giacomo Corrielli, Ivan Labanca, Angelo Gulinatti, Ivan Rech, Roberto Osellame, Giulia Acconcia, Francesco Ceccarelli + Anton Babaev - Concentration Matters: Enhancing Particle Settling in Narrow Tilted Channels - https://arxiv.org/abs/2512.06539 - arXiv:2512.06539v1 Announce Type: new -Abstract: Particles are known to sediment faster in containers with tilted walls than in vertical ones, a phenomenon known as the Boycott effect. In this work, we investigate how the tilt angle influences sedimentation in narrow channels across different particle volume fractions. Using particle-resolved computational fluid dynamics simulations, we reveal that there exists a concentration-dependent optimal tilt angle that maximizes sedimentation rates. Furthermore, at large tilt angles, the flow profiles across the channel deviate from the classical parabolic shape. We show that these non-parabolic profiles can be accurately captured by a one-dimensional Brinkman model, providing a predictive framework for understanding and tuning sedimentation in tilted geometries. Our findings demonstrate the potential to control and optimize particle settling by adjusting the channel tilt according to particle concentration, opening new possibilities for design in industrial and laboratory processes. - oai:arXiv.org:2512.06539v1 - physics.flu-dyn - cond-mat.soft - Tue, 09 Dec 2025 00:00:00 -0500 + PyMieDiff: A differentiable Mie scattering library + https://arxiv.org/abs/2512.08614 + arXiv:2512.08614v1 Announce Type: new +Abstract: Light scattering by spherical-shaped particles of sizes comparable to the wavelength is foundational in many areas of science, from chemistry to atmospheric science, photonics and nanotechnology. With the new capabilities offered by machine learning, there is a great interest in end-to-end differentiable frameworks for scattering calculations. Here we introduce PyMieDiff, a fully differentiable, GPU-compatible implementation of Mie scattering for core-shell particles in PyTorch. The library provides native, autograd-compatible spherical Bessel and Hankel functions, vectorized evaluation of Mie coefficients, and APIs for computing efficiencies, angular scattering, and near-fields. All inputs - geometry, material dispersion, wavelengths, and observation angles and positions - are represented as tensors, enabling seamless integration with gradient-based optimisation or physics-informed neural networks. The toolkit can also be combined with "TorchGDM" for end-to-end differentiable multi-particle scattering simulations. PyMieDiff is available under an open source licence at https://github.com/UoS-Integrated-Nanophotonics-group/MieDiff. + oai:arXiv.org:2512.08614v1 + physics.optics + physics.comp-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Dipankar Kundu, Florencio Balboa Usabiaga, Adolfo V\'azquez-Quesada, Marco Ellero + Oscar K. C. Jackson, Simone De Liberato, Otto L. Muskens, Peter R. Wiecha - Observed enhanced emission at higher-order exceptional points in RF circuits - https://arxiv.org/abs/2512.06544 - arXiv:2512.06544v1 Announce Type: new -Abstract: The Purcell effect -- stemming directly from the celebrated Fermi's Golden Rule -- links the enhanced emissivity of an emitter to the local density of states (LDoS) of a surrounding cavity. Under typical circumstances the LDoS is assumed to have a Lorentzian lineshape. Here, we go beyond the traditional Purcell framework by designing RF cavities with non-Lorentzian LDoS caused by higher-order non-Hermitian exceptional point degeneracies (EPDs) where $N\geq 2$ eigenfrequencies and their associated eigenmodes coalesce. We experimentally demonstrate a non-conventional emissivity enhancement (as compared to the isolated resonance regime) that increases with the EPD order $N$. The theoretical analysis traces its origin to an $N$-th power Lorentzian LDoS line shape that dominates under judicious spatially designed cavity losses. Our results reveal a new route to design cavities that do not rely on ultrahigh $Q$-factor resonators or small modal volumes. - oai:arXiv.org:2512.06544v1 + Gradient-based optimization of scatterer arrangements based on the T-Matrix method + https://arxiv.org/abs/2512.08615 + arXiv:2512.08615v1 Announce Type: new +Abstract: The demand for inverse design is increasing as the ability to fabricate sub-10 nm features expands the design space by orders of magnitude. Efficient inverse design benefits from differentiable models of light-structure interaction. While traditional full-wave solvers based on finite differences, finite elements, or Fourier modal methods have already been presented for that purpose, a dedicated tool adapted for performing multiple scattering simulations is still lacking. To overcome this limitation, we provide a multiple-scattering framework compatible to automatic differentiation, suitable for treating periodic and non-periodic arrangements of scatterers. It yields exact gradients regarding geometric and positional parameters in finite clusters and infinite metasurfaces. In this work, we use spheres as the elementary building blocks to demonstrate the framework's capabilities as a standalone tool. However, the framework is adaptable to arbitrarily shaped scatterers, provided the individual T-matrices are calculated using differentiable full-wave Maxwell solvers. Since the gradients are obtained simultaneously in a single backward pass, the framework is well-suited for moderately dimensional problems. It is also possible to combine multiple performance goals into a single objective function. The versatility of our method is illustrated in proof-of-concept examples that focus on various aspects of Kerker-type physics. In the first example, a finite cluster of scatterers is optimized in order to reach a high forward-to-backward scattering ratio, and we show experimental feasibility of the designs. In the second example, a metasurface made from multiple scatterers in each unit cell is designed to maximize the reflectance contrast between orthogonal linear polarizations of the incident light. We make the framework publicly available at https://github.com/tfp-photonics/dreams. + oai:arXiv.org:2512.08615v1 physics.optics - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Nicolas Wyszkowski, Arunn Suntharalingam, Max Vitek, Arkady Kurnosov, Lucas J. Fern\'andez-Alc\'azar, Tsampikos Kottos + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Nigar Asadova (Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Germany), Jan David Fischbach (Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Germany), Renaud Vall\'ee (Centre de Recherche Paul Pascal, University of Bordeaux, Pessac, France), Yannick Augenstein (Flexcompute Inc, Belmont, MA, USA), Dmytro Vovchuk (Institute of Photonics, Electronics and Telecommunications, Riga Technical University, Riga, Latvia), Anton Kharchevskii (School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel), Pavel Ginzburg (School of Electrical Engineering, Tel Aviv University, Tel Aviv, Israel), Carsten Rockstuhl (Institute of Nanotechnology, Karlsruhe Institute of Technology, Karlsruhe, Germany) - An Euler-Lagrangian Multiphysics Coupling Framework for Particle-Laden High-Speed Flows - https://arxiv.org/abs/2512.06548 - arXiv:2512.06548v1 Announce Type: new -Abstract: Particle-laden effects in high-speed flows require a coupled Euler and Lagrangian prediction technique with varying fidelity of thermochemical models, depending on the simulation conditions of interest. This requirement makes the development of a conventional monolithic solver challenging to manage the different fidelity of the thermochemical models within a single computational framework. To address this, the present study proposes a multi-solver framework for the coupled Euler-Lagrangian predictions applicable to various particle-laden high-speed flow conditions. Volumetric and surface couplings are established between a particle solver ORACLE (OpenFOAM-based lagRAngian CoupLEr) and a thermochemical nonequilibrium flow solver based on an adaptable data exchange algorithm. The developed framework is then validated by predicting particle-laden supersonic nozzle flows and aerothermal heating around a hypersonic Martian atmospheric entry capsule. Finally, a quasi-1D approximation is proposed in conjunction with a surrogate method to efficiently and accurately predict particle-laden surface erosion, with quantified parametric uncertainty, for hypersonic aerothermal characterization. - oai:arXiv.org:2512.06548v1 + Stretching and breaking of particles in compressible random flows + https://arxiv.org/abs/2512.08632 + arXiv:2512.08632v1 Announce Type: new +Abstract: A key feature of turbulent suspensions that involve floating particles on the surface or inertial particles in the bulk is the compressibility of the effective particle-phase velocity field. Little, however, is known about the effects of small-scale flow compressibility on the stretching and breaking of particles. Here, we gain insight into the nature of these effects by studying the deformation of tiny particles in model fluctuating flows. We consider a generic particle with extensional dynamics that are governed by a vector model, which accounts for elasticity, internal viscosity, and non-affine deformation. Applying the dynamical systems approach of Balkovsky, Fouxon & Lebedev (2000), we first obtain general results for the stationary statistics of particle extension in compressible chaotic flows. We then specialize to a time-decorrelated Gaussian random flow and derive an exact solution for the Batchelor regime of the compressible Kraichnan model. We also perform numerical simulations for a time-correlated renewing flow. While straining is suppressed on the average in compressible flows, our results show that large deviations of the strain rate strongly stretch particles and give rise to a power-law distribution of extensions. Extreme straining events are particularly important for stiff particles and, in the examples considered here, give rise to a counter-intuitive effect: stiff particles stretch more and break faster in flows of increasing compressibility. Highly-elastic particles, whose deformation is dictated by the mean straining, stretch less and break slower. Though based on specific random flows, our work shows how compressibility can affect the extensional dynamics of particles by altering the fluctuations of the strain rate, including its large deviations. + oai:arXiv.org:2512.08632v1 physics.flu-dyn - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + cond-mat.stat-mech + nlin.CD + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Hyeon Woo Nam, Tae Woong Jeong, Sung Min Jo + Dipankar Roy, Marco Martins Afonso, Jason R. Picardo, Dario Vincenzi - Mount Rainier and Liberty Cap Elevation Survey 2025 - https://arxiv.org/abs/2512.06567 - arXiv:2512.06567v1 Announce Type: new -Abstract: In 2024, we discovered that Columbia Crest, the historical summit of Mount Rainier, was no longer the highest point on the mountain. Instead, a point 133 m (436 ft) to the south along the southwest rim (SW Rim) was determined to be the new highest point on Mount Rainier. The Columbia Crest icecap melted down 6.64 m (21.8 ft) since 1998. A nearby peak, Liberty Cap, melted down 8.02 m (26.3 ft) since 2007. For this report, updated elevation measurements were taken in late summer 2025 of Columbia Crest and Liberty Cap. Columbia Crest melted an additional 0.37 m (1.2 ft) and Liberty Cap melted 0.67 m (2.2 ft) over the last year. To understand how Mount Rainier's summit may continue to evolve, we used ground-penetrating radar (GPR) to measure the thickness of the Columbia Crest icecap and Liberty Cap. As of 2025, ice is approximately 2 m - 5 m (6.6 ft - 16.5 ft) thick near the summit of Columbia Crest and 10 m - 13 m (32.8 ft - 42.7ft) thick near the summit of Liberty Cap. Using recent measurements by our team and other surveyors, melt rates for Columbia Crest have been -0.27 m/year (-0.9 ft/year) since 1998 (R squared = 0.990) and -0.49 m/year (-1.6 ft/year) for Liberty Cap since 2007 (R squared = 0.998). Based on the elevation of the nearest high-elevation visible rock, Liberty Cap will lose its status as an ice-capped peak by 2041. Assuming recent rates of change continue, it will melt to bedrock by 2047. Columbia Crest is already no longer the highest point on Mount Rainier, and it will likely melt to bedrock by 2045. As of 2025, our results indicate that the summit of Mount Rainier on the SW Rim is at an elevation of 4391.04 m (14406.3 ft +/- 0.1 ft) (NAVD88). - oai:arXiv.org:2512.06567v1 - physics.geo-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Centrifugal instability of Taylor-Couette flow in stratified and diffusive fluids + https://arxiv.org/abs/2512.08664 + arXiv:2512.08664v1 Announce Type: new +Abstract: The linear and non-linear dynamics of centrifugal instability in Taylor-Couette flow are investigated when fluids are stably stratified and highly diffusive. One-dimensional local linear stability analysis (LSA) on cylindrical Couette flow confirms that the stabilising role of stratification on centrifugal instability is suppressed by strong thermal diffusion (i.e. low Prandtl number $Pr$). For $Pr\ll1$, it is verified that the instability dependence on thermal diffusion and stratification with the non-dimensional Brunt-V\"ais\"al\"a frequency $N$ can be prescribed by a single rescaled parameter $P_{N}=N^{2}Pr$. From direct numerical simulation (DNS), various non-linear features such as axisymmetric Taylor vortices at saturation, secondary instability leading to non-axisymmetric patterns or transition to chaotic states are investigated for various values of $Pr\leq1$ and the Reynolds number $Re_{i}$. Two-dimensional bi-global LSA on axisymmetric Taylor vortices, which appear as primary centrifugal instability saturates nonlinearly, is also performed to find the secondary critical Reynolds number $Re_{i,2}$ at which the Taylor vortices become unstable by non-axisymmetric perturbation. The bi-global LSA reveals that $Re_{i,2}$ increases (i.e. the onset of secondary instability is delayed) in the range $10^{-3}<Pr<1$ at $N=1$ or as $N$ increases at $Pr=0.01$. Secondary instability leading to highly non-axisymmetric or irregular chaotic patterns is further investigated by the 3D DNS. The Nusselt number $Nu$ is also computed from the torque at the inner cylinder for various $Pr$ and $Re_{i}$ at $N=1$ to describe how the angular momentum transfer increases with $Re_{i}$ and how $Nu$ varies differently for saturated and chaotic states. + oai:arXiv.org:2512.08664v1 + physics.flu-dyn + astro-ph.SR + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Eric Gilbertson, Larry Signani, Branden Joy, Daniel McGrath, Darin Loucks, Ethan O'Connor, Shannon Cheng, Scott Hotaling + http://creativecommons.org/licenses/by/4.0/ + 10.1017/jfm.2025.261 + Junho Park - Calendar Time Local Earthquake Forecasts from Earthquake Nowcasts: A Do-It-Yourself (DIY) Ensemble Method - https://arxiv.org/abs/2512.06572 - arXiv:2512.06572v1 Announce Type: new -Abstract: A previous paper discussed a method that builds on local earthquake nowcasts to produce fixed natural time forecasts, where natural time represents counts of small earthquakes since the last large earthquake. In this second paper we extend the natural time forecast to calendar time forecasts using an ensemble approach. The Gutenberg-Richter (GR) magnitude-frequency relation, which was the basis for both methods, states that for every large target earthquake of magnitude greater than MT , there are on average NGR small earthquakes of magnitude MS. The only assumption in our method is that the statistics of the local region are the same as in the larger surrounding regions. The method has significant skill, as defined by the Receiver Operating Characteristic (ROC) test, which improves as time since the last major earthquake increases. The probability is conditioned on the number of small earthquakes n(t) that have occurred since the last large earthquake. We do not need to assume a probability model, the probability is instead computed directly as the Positive Predictive Value (PPV) associated with the ROC curve. We find that for short time intervals (months), the forecast shows strong main shock clustering, followed by a gradual buildup of probability over the following years leading to the next large earthquake ("elastic rebound"). We apply the method to the same local region as in our first paper around Los Angeles, California, following the January 17, 1994 magnitude M6.7 Northridge earthquake. - oai:arXiv.org:2512.06572v1 - physics.geo-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Atomic and molecular systems for radiation thermometry + https://arxiv.org/abs/2512.08668 + arXiv:2512.08668v1 Announce Type: new +Abstract: Atoms and simple molecules are excellent candidates for new standards and sensors because they are both all identical and their properties are determined by the immutable laws of quantum physics. Here, we introduce the concept of building a standard and sensor of radiative temperature using atoms and molecules. Such standards are based on precise measurement of the rate at which blackbody radiation (BBR) either excites or stimulates emission for a given atomic transition. We summarize the recent results of two experiments while detailing the rate equation models required for their interpretation. The cold atom thermometer (CAT) uses a gas of laser cooled $^{85}$Rb Rydberg atoms to probe the BBR spectrum near 130~GHz. This primary, {\it i.e.}, not traceable to a measurement of like kind, temperature measurement currently has a total uncertainty of approximately 1~\%, with clear paths toward improvement. The compact blackbody radiation atomic sensor (CoBRAS) uses a vapour of $^{85}$Rb and monitors fluorescence from states that are either populated by BBR or populated by spontaneous emission to measure the blackbody spectrum near 24.5~THz. The CoBRAS has an excellent relative precision of $u(T)\approx 0.13$~K, with a clear path toward implementing a primary + oai:arXiv.org:2512.08668v1 + physics.atom-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - John B Rundle, Ian Baughmann, Andrea Donnellan, Lisa Grant Ludwig, Geoffrey C Fox, Kazuyoshi Nanjo + http://creativecommons.org/publicdomain/zero/1.0/ + Stephen P. Eckel, Eric B. Norrgard, Christopher Holloway, Nikunjkumar Prajapati, Noah Schlossberger, Matthew Simons - Geometry-Induced Vacuum Polarization and Mode Shifts in Maxwell-Klein-Gordon Theory - https://arxiv.org/abs/2512.06605 - arXiv:2512.06605v1 Announce Type: new -Abstract: Geometric confinement is known to modify single-particle dynamics through effective potentials, yet its imprint on the interacting quantum vacuum remains largely unexplored. In this work, we investigate the Maxwell--Klein--Gordon system constrained to curved surfaces and demonstrate that the geometric potential $\Sigma_{\mathrm{geom}}(\mathbf{r})$ acts as a local renormalization environment. We show that extrinsic curvature modifies the scalar loop spectrum, entering the vacuum polarization as a position-dependent mass correction $M^2(\mathbf{r}) \to m^2 + \Sigma_{\mathrm{geom}}(\mathbf{r})$. This induces a finite, gauge-invariant ``geometry-induced running'' of the electromagnetic response. In the long-wavelength regime ($|{\bf Q}|R \ll 1$), we derive a closed-form expression for the relative frequency shift $\Delta\omega/\omega$, governed by the overlap between the electric energy density and the geometric potential. Applying this formalism to Gaussian bumps, cylindrical shells, and tori, we identify distinct spectral signatures that distinguish these quantum loop corrections from classical geometric optics. Our results suggest that spatial curvature can serve as a tunable knob for ``vacuum engineering,'' offering measurable shifts in high-$Q$ cavities and plasmonic systems. - oai:arXiv.org:2512.06605v1 - physics.optics - gr-qc - math-ph - math.MP - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Machine learning for smell: Ordinal odor strength prediction of molecular perfumery components + https://arxiv.org/abs/2512.08683 + arXiv:2512.08683v1 Announce Type: new +Abstract: Predicting olfactory perception directly from molecular structure is central to fragrance design that plays a role in a wide range of industries, such as perfumery, food and beverage, and health care. Among olfactory attributes, odor strength is a key factor in shaping odor perception, but its modeling has been impeded by scarce and fragmented intensity data. In this work, we introduce an ordinal odor strength data set of over 2,000 molecules by integrating two different public sources, mapping structures to odorless, low, medium, and high categories. Across several molecular encodings and supervised learning algorithms we compared different prediction strategies. Dimensionality reduction and SHAP analysis identifies molecular size, polarity, ring features, and branching as primary drivers, consistent with mass-transport constraints on volatility, sorption, and receptor access. This scalable ordinal framework enables reliable odor-strength estimation for novel molecules and provides a foundation for in silico fragrance design. + oai:arXiv.org:2512.08683v1 + physics.chem-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Li Wang, Jun Wang, Yong-Long Wang + Peter Fichtelmann, Julia Westermayr - Half-explicit Runge-Kutta integrators for variational multiscale turbulence modeling: Toward higher-order accuracy in space and time - https://arxiv.org/abs/2512.06626 - arXiv:2512.06626v1 Announce Type: new -Abstract: The residual-based variational multiscale (VMS) formulation has achieved remarkable success in large-eddy simulation of turbulent flows. However, its temporal discretization has largely remained limited to second-order implicit schemes. The present work aims at advancing this direction through the introduction of Runge-Kutta (RK) schemes within the VMS framework in a mathematically consistent manner. Guided by the Rothe method, the half-explicit RK scheme is employed as its accuracy is theoretically guaranteed for index-2 differential-algebraic equations. Owing to the explicit treatment of the nonlinear term, the resulting spatial problem exhibits a structure analogous to that of the Darcy equation. Following the philosophy of the VMS analysis, a subgrid-scale model is derived without invoking linearization based on perturbation series and related assumptions. The analysis further reveals that the parameter in the subgrid model is independent of the spatial mesh size. Fourier analysis demonstrates that the Rothe method, compared with the conventional vertical method of lines, provides improved dissipation and dispersion properties and exhibits a larger stability region for convection-dominated regimes. In the Taylor-Green vortex benchmark, the proposed schemes demonstrate superior performance as a large-eddy simulation model, achieving higher fidelity in predicting the kinetic energy evolution, energy spectra, and vortex structures than the conventional VMS formulation. Simulations of the open cavity flow further show that the proposed schemes can accurately capture the periodic limit cycle caused by the supercritical Hopf bifurcation, confirming its effectiveness and fidelity for highly sensitive flow instability problems. - oai:arXiv.org:2512.06626v1 - physics.flu-dyn - cs.NA - math.NA - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Plasma waveguides for high-intensity laser pulses + https://arxiv.org/abs/2512.08690 + arXiv:2512.08690v1 Announce Type: new +Abstract: Fundamental to many applications of laser pulses in science and technology is an extended interaction length with matter that significantly exceeds the distance over which the pulse would normally diffract and transversely spread. At low intensity, the interaction could simply be the linear refraction provided by a glass optical fiber to keep the pulse from spreading. At increased pulse intensity, more than diffraction-free pulse transport is of interest: an extended interaction length of high intensity light can give rise to bright secondary sources of photons, and at relativistic intensities, beams of high energy charged particles. As generation of these secondary sources requires laser intensities well above the threshold for ionization of atoms, new methods for defeating pulse diffraction in a plasma have been developed. Chief among them are plasma waveguides: optical fibers composed of plasma that have characteristic mode structure. This article reviews the methods and theory of plasma waveguides, highlighting the recent development of meter-scale plasma waveguides that have been instrumental to the laser acceleration of high charge electron beams to ~10 GeV. + oai:arXiv.org:2512.08690v1 + physics.plasm-ph + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yujie Sun, Chi Ding, Ju Liu + http://creativecommons.org/licenses/by/4.0/ + J. E. Shrock, B. Miao, E. Rockafellow, H. M. Milchberg - Wide field-of-view and large depth-of-field metalenses - https://arxiv.org/abs/2512.06635 - arXiv:2512.06635v1 Announce Type: new -Abstract: The ability to visualize both macroscopic and microscopic features over an extended field of view is essential for endoscopic imaging and other applications ranging from machine vision to microscopy. However, miniaturizing endoscopes introduces inherent trade-offs between size and optical performance, including field-of-view (FOV), depth-of-field (DOF), and resolution. These constraints limit the use of microendoscopes in clinical settings such as early cancer detection within narrow, hard-to-access anatomical regions, including the lung, ovaries, and pancreas. State-of-the-art microendoscopes typically rely on microlens assemblies that increase both cost and size. Their large f-numbers also hinder the collection of high-resolution information from live tissue. In this work, we present two compact metalens designs that provide wide FOV, extended DOF, and high resolution, enabled by custom-tailored point spread functions (PSFs). The devices achieve a full 172 degrees FOV, an extended DOF from 0.4 mm to beyond 300 mm, and a resolution of 30 line pairs per millimeter, all within a 1 mm x 1 mm x 0.2 mm footprint. A key advantage of our approach is the ability to transition seamlessly between low and high magnification without mechanical refocusing. Final images are reconstructed through backend deconvolution, highlighting the potential of hybrid imaging systems that integrate computational techniques with flat-optics components. - oai:arXiv.org:2512.06635v1 - physics.optics + Electron Emission Yield Datasets Under Electron Impact From Surfaces Characterized In Situ by XPS or AES + https://arxiv.org/abs/2512.08693 + arXiv:2512.08693v1 Announce Type: new +Abstract: We present the measurement, characterization, and calibration procedures used to produce a series of datasets for various conductive and semiconductive materials. The data, provided, include emission yields as a function of incident electron energy together with surface composition obtained from X-Ray Photoelectron Spectroscopy or Auger Electron Spectroscopy analyses. Initial datasets cover copper and gold, with additional materials to be released on arXiv. + oai:arXiv.org:2512.08693v1 physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + cond-mat.mtrl-sci + Wed, 10 Dec 2025 00:00:00 -0500 + new + http://creativecommons.org/licenses/by-nc-sa/4.0/ + M. Belhaj, S. dadouch + + + Incoherent repumping scheme in the $^{88}$Sr$^{+}$ five-level manifold + https://arxiv.org/abs/2512.08710 + arXiv:2512.08710v1 Announce Type: new +Abstract: Laser-cooled trapped ions are at the heart of modern quantum technologies and their cooling dynamics often deviate from the simplified two-level atom model. Doppler cooling of the $^{88}$Sr$^{+}$ ion involves several electronic levels and repumping channels that strongly influence fluorescence.In this work, we study a repumping scheme for the $^{88}$Sr$^{+}$ ion by combining precision single-ion spectroscopy with comprehensive numerical modeling based on optical Bloch equations including 18 Zeeman sublevels. We show that, although the observed fluorescence spectra retain a Lorentzian lineshape, their width and amplitude cannot be explained by a two-level atom description. Moreover, we find the optimal repumping conditions for maximizing the photon scattering rate. + oai:arXiv.org:2512.08710v1 + physics.atom-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Louis Martin-Monier, Zhaoyi Li, Fan Yang, Mikhail Shalaginov, Luigi Ranno, Jia Xu Brian Sia, Tian Gu, Juejun Hu + Valentin Martimort, Sacha Guesne, Derwell Drapier, Vincent Tugaye, Lilay Gros-Desormeaux, Valentin Cambier, Albane Douillet, Luca Guidoni, Jean-Pierre Likforman - A Capacitor Model of the Helical Deflector: Revisiting Shamaev's Proposal and the Model in the Book - https://arxiv.org/abs/2512.06651 - arXiv:2512.06651v1 Announce Type: new -Abstract: A RF helical deflector is a type of electron and ion optics device that applies a time-dependent rotating transverse electric or magnetic field by means of time-dependent RF voltage applied on two opposite conducting helical structures (wires, ribbons or other) to deflect charged particles (a single, bunch or beam) in a circular or spiral path. It is a perspective direct timing system being concurrent for reaching picosecond time resolution, and have promise being excellent candidate for high precision time-of-flight detection. As a timing system, it converts the temporal structure of an electron beam into a spatial pattern -- particularly, an ellipse in the case of a single-frequency RF voltage and continuous electron beam. - I propose a capacitor model of a RF helical deflector and compare it with the existing model in the Book, interpret it and provide understanding of it. Furthermore, I analyze the latter finding analytical formulas for the applied electric field, for ellipse sizes (semi-axes) and rotation angle, lengths of the ellipse line corresponding to the duration of electron bunches or beams. The present article touches the topic of getting circle on resonance limit and the deflection sensitivity. - oai:arXiv.org:2512.06651v1 - physics.acc-ph - physics.app-ph - physics.class-ph - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 + Long-time evolution of density layers and interfaces in forced stably-stratified flows + https://arxiv.org/abs/2512.08714 + arXiv:2512.08714v1 Announce Type: new +Abstract: Stably stratified fluids subject to sustained forcing are known to develop step-like density "staircases", where nearly homogeneous layers alternate with thin interfaces of strong stratification. However, long-time numerical investigations of this phenomenon have been limited by the intrinsically slow evolution of large-scale modes and the sensitivity of stratified turbulence to physical parameters. We present direct numerical simulations of forced Boussinesq flows for three stratification strengths (Fr = 0.42, 0.22, 0.076) and of unprecedented time extensions - up to O(10000) turnover times - with the purpose of reproducing and studying the very slow coarsening of the layered state. A large-scale friction term is introduced to arrest shear-mode growth and mimic finite-domain constraints. Staircase formation is observed for both medium and strong stratified cases, following two different coarsening dynamics: interfaces decaying or merging. While kinetic energy remains quasi-stationary during interface decay, it exhibits sharp bursts during merging events. The emergence and persistence of density steps can be explained by the non-monotonic relation between buoyancy flux and buoyancy gradient. Intermittency in vertical velocity and density fluctuations is confined to the vicinity of layer-interface boundaries, indicating that strong events arise from the interaction between turbulent mixing and layer formation rather than from regions of large density gradients alone. + oai:arXiv.org:2512.08714v1 + physics.flu-dyn + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Hayk L. Gevorgyan + Niccolo Cocciaglia, Fabio Bonaccorso, Alessandra Sabina Lanotte, Luca Biferale - Phase-multiplexed optical computing: Reconfiguring a multi-task diffractive optical processor using illumination phase diversity - https://arxiv.org/abs/2512.06658 - arXiv:2512.06658v1 Announce Type: new -Abstract: We report a monochrome multi-task diffractive network architecture that leverages illumination phase multiplexing to dynamically reconfigure its output function and accurately implement a large group of complex-valued linear transformations between an input and output aperture. Each member of the desired group of T unique transformations is encoded and addressed with a distinct 2D illumination phase profile, termed "phase key", which illuminates the input aperture, activating the corresponding transformation at the output field-of-view. A common diffractive optical network, optimized with T phase keys, demultiplexes these encoded inputs and accurately executes any of the T distinct linear transformations at its output. We demonstrate that a diffractive network composed of N = 2 x T x Ni x No optimized diffractive features can realize T distinct complex-valued linear transformations, accurately executed for any complex field at the input aperture, where Ni and No refer to the input/output pixels, respectively. In our proof-of-concept numerical analysis, T = 512 complex-valued transformations are implemented by the same monochrome diffractive network with negligible error using illumination phase diversity. Compared with wavelength-multiplexed diffractive systems, phase-multiplexing architecture significantly lowers the transformation errors, potentially enabling larger-scale optical transformations to be implemented through a monochrome processor. Phase-multiplexed multi-task diffractive networks would enhance the capabilities of optical computing and machine-vision systems. - oai:arXiv.org:2512.06658v1 - physics.optics - cs.NE + Reducing dislocation defect levels via sub-melt nanosecond pulsed-laser induced densification of diamond + https://arxiv.org/abs/2512.08719 + arXiv:2512.08719v1 Announce Type: new +Abstract: Dislocations and polishing-induced defect networks in synthetic diamond generate local strain fields that broaden Raman features and limit optical, thermal, and electronic performance. Sub-melt laser annealing has emerged as a route to repair near-surface defects without graphitization, yet quantitative evidence of densification, defect depletion, and property recovery remains limited. Here, we show that nanosecond pulsed-laser annealing (PLA) can relax dislocation-associated strain in single-crystal CVD diamond by compacting and reorganizing the damaged near-surface region. Single- and two-pulse PLA were applied, and structural evolution was quantified using co-registered ISO 25178 white-light interferometry, depth-resolved Raman spectroscopy, and cross-sectional STEM with geometric phase analysis (GPA). Across a 5x6 grid(n = 30), responsive regions show large reductions in local slope (Sdq 45-65%), developed area (Sdr 60-90%), height spread (Sp, Sz 30-65%), void volume (Vv 57-60%), and roughness amplitude (Sa, Sq 48-57%), consistent with densification of ~4-6.5 nm. Raman profiling reveals narrowing of the diamond line and improved spectral uniformity to depths of ~2-3 {\mu}m, indicating relaxation of dislocation-mediated strain beyond the compaction layer. STEM-GPA strain maps confirm smoother strain fields, reduced hotspots, and redistribution of localized strain concentrations after PLA. These results show that sub-melt PLA reduces dislocation-driven strain by compacting surface-connected free volume and reorganizing defect networks. The approach provides a scalable path to upgrade industrial-grade diamond including homoepitaxial, heteroepitaxial, and polycrystalline CVD to low-defect, device-ready surfaces relevant to high-power electronics, photonics, and quantum substrates. + oai:arXiv.org:2512.08719v1 physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + cond-mat.mtrl-sci + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Xiao Wang, Aydogan Ozcan + Adam H. Khan, Tae Sung Kim, Gabe Guss, Ted A. Laurence, Sonny S. Ly, Thejaswi U. Tumkur, Afaq H. Piracha - How do cold pools influence the size of tropical cyclone embryos? - https://arxiv.org/abs/2512.06668 - arXiv:2512.06668v1 Announce Type: new -Abstract: The size of tropical cyclone (TC) embryos is an essential predictor of TC genesis. Recent studies have identified cold pools and planetary rotation as factors that increase and decrease TC embryo size. While the planetary rotation effect has been depicted using a quasi-geostrophic (QG) model, the cold pool effect still lacks a theoretical model. This paper presents a cloud chain model to derive the length scale regarding the influence of cold pools on the TC embryo vortex. Within the model, the amount of rain evaporation during a single convective event determines the wind speed and humidity at the cold pool edge, influencing the amount of sub-cloud moisture convergence for the next-generation convection and, therefore, the intensity of the next-generation cold pool. A perturbation analysis shows that cold pools exhibit a nonlocal dependence on air-column humidity, with the influence range determined by the cold pool size and a convective memory weight. The memory weight relies on the sum of the contributions of mechanical lifting and thermodynamic forcing to convective initiation. A crucial parameter is the ratio of rain evaporation to surface evaporation in a cold pool. By coupling the cloud chain model with the QG equation, an analytical expression for the TC embryo size is obtained. The theory captures the trend but overestimates the TC embryo size in cloud-permitting simulations. The deviation might be due to the oversimplification in estimating the fractional contribution of cold pools to convective initiation. - oai:arXiv.org:2512.06668v1 - physics.ao-ph - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 + Topological Braiding and Dynamic Probing of Phase Transitions at Temporal Interfaces in Non-Hermitian Synthetic Dimensions + https://arxiv.org/abs/2512.08736 + arXiv:2512.08736v1 Announce Type: new +Abstract: Non-Hermitian systems give rise to distinct topological phenomena, yet their manifestations at temporal interfaces characterized by abrupt changes in system parameters remain largely unex plored. Upon an abrupt alteration of the Hamiltonian in a one-dimensional non-Hermitian sys tem,the ensuring temporal interface excites both reflected and refracted wave modes. By intro ducing a chiral-symmetric Hamiltonian, this study reveals the topological effects at such temporal interfaces. We find that the reflection and refraction coefficients exhibit a topological braiding struc ture. This structure is directly determined by the difference in the topological invariants across the interface, establishing a bulk-boundary correspondence for temporal interfaces in non-Hermitian systems. Furthermore, we propose a dynamical probe that leverages the geometric similarity of eigenstates at the temporal interface to detect topological phase transitions. These findings estab lish a fundamental connection between topological braiding and nonreciprocal dynamics at temporal interfaces, providing a platform to explore phase transition detection and nonreciprocal phenomena in time-varying non-Hermitian systems. + oai:arXiv.org:2512.08736v1 + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Hao Fu + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Yuanhang Jiang, Jianfei Li, Chengxi Yang, Ziyi Liu, Chen Chen, Hongyu Liu, Zhongxiang Zhou, Jingfeng Yao, Chengxun Yuan - Learning-based Link Prediction Methods Integrating Network Topological Features and Embedding Representations - https://arxiv.org/abs/2512.06677 - arXiv:2512.06677v1 Announce Type: new -Abstract: Link prediction, as a frontier task in complex network topology analysis, aims to infer the existence of latent links between node pairs based on observed nodes and structural information. We propose an ensemble link prediction model that integrates network topology features and embedding representations (TELP), designed to overcome the limitations of conventional heuristic methods in capturing node attributes and deep structural patterns, as well as the weak interpretability and limited generalization of learning-based approaches. TELP leverages a multi-stage architecture. Local connectivity patterns are captured through network-type-aware selection of homogeneous and heterogeneous topology features, which also promotes interpretability. To incorporate global structure, Node2Vec embeddings are generated and fused with these topology features, resulting in comprehensive multi-dimensional representations. Building on this enriched feature space, an ensemble of logistic regression, random forest, and XGBoost models is deployed to maximize predictive performance and robustness. Experiments on nine classical benchmark networks demonstrate that TELP achieves superior AUC and AP performance compared with traditional heuristic approaches and mainstream graph neural network models, while ablation studies further confirm that feature fusion and ensemble strategies are essential for optimal performance. - oai:arXiv.org:2512.06677v1 + Adaptive cut reveals multiscale complexity in networks + https://arxiv.org/abs/2512.08741 + arXiv:2512.08741v1 Announce Type: new +Abstract: Hierarchical clustering and community detection are important problems in machine learning and complex network analysis. A common approach to identify clusters is to simply cut dendrograms at some threshold. However, single-level cuts are often suboptimal in terms of capturing underlying structure in the data, especially when the dendrogram is unbalanced. In this paper, we present the adaptive cut, a novel method that leverages the hierarchical structure of dendrograms by employing multi-level cuts to overcome the limitations of single-level approaches. The adaptive cut optimizes an objective function using a Markov chain Monte Carlo with simulated annealing, resulting in better partitions. We demonstrate the effectiveness of the adaptive cut through applications to link clustering and modularity optimization, but note that the method is applicable to any clustering task that relies on a dendrogram and an objective function. Beyond the adaptive cut, we introduce the balancedness score, an information-theoretic metric that quantifies how balanced a dendrogram is. Balancedness predicts the potential benefits of using multi-level cuts. For the community detection examples, we evaluate our method on more than 200 real-world networks and multiple synthetic datasets, demonstrating significant improvements in partition density and modularity over traditional single-cut approaches. In addition, we show the generality of the adaptive cut by applying it across various hierarchical clustering techniques and objective functions. Our results indicate that the adaptive cut provides a robust and versatile tool for improving clustering outcomes. + oai:arXiv.org:2512.08741v1 physics.soc-ph - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Zi-Xuan Jin, Jun-Fan Yi, Ke-Ke Shang + Louis Boucherie, Yong-Yeol Ahn, Sune Lehmann - Optimal experimental design with k-space data: application to inverse hemodynamics - https://arxiv.org/abs/2512.06712 - arXiv:2512.06712v1 Announce Type: new -Abstract: Subject-specific cardiovascular models rely on parameter estimation using measurements such as 4D Flow MRI data. However, acquiring high-resolution, high-fidelity functional flow data is costly and taxing for the patient. As a result, there is growing interest in using highly undersampled MRI data to reduce acquisition time and thus the cost, while maximizing the information gain from the data. Examples of such recent work include inverse problems to estimate boundary conditions of aortic blood flow from highly undersampled k-space data. The undersampled data is selected based on a predefined sampling mask which can significantly influences the performance and the quality of the solution of the inverse problem. While there are many established sampling patterns to collect undersampled data, it remains unclear how to select the best sampling pattern for a given set of inference parameters. In this paper we propose an Optimal Experimental Design (OED) framework for MRI measurements in k-space, aiming to find optimal masks for estimating specific parameters directly from k-space. As OED is typically applied to sensor placement problems in spatial locations, this is, to our knowledge, the first time the technique is used in this context. We demonstrate that the masks optimized by employing OED consistently outperform conventional sampling patterns in terms of parameter estimation accuracy and variance, facilitating a speed-up of 10x of the acquisition time while maintaining accuracy. - oai:arXiv.org:2512.06712v1 - physics.med-ph - cs.NA - math.NA - Tue, 09 Dec 2025 00:00:00 -0500 + The new truly cylindrical tracker for the ALICE ITS3 + https://arxiv.org/abs/2512.08748 + arXiv:2512.08748v1 Announce Type: new +Abstract: The ALICE collaboration is preparing an upgrade of the three innermost layers of the current Inner Tracking System (ITS) during the next LHC long shutdown (LS3). The new ITS detector will use wafer-scale (up to \SI{27}{cm} in length) Monolithic Active Pixel Sensors with a \SI{65}{nm} CMOS Image Sensor process, thinned to \SI{50}{\micro m} and bent around the beam pipe. The planned upgrade will allow the use of only two sensors per tracker layer, kept in place by just two mechanical supports at the edges and two thin carbon fibre supports at the sensor border. The substitution of water cooling with air cooling will lead to an expected reduction of the material budget per-layer from $\sim$0.36\% $X_0$ of the current detector to 0.09\% $X_0$. The R\&D process also led to the development of a new sensor variant with an additional low dose n-type implant to the previous detector. This improves charge collection speed, confirms a spatial resolution of about \SI{5}{\micro m}, a detection efficiency greater than 99\% and an excellent radiation tolerance. Large area prototypes proved the possibility to have an active area greater than 90\%, and a fake hit rate lower than \SI{e-6}{hits/pixel/event} without loosing detection efficiency. This proceeding will show the above innovations, with particular attention to a small area analogue test structure featuring a front-end which can be monitored via an on-chip Operational Amplifier buffer that preserves the steep signal edge (few hundreds of ps) in order to study the sensor timing performance. The characterization proved a time resolution of \SI{63}{ps} on average and \SI{50}{ps} for signal passing right under the electrode with a detection efficiency above 99\%. + oai:arXiv.org:2512.08748v1 + physics.ins-det + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Miriam L\"ocke, Ahmed Attia, Dariusz Uc\'inski, Crist\'obal Bertoglio + Stefania Perciballi (and on behalf of the ALICE Collaboration) - Application of Time-Controlled Critical Point in Pressure Reducing Valves. A Case Study in North Spain - https://arxiv.org/abs/2512.06735 - arXiv:2512.06735v1 Announce Type: new -Abstract: Potable water utilities are currently making great efforts to reduce leakage rates and assure long-term supply to the population due to the challenges of climate change, growing population and water shortage scenarios that have been on them over the last years. One of the most employed methods to reduce leakage includes the installation of pressurereducing valves along the water distribution network and the utilization of pressure management schemes. Pressure management includes different types of control models, which are applied according to the requirements of each site. The most advanced and sophisticated scheme is critical point control, which relies on a flow signal from a measuring device or online communication between the critical point and the valve. This paper proposes the utilization of a seasonal autoregressive integrated moving average, or the SARIMA model, to correlate pressure at the outlet of the valve and pressure on the critical point of the area supplied, aiming to set a fixed pressure in the critical point. The SARIMA model is developed according to historical data logged in the field and then validated. Later, the SARIMA model was tested on a real location in the village of Noja, Spain. The analysis of the field test results prove that the proposed model is feasible to be used since there is no significance difference between the target values set in the critical point and the real values measured in the field. The research proves that the SARIMA model can be used as an alternative for critical point control in water distribution networks when no flow signal is available or when communication between the critical point and the pressure reducing valve is not an option. - oai:arXiv.org:2512.06735v1 - physics.app-ph - stat.AP - Tue, 09 Dec 2025 00:00:00 -0500 + Optimal navigation in two-dimensional regular and turbulent flows + https://arxiv.org/abs/2512.08766 + arXiv:2512.08766v1 Announce Type: new +Abstract: Zermelo's navigation problem seeks the trajectory of minimal travel time between two points in a fluid flow. We address this problem for an agent -- such as a micro-robot or active particle -- that is advected by a two-dimensional flow, self-propels at a fixed speed smaller than or comparable to the characteristic flow velocity, and can steer its direction. The flows considered span increasing levels of complexity, from steady solid-body rotation to the Taylor-Green flow and fully developed turbulence in the inverse cascade regime. Although optimal control theory provides time-minimizing trajectories, these solutions become unstable in chaotic regimes realized for complex background flows. To design robust navigation strategies under such conditions, we apply reinforcement learning. Both action-value (Q-learning) and policy-gradient (one-step actor-critic) methods achieve successful navigation with comparable performance. Crucially, we show that agents trained on coarse-grained flows -- retaining only large-scale features -- generalize effectively to the full turbulent field. This robustness to incomplete flow information is essential for practical navigation in real-world oceanic and atmospheric environments. + oai:arXiv.org:2512.08766v1 + physics.flu-dyn + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - 10.3390/app13105845 - Appl. Sci. 2023, 13(10), 5845 - Andres Ortega-Ballesteros, David Munoz-Rodriguez, Maria-Jesus Aguilera-Urena, Francisco Javier de los Santos-Zarco, Alberto-Jesus Perea-Moreno + Vladimir Parfenyev - Leveraging Pre-trained Neural Network Models for the Classification of Tumor Cells Analyzed by Label-free Phase Holotomographic Microscopy - https://arxiv.org/abs/2512.06808 - arXiv:2512.06808v1 Announce Type: new -Abstract: Can a single label-free image reveal whether cancer cells were exposed to chemotherapy? We present an innovative methodology on the label-free and high-resolution imaging properties of phase holotomographic microscopy coupled with neural network models for the classification of cancer cells. Using 3D phase holotomographic microscopy, we imaged live A549 lung cancer cells with and without paclitaxel, converted stacks to 2D maximum-intensity projections, and evaluated pre-trained convolutional networks (VGG16, ResNet18, DenseNet121, and EfficientNet-B0) for binary classification of treatment status. EfficientNet-B0 achieved 96.9 % accuracy on unsegmented images. Refractive index analysis revealed bimodal distribution in treated cells, reflecting heterogeneous biophysical responses to paclitaxel exposure and supporting the network's ability to detect subtle, label-free indicators of drug action. As further proof-of-concept, the same pipeline separated holotomographic images of label-free, high versus low-graded urothelial cancer cells with high accuracy (90.6 %). These findings highlight the potential of integrating label-free holotomographic imaging with deep learning techniques for rapid and efficient classification of tumor cells, paving the way for advancements in treatment optimization and personalized diagnostic strategies. - oai:arXiv.org:2512.06808v1 + Photonic electrometry using a piezoelectric-Pockels microresonator + https://arxiv.org/abs/2512.08773 + arXiv:2512.08773v1 Announce Type: new +Abstract: Facilitated by low-noise laser frequency locking, optical microresonators with the Pockels effect have shown unprecedented high resolutions in sensing electrical field. However, the requirement for tunable and low-noise laser sources considerably increases the cost and the size of the system, thereby limiting the industrial applicability of the microresonator-based technology. Here, we explore the possibility of using a low-cost fixed-frequency semiconductor laser as the pump laser to perform radiofrequency electrometry. A resonant mode in a lithium niobate microresonator is frequency-locked to the laser using the electrooptic effect. This same effect also underlies the radiofrequency electric-field sensing mechanism. Our experimental results show that the electrometry resolution can be maintained at signal frequencies beyond the optical resonance bandwidth and that the signal-to-noise ratio does not change with varied coupling conditions as long as the laser frequency noise is the dominant noise source of the system. In addition, narrowband electrooptic sensitivity enhancement is observed at frequencies of the microresonator's piezoelectric resonances, resulting in a resolution enhancement factor of approximately 3 at signal frequencies around 4 MHz. Our work advances the photonic resonant electrometry technology by studying the bandwidth limitation, and opens the road to the employment of low-cost lasers in high-resolution sensing applications. + oai:arXiv.org:2512.08773v1 physics.optics - physics.app-ph - physics.bio-ph - q-bio.CB - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Leonor V. C. Losa, Temple A. Douglas, Lia Santos, Raquel Monteiro, Isabel Calejo, Raphael F. Canadas, Jana B. Nieder + 10.1103/6bkw-m89n + Suwan Sun, Hairun Guo, Andre Luiten, Wenle Weng - Nonperturbative low harmonics generation in low-frequency laser field - https://arxiv.org/abs/2512.06816 - arXiv:2512.06816v1 Announce Type: new -Abstract: Solving numerically three-dimensional non-stationary Schr\"odinger equation, we find the atomic response to the quasi-static electric field We suggest a semi-phenomenological approximation of this response which describes well the {\it ab initio} numerical calculation result both for low and high intensities (up to $1.4 \cdot 10^{14}$ W/cm$^2$). In particular, this approximation describes the nonperturbative increase or the third harmonic generation efficiency with the laser intensity, as well as the dependence of the optical ratification signal in the two-color field on the phase difference between the fields. Making the calculations for the realistic laser frequencies, we find that our approach is applicable up to fundamental frequencies of about 1 eV. - oai:arXiv.org:2512.06816v1 - physics.optics - physics.atom-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Injection dynamics in spin-wave active ring oscillator (SWARO) + https://arxiv.org/abs/2512.08796 + arXiv:2512.08796v1 Announce Type: new +Abstract: We investigated injection locking in spin-wave active ring oscillators (SWAROs) operating in the multi-mode regime. By applying external RF signals with varying frequency and power, we identified the locking behavior of individual modes and extracted the total locking ranges from spectral measurements. The results show asymmetric evolution of the lower and upper locking boundaries with drive power for the lower-frequency SWARO modes, while the highest-frequency mode exhibits nearly symmetric behavior. A maxi- mum locking range of over 11 MHz is observed at a drive power of -10 dBm. To interpret these results, we develop an Adler-like model that captures the dependence of the locking range on drive power, showing good agreement for the higher-frequency modes. For the lowest-frequency mode, however, the model underestimates the locking range at low drive and saturates at high drive power levels, while the experimental range increases mono- tonically, indicating the influence of multi-mode interactions. These findings establish SWARO as a useful platform for exploring injection phenomena in spin-wave ring systems with delayed feedback and motivate the development of extended injection models that account for multi-mode dynamics. + oai:arXiv.org:2512.08796v1 + physics.app-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - S. A. Bondarenko, V. V. Strelkov + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Anirban Mukhopadhyay, Ihor I. Syvorotka, Anil Prabhakar - Birth of a bubble: Drop impact onto a thin liquid film for an immiscible three-fluid system - https://arxiv.org/abs/2512.06819 - arXiv:2512.06819v1 Announce Type: new -Abstract: When a drop impacts a solid substrate or a thin liquid film, a thin gas disc is entrapped due to surface tension, the gas disc retracts into one or several bubbles. While the evolution of the gas disc for impact on solid substrate or film of the same fluid as the drop have been largely studied, little is known on how it varies when the liquid of the film is different that of the drop. We study numerically the latter unexplored area, focussing on the contact between the drop and the film, leading to the formation of the air bubble. The volume of fluid method was adapted to three fluids in the framework of Basilisk solver. The numerical simulations show that the deformation of the liquid film due to the air cushioning plays a crucial role in the bubble entrapment. A new model for the contact time and the entrapment geometry was deduced from the case of the impact on a solid substrate. This was done by considering the deformation of the thin immiscible liquid layer during impact depending mainly on its thickness and viscosity. The lubrication of the gas layer was found to be the major effect governing the bubble entrapment. However the film viscosity was also identified as having a critical role in bubble formation and evolution; the magnitude of its influence was also quantified. - oai:arXiv.org:2512.06819v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 + CIEMAT-QI4X: a reactor-relevant quasi-isodynamic stellarator configuration compatible with an island divertor + https://arxiv.org/abs/2512.08825 + arXiv:2512.08825v1 Announce Type: new +Abstract: A four-field-period quasi-isodynamic stellarator configuration is presented that exhibits small neoclassical and electrostatic turbulent transport, good fast-ion confinement over a wide range of $\beta$ values, small bootstrap current and an edge island structure compatible with an island divertor. This configuration, called CIEMAT-QI4X, has been obtained by building on the optimization strategy and sophisticating the methods employed in [S\'anchez E. et al 2023 Nucl. Fusion 63 066037]. The optimization has been improved by incorporating metrics to control Mercier stability and by enforcing strict constraints on the rotational transform profile to achieve nested toroidal surfaces in the confinement region and a divertor island structure at the plasma edge. Specifically, CIEMAT-QI4X has a 4/4 island chain at the edge that is resilient at least up to $\beta=4\%$, even when the bootstrap current is included. A corresponding set of filamentary coils is presented that generates the configuration with enough accuracy to preserve the aforementioned physics properties. In terms of physics performance, CIEMAT-QI4X establishes as a candidate for a stellarator fusion reactor design. + oai:arXiv.org:2512.08825v1 + physics.plasm-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1017/jfm.2025.195 - Journal of Fluid Mechanics , Volume 1009 , 10 May 2025 , A8 - Pierre-Antoine Ma\"es, Alidad Amirfazli, Christophe Josserand + E. S\'anchez, J. L. Velasco, I. Calvo, J. M. Garc\'ia-Rega\~na, C. Salcuni, J. A. Alonso - Inertial rotation of a small oblate spheroid in a simple shear flow - https://arxiv.org/abs/2512.06822 - arXiv:2512.06822v1 Announce Type: new -Abstract: We compare experiments and fully-resolved particle simulations designed to match the experimental conditions of a weakly inertial, neutrally buoyant, moderately oblate spheroid in shear flow under confinement. Experimental and numerical results are benchmarked against theory valid for asymptotically small particle Reynolds numbers and for unconfined systems. By considering the combined effects of confinement and inertia, sensitivity to initial conditions, and the time span of observation, we reconcile the findings of theory, experiments, and numerical simulations. Furthermore, we demonstrate that confinement significantly influences the orientational stability of log-rolling spheroids compared to weak inertia, with the primary consequence being a reduced drift rate towards the stable log-rolling orbit. - oai:arXiv.org:2512.06822v1 - physics.flu-dyn - physics.app-ph - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Near real-time channel selection for Distributed Acoustic Sensing technology + https://arxiv.org/abs/2512.08845 + arXiv:2512.08845v1 Announce Type: new +Abstract: Distributed Acoustic Sensing (DAS) technology is advancing seismic monitoring by providing dense observations near earthquake sources. However, the resulting data volumes often limit real-time processing capability, with most seismological applications focusing on retrospective analysis of seismic sequences. To address this challenge, we introduce ORION, a fast and versatile selector of high-quality DAS channels that efficiently reduces the amount of data to analyze. The method first adopts spatial clustering to identify cable segments with similar geometrical attributes (e.g, azimuth), and then performs channel selection within each section using waveform attributes (e.g., signal-to-noise ratio); this approach enables spatial sub-sampling while preserving azimuthal coverage. We demonstrate the flexibility of the selector across several cable geometries. Finally, we analyze a seismic sequence using ORION-selected channels and compare the source locations with those from a more conventional uniform distribution of channels along the cable, showing improvements in hypocenter accuracy. + oai:arXiv.org:2512.08845v1 + physics.geo-ph + Wed, 10 Dec 2025 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ - Ziqi Wang, Xander M. de Wit, Davide Di Giusto, Laurence Bergougnoux, Elisabeth Guazzelli, Cristian Marchioli, Bernhard Mehlig, Federico Toschi + Emanuele Bozzi, Giulio Pascucci, Giacomo Rapagnani, Gian Maria Bocchini, Rebecca Harrington, Arantza Ugalde, Gilberto Saccorotti, Francesco Grigoli - Thermal one-loop self-energy correction for hydrogen-like systems: relativistic approach - https://arxiv.org/abs/2512.06828 - arXiv:2512.06828v1 Announce Type: new -Abstract: Within a fully relativistic framework, the one-loop self-energy correction for a bound electron is derived and extended to incorporate the effects of external thermal radiation. In a series of previous works, it was shown that in quantum electrodynamics at finite temperature (QED), the description of effects caused by blackbody radiation can be reduced to using the thermal part of the photon propagator. As a consequence of the non-relativistic approximation in the calculation of the thermal one-loop self-energy correction, well-known quantum-mechanical (QM) phenomena emerge at successive orders: the Stark effect arises at leading order in $\alpha Z$, the Zeeman effect appears in the next-to-leading non-relativistic correction, accompanied by diamagnetic contributions and their relativistic refinements, among other perturbative corrections. The fully relativistic approach used in this work for calculating the SE contribution allows for accurate calculations of the thermal shift of atomic levels, in which all these effects are automatically taken into account. The hydrogen atom serves as the basis for testing a fully relativistic approach to such calculations. Additionally, an analysis is presented of the behavior of the thermal shift caused by the thermal one-loop correction to the self-energy of a bound electron for hydrogen-like ions with an arbitrary nuclear charge $Z$. The significance of these calculations lies in their relevance to contemporary high-precision experiments, where thermal radiation constitutes one of the major contributions to the overall uncertainty budget. - oai:arXiv.org:2512.06828v1 - physics.atom-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Axial Symmetric Navier Stokes Equations and the Beltrami /anti Beltrami spectrum in view of Physics Informed Neural Networks + https://arxiv.org/abs/2512.08846 + arXiv:2512.08846v1 Announce Type: new +Abstract: In this paper, I further continue an investigation on Beltrami Flows began in 2015 with A. Sorin and amply reprised and developed in 2022 with M. Trigiante. Instead of a compact $3$-torus $T^3=\mathbb{R}^3/\Lambda$ where $\Lambda$ is a crystallographic lattice, as done in previous work, here I considered flows confined in a cylinder with identified opposite bases. In this topology I considered axial symmetric flows and found a complete basis of axial symmetric harmonic $1$-forms that, for each energy level, decomposes into six components: two Beltrami, two anti-Beltrami and two closed forms. These objects, that are written in terms of trigonometric and Bessel functions, constitute a function basis for an $L^2$ space of axial symmetric flows. I have presented a general scheme for the search of axial symmetric solutions of Navier Stokes equation by reducing the latter to an hierachy of quadratic relations on the development coefficients of the flow in the above described functional basis. It is proposed that the coefficients can be determined by means of a Physics Informed like Neural Network optimization recursive algorithm. Indeed the present paper provides the theoretical foundations for such a algorithmic construction that is planned for a future publication. + oai:arXiv.org:2512.08846v1 + physics.flu-dyn + cs.IT + math-ph + math.IT + math.MP + math.OC + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - M. Reiter, D. Solovyev, A. Bobylev, D. Glazov, T. Zalialiutdinov + http://creativecommons.org/licenses/by/4.0/ + Pietro Fr\'e - FGE: A Fast Free-Boundary Grad-Shafranov Evolutive Solver - https://arxiv.org/abs/2512.06847 - arXiv:2512.06847v1 Announce Type: new -Abstract: Accurate and rapid simulation of the free boundary tokamak plasma equilibrium evolution is essential for modern plasma control, stability analysis, and scenario development. This paper presents the Free-Boundary Grad-Shafranov Evolutive (FGE) code, a highly flexible and control-oriented solver designed to address the challenges posed by advanced plasma configurations across a range of devices. FGE evolved from the FBT and LIUQE codes and is part of the MEQ suite, sharing many of the low-level optimized functions. It self-consistently solves the free-boundary Grad-Shafranov equation coupled with circuit equations for external conductors and models for plasma profile evolution. The code implements a fully non-linear, Newton-based framework with multiple, highly optimized solver options, state representations, and residual formulations that enable rapid computation across different simulation setups. A key capability is the self-consistent integration of various 0D and 1D current diffusion equations (CDEs) to model the resistive evolution of the plasma current profile as well as the ability to model plasmas with multiple magnetic axes (Doublets). Furthermore, FGE allows to linearize the plasma dynamics around a given equilibrium to generate a state-space model suitable for controller design and analysis. Numerical studies are presented demonstrating the code's speed of convergence and validating its performance against experimental data. Furthermore, benchmarks against the RAPTOR and KINX codes for profile evolution and vertical growth rate estimates are presented highlighting FGE's capabilities for both prediction and analysis. - oai:arXiv.org:2512.06847v1 - physics.plasm-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Cultural evolution of human beauty standards + https://arxiv.org/abs/2512.08861 + arXiv:2512.08861v1 Announce Type: new +Abstract: Beauty standards shape self-perception and health through social comparison and objectification, while exposure to idealized imagery exacerbates body-image concerns. Media and fashion are central arbiters of these ideals, yet long-term, quantitative, intersectional studies on how representation has changed remain scarce. We assembled a dataset of 793199 records spanning 25 years of advertising, magazine covers, runway shows, and editorials to quantify changes in anthropometric and demographic representation. We find a paradox in the evolution of beauty ideals: while representational diversity has increased, the median model physique remains stable. This is driven by selective plus-size inclusion at the upper tail, while the typical physique continues to diverge from the US population. Intersectionally, non-white models are 4.5 times more likely to be plus-size, indicating that progress in size inclusivity falls disproportionately on multiple underrepresented identities. Stratifying the industry via a data-driven prestige hierarchy, we find that thinness is overrepresented at the top tier. Finally, comparing two regulatory interventions we observe that numeric thresholds are more effective at reducing underweight appearances. Our results quantify the cultural evolution in media and fashion, revealing that inclusion has increased; however, gains are uneven and intersectionally concentrated on size and ethnicity, whereas the prevailing thin ideal remains largely unchanged. + oai:arXiv.org:2512.08861v1 + physics.soc-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Cosmas Hei{\ss}, Antoine Merle, Francesco Carpanese, Federico Felici, Craig Donner, Stefano Marchioni, Alessandro Mari, Olivier Sauter + http://creativecommons.org/licenses/by/4.0/ + Louis Boucherie, Sagar Kumar, Katharina Ledebur, August Lohse, Karolina Sliwa - Controllable Emergence of Multiple Topological Anderson Insulator Phases in Photonic Su-Schrieffer-Heeger Lattices - https://arxiv.org/abs/2512.06851 - arXiv:2512.06851v1 Announce Type: new -Abstract: We investigate the emergence and control of multiple topological Anderson insulator (TAI) phases in a one-dimensional Su-Schrieffer-Heeger (SSH) waveguide lattice with generalized Bernoulli-type disorder introduced in the intradimer couplings. By systematically varying the disorder configuration -- including the values and probabilities of the multivariate distribution -- we demonstrate that both the number and width of TAI phases can be precisely engineered. Analytical determination of topological phase boundaries via the inverse localization length shows excellent agreement with numerical simulations. Our results reveal a rich landscape of disorder-induced topological phase transitions, including multiple reentrant TAI phases that arise as the disorder amplitude increases. Furthermore, we show that the mean chiral displacement serves as a sensitive probe for detecting these topological transitions, providing a practical route for experimental realization in photonic waveguide lattices. This work establishes a versatile framework for designing quantum and photonic materials with customizable topological properties driven by tailored disorder. - oai:arXiv.org:2512.06851v1 - physics.optics - cond-mat.dis-nn - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Spreading processes on heterogeneous active systems: spreading threshold, immunization strategies, and vaccination noise + https://arxiv.org/abs/2512.08878 + arXiv:2512.08878v1 Announce Type: new +Abstract: We study spreading processes in two-dimensional systems of heterogeneous active agents that exhibit different individual active speeds. We obtain, combining kinetic and complex network theory, an analytical expression for the spreading threshold that depends not only on the first but also second moment of the speed distribution. Moreover, we prove that spreading can even occur for vanishing average active speed. Furthermore, we find that random vaccination strategies are ineffective in heterogeneous active systems, whereas targeted ones are effective. We also show that vaccination acts as (quenched) noise: it can decrease or increase the outbreak size. Our results offer insights into how information propagates in heterogeneous populations of active agents. + oai:arXiv.org:2512.08878v1 + physics.bio-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Ruijiang Ji, Yunbo Zhang, Shu Chen, Zhihao Xu + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Benjam\'in Marcolongo, Gustavo J. Sibona, Fernando Peruani - The macroscopic contact angle of water on ice - https://arxiv.org/abs/2512.06853 - arXiv:2512.06853v1 Announce Type: new -Abstract: Wettability quantifies the affinity of a liquid over a substrate, and determines whether the surface is repellent or not. When both the liquid and the solid phases are made of the same chemical substance and are at thermal equilibrium, complete wetting is expected in principle, as observed for instance with drops of molten metals spreading on their solid counterparts. However, this is not the case for water on ice. Although there is a growing consensus on the partial wetting of water on ice and several estimates available for the value of the associated contact angle, the question of whether these values correspond to the equilibrium angle without thermal effects is still open. In the present paper, we address this issue experimentally and demonstrate the existence of a macroscopic contact angle of water on ice using theoretical arguments. Indeed, when depositing water droplets on smooth ice layers with accurately controlled surface temperatures, we observe that spreading is unaffected by thermal effects and phase change close enough to the melting point. Whereas the short time \C{motion of the contact line} is driven by an inertial-capillary balance, the evolution towards equilibrium is described by a viscous-capillary dynamics and is therefore capillary - and not thermally - related. Moreover, we show that this contact angle remains constant for undercoolings below 1 K. This way, we show the existence of a non-zero equilibrium contact angle of water on ice, that it is very close to 12$^\circ$. We anticipate this key finding to significantly improve the understanding of capillary flows in the presence of phase change, which is especially useful in the context of ice morphogenesis and of glaciology, but also in the aim of developing numerical methods for resolving triple-line dynamics. - oai:arXiv.org:2512.06853v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 + Dual-wavelength Fourier Ptychographic Topography + https://arxiv.org/abs/2512.08883 + arXiv:2512.08883v1 Announce Type: new +Abstract: We introduce a dual-wavelength Fourier ptychographic topography (FPT) method that extends the lambda/2 height-range limit of single-wavelength FPT. By reconstructing complex fields at two illumination wavelengths and exploiting their phase difference, the method achieves an effective synthetic wavelength lambda_s and an unambiguous range of lambda_s/2 without reducing lateral resolution. A noise-robust wrapped-number search is used to select per-pixel integer pairs (k1, k2), and a global refinement with circular TV regularization and soft bounds improves stability and preserves height discontinuities. The approach is validated through rigorous scattering-model-based simulations and experiments on structured silicon samples, demonstrating accurate height recovery in regimes where single-wavelength FPT exhibits phase wrapping. We analyze the limits of the FPT forward model and identify aspect ratio (AR) and phase modulation transfer function (ph-MTF) as key predictors of reconstruction fidelity. Simulations and experiments show that increasing AR beyond a practical threshold causes loss of high-frequency phase transfer and destabilizes dual-wavelength unwrapping. Within this AR range, dual-wavelength FPT provides robust, high-resolution topography suitable for semiconductor and industrial metrology. + oai:arXiv.org:2512.08883v1 + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1017/jfm.2025.10609 - Journal of Fluid Mechanics , Volume 1019 , 25 September 2025 , A3 - W. Sarlin, D. V. Papa, R. Grivet, A. Rosenbaum, A. Huerre, T. S\'eon, C. Josserand + Yi Shen, Tongyu Li, Hao Wang, Jinyong Kim, Hojun Lee, Wookrae Kim, Jonghyeok Park, Junho Shin, Seungbeam Park, Lei Tian - Synchronous Differential Hot-charge Emission Spectroscopy: The Principle - https://arxiv.org/abs/2512.06855 - arXiv:2512.06855v1 Announce Type: new -Abstract: Energy-level alignment (ELA) at buried interfaces between electrode and molecular materials sets charge injection barriers, carrier selectivity, and ultimately device efficiency, yet it is challenging to quantify under operating conditions. Hot-charge emission spectroscopy (HotES) probes ELA by injecting ballistic carriers across a tunneling oxide. Yet, the technique inherently convolutes the molecular response with a strong, energy-dependent tunneling background, complicating the isolation of the true ELA. We introduce synchronous differential HotES (sd-HotES), defined as the ratio of the differential conductance of the hot-charge and tunneling channels of the HotES. Physical modeling and numerical simulations validate that this ratio directly reconstructs the intrinsic molecular charge transmission, enabling the threshold-free and probe-bias-insensitive extraction of ELA. By effectively eliminating the masking tunneling background, sd-HotES substantially boosts detection sensitivity; weak spectral features previously hidden in conventional HotES become clearly resolvable, as demonstrated in lock-in simulations including realistic noise. This study establishes the fundamental operating principles of sd-HotES and highlights it as a powerful, broadly applicable strategy for accessing buried interface properties for the study of molecular and hybrid devices. - oai:arXiv.org:2512.06855v1 - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 + A microstructural rheological model for transient creep in polycrystalline ice + https://arxiv.org/abs/2512.08907 + arXiv:2512.08907v1 Announce Type: new +Abstract: The slow creep of glacial ice plays a key role in sea-level rise, yet its transient deformation remains poorly understood. Glen's flow law, where strain rate is simply a function of stress, cannot predict the time-dependent creep behavior observed in experiments. Here we present a physics-based rheological model that captures all three regimes of transient creep in polycrystalline ice. The key components of the model are a series of Kelvin-Voigt mechanical elements that produce a power-law (Andrade) creep, and a single viscous element with microstructure and stress dependence that represents reorientation in the polycrystalline grains. The interplay between these components produces a minimum in the strain rate at approximately 1% strain, which is a universal but unexplained feature reported in experiments. Due to its transient nature, the model exhibits fractional power-law exponents in the stress dependence of the strain rate minimum, which has been conventionally interpreted as independent physical processes. Taken together, we provide a compact, mechanistic framework for transient ice rheology that generalizes to other polycrystalline materials and can be integrated into constitutive laws for ice-sheet models. + oai:arXiv.org:2512.08907v1 + physics.geo-ph + cond-mat.soft + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Xuan Ji, Wen Chen, Xi Yu + http://creativecommons.org/licenses/by/4.0/ + Alex J. Vargas, Ranjiangshang Ran, Justin C. Burton - Revisiting the Acousto-Electric Effect - https://arxiv.org/abs/2512.06860 - arXiv:2512.06860v1 Announce Type: new -Abstract: The goal of this paper is to provide a new perspective on the acousto-electric effect by deriving a wave equation for the acoustic field that is akin to Stokes 1845 viscous wave equation and in which the phonon-electron interaction provides the loss/gain term. We hope this new perspective may provide some insight into the workings of the acousto-electric effect, and we use it to build connections to other areas of research, in particular inertial motion superradiance and the Zel'dovich effect. - oai:arXiv.org:2512.06860v1 - physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Effect of the Gradient of the Spin-Polarization in Density Functional Approximations + https://arxiv.org/abs/2512.08913 + arXiv:2512.08913v1 Announce Type: new +Abstract: The construction of non-empirical density functional approximations is typically guided by the satisfaction of exact constraints. An important constraint is the recovery of the gradient expansion for slowly varying electron densities. In prior constructions of semilocal density functional approximations, the $\nabla \zeta$-dependent terms in the gradient expansion of the correlation have been dropped, where $\zeta$ is the relative spin polarization. We propose a scheme by which such terms can be reintroduced into already constructed functionals without significantly affecting other constraints and norms. We implement this scheme on the Strongly Constrained and Appropriately Normed (SCAN) functional to construct a $\nabla \zeta$-corrected version of SCAN. The resulting functional is shown to provide improvements in transition-metal atoms and molecules without significantly affecting SCAN's accurate description of $sp$-systems. For the binding energy curve of the chromium dimer Cr$_2$, the SCAN underbinding is fully corected at large bond lengths and reduced at short bond lengths. + oai:arXiv.org:2512.08913v1 + physics.chem-ph + Wed, 10 Dec 2025 00:00:00 -0500 new - http://creativecommons.org/licenses/by/4.0/ - Ewan M Wright, John Mack, Alex Wendt, Austin Burrington, Will Roberts, Dalton Anderson, Matt Eichefield + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Rohan Maniar, John P. Perdew - BO-PBK: A comprehensive solver for dispersion relations of obliquely propagating waves in magnetized multi-species plasma with anisotropic loss-cone drift product-bi-kappa distribution - https://arxiv.org/abs/2512.06901 - arXiv:2512.06901v1 Announce Type: new -Abstract: We present BO-PBK (BO-Product-Bi-Kappa), a new solver for kinetic dispersion relations of obliquely propagating waves in magnetized plasmas with complex velocity distributions. It reformulates the linearized Vlasov-Maxwell system into a compact eigenvalue problem, enabling direct computation of multiple wave branches and unstable modes without iterative initial-value searches. Key innovations include a unified framework supporting product-bi-kappa, kappa-Maxwellian, bi-Maxwellian, and hybrid distributions with multi-component and loss-cone features; a concise rational-form eigenvalue formulation; and a 2--3 times reduction in matrix dimensions compared to the BO-KM solver, with improved efficiency at larger kappa indices. Benchmark tests confirm accurate reproduction of standard kinetic results and efficient resolution of waves and instabilities. BO-PBK thus provides a computationally efficient tool for wave and stability analysis in space and laboratory plasmas. - oai:arXiv.org:2512.06901v1 - physics.plasm-ph - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Strong Mode Coupling via Quasi-Bound States in the Continuum in Bianisotropic Metasurfaces + https://arxiv.org/abs/2512.08927 + arXiv:2512.08927v1 Announce Type: new +Abstract: Electromagnetic mode coupling plays a key role in many resonant effects in nanophotonics. This coupling is also responsible for the appearance of bianisotropy, where electric and magnetic responses become interconnected through the interaction of their respective modes. In this work, we develop a simple and general temporal coupled-mode theory model to describe off-diagonal chiral bianisotropy. Using quasi-bound states in the continuum (q-BICs), we demonstrate how to control the hybridization of modes with opposite symmetries, resulting in Rabi-like splitting between the hybrid states in the regime of strong electromagnetic mode coupling. Beyond revealing the physical origin of the hybrid modes, our model predicts and explains the emergence of dual-band asymmetric reflection and absorption, and how to achieve maximum directional absorption difference. The theoretical predictions are verified by full-wave simulations, showing very good agreement with theory. Furthermore, very strong reciprocal bianisotropy is demonstrated with the use of q-BICs in a deeply subwavelength metasurface in the optical frequency range. Our results provide a clear physical picture of the interaction process between modes, offering a compact theoretical framework for understanding and designing bianisotropic dielectric metasurfaces not only in the traditional regime but also in the strong coupling regime. + oai:arXiv.org:2512.08927v1 + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Wei Bai, Huasheng Xie + Luis Manuel M\'a\~nez-Espina, Bahman Amrahi, Viktar Asadchy, Ana D\'iaz-Rubio - "Be Better Than You Need to Be": A-Level Physics Students' Rants, Resilience and Peer Pedagogy on TikTok - https://arxiv.org/abs/2512.06923 - arXiv:2512.06923v1 Announce Type: new -Abstract: Amid the growth of social media, students increasingly turn to short-form platforms for study support and advice. This study examines how A-level Physics is portrayed by student creators on TikTok, a popular platform amongst students for peer-to-peer educational guidance, information sharing, and collective knowledge building. Using reflexive thematic analysis of 57 TikTok videos via #alevelphysics, we explore how A-level Physics is characterised and what pathways to success are constructed within these informal discourses. The findings show that the subject is depicted as both intellectually demanding and emotionally taxing, with the examination system perceived as a flawed gatekeeper. Creators narrate their experiences through a blend of hyperboles, frustration, and resilience, offering sophisticated peer-generated pedagogies alongside cautionary tales. Recommendations emphasise strategic resource curation, sustained practice, systematic memorisation, and a mindset of deliberate over-preparation. These portrayals of subject demands and agentic responses resonate with prior research on the cultural construction of physics as hard and exclusionary, while also illustrating how affinity spaces on social media enable students to reframe difficulty through shared feelings and tactics. We discuss the value of student-led online discourses about high-stakes examinations for educators in supporting prospective and current physics students. - oai:arXiv.org:2512.06923v1 - physics.ed-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Wonyong Park + Icy worlds: Moons and Dwarf Planets + https://arxiv.org/abs/2511.18776 + arXiv:2511.18776v1 Announce Type: cross +Abstract: In the outer solar system beyond Jupiter, water ice is a dominant component of planetary bodies, and most solid objects in this region are classified as icy bodies. Icy bodies display a remarkable diversity of geological, geophysical, and atmospheric processes, which differ fundamentally from those of the rocky terrestrial planets. Evidence from past and ongoing spacecraft missions has revealed subsurface oceans, cryovolcanic activity, and tenuous but persistent atmospheres, showing that icy bodies are active and evolving worlds. At the same time, major questions remain unresolved, including the chemical properties of icy materials, the geological histories of their surfaces, and the coupling between internal evolution and orbital dynamics. Current knowledge of the surfaces, interiors, and atmospheres of the principal icy bodies is built on spacecraft measurements, telescopic observations, laboratory experiments, and theoretical modeling. Recent contributions from Juno, JWST, and stellar occultation studies have added valuable constraints on atmospheric composition, interior structure, and surface activity. Looking ahead, missions such as JUICE, Europa Clipper, Dragonfly, and the Uranus Orbiter and Probe are expected to deliver substantial progress in the study of icy bodies. Their findings, combined with continued Earth- and space-based observations and laboratory studies, will be critical for assessing the potential habitability of these environments and for placing them within a broader framework of planetary system formation and evolution. + oai:arXiv.org:2511.18776v1 + astro-ph.EP + physics.geo-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by/4.0/ + 10.1093/acrefore/9780190647926.013.87 + Jun Kimura - ExPUFFIN: Thermodynamic Consistent Viscosity Prediction in an Extended Path-Unifying Feed-Forward Interfaced Network - https://arxiv.org/abs/2512.06927 - arXiv:2512.06927v1 Announce Type: new -Abstract: Accurate prediction of liquid viscosity is essential for process design and simulation, yet remains challenging for novel molecules.Conventional group-contribution models struggle with isomer discrimination, large molecules, and parameter availability, while purely data-driven graph neural networks (GNNs) demand large datasets and offer limited interpretability. Even when feasible to be applied, purely data-driven models lack thermodynamic consistency in their predictions and are not a reliable solution.This work introduces ExPUFFIN, an extended version of the Path-unifying Feed-Forward Interfaced Network, consisting of a hybrid GNN-based framework that directly predicts temperature-dependent viscosities of pure hydrocarbons from molecular graphs, while enforcing mechanistic inductive biases in the output layer to ensure thermodynamic consistency. Molecular information is given as graph structures, encoded as a graph convolutional network, and mapped to an inductive bias neuron based on two thermophysical correlations:a three-parameter Andrade-type equation and a four-parameter empirical viscosity-temperature relation. The accuracy of these models is compared with a solely data-driven prediction. The Andrade-based ExPUFFIN variant reduces RMSE compared to the purely data-driven baseline of 37 percent and yields smooth, physically consistent interpolation and extrapolation of viscosity-temperature curves, properties that are not observed in purely data-driven models. The empirical ExPUFFIN model provides comparable accuracy while retaining robust trends. Overall, embedding physics-based structure in GNN outputs improves accuracy, robustness, and transferability, enabling reliable viscosity predictions for complex hydrocarbon molecules. The approach is readily extendable to other properties and significantly broader chemical domains. - oai:arXiv.org:2512.06927v1 - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Carine Menezes Rebello, Ulderico Di Caprio, Jenny Steen-Hansen, Bruno Rodrigues, Erbet Almeida Costa, Anderson Rapello dos Santos, Flora Esposito, Mumin Enis Leblebici, Idelfonso B. R. Nogueira + Effective Field Theory Perspective On King Non-linearity + https://arxiv.org/abs/2512.03157 + arXiv:2512.03157v1 Announce Type: cross +Abstract: Precision spectroscopic measurements of isotope shifts have recently reached a high level of accuracy. Tests of King non-linearity (NL) along isotope chains have been proposed as a tool to search for fifth-force mediators. At the same time, these tests can potentially teach us about the structure of heavy nuclei at unprecedented precision, where King NL has already been observed in several systems. A robust interpretation of the existing data, however, is hampered by incomplete control over the Standard Model (SM) contributions. We develop a systematic effective field theory framework, matching the SM onto scalar non-relativistic QED in the infinite nuclear mass limit and then onto quantum-mechanical potentials. This approach organizes all nuclear effects into a small set of Wilson coefficients and cleanly separates short- and long-distance physics. We show that the commonly used treatment of the $\langle r^2\rangle^2$ term needs to be reconsidered, as it arises only at second-order in perturbation theory, and we derive the long-range $1/r^4$ potential from nuclear polarizability. Applying the framework to hydrogen-like systems, we provide a transparent classification of SM sources of King NL relevant for current and future isotope-shift experiments. The formalism can be applied to learn about the shape of the heavy scalar nuclei at a higher level of precision and detail than what was previously attainable. + oai:arXiv.org:2512.03157v1 + hep-ph + nucl-th + physics.atom-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by/4.0/ + Beno\^it Assi, Sam Carey, Sebastian J\"ager, Gabriel Lee, Gil Paz, Gilad Perez, Jure Zupan - Finite Volume Thermodynamics of an Ideal Gas in a Periodic Box - https://arxiv.org/abs/2512.06955 - arXiv:2512.06955v1 Announce Type: new -Abstract: Approach to the thermodynamic limit of a non-relativistic ideal gas in a periodic box is investigated. The single particle wave function obeys twisted boundary condition, $\psi(L)=e^{i\theta}\psi(0)$ for which the free particle spectrum is constructed in terms of the twist angle, $\theta$. The exact density of states is utilized to construct finite-size corrections of thermodynamic observables. Leading finite volume corrections in the free energy do not arise due to the boundary -- its implication for mixing entropy is examined. Finite volume corrections to the average energy, its fluctuations and the pressure are also examined with corrections arising exclusively through the boundary condition. However, the equation of state, the ratio of pressure to energy density, remains unmodified by the boundary. - oai:arXiv.org:2512.06955v1 + Thermal stability originates the vanishing of the specific heats at the absolute zero + https://arxiv.org/abs/2512.05129 + arXiv:2512.05129v2 Announce Type: cross +Abstract: The relationship between the vanishing of the heat capacities as $T\to0^+$ and the thermal stability is examined. The heat capacities vanish as fast as or faster than $T$ as $T\to0^+$ for states at the phase space boundary ($T=0$) to sustain the standard thermal stability criterion $U_{ss}>0$. Conversely, weakly vanishing heat capacities, which signify a loss of curvature in $U(S)$ at $T=0$, are the signature of a critical condition precisely at $T=0$, as exemplified in marginal Fermi liquids. Therefore, the vanishing of the specific heat should be viewed not as a new law but as a confirmatory result of the existing framework of thermodynamics. + oai:arXiv.org:2512.05129v2 + cond-mat.stat-mech + cond-mat.str-el + physics.chem-ph physics.class-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new + physics.hist-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Prabal Adhikari, Sona Baghiyan, Rayn Samson + 10.1088/1402-4896/ae22a5 + Physica Scripta 2025 100 125206 + Mart\'in-Olalla, Jos\'e Mar\'ia - Against the point-like nature of the electron - https://arxiv.org/abs/2512.06965 - arXiv:2512.06965v1 Announce Type: new -Abstract: Experts in quantum field theory (QFT) generally answer the question of the ``size of an electron'' with ``point-like''. On the other hand, QFT recognizes quantum effects, shielding by virtual particles, the so-called polarization cloud, which should describe the size of physical electrons. Scattering experiments with electrons, such as those carried out in high-energy experiments at particle accelerators, should be able to clarify whether physical electrons are really point-like, as claimed by experts and in textbooks. In this article, I show that both the formulas of QFT and the corresponding cross sections are consistent with an extent of the electron of the size of the classical electron radius. The assumption that the relativistic energy of electrons in the high-energy limit consists solely of deformation energy from the extended electron density distribution allows for a simple interpretation of the experimental cross sections. For this reason, I refer to classical models in 1+1 and 3+1 dimensions that have precisely this property. The difference between the terms point-like, structureless, and substructureless is highlighted. The usual objections to the claim that the electron radius is finite and has already been measured in electron scattering experiments are discussed. - oai:arXiv.org:2512.06965v1 - physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new + Numerical Algebraic Geometry for Energy Computations on Tensor Train Varieties + https://arxiv.org/abs/2512.06939 + arXiv:2512.06939v1 Announce Type: cross +Abstract: We study energy minimization problems in quantum chemistry through the lens of computational algebraic geometry. We focus on minimizing the Rayleigh quotient of a Hamiltonian over a tensor train variety. The complex critical points of this problem approximate eigenstates of the quantum system, with the global minimum approximating the ground state. We call the number of critical points the Rayleigh-Ritz degree. + After introducing tensor train varieties, we identify instances when they are Segre products of projective spaces. We also report what we know about the defining ideals of tensor trains. We present a birational parametrization of them from products of Grassmannians. Along the way, we study the Rayleigh-Ritz degree, and we introduce the Rayleigh-Ritz discriminant, which describes Hamiltonians that lead to deficient number of critical points. We use homotopy continuation to compute all critical points of this optimization problem over various tensor train and determinantal varieties. Finally, we use these results to benchmark state-of-the-art methods, the Alternating Linear Scheme and Density Matrix Renormalization Group. + oai:arXiv.org:2512.06939v1 + math.AG + math.OC + physics.chem-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Manfried Faber + Viktoriia Borovik, Hannah Friedman, Serkan Ho\c{s}ten, Max Pfeffer - Lineshape response of plastic scintillator to pair production of 4.44 MeV gamma's - https://arxiv.org/abs/2512.07023 - arXiv:2512.07023v1 Announce Type: new -Abstract: We measure the distribution of energy deposited in a 40x88 mm plastic scintillator by e+ e- pair production of 4.44 MeV gamma-rays. We observe the double-escape peak of 3.42 MeV from pair production by tagging 511 keV annihilation radiation in two high-Z scintillators. The source is a standard commercial neutron source using alpha-emitting 241Am encapsulated with 9Be, which has a reaction branch feeding the first Ipi=2+ state of 12C making the 4.44 MeV gamma-rays. We demonstrate the extraction of the double-escape peak from the large neutron-produced backgound, and explore some of the features and difficulties of this technique with our apparatus. - oai:arXiv.org:2512.07023v1 - physics.ins-det - nucl-ex - Tue, 09 Dec 2025 00:00:00 -0500 - new + Solar neutron and muon detection on November 11, 2025: First simultaneous recovery of energy spectra + https://arxiv.org/abs/2512.07859 + arXiv:2512.07859v1 Announce Type: cross +Abstract: Ground Level Enhancement (GLE) events provide rare opportunities to study high-energy solar particle acceleration through direct detection of secondary radiation at ground level. On November 11, 2025, the Aragats Solar Neutron Telescope (ASNT) recorded a statistically significant increase in high-energy neutron and muon fluxes associated with an X5.1 flare and the subsequent Solar Energetic Proton (SEP) event. The event displayed a unique dual-peak profile: an initial hard component at 10 28 UT, followed by a softer yet still energetic peak at 10 45 UT. For the first time, we report simultaneous energy spectra of atmospheric neutrons and muons measured in the 10 600 MeV range at Aragats. Broken-power-law fits reveal a clear temporal evolution of acceleration conditions, evidenced by spectral indices declining with energy. These findings highlight the unique capabilities of the ASNT as an instrument for studying extreme solar particle acceleration. + oai:arXiv.org:2512.07859v1 + astro-ph.SR + physics.ao-ph + physics.space-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - 10.1016/j.nima.2023.168490 - Nucl. Instru. Meth. A 1055 168490 (2023) - Melisa Ozen, John A. Behr, Michelle Khoo, Felix Klose, Alexandre Gorelov, Dan Melconian + A. Chilingarian, B. Sargsyan, L. Kozliner, T. Karapetyan - The Fine-Structure Constant as a Scaled Quantity - https://arxiv.org/abs/2512.07027 - arXiv:2512.07027v1 Announce Type: new -Abstract: The fine-structure constant alpha approximately 1/137 is traditionally regarded as a fundamental dimensionless parameter. I argue instead that alpha is a scaled quantity that arises only where the structural scales contributed by classical electromagnetism (e), quantum mechanics (h-bar), and special relativity (c) intersect. None of these theories, taken individually, supplies the independent scales required to define alpha. The constant first appears when relativistic corrections are added to the Schrodinger-Bohr description of hydrogen (Sommerfeld), and it becomes the structural coupling in quantum electrodynamics, where quantum and relativistic effects modify the classical electromagnetic interaction. Expressing the governing laws in canonical form reveals this dependence and eliminates representational artifacts that make alpha appear fundamental. The running of alpha in QED further demonstrates its status as a scale-dependent coupling rather than a universal constant. I conclude that alpha is a domain-specific structural ratio reflecting contingent relationships among independent physical scales. - oai:arXiv.org:2512.07027v1 - physics.hist-ph - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new + Softly Symbolifying Kolmogorov-Arnold Networks + https://arxiv.org/abs/2512.07875 + arXiv:2512.07875v1 Announce Type: cross +Abstract: Kolmogorov-Arnold Networks (KANs) offer a promising path toward interpretable machine learning: their learnable activations can be studied individually, while collectively fitting complex data accurately. In practice, however, trained activations often lack symbolic fidelity, learning pathological decompositions with no meaningful correspondence to interpretable forms. We propose Softly Symbolified Kolmogorov-Arnold Networks (S2KAN), which integrate symbolic primitives directly into training. Each activation draws from a dictionary of symbolic and dense terms, with learnable gates that sparsify the representation. Crucially, this sparsification is differentiable, enabling end-to-end optimization, and is guided by a principled Minimum Description Length objective. When symbolic terms suffice, S2KAN discovers interpretable forms; when they do not, it gracefully degrades to dense splines. We demonstrate competitive or superior accuracy with substantially smaller models across symbolic benchmarks, dynamical systems forecasting, and real-world prediction tasks, and observe evidence of emergent self-sparsification even without regularization pressure. + oai:arXiv.org:2512.07875v1 + cs.LG + cs.NE + physics.data-an + stat.ML + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Harry Sticker + James Bagrow, Josh Bongard - Alterations of brain tissue structural complexity and disorder in Alzheimer's disease (AD): Fractal, multifractal, fractal transformation, and disorder strength analyses - https://arxiv.org/abs/2512.07061 - arXiv:2512.07061v1 Announce Type: new -Abstract: Alzheimer's disease (AD) is characterized by progressive microstructural deterioration in brain tissue, yet conventional imaging and histopathology often lack the sensitivity needed to detect subtle early-stage changes. Here, we present a multiparametric framework combining fractal and multifractal analysis and their distributions to quantify structural alterations in human brain tissue affected by AD. Moreover, from the fractal and multifractal formalism, we introduced an innovative fractal functional distribution method, a novel technique that transforms fractal distribution into a Gaussian form. Statistically, these distribution parameters are easy to interpret and can distinguish between control and diseased tissues. Across samples, we identify pronounced threshold-dependent behavior of fractal and multifractal parameters, reflecting the intrinsic sparsity and heterogeneous intensity landscape of brain tissue. These threshold-sensitive signatures provide a framework for quantitative stage detection and may serve as biomarkers for early pathological transitions. In addition, we studied structural disorder and complexity using our established light localization technique, inverse participation ratio (IPR) analysis. IPR-based analysis demonstrates that increasing IPR pixel size highlights the elevation of structural alterations with disease progression. Together, these integrative analyses establish a robust, multi-scale quantitative framework for detecting microstructural alterations in AD, providing a promising foundation for early diagnosis and improved pathological assessment. - oai:arXiv.org:2512.07061v1 - physics.med-ph - nlin.CD - physics.bio-ph - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new + Revised comment on the paper titled "The Origin of Quantum Mechanical Statistics: Insights from Research on Human Language + https://arxiv.org/abs/2512.07881 + arXiv:2512.07881v1 Announce Type: cross +Abstract: This short note comments on \citet{Aerts2024Origin}, which proposes that ranked word frequencies in texts should be read through the lens of Bose--Einstein (BE) statistics and even used to illuminate the origin of quantum statistics in physics. The core message here is modest: the paper offers an interesting analogy and an eye-catching fit, but several key steps mix physical claims with definitions and curve-fitting choices. We highlight three such points: (i) a normalization issue that is presented as "bosonic enhancement", (ii) an identification of rank with energy that makes the BE fit only weakly diagnostic of an underlying mechanism, and (iii) a baseline comparison that is too weak to support an ontological conclusion. We also briefly flag a few additional concerns (interpretation drift, parameter semantics, and reproducibility). + oai:arXiv.org:2512.07881v1 + q-bio.NC + physics.hist-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Santanu Maity, Mousa Alrubayan, Mohammad Moshahid Khan, Prabhakar Pradhan + Miko{\l}aj Sienicki, Krzysztof Sienicki - Onset of separation unsteadiness in hypersonic shock boundary layer interaction on a cone-step - https://arxiv.org/abs/2512.07089 - arXiv:2512.07089v1 Announce Type: new -Abstract: Shock-boundary layer interactions (SBLI) on hypersonic cone step flows exhibit a range of intrinsic unsteady behaviors, from shear-layer oscillations to large-scale pulsations. This work investigates the unsteadiness in a cone-step geometry at Mach 6 under quiet flow conditions at different freestream Reynolds numbers using time-resolved Schlieren imaging and spectral proper orthogonal decomposition (SPOD). Experimental results are compared with high-fidelity axisymmetric and three-dimensional simulations. Results demonstrate regime transition in the parameter space, across the unsteadiness boundary, all the way from shear-layer breakdown to shock system oscillations and ultimately to large-amplitude pulsations. The dominant mode in the experiments and the simulations corresponds to a Strouhal number St ~ 0.17 for small oscillations reducing to St ~ 0.13 for large pulsations. A detailed description of the unsteady shock dynamics, the instability of the shear layer during onset of unsteadiness and an analysis of the nonlinear limit cycle is presented. - oai:arXiv.org:2512.07089v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - new + SATMO: a Multi-Planet Thermal Analysis Tool for CubeSat Missions + https://arxiv.org/abs/2512.07896 + arXiv:2512.07896v1 Announce Type: cross +Abstract: The expansion of commercial launch capabilities has significantly increased opportunities for interplanetary small satellite (SmallSat) missions. As researchers plan for more missions beyond Earth, there is a demand for accessible tools that help better predict and understand the thermal effects on their spacecraft in orbital environments around Earth and other bodies. While commercial thermal analysis tools offer high-fidelity modeling capabilities and results, they are often expensive and require extensive training to be used effectively. This paper details a framework for a user-friendly Satellite Thermal Model (SATMO) to support the early stages of space mission planning for CubeSats orbiting Earth and other Solar System bodies. SATMO is an open-source, MATLAB-based, six-node thermal analysis program designed for satellites in low-altitude circular orbits. Although SATMO requires a MATLAB license -- typically inexpensive or institutionally provided in academic settings -- it remains substantially more accessible than professional thermal analysis software. SATMO requires an internet connection for some features but does not rely on additional MATLAB toolboxes. The SATMO modeling approach is validated with the space industry standard Thermal Desktop software, with temperatures comparable to within 1.17$^\circ$C for a 10 cm $\times$ 10 cm $\times$ 10 cm CubeSat in various configurations, orbiting around primary bodies including Earth, Venus, and Mars. An example use case of SATMO is presented with a Mars-orbiting CubeSat to demonstrate its functionalities and the outputs available to users. SATMO offers increased accessibility to satellite thermal modeling for the research community, enabling quick thermal trade studies and interplanetary mission plans. + oai:arXiv.org:2512.07896v1 + astro-ph.IM + physics.app-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Chase Jenquin, Eric L. Cui, Anubhav Dwivedi, G. S. Sidharth, Joseph S. Jewell + Alexander Chipps, Daniel Forgette, Kerri Cahoy - Surrogate-assisted airfoil optimization in rarefied gas flows - https://arxiv.org/abs/2512.07093 - arXiv:2512.07093v1 Announce Type: new -Abstract: With growing interest in space exploration, optimized airfoil design has become increasingly important. However, airfoil design in rarefied gas flows remains underexplored because solving the Boltzmann equation formulated in a six dimensional phase space is time consuming. To address this problem, a solver-in-the-loop Bayesian optimization framework for symmetric, thickness-only airfoils is developed. First, airfoils are parameterized using a class shape transformation that enforce geometric admissibility. Second, a Gaussian process expected improvement surrogate is coupled in batches to a fast converging, asymptotic preserving Boltzmann solver for sample efficient exploration. Drag minimizing airfoils are identified in a wide range of gas rarefaction. It is found that, at Mach numbers Ma=2 and 4, the streamwise force increases with the gas rarefaction and shifts from pressure dominated to shear dominated drag, while optimization reduces drag at all conditions. The benefit of optimization peaks in the weakly rarefied regime, about 30% at Ma=2 and 40 to 50% at Ma=4, and falls to a few percent in transition and free-molecular flow regimes. Drag decomposition shows that these gains come mainly from reduced pressure drag, with viscous drag almost unchanged. The optimal airfoils form a coherent rarefaction-aware family: they retain a smooth, single-peaked thickness profile, are aft-loaded at low gas rarefaction, and exhibit a forward shift of maximum thickness and thickness area toward mid-chord as gas rarefaction increases. These trends provide a physically interpretable map that narrows the design space. - oai:arXiv.org:2512.07093v1 + CFD-copilot: leveraging domain-adapted large language model and model context protocol to enhance simulation automation + https://arxiv.org/abs/2512.07917 + arXiv:2512.07917v1 Announce Type: cross +Abstract: Configuring computational fluid dynamics (CFD) simulations requires significant expertise in physics modeling and numerical methods, posing a barrier to non-specialists. Although automating scientific tasks with large language models (LLMs) has attracted attention, applying them to the complete, end-to-end CFD workflow remains a challenge due to its stringent domain-specific requirements. We introduce CFD-copilot, a domain-specialized LLM framework designed to facilitate natural language-driven CFD simulation from setup to post-processing. The framework employs a fine-tuned LLM to directly translate user descriptions into executable CFD setups. A multi-agent system integrates the LLM with simulation execution, automatic error correction, and result analysis. For post-processing, the framework utilizes the model context protocol (MCP), an open standard that decouples LLM reasoning from external tool execution. This modular design allows the LLM to interact with numerous specialized post-processing functions through a unified and scalable interface, improving the automation of data extraction and analysis. The framework was evaluated on benchmarks including the NACA~0012 airfoil and the three-element 30P-30N airfoil. The results indicate that domain-specific adaptation and the incorporation of the MCP jointly enhance the reliability and efficiency of LLM-driven engineering workflows. + oai:arXiv.org:2512.07917v1 + cs.SE + cs.AI physics.flu-dyn - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Xiaoda Li, Ruifeng Yuan, Yanbing Zhang, Lei Wu + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Zhehao Dong, Shanghai Du, Zhen Lu, Yue Yang - Superconducting Nanowire Single-Photon Detectors for Enhanced Biomedical Imaging - https://arxiv.org/abs/2512.07138 - arXiv:2512.07138v1 Announce Type: new -Abstract: Significance: Superconducting nanowire single-photon detectors (SNSPDs; also known as SSPDs) show enormous promise for low-light biomedical imaging by offering exceptional sensitivity, picosecond timing resolution, and broad spectral coverage. Aim: This perspective evaluates the role of SNSPDs by comparing their performance with other photon-counting detectors for emerging biomedical imaging applications. Approach: We outline the need for ultrasensitive detectors for biophotonics, summarize SNSPD operating principles and compare their performance with established photon-counting devices. We highlight applications in which SNSPDs enable new imaging capabilities and discuss system-level challenges and technological developments that are critical to future applications, including clinical translation. Results: SNSPDs offer advantages in signal-to-noise ratio, temporal precision, and detection bandwidth, enabling deeper tissue imaging, high-precision fluorescence lifetime measurements, and quantum-enhanced imaging modalities. Advances in scalable arrays, cryogenic miniaturization, and improved signal collection are reducing barriers to widespread adoption. Conclusions: SNSPDs are poised to transform photon-limited biomedical imaging. As device performance and system integration continue to advance, their adoption in imaging platforms is expected to accelerate. Combining SNSPDs with advancements in the excitation pathway, such as structured-light excitation with Bessel beams, aberration correction, and wavefront shaping, shows promise for delivering unprecedented imaging capabilities and broadening both the preclinical and clinical utility of these detectors. - oai:arXiv.org:2512.07138v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new + Microlensing Signatures of Dyson Sphere-like Structures around Primordial Black Holes as Technosignatures of Extraterrestrial Advanced Civilizations + https://arxiv.org/abs/2512.07924 + arXiv:2512.07924v1 Announce Type: cross +Abstract: We investigate the microlensing detectability of extraterrestrial technosignatures originating from Dyson sphere \textendash like structures, such as Dyson Swarms surrounding primordial black holes (PBHs). These hypothetical swarms consist of stochastically varying, partially opaque structures that could modulate standard microlensing light curves through time-dependent transmission effects. We introduce a probabilistic framework that includes a stochastic transmission model governed by variable optical depth and random gap distributions. We perform a parameter scan and generate heatmaps of the optical transit duration. We study the infrared excess radiation and peak emission wavelength as complementary observational signatures. Additionally, we define and analyze the effective optical depth and the anomalous microlensing event rate for these stochastic structures. Our findings provide a new avenue for searching for extraterrestrial advanced civilizations by extending microlensing studies to include artificial, dynamic modulation signatures. + oai:arXiv.org:2512.07924v1 + astro-ph.IM + astro-ph.CO + astro-ph.EP + physics.pop-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Emi Cora Valmai Hughes, Avinash Upadhya, Kishan Dholakia + Shant Baghram - Quantitative Characterization of Brain Tissue Alterations in Brain Cancer Using Fractal, Multifractal, and IPR Metrics - https://arxiv.org/abs/2512.07148 - arXiv:2512.07148v1 Announce Type: new -Abstract: We studied the structural alterations between healthy and diseased brain tissues using a multiparametric framework combining fractal analysis, fractal functional transformation, multifractal analysis, and the Inverse Participation Ratio (IPR) analysis. Accurate characterization of brain tissue microstructure is crucial for early detection and diagnosis of cancer. By applying box-counting methods on brightfield microscopy images, we estimated the fractal dimension (Df) and its logarithmic (ln(Df)) and functional (ln(Dtf)) forms to highlight spatial irregularities in the tissue architecture. While Df and ln(Df) exhibited long-tailed distributions distinguishing healthy from cancer tissues, ln(Dtf) provided significantly improved differentiation by emphasizing local structural variations. Additionally, multifractal analysis revealed broader f({\alpha}) vs {\alpha} curves in cancerous samples, reflecting higher heterogeneity. IPR analysis based on light localization further demonstrated increased nanoscale variations in mass density, reflecting higher structural disorder in cancer tissues. Combining these complementary approaches creates a robust framework for measuring tissue complexity and holds great potential to improve microscopic diagnostic methods for brain cancer detection. - oai:arXiv.org:2512.07148v1 - physics.med-ph - physics.bio-ph - physics.comp-ph - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new + Vortex leapfrogging and superfluid dissipation mechanisms in a fluid of light + https://arxiv.org/abs/2512.07935 + arXiv:2512.07935v1 Announce Type: cross +Abstract: We report the experimental observation of vortex leapfrogging in a two-dimensional fluid of light. By imprinting two vortex-antivortex pairs and tracking their real-time evolution through phase-resolved imaging, we observe a dynamics that is accurately described by a point-vortex model with an outward background flow. By precisely controlling the initial vortex separation, we identify configurations in which leapfrogging breaks down and determine the corresponding dissipation mechanisms. The first originates from phase-slip events occurring at large injected velocities. The second arises when the injection of multi-charged vortices leads to the formation of a dispersive shock wave which acts as a continuous source of phase slippage. These mechanisms advance our understanding of vortex dynamics and dissipation in superfluids. + oai:arXiv.org:2512.07935v1 + cond-mat.quant-gas + physics.flu-dyn + quant-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Mousa Alrubayan, Santanu Maity, Prabhakar Pradhan + Myrann Baker-Rasooli, Nathan du Toit, Nicolas Pavloff, Quentin Glorieux - Optimization of gain uniformity in thermal bonding Micromegas for the PandaX-III experiment - https://arxiv.org/abs/2512.07151 - arXiv:2512.07151v1 Announce Type: new -Abstract: Micro-pattern gas detectors (MPGDs) are widely utilized in physics experiments owing to their excellent spatial resolution and high-rate capabilities. Within the PandaX-III experiment, which aims to investigate neutrinoless double beta decay, Micromegas detectors serve as charge readout devices. High energy resolution is a critical requirement for the readout plane in this context, and gain uniformity significantly impacts the achievable resolution, primarily because of the extended tracks of primary ionization electrons. However, scaling up MPGDs to larger active areas exacerbates the challenge of maintaining gain uniformity, and effectively controlling the uniformity of the avalanche gap is a key factor in the detector manufacturing process via the thermal bonding method. This study demonstrates that optimizing the thermal bonding films specifically at the detector edges can effectively improve the gain uniformity, achieving a gain uniformity of < 5% over the entire 200*200 mm2 active area in a 1 bar Ar/isobutane (96.5/3.5) gas mixture. Additionally, the gain uniformity of approximately 14% was characterized at high pressures of up to 10 bar, revealing promising potential for high resolution measurements in the PandaX-III experiment and other high-pressure applications. - oai:arXiv.org:2512.07151v1 - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/publicdomain/zero/1.0/ - Yunzhi Peng, Yuanchun Liu, Zhiyong Zhang, Shaobo Wang, Jianbei Liu, Ming Shao, Yi Zhou + Neutrino Effects on Atomic Measurements of the Weinberg Angle + https://arxiv.org/abs/2512.07938 + arXiv:2512.07938v1 Announce Type: cross +Abstract: We derive a complete expression for the neutrino-mediated quantum force beyond the four-Fermi approximation within the Standard Model. Using this new result, we study the effect of atomic parity violation caused by neutrinos. We find that the neutrino effect is sizable compared to the current experimental sensitivity and can also significantly affect the value of the Weinberg angle measured in atomic systems. This offers a promising method for detecting the neutrino force in the future and facilitates the application of precision atomic physics as a probe for neutrino physics and the electroweak sector of the Standard Model. + oai:arXiv.org:2512.07938v1 + hep-ph + hep-ex + physics.atom-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Mitrajyoti Ghosh, Yuval Grossman, Chinhsan Sieng, Bingrong Yu - Phase Space Modeling of Extended Sources Based on Wigner Distribution and Hamiltonian Optics - https://arxiv.org/abs/2512.07161 - arXiv:2512.07161v1 Announce Type: new -Abstract: Precise modeling of extended sources is a central challenge in modern optical engineering, laser physics, and computational lithography. Unlike ideal point sources or completely incoherent thermal radiation sources, real-world light sources -- such as high-power laser diode arrays, superluminescent diodes (SLD), extreme ultraviolet (EUV) lithography sources, and beams transmitted through atmospheric turbulence -- typically exhibit partial spatial coherence. - Traditional geometric optics based on ray tracing ignores diffraction and interference effects; while classical wave optics is accurate, the computational cost of handling four-dimensional correlation functions for partially coherent fields is enormous. To balance computational efficiency and physical accuracy, phase space optics provides a unified theoretical framework. By introducing the Wigner distribution function (WDF), we can map the light field into a joint space-time-spatial frequency domain $(\bm{r}, \bm{p})$. This description not only retains all the information of wave optics (including interference terms) but also naturally transitions to the ray description of Hamiltonian optics in the short-wavelength limit, governed by Liouville's theorem of phase space volume conservation. - This report aims to establish optimal modeling methods based on phase space and Hamiltonian optics for different types of extended sources such as partially coherent light, fully coherent light, and quasi-homogeneous light. The report will derive in detail the mathematical models for each source type and provide strict criteria for the applicability of geometric optics models using mathematical tools such as the Moyal expansion and generalized Fresnel number. - oai:arXiv.org:2512.07161v1 - physics.optics + Classical and quantum dynamics of a particle confined in a paraboloidal cavity + https://arxiv.org/abs/2512.08021 + arXiv:2512.08021v1 Announce Type: cross +Abstract: We present a classical and quantum analysis of a particle confined in a three-dimensional paraboloidal cavity formed by two confocal paraboloids. Classically, the system is integrable and presents three independent constants of motion, namely, the energy, the $z$-component of the angular momentum, and a third dynamical constant associated with the paraboloidal geometry, which can be derived from the separability of the Hamilton--Jacobi equation. We derive closed-form analytical expressions for the actions, which allow us to determine the two conditions to get periodic closed trajectories. We classify these trajectories through the indices $(s,t,\ell)$. The caustic paraboloids that bound the motion provide a complete geometric characterization of admissible trajectories. Quantum mechanically, separability of the Schr\"odinger equation in parabolic coordinates yields eigenmodes described by Whittaker functions. We determine the energy spectrum and identify degeneracies arising not only from azimuthal symmetry but also from specific cavity deformations. A direct correspondence between classical trajectories and quantum eigenstates reveals that probability densities concentrate in the classically allowed region with controlled penetration into forbidden zones. + oai:arXiv.org:2512.08021v1 + quant-ph math-ph math.MP - Tue, 09 Dec 2025 00:00:00 -0500 - new + physics.class-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Rongqi Shang, Donglin Ma + \'Angel E. Reyna-Cruz, Julio C. Guti\'errez-Vega - Shock trapping and inertial escape: Dust-particle clustering in compressible turbulence - https://arxiv.org/abs/2512.07164 - arXiv:2512.07164v1 Announce Type: new -Abstract: We study the dynamics and clustering of dust particles with inertia in shock-dominated compressible turbulence using the two-dimensional, stochastically forced Burgers equation. At small Stokes numbers, shock trapping leads to extreme density inhomogeneities and nearly singular aggregation, with correlation dimensions approaching zero. With increasing inertia, particles undergo inertial escape and intermittently cross shock fronts, producing a sharp crossover from shock-dominated trapping to quasi-ballistic dynamics. This crossover is accompanied by a pronounced reduction in density fluctuations, a continuous increase of the correlation dimension from zero to the embedding dimension, and a power-law dependence of density fluctuations on the Stokes number over an extended intermediate regime. In this regime, particle distributions show scale-free coarse-grained density statistics arising from repeated trap--escape dynamics. This behaviour is qualitatively distinct from inertial-particle clustering in incompressible turbulence and is directly relevant to dust concentration in shock-rich regions of protoplanetary discs and other compressible astrophysical environments. - oai:arXiv.org:2512.07164v1 - physics.flu-dyn - astro-ph.EP - astro-ph.GA - nlin.CD - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Anikat Kankaria, Samriddhi Sankar Ray + Observation of a Topological Berry Phase with a Single Phonon in an Ion Microtrap Array + https://arxiv.org/abs/2512.08037 + arXiv:2512.08037v1 Announce Type: cross +Abstract: Controlled quantum mechanical motion of trapped atomic ions can be used to simulate and explore collective quantum phenomena and to process quantum information. Groups of cold atomic ions in an externally applied trapping potential self-organize into "Coulomb crystals" due to their mutual electrostatic repulsion. The motion of the ions in these crystals is strongly coupled, and the eigenmodes of motion all involve multiple ions. While this enables studies of many-body physics, it limits the flexibility and tunability of the system as a quantum platform. Here, we demonstrate an array of trapped ions in individual trapping sites whose motional modes can be controllably coupled and decoupled by tuning the local applied confining potential for each ion. We show that a single motional quantum, or phonon, can be coherently shared among two or three ions confined at the vertices of an equilateral triangle 30 $\mu$m on a side. We can adiabatically tune the ion participation in the motional modes around a closed contour in configuration space, observing that the single-phonon wavefunction acquires a topological Berry phase if the contour encircles a conical intersection of motional eigenvalue surfaces. We observe this phase by single-phonon interference and study its breakdown as the motional mode tuning becomes non-adiabiatic. Our results show that precise, individual quantum control of ion motion in a two-dimensional array can provide unique access to quantum multi-body effects. + oai:arXiv.org:2512.08037v1 + quant-ph + physics.atom-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by/4.0/ + Justin F. Niedermeyer, Nathan K. Lysne, Katherine C. McCormick, Jonas Keller, Craig W. Hogle, Matthew G. Blain, Roman Schmied, Robert J\"ordens, Susanna L. Todaro, David J. Wineland, Andrew C. Wilson, Daniel H. Slichter, Dietrich Leibfried - Heterogeneous back-end-of-line integration of thin-film lithium niobate on active silicon photonics for single-chip optical transceivers - https://arxiv.org/abs/2512.07196 - arXiv:2512.07196v1 Announce Type: new -Abstract: The explosive growth of artificial intelligence, cloud computing, and large-scale machine learning is driving an urgent demand for short-reach optical interconnects featuring large bandwidth, low power consumption, high integration density, and low cost preferably adopting complementary metal-oxide-semiconductor (CMOS) processes. Heterogeneous integration of silicon photonics and thin-film lithium niobate (TFLN) combines the advantages of both platforms, and enables co-integration of high-performance modulators, photodetectors, and passive photonic components, offering an ideal route to meet these requirements. However, process incompatibilities have constrained the direct integration of TFLN with only passive silicon photonics. Here, we demonstrate the first heterogeneous back-end-of-line integration of TFLN with a full-functional and active silicon photonics platform via trench-based die-to-wafer bonding. This technology introduces TFLN after completing the full CMOS compatible processes for silicon photonics. Si/SiN passive components including low-loss fiber interfaces, 56-GHz Ge photodetectors, 100-GHz TFLN modulators, and multilayer metallization are integrated on a single silicon chip with efficient inter-layer and inter-material optical coupling. The integrated on-chip optical links exhibit greater than 60 GHz electrical-to-electrical bandwidth and support 128-GBaud OOK and 100-GBaud PAM4 transmission below forward error-correction thresholds, establishing a scalable platform for energy-efficient, high-capacity photonic systems. - oai:arXiv.org:2512.07196v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new + Emergent memory in cell-like active systems + https://arxiv.org/abs/2512.08058 + arXiv:2512.08058v1 Announce Type: cross +Abstract: Active systems across scales, ranging from molecular machines to human crowds, are usually modeled as assemblies of self-propelled particles driven by internally generated forces. However, these models often assume memoryless dynamics and no coupling of internal active forces to the environment. Here, guided by the example of living cells, which have recently been shown to display multi-timescale memory effects, we introduce a general theoretical framework that goes beyond this paradigm by incorporating internal state dynamics and environmental sensing into active particle models. We show that when the self-propulsion of an agent depends on internal variables with their own complex dynamics - modulated by local environmental cues - environmental memory spontaneously emerges and gives rise to new classes of behaviours. These include memory-induced responses, adaptable localization in complex landscapes, suppression of motility-induced phase separation, and enhanced jamming transitions. Our results demonstrate how minimal information processing capabilities, intrinsic to non-equilibrium agents with internal states like living cells, can profoundly influence both individual and collective behaviours. This framework bridges cell-scale activity and large-scale intelligent motion in cell assemblies, and opens the way to the quantitative analysis and design of systems ranging from synthetic colloids to biological collectives and robotic swarms. + oai:arXiv.org:2512.08058v1 + cond-mat.stat-mech + physics.bio-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Lingfeng Wu, Zhonghao Zhou, Weilong Ma, Haohua Wang, Ziliang Ruan, Changjian Guo, Shiqing Gao, Zhishan Huang, Lu Qi, Jie Liu, Jing Feng, Dapeng Liu, Kaixuan Chen, Liu Liu + Marc Besse, Rapha\"el Voituriez - Information-Thermodynamic Bounds on Planetary Biosphere Productivity and Their Observational Tests - https://arxiv.org/abs/2512.07199 - arXiv:2512.07199v1 Announce Type: new -Abstract: The productivity of a planetary biosphere is limited by how its free-energy budget is partitioned between maintaining a habitable environment, driving metabolism, and processing heritable information. We derive an upper bound on net primary productivity (NPP) from non-equilibrium thermodynamics and information theory, given a planet's usable free-energy flux and a few coarse-grained biological parameters. The bound subtracts an irreducible power cost of heritable information processing -- set by global template-copying rates, copying fidelity, alphabet size, and proofreading work -- from the planetary power budget before converting the remainder into biomass. This yields an ``information-productivity trade-off'': at fixed planetary power, higher copying rates, lower error rates, larger alphabets, or more intensive proofreading all lower the ceiling on biomass production. Using conservative parameter choices, we show that Earth lies well below this ceiling, whereas low-flux environments such as M-dwarf habitable zones and subsurface ocean worlds can be driven into an information-limited regime where only modest combinations of productivity and heritable complexity are attainable. We outline how future exoplanet observations of stellar irradiation, climate, atmospheric disequilibria, and temporal variability could be used to place physics-based upper limits on NPP and compare them with independent productivity estimates. - oai:arXiv.org:2512.07199v1 + Understanding the temperature response of biological systems: From empirical fits to mechanistic frameworks + https://arxiv.org/abs/2512.08074 + arXiv:2512.08074v1 Announce Type: cross +Abstract: Virtually every biological rate changes with temperature, but the mechanisms underlying these responses differ between different processes. Here, we bring together the main theoretical approaches used to describe temperature-rate relationships, ranging from empirical curve shapes to reaction-level kinetics and network-based dynamical frameworks. These models highlight how temperature influences not only the speed of elementary reactions, but also the behavior that emerges when many reactions interact through regulation, feedback, or stochastic transitions. By outlining the assumptions and implications of each perspective, we aim to clarify how different modeling strategies connect molecular processes to physiological temperature response curves and to point toward integrative frameworks that can better explain the diversity of biological thermal responses. + oai:arXiv.org:2512.08074v1 + q-bio.QM + cond-mat.soft + cond-mat.stat-mech + nlin.AO physics.bio-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Slava G. Turyshev + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by/4.0/ + Simen Jacobs, Julian Voits, Nikita Frolov, Ulrich S. Schwarz, Lendert Gelens - Unitary Coupled-Cluster based Self-Consistent Electron Propagator Theory for Electron-Detached and Electron-Attached States: A Quadratic Unitary Coupled-Cluster Singles and Doubles Method and Benchmark Calculations - https://arxiv.org/abs/2512.07207 - arXiv:2512.07207v1 Announce Type: new -Abstract: A unitary coupled-cluster (UCC)-based self-consistent electron propagator theory (EPT) is proposed for the description of electron-detached and electron-attached states. Two practical schemes, termed IP/EA-UCC3 and IP/EA-qUCCSD, are developed and implemented within the UCC singles and doubles (UCCSD) framework using the perturbative and commutator-based truncation strategy for the similarity-transformed Hamiltonian $\bar{H}$. The numerical performance of these UCC-based EPT methods is extensively evaluated against full configuration interaction (FCI) reference data and compared with established approaches, including IP/EA-ADC(3), IP/EA-ADC(4) and IP/EA-EOM-CCSD. Benchmark calculations demonstrate that IP-qUCCSD achieves the highest overall accuracy among Hermitian ionized-state methods for one-hole (1h)-dominated IPs of closed-shell systems, with a mean absolute deviation (MAD) of 0.19 eV and standard deviation (SD) of 0.13 eV. Remarkably, despite the absence of triple-excitation contributions, IP-qUCCSD outperforms the higher-order ADC(4) method. For one-particle (1p)-dominated EA calculations, all tested methods exhibit comparable accuracy. - oai:arXiv.org:2512.07207v1 - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yu Zhang, Junzi Liu + Predicting interstitial elements in Refractory Complex Concentrated Alloys + https://arxiv.org/abs/2512.08080 + arXiv:2512.08080v1 Announce Type: cross +Abstract: Refractory complex concentrated alloys, composed of multiple principal refractory elements, are promising candidates for high-temperature structural applications due to their exceptional thermal stability and high melting points. However, their mechanical performance is often compromised by interstitial impurities, particularly oxygen, nitrogen, and carbon, which segregate to grain boundaries and promote embrittlement. In this study, we investigate the solubility and thermodynamic behavior of oxygen interstitials in a model NbTiHfTa RCCA system. We synthesized NbTiHfTa alloys with varying oxygen contents via plasma arc melting and characterized their phase evolution and microstructure using XRD, SEM, and TEM. Complementary computational modeling was performed using machine-learning interatomic potentials integrated with Monte Carlo simulations to probe oxygen interactions at the atomic scale. Our results reveal a solubility limit for oxygen between 0.8 and 1.0 atomic percentage, beyond which HfO2 formation is energetically favorable. This combined experimental-computational framework provides a predictive approach for managing interstitial behavior in RCCAs, enabling improved alloy design strategies for enhanced mechanical performance. + oai:arXiv.org:2512.08080v1 + cond-mat.mtrl-sci + physics.atom-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by/4.0/ + Aomin Huang, Siya Zhu, Calvin Belcher, Ryker Rigsby, Diran Apelian, Raymundo Arr\'oyave, Enrique J. Lavernia - Dynamics of the velocity fluctuations in sedimenting suspensions of rigid fibres - https://arxiv.org/abs/2512.07258 - arXiv:2512.07258v1 Announce Type: new -Abstract: We use direct numerical simulations to investigate fluid-solid interactions in suspensions of rigid fibres settling under gravity in a quiescent fluid. The solid-to-fluid density ratio is $\mathcal{O}(100)$, while the Galileo number ($Ga$) and fibre concentration ($n\ell_f^3$) are varied over the ranges $Ga \in [180, 900]$ and $n\ell_f^3 \in [0.36, 23.15]$; $\ell_f$ denotes the fibre length and $n$ the number density. At high $Ga$ and/or low $n\ell_f^3$, fibres cluster into gravity-aligned streamers with elevated concentrations and enhanced settling velocities, disrupting the flow homogeneity. As $Ga$ increases and/or $n\ell_f^3$ decreases, the fluid-phase kinetic energy rises and the energy spectrum broadens, reflecting enhanced small-scale activity. The flow anisotropy is assessed by decomposing the energy spectrum into components aligned with and transverse to gravity. Vertical fluctuations are primarily driven by fluid-solid interactions, while transverse ones are maintained by pressure-strain effects that promote isotropy. With increasing $Ga$, nonlinear interactions become more prominent, producing a net forward energy cascade toward smaller scales, punctuated by localised backscatter events. Analysis of the local velocity gradient tensor reveals distinct flow topologies: at low $Ga$, the flow is dominated by axisymmetric compression and two-dimensional straining; at high $Ga$, regions of high fibre concentration are governed by two-dimensional strain, while voids are associated with axisymmetric extension. The fluid motion is predominantly extensional rather than rotational. - oai:arXiv.org:2512.07258v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Alessandro Chiarini, Emanuele Gallorini, Marco Edoardo Rosti + Moire-Engineered Ferroelectric Transistors for Nearly Trap-free, Low-Power and Non-Volatile 2D Electronics + https://arxiv.org/abs/2512.08086 + arXiv:2512.08086v1 Announce Type: cross +Abstract: Long-range moire patterns in twisted WSe2 enable a built-in, moire-length-scale ferroelectric polarization that can be directly harnessed in electronic devices. Such a built-in ferroic landscape offers a compelling means to enable ultralow-voltage and non-volatile electronic functionality in two-dimensional materials; however, achieving stable polarization control without charge trapping has remained a persistent challenge. Here, we demonstrate a moire-engineered ferroelectric field-effect transistor (FeFET) utilizing twisted WSe2 bilayers that leverages atomically clean van der Waals interfaces to achieve efficient polarization-channel coupling and trap-suppressed, ultralow-voltage operation (subthreshold swing of 64 mV per decade). The device exhibits a stable non-volatile memory window of 0.10 V and high mobility, exceeding the performance of previously reported two-dimensional FeFET and matching that of advanced silicon-based devices. In addition, capacitance-voltage spectroscopy, corroborated by self-consistent Landau-Ginzburg-Devonshire modeling, indicates ultrafast ferroelectric switching (~0.5 microseconds). These results establish moire-engineered ferroelectricity as a practical and scalable route toward ultraclean, low-power, and non-volatile 2D electronics, bridging atomistic lattice engineering with functional device architectures for next-generation memory and logic technologies. + oai:arXiv.org:2512.08086v1 + cond-mat.mtrl-sci + cond-mat.mes-hall + cond-mat.str-el + physics.app-ph + quant-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by/4.0/ + Arup Singha, Shaili Sett, Kenji Watanabe, Takashi Taniguchi, Arindam Ghosh, Rahul Debnath - Preliminary Study of the Effects of Leading-Edge Serration on a Two-Section Planar Wing in ground-effect at Low Reynolds Number - https://arxiv.org/abs/2512.07270 - arXiv:2512.07270v1 Announce Type: new -Abstract: A preliminary study has been conducted on the effects of serration on the leading-edge of a two-element trapezoidal wing placed both out-of- and in-ground effect. Aerodynamic performance and flow behaviour were evaluated numerically and validated experimentally. Results indicate an increase in maximum lift coefficient and stall angle obtained implementing a serrated leading-edge geometry due to the flow being re-energized by the formation of a series of counter-rotating pairs of vortices. - Results from the analysis of the wing in ground effect appear less well defined. Both leading-edge geometries -- straight and serrated -- show an increase in efficiency due to the proximity to the ground. The wing with the straight leading-edge geometry shows constant improvement up to stall, whilst numerical results show a significant decrease in lift performance at high angles of attack. This may be caused by the lower-fidelity numerical model implemented at higher angles of attack, thus yielding less accurate results. - oai:arXiv.org:2512.07270v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Arnold Lafond-Saunierr, Simone Basile, Paloma Pizarro, Kiana Yamamoto, Hassan M. Nagib, Ricardo Vinuesa, Raffaello Mariani + Enhancing Hole Mobility in Monolayer $WSe_{2}$ p-FETs via Process-Induced Compression + https://arxiv.org/abs/2512.08148 + arXiv:2512.08148v1 Announce Type: cross +Abstract: Understanding the interactions between strain, interfacial mechanics, and electrical performance is critical for designing beyond silicon electronics based on hetero-integrated 2D materials. Through combined experiment and simulation, we demonstrated and analyzed the enhancement of hole mobility in p-type monolayer $WSe_{2}$ field effect transistors (FETs) under biaxial compression. We tracked FET performance versus strain by incrementing compressive strain to $WSe_{2}$ channels via sequential AlOx deposition and performing intermediate photoluminescence and transport measurements. The hole mobility factor increased at a rate of 340 $\pm$ 95 %/%$\epsilon$, and the on-current factor increased at a rate of 460 $\pm$ 340 %/%$\epsilon$. Simulation revealed that the enhancement under compression arises primarily from a reduction in inter-valley scattering between the $\Gamma$--K valence bands, and the rate is robust against variations in carrier density, impurity density, or dielectric environment. These findings show that compressive strain is a powerful technique for enhancing performance in 2D p-FETs and that it is multiplicative with defect and doping engineering. + oai:arXiv.org:2512.08148v1 + cond-mat.mtrl-sci + physics.app-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by-nc-sa/4.0/ + He Lin Zhao, Sheikh Mohd Ta-Seen Afrid, Dongyoung Yoon, Zachary Martin, Zakaria Islam, Sihan Chen, Yue Zhang, Pinshane Y. Huang, Shaloo Rakheja, Arend M. van der Zande - Modified vacuum polarization in the presence of a plasma - https://arxiv.org/abs/2512.07283 - arXiv:2512.07283v1 Announce Type: new -Abstract: We study vacuum polarization due to strong fields, in the presence of an electron-positron plasma. For this purpose, we expand quantum kinetic equations using weak fields and slow temporal scales as expansion parameters. It is demonstrated that the evolution of the Dirac field can be described by classical-like distribution functions for electrons and positrons, which are weakly coupled through quantum interactions. Furthermore, we deduce that these coupling terms give rise to well-known expressions for vacuum polarization, in addition to quantum modifications proportional to the content of real particles. Depending on the initial plasma density, the dominant quantum corrections to classical evolution may arise from real particle couplings or from the vacuum polarization associated with virtual particles. The implications of our results are discussed. - oai:arXiv.org:2512.07283v1 - physics.plasm-ph - hep-ph - hep-th - Tue, 09 Dec 2025 00:00:00 -0500 - new + A Transcorrelated Wave-Function Framework for Solids: An Application to Bulk and Defected Silicon + https://arxiv.org/abs/2512.08276 + arXiv:2512.08276v1 Announce Type: cross +Abstract: Accurate wave-function descriptions of pristine and defected solids remain challenging due to the simultaneous presence of finite-size, basis-set, and correlation errors. While embedding techniques alleviate finite-size effects and correlated wave-function approaches systematically improve correlation, basis-set incompleteness continues to limit practical accuracy. Here we present a study of transcorrelated (TC) many-body wave-function methods on properties of solid state systems. We augment the existing xTC theory to periodic systems, and establish an unified transcorrelated embedding framework that integrates periodic TC theory with fragment-based correlated solvers. Using silicon as a test case, we validate the method against coupled-cluster, FCIQMC, and diffusion Monte Carlo benchmarks for bulk. Then we apply TC embedding to calculation of formation energies of two silicon self-interstitials. The TC Hamiltonian yields rapid basis convergence and quantitatively reliable defect formation energies at the triple-$\zeta$ level, substantially reducing the basis-set bottleneck for wave-function treatments of crystalline defects. + oai:arXiv.org:2512.08276v1 + cond-mat.mtrl-sci + physics.comp-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Sebastian Lundstr\"om, Philip Semr\'en, Haidar Al-Naseri, Gert Brodin + Kristoffer Simula, Johannes Hauskrecht, Evelin Martine Corvid Christlmaier, Pablo Lopez-Rios, Daniel Kats, Denis Usvyat, Ali Alavi - Bound and Resonant States of Muonic Few-Body Coulomb Systems: Extended Stochastic Variational Approach - https://arxiv.org/abs/2512.07323 - arXiv:2512.07323v1 Announce Type: new -Abstract: We compute the bound and resonant states of hydrogen-like muonic ions ($\mu\mu p$, $\mu\mu d$, $\mu\mu t$) and three-body muonic molecular ions ($pp\mu$, $pd\mu$, $pt\mu$, $dd\mu$, $dt\mu$, $tt\mu$), and the four-body double-muonic hydrogen molecule ($\mu\mu pp$) using an extended stochastic variational method combined with complex scaling. The approach provides a unified treatment of bound and quasibound states and achieves an energy accuracy better than $0.1~\mathrm{eV}$ across all systems studied. Complete spectra below the corresponding $n=2$ atomic thresholds are obtained, including several previously unresolved shallow resonances in both three- and four-body sectors. - oai:arXiv.org:2512.07323v1 - physics.atom-ph - hep-ex - hep-ph - nucl-ex - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Liang-Zhen Wen, Shi-Lin Zhu - - - Coherent Field Emission Upon Ultrafast Laser Irradiation of the Tip Plasmon - https://arxiv.org/abs/2512.07324 - arXiv:2512.07324v1 Announce Type: new -Abstract: Irradiation of sharp silver tips with femtosecond laser pulses leads to photoassisted coherent field emission without a static field. We reconstruct the time profile of the emission, and show that the process is entirely governed by the collective response of the tip plasmon and its field emission. Weak-field optical excitation leads to multiphoton absorption and field emission from the tip apex due to the enhanced local field. The attendant sharp field gradient ensures ponderomotive acceleration of emitted electrons and non-local light-matter interaction. The crossover regime in which simultaneous multiphoton absorption and optical field emission take place is evidenced by the time profile of electron emission correlation, laser power dependence, and polarization angle dependence of each harmonic current. - oai:arXiv.org:2512.07324v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Joonhee Lee, Shawn M. Perdue, Alejandro Rodriguez Perez, V. Ara Apkarian - - - Realizing on-demand all-to-all selective interactions between distant spin ensembles - https://arxiv.org/abs/2512.07326 - arXiv:2512.07326v1 Announce Type: new -Abstract: Achieving all-to-all coherent networks is critical for the advancement of large-scale coherent computing and communication protocols. By exploiting the resonant dipole-dipole interaction between distant spin ensembles coupled to a one-dimensional coplanar waveguide (CPW) terminated by a mirror, we successfully demonstrate an on-demand all-to-all selective coherent network between four spin ensembles. Furthermore, by repositioning the spin ensembles along the CPW, we achieve collective coupling, and demonstrate coherent energy exchange between multiple spin ensembles in the time domain. These results strongly indicate the potential of this device as a medium-scale all-to-all network structure, which is poised to advance the exploration of many-body physics and enhance coherent information processing capabilities. - oai:arXiv.org:2512.07326v1 - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - C. -X. Run, K. -T. Lin, K. -M. Hsieh, B. -Y. Wu, W. -M. Zhou, G. -D. Lin, A. F. Kockum, I. -C. Hoi - - - Two-dimensional RMSD projections for reaction path visualization and validation - https://arxiv.org/abs/2512.07329 - arXiv:2512.07329v1 Announce Type: new -Abstract: Transition state or minimum energy path finding methods constitute a routine component of the computational chemistry toolkit. Standard analysis involves trajectories conventionally plotted in terms of the relative energy to the initial state against a cumulative displacement variable, or the image number. These dimensional reductions obscure structural rearrangements in high dimensions and may often be trajectory dependent. This precludes the ability to compare optimization trajectories of different methods beyond the number of calculations, time taken, and final saddle geometry. We present a method mapping trajectories onto a two-dimension surface defined by a permutation corrected root mean square deviation from the reactant and product configurations. Energy is represented as an interpolated color-mapped surface constructed from all optimization steps using radial basis functions. This representation highlights optimization trajectories, identifies endpoint basins, and diagnoses convergence concerns invisible in one-dimensional profiles. We validate the framework on a cycloaddition reaction, showing that a machine-learned potential saddle and density functional theory reference lie on comparable energy contours despite geometric displacements. - oai:arXiv.org:2512.07329v1 - physics.chem-ph - cond-mat.mtrl-sci - cs.LG - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Rohit Goswami (Institute IMX and Lab-COSMO, \'Ecole polytechnique f\'ed\'erale de Lausanne) - - - Three-Octave Supercontinuum Generation in Thick Crystalline Aluminum Nitride Waveguides - https://arxiv.org/abs/2512.07334 - arXiv:2512.07334v1 Announce Type: new -Abstract: We report an efficient extension of supercontinuum generation through dispersion engineering of crystalline aluminum nitride (AlN)-on-sapphire waveguides. Using a tailored epitaxial regrowth of AlN epilayers and an optimized fabrication protocol, the dispersion sensitivity to the waveguide cross-section was enhanced allowing for a significant reach extension of both short and long dispersive wave with optimized pumping conditions, reaching down to 550 nm in the visible and up to 4.5 {\mu}m in the mid-infrared. - oai:arXiv.org:2512.07334v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - 10.1364/OL.577343 - Opt. Lett. 50, 7147-7150 (2025) - Samantha Sbarra, Samuele Brunetta, Pierre Arnaud Demongodin, Jean-Fran\c{c}ois Carlin, Nicolas Grandjean, Rapha\"el Butt\'e, Camille-Sophie Br\`es - - - Optical clocks with accuracy validated at the 19th digit - https://arxiv.org/abs/2512.07346 - arXiv:2512.07346v1 Announce Type: new -Abstract: We report a comprehensive evaluation of all known sources of systematic uncertainty for two independent $^{176}$Lu$^+$ single-ion optical references, finding total systematic uncertainty of $1.1\times10^{-19}$ and $1.4\times10^{-19}$ for the two individual systems and $9.6\times10^{-20}$ for the difference. Through direct comparison via correlation spectroscopy, we demonstrate a relative frequency agreement of $-2.4\pm(5.7)_\mathrm{stat}\pm(1.0)_\mathrm{sys}\times10^{-19}$, where `stat' and `sys' indicate the statistical and systematic uncertainty, respectively. The comparison uncertainty is statistically limited after approximately 200 hours of averaging with a measurement instability of $4.8\times10^{-16}(\tau/\mathrm{s})^{-1/2}$. - oai:arXiv.org:2512.07346v1 - physics.atom-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - K. J. Arnold, M. D. K. Lee, Zhao Qi, Qichen Qin, Zhang Zhao, N. Jayjong, M. D. Barrett - - - A Tri-Band Shared-Aperture Base Station Antenna Array Covering 5G Mid-Band and 6G Centimetric Wave Band - https://arxiv.org/abs/2512.07392 - arXiv:2512.07392v1 Announce Type: new -Abstract: This work proposes a tri-band shared-aperture antenna array with three wide bands, covering the 5G mid-band and the 6G centimetric band, which is a promising candidate for future 6G base station antennas. The challenge of suppressing interferences, including scattering and coupling, in the tri-band array is holistically addressed across wide bands. Guided by characteristic mode analysis (CMA), a segmented spiral radiator is efficiently developed to mitigate scattering and coupling at high frequencies while preserving radiation performance at low frequencies. Compared to a conventional tube radiator, the proposed spiral exhibits a reduced radar cross-section (RCS) over an ultra-wide range of 4.7-21.5 GHz (128.2%). With the aid of serial resonators, impedance matching of the segmented-spiral-based dipole antenna is achieved across the low band (LB) of 3.05-4.68 GHz (42.2%), spanning the 5G band 3.3-4.2 GHz. Moreover, suppressors are placed near the LB ports to further reduce the cross-band coupling. Middle band (MB) and high band (HB) antennas operate in 6.2-10.0 GHz (46.9%) and 10.0-15.6 GHz (43.8%), respectively, collectively covering the anticipated 5G-Advanced and 6G centimetric band of 6.425-15.35 GHz. Both the MB and HB antennas employ a planar magnetoelectric (ME) dipole structure, which prevents common-mode resonances in the LB and MB, and mitigates the scattering from the MB antenna in the HB. In this tri-band array, radiation patterns remain undistorted across the LB, MB, and HB, and the isolation between any two ports exceeds 20 dB over all three bands. - oai:arXiv.org:2512.07392v1 - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Shang-Yi Sun, Hai-Han Sun, Can Ding, Y. Jay Guo - - - Memory effects in wave-induced microplastic transport - https://arxiv.org/abs/2512.07402 - arXiv:2512.07402v1 Announce Type: new -Abstract: Microplastics are transported by ocean surface waves in ways that depart significantly from the Stokes drift of fluid parcels, and accurate modeling of this transport requires accounting for forces beyond linear drag. Existing modeling of microplastic transport often neglect the Basset-Boussinesq history force, effectively limiting their use to the smallest particle sizes. Here, we extend the applicability of these models by implementing the history term with a multistep integration scheme, allowing us to capture the transport of larger microplastics in linear surface waves of arbitrary depth. We quantify when the Basset-Boussinesq history force significantly affects microplastic transport by surface gravity waves. We show that memory effects become the leading-order horizontal drag once $S=St/\gamma^2$ exceeds a critical value $S\approx 0.25$, where $St$ is the Stokes number and $\gamma$ is the density ratio of the particle and the fluid. The corresponding critical $St$ number is found to be a factor of about three smaller than that given by classical inertial estimates that neglect history effects. These results help provide regime maps that can be used to indicate when history effects can be safely neglected. Our simulations also reveal that history effects significantly increase horizontal transport distances and enhance orbit shearing of particle ensembles. - oai:arXiv.org:2512.07402v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Mary Eby, Cathal Cummins - - - Determinations of angular stiffness in rotational optical tweezers - https://arxiv.org/abs/2512.07414 - arXiv:2512.07414v1 Announce Type: new -Abstract: Rotational optical tweezers are used to probe the mechanical properties of unknown microsystems. Quantifying the angular trap stiffness is essential for interpreting the rotational dynamics of probe particles. While methods for trap stiffness calibration are well established for translational degrees of freedom, angular trapping has been largely overlooked and is often assumed to behave analogously to translational dynamics. However, rotational and translational motions are sensitive to distinct experimental parameters and offer separate insights. This work covers passive analysis techniques for calibrating the angular trap stiffness and examines the influence of several factors unique to rotational optical tweezers. We show that the parameters of an ancillary measurement beam can be tuned to minimise its influence on angular trapping dynamics, while offering unprecedented improvements for nanoparticle analysis. We also explore the combined effects of shape-induced and material birefringence in spheroidal vaterite probes, and present a framework for assessing hydrodynamic and inertial contributions. These results provide a foundation for characterising rotational optical tweezers independent from translational models. - oai:arXiv.org:2512.07414v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Mark L. Watson, Alexander B. Stilgoe, Halina Rubinsztein-Dunlop - - - Floquet states on disclinations - https://arxiv.org/abs/2512.07422 - arXiv:2512.07422v1 Announce Type: new -Abstract: We show that periodic longitudinal modulation of waveguide arrays with disclination can result in the appearance of previously unexplored Floquet modes bound to the disclination core. Such modes arise due to oscillations of the waveguides in the array, periodically switching the structure between topological and trivial phases on each modulation period, so that on average it seems trivial. Localization of such modes depends on the amplitude of waveguide oscillations. Depending on the discrete rotational symmetry of the arrays with disclinations, these modes exhibit distinct spatial profiles unattainable in periodic lattices. Propagation in a medium with focusing cubic nonlinearity reveals that these Floquet states remain localized below a critical power threshold, indicating the possibility of the formation of disclination-bound Floquet solitons. Our results unveil a new regime of localization in photonic systems, bridging disclination topology, Floquet engineering, and nonlinearity. - oai:arXiv.org:2512.07422v1 - physics.optics - nlin.PS - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Chaos, Solitons and Fractals (2025) - K. Sabour, S. K. Ivanov, A. Ferrando, Y. V. Kartashov - - - Microseismic event classification with a lightweight Fourier Neural Operator model - https://arxiv.org/abs/2512.07425 - arXiv:2512.07425v1 Announce Type: new -Abstract: Real-time monitoring of induced seismicity is crucial for mitigating operational hazards, relying on the rapid and accurate classification of microseismic events from continuous data streams. However, while many deep learning models excel at this task, their high computational requirements often limit their practical application in real-time monitoring systems. To address this limitation, a lightweight model based on the Fourier Neural Operator (FNO) is proposed for microseismic event classification, leveraging its inherent resolution-invariance and computational efficiency for waveform processing. In the STanford EArthquake Dataset (STEAD), a global and large-scale database of seismic waveforms, the FNO-based model demonstrates high effectiveness for trigger classification, with an F1 score of 95% even in the scenario of data sparsity in training. The new FNO model greatly decreases the computer power needed relative to current deep learning models without sacrificing the classification success rate measured by the F1 score. A test on a real microseismic dataset shows a classification success rate with an F1 score of 98%, outperforming many traditional deep-learning techniques. A combination of high success rate and low computational power indicates that the FNO model can serve as a methodology of choice for real-time monitoring of microseismicity for induced seismicity. The method saves computational resources and facilitates both post-processing and real-time seismic processing suitable for the implementation of traffic light systems to prevent undesired induced seismicity. - oai:arXiv.org:2512.07425v1 - physics.geo-ph - cs.LG - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Ayrat Abdullin, Umair bin Waheed, Leo Eisner, Abdullatif Al-Shuhail - - - Efficient mapping and tracking the properties of micromechanical resonators using phase-lock loops with closely-spaced frequencies - https://arxiv.org/abs/2512.07427 - arXiv:2512.07427v1 Announce Type: new -Abstract: Studying the dynamical behavior of micro- and nano-mechanical systems (MEMS and NEMS) is essential in various fields from nonlinear dynamics to quantum technologies. Hence, it is important to be able to precisely monitor the mechanical properties of MEMS and NEMS devices. In this work, we show how to track and spatially map various properties of a mechanical resonator, such as frequency shift, linewidth, and nonlinearity, by aptly choosing three closely-spaced drive frequencies and using phase-locked loops. This technique tracks changes in the system faster and more efficiently, without the need for repeated frequency sweeps of the oscillator response, simply by employing three phase-locked tones. - oai:arXiv.org:2512.07427v1 - physics.optics - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Agnes Zinth, Samer Houri, Menno Poot - - - Wedge Design - https://arxiv.org/abs/2512.07444 - arXiv:2512.07444v1 Announce Type: new -Abstract: The space in front of a projector or camera can be folded into a light-guide by total-internal reflection if the guide is tapered like a wedge. This article explains how to calculate both flat and curved wedges by scaling a thin version designed using the principle that the product of thickness and the sin of ray angle is constant in a smoothly varying guide. - oai:arXiv.org:2512.07444v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Adrian Travis - - - Social welfare optimisation in well-mixed and structured populations - https://arxiv.org/abs/2512.07453 - arXiv:2512.07453v1 Announce Type: new -Abstract: Research on promoting cooperation among autonomous, self-regarding agents has often focused on the bi-objective optimisation problem: minimising the total incentive cost while maximising the frequency of cooperation. However, the optimal value of social welfare under such constraints remains largely unexplored. In this work, we hypothesise that achieving maximal social welfare is not guaranteed at the minimal incentive cost required to drive agents to a desired cooperative state. To address this gap, we adopt to a single-objective approach focused on maximising social welfare, building upon foundational evolutionary game theory models that examined cost efficiency in finite populations, in both well-mixed and structured population settings. Our analytical model and agent-based simulations show how different interference strategies, including rewarding local versus global behavioural patterns, affect social welfare and dynamics of cooperation. Our results reveal a significant gap in the per-individual incentive cost between optimising for pure cost efficiency or cooperation frequency and optimising for maximal social welfare. Overall, our findings indicate that incentive design, policy, and benchmarking in multi-agent systems and human societies should prioritise welfare-centric objectives over proxy targets of cost or cooperation frequency. - oai:arXiv.org:2512.07453v1 - physics.soc-ph - cs.AI - cs.MA - math.OC - nlin.AO - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Van An Nguyen, Vuong Khang Huynh, Ho Nam Duong, Huu Loi Bui, Hai Anh Ha, Quang Dung Le, Le Quoc Dung Ngo, Tan Dat Nguyen, Ngoc Ngu Nguyen, Hoai Thuong Nguyen, Zhao Song, Le Hong Trang, The Anh Han - - - Optimized Machine Learning Methods for Studying the Thermodynamic Behavior of Complex Spin Systems - https://arxiv.org/abs/2512.07458 - arXiv:2512.07458v1 Announce Type: new -Abstract: This paper presents a systematic study of the application of convolutional neural networks (CNNs) as an efficient and versatile tool for the analysis of critical and low-temperature phase states in spin system models. The problem of calculating the dependence of the average energy on the spatial distribution of exchange integrals for the Edwards-Anderson model on a square lattice with frustrated interactions is considered. We further construct a single convolutional classifier of phase states of the ferromagnetic Ising model on square, triangular, honeycomb, and kagome lattices, trained on configurations generated by the Swendsen-Wang cluster algorithm. Computed temperature profiles of the averaged posterior probability of the high-temperature phase form clear S-shaped curves that intersect in the vicinity of the theoretical critical temperatures and allow one to determine the critical temperature for the kagome lattice without additional retraining. It is shown that convolutional models substantially reduce the root-mean-square error (RMSE) compared with fully connected architectures and efficiently capture complex correlations between thermodynamic characteristics and the structure of magnetic correlated systems. - oai:arXiv.org:2512.07458v1 - physics.comp-ph - cond-mat.dis-nn - cs.LG - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Dmitrii Kapitan, Pavel Ovchinnikov, Konstantin Soldatov, Petr Andriushchenko, Vitalii Kapitan - - - Anomalous Wave-Packet Dynamics in One-Dimensional Non-Hermitian Lattices - https://arxiv.org/abs/2512.07484 - arXiv:2512.07484v1 Announce Type: new -Abstract: Non-Hermitian (NH) systems have attracted great attention due to their exotic phenomena beyond Hermitian domains. Here we study the wave-packet dynamics in general one-dimensional NH lattices and uncover several unexpected phenomena. The group velocity of a wave packet during the time evolution in such NH lattices is not only governed by the real part of the band structure but also by its imaginary part. The momentum also evolves due to the imaginary part of the band structure, which can lead to a self-induced Bloch oscillation in the absence of external fields. Furthermore, we discover the wave-packet dynamics can exhibit disorder-free NH jumps even when the energy spectra are entirely real. Finally, we show that the NH jumps can lead to both positive and negative temporal Goos--H\"{a}nchen shifts at the edge. - oai:arXiv.org:2512.07484v1 - physics.optics - cond-mat.dis-nn - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yanyan He, Tomoki Ozawa - - - Merging exceptional point and quasi-bound state in the continuum in nanophotonic cavities - https://arxiv.org/abs/2512.07494 - arXiv:2512.07494v1 Announce Type: new -Abstract: In conventional eigenvalue analyses of non-Hermitian systems, the coupling of two modes does not lead to the coexistence of an exceptional point (EP) and a quasi-bound state in the continuum (QBIC) at the same spectral position. Here, we theoretically demonstrate that introducing an excitation-phase degree of freedom enables the merging of an EP and a QBIC (or even a BIC) in nanophotonic cavities. Using coupled mode theory, we reveal the underlying mechanism of this phenomenon and further validate it via numerical simulations on practical stacked structures. In the EP-QBIC regime, the mode quality (Q) factor can be enhanced by over one order of magnitude. Moreover, we systematically investigate the formation conditions for EP-QBIC states and conventional QBICs. Additionally, introducing an excitation-phase degree of freedom in a pure plasmonic structure allows the Q factor to increase by over 15 times due to QBIC formation-even breaking through the limit imposed by material loss. - oai:arXiv.org:2512.07494v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Xiao-Jing Du, Xi-Hua Guan, Yue You, Lin Ma, Jun He, Zhong-Jian Yang - - - The use of a simple digital weather station (not only) in teaching physics - https://arxiv.org/abs/2512.07513 - arXiv:2512.07513v1 Announce Type: new -Abstract: One of key goals of contemporary physics (and, realistically, STEM) education is to develop students' science literacy and critical thinking skills. In this paper, we present the construction and use of several versions of a simple school-based digital weather station that students can use to measure fundamental physical quantities (temperature, pressure, air humidity, light intensity) as part of school activities. The weather stations were constructed at our workplace using an Arduino microcontroller, BBC micro: bit, and the school measurement system Coach. This paper proposes not only the design and related programming of the weather stations but also how students can collect, analyse, and interpret measured data, thereby learning scientific methods and developing science literacy and critical thinking. This hands-on approach also develops students' experimental skills, emphasizes the cross-curricular relationships between physics, computer science and geography, and teaches them to work with accurate data in the context of real environmental problems. - oai:arXiv.org:2512.07513v1 - physics.ed-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by-nc-nd/4.0/ - 10.1088/1742-6596/3155/1/012015 - Martin Hru\v{s}ka, Martin Plesch - - - An effective bath state approach to model infrared spectroscopy and intramolecular dynamics in complex molecules - https://arxiv.org/abs/2512.07517 - arXiv:2512.07517v1 Announce Type: new -Abstract: When a molecule contains more than a few atoms, its full-dimensional dynamics becomes untractable, especially when introducing temperature effects. In such a case, it can be interesting to focus only on a few degrees of freedom and to model the rest of the molecule as a finite-dimensional bath. In this prospect, we extend the effective bath state (EBS) method that we had first developed and benchmarked in [J. Chem. Phys. \textbf{160}, 044107 (2024)] to describe the spectroscopy and intramolecular dynamics of complex isolated molecules. The EBS method is a system-bath approach based on the coarse-graining of the bath into a reduced set of effective energy states. It allows for a significant reduction of the bath dimension and makes finite-temperature calculations more accessible. In order to treat a realistic molecule, the method is extended to include polynomial couplings in the bath coordinates. The ability of the method to model temperature-resolved infrared spectra and to follow population transfers between the vibrational modes of the molecule is first tested on a 10-mode model system. The extended method is then applied to the realistic case of phenylacetylene. - oai:arXiv.org:2512.07517v1 - physics.chem-ph - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Lo\"ise Attal, Cyril Falvo, Pascal Parneix - - - Self-Error Correcting Method for Magnetic-Array-Type Current Sensors in Multi-Core Cable Applications - https://arxiv.org/abs/2512.07521 - arXiv:2512.07521v1 Announce Type: new -Abstract: Data-driven methods enable online assessment of error states in magnetic-array-type current sensors, and long-term measurement stability can be enhanced through further self-error correction. However, when the magnetic-array-type current sensors are applied to multi-conductor systems such as multi-core cables, the time-varying correlations among conductor currents may degrade the performance of multi-latent-variable data-driven models for error evaluation. To address this issue, this paper proposes a robust self-error correcting method for magnetic-array-type current sensors even under significant variations in phase current correlations (e.g., large fluctuations in three-phase current imbalance). By incorporating phase current decoupling and principal component analysis (PCA), the correlation analysis of multi-latent variables (i.e., multi-conductor currents) is transformed into a single-latent-variable (corresponding to single phase current) modeling problem. Experimental results demonstrate that the proposed method effectively detects error drifts of magnetic field sensors as low as $2\times10^{-3}$ in relative error and $2\times10^{-3}$ rad in phase error. Accurate evaluation and correction of each magnetic field sensor's error drifts substantially eliminates the overall error drift in the magnetic-array-type current sensor, validating the feasibility and effectiveness of the proposed self-error correcting method. - oai:arXiv.org:2512.07521v1 - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Xiaohu Liu, Keyu Hou, Kang Ma, Jian Liu, Angang Zheng, Zhengwei Qu, Wei Zhao, Lisha Peng, Songling Huang, Shisong Li - - - Modular Construction of Jastrow Factors for the Transcorrelated Method - https://arxiv.org/abs/2512.07530 - arXiv:2512.07530v1 Announce Type: new -Abstract: In this work, we explore the reuse of terms in the Jastrow factor between systems for use in the transcorrelated method, to reduce the number of optimisable parameters for a given system. In particular, we propose a workflow in which atom-specific parts of Jastrow factors, optimised in atoms, may be reused in the molecule, with only a few parameters in the electron-electron part of the Jastrow left to optimise, while maintaining performance. We find that the modified workflow not only reduces the number of terms needing to be optimised, but also improves the accuracy of xTC-CCSD(T) energies. - oai:arXiv.org:2512.07530v1 - physics.chem-ph - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - J. Philip Haupt, Maria-Andreea Filip, Evelin Martine Corvid Christlmaier, Yifan Cheng, Johannes Hauskrecht, Ali Alavi - - - Site-controlled quantum dot arrays edge-coupled to integrated silicon nitride waveguides and devices - https://arxiv.org/abs/2512.07535 - arXiv:2512.07535v1 Announce Type: new -Abstract: The scalability of quantum photonic integrated circuits opens the path towards large-scale quantum computing and communication. To date, this scalability has been limited by the stochastic nature of the quantum light sources. Moreover, hybrid integration of different platforms will likely be necessary to combine state-of-the-art devices into a functioning architecture. Here, we demonstrate the active alignment and edge-coupling of arrays of ten site-controlled gallium arsenide quantum dots to an array of ten silicon nitride single-mode waveguides, at cryogenic temperatures. The coupling is facilitated by the fabrication of nanopillars, deterministically self-aligned around each quantum dot, leading to a high-yield and regular array of single-photon sources. An on-chip beamsplitter verifies the triggered emission of single photons into the silicon nitride chip. The low inhomogeneous broadening of the ensemble enables us to observe the spectral overlap of adjacent site-controlled emitters. Across the array of waveguides, the signal collected from each coupled quantum dot is consistently and reproducibly 0.17 relative to the free-space collection from the very same single-photon source. Comparing measurement with waveguide simulations, we infer that absolute coupling efficiencies of $\approx 5 \%$ are currently obtained between our quantum dots and the waveguides. - oai:arXiv.org:2512.07535v1 - physics.optics - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - John O'Hara, Nicola Maraviglia, Mack Johnson, Jesper H{\aa}kansson, Salvador Medina, Gediminas Juska, Luca Colavecchi, Frank H. Peters, Brian Corbett, Emanuele Pelucchi - - - XMCQDPT2-Fidelity Transfer-Learning Potentials and a Wavepacket Oscillation Model with Power-Law Decay for Ultrafast Photodynamics - https://arxiv.org/abs/2512.07537 - arXiv:2512.07537v1 Announce Type: new -Abstract: A central pursuit in theoretical chemistry is the accurate simulation of photochemical reactions, which are governed by nonadiabatic transitions through conical intersections. Machine learning has emerged as a transformative tool for constructing the necessary potential energy surfaces, but applying it to excited states faces a fundamental barrier: the cost of generating high-level quantum chemistry data. We overcome this challenge by developing machine-learning interatomic potentials (MLIPs) that achieve multi-state multi-reference perturbation theory accuracy through various techniques, such as transfer, multi-state, and $\Delta$-learning. Applied to the methaniminium cation, our highest-fidelity transfer-learning model uncovers its complete photodissociation landscape following S$_2$ photoexcitation. The comprehensive XMCQDPT2/SA(3)-CASSCF(12,12) electronic structure description captures all competing decay channels, including S$_1$ branching into photoisomerization and direct H$_2$-loss pathways. Our results show that the population dynamics generally depends on the MLIP model, correlating with its performance. At the same time, the introduction of MLIP-uncertainty corrections based on the predictions of an ensemble of models brings different approaches into agreement, validating this metric as essential for reliable dynamics. To interpret the population dynamics, we introduce a wavepacket oscillation model - a mechanistically transparent, power-law kinetics framework that extracts state-specific lifetimes directly from first-principles simulations. The model quantitatively reproduces the ultrafast decay, creating a direct link between quantum transition probabilities and classical rate constants. The kinetic fits yield channel-specific lifetimes, supporting the recently discovered photochemical pathway mediated by a novel $\sigma\pi^*/S_0$ conical intersection. - oai:arXiv.org:2512.07537v1 - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Ivan V. Dudakov, Pavel M. Radzikovitsky, Dmitry S. Popov, Denis A. Firsov, Vadim V. Korolev, Daniil N. Chistikov, Vladimir E. Bochenkov, Anastasia V. Bochenkova - - - Synchronization of Weak Signals in Dynamic Systems - https://arxiv.org/abs/2512.07551 - arXiv:2512.07551v1 Announce Type: new -Abstract: The present study proposes a methodology that combines the 'Duffing oscillator system' and the 'Kuramoto oscillator network' to explore the synchronization of weak signals in dynamic systems. The first step of the procedure is to detect weak periodic or quasi-periodic signals in noisy data collected from the quantifiable processes of any dynamical system using the Duffing oscillator system. The second step is to investigate how the interaction of these weak signals can be synchronized using the Kuramoto oscillator network model. This methodology was applied to seismic signals. The present study has shown that this methodology has great potential for investigating the weak signal synchronisation present within dynamic systems, as evidenced by the analysis of seismic data. - oai:arXiv.org:2512.07551v1 - physics.soc-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Mahmut Akilli - - - A Reconfigurable Circuit Strategy and Its Application in Low-Power Rectifier for Ambient Energy Harvesting - https://arxiv.org/abs/2512.07593 - arXiv:2512.07593v1 Announce Type: new -Abstract: In ambient electromagnetic energy harvesting systems, the input power to the rectifier is low. To improve rectification efficiency, Schottky diodes, which are sensitive to low power, are commonly selected as rectifying devices to convert microwave power into dc power. However, low-power rectifying diodes typically have low reverse breakdown voltages, making them susceptible to reverse breakdown under high power conditions. This letter proposes a low-power rectifier with reconfigurable function. The rectifying diode is connected in parallel with the p-i-n diode. At low input power, the output dc voltage is low, and the p-i-n diode remains off, having no impact on the rectifier operation. As the input power increases, the p-i-n diode turns on, causing change in circuit structure and impedance mismatch. This leads to increased reflected power, thereby preventing the rectifying diode from receiving excessive power. In addition, the turn-on voltage of the p-i-n diode is lower than the reverse breakdown voltage of the rectifying diode, protecting it from reverse breakdown. - oai:arXiv.org:2512.07593v1 - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - 10.1109/TPEL.2025.3589183 - IEEE Transactions on Power Electronics, vol. 40, no. 11, pp. 16100-16104, Nov. 2025 - Zhongqi He, Haoming He, Liping Yan, Changjun Liu - - - Microfluidic gratings for X-ray Phase Contrast Imaging - https://arxiv.org/abs/2512.07598 - arXiv:2512.07598v1 Announce Type: new -Abstract: Fabrication of X-ray gratings has surged in the last two decades thanks to their vast employment in X-ray Phase Contrast Imaging, an imaging technique able to boost X-ray sensitivity to detect otherwise invisible details. These high aspect ratio devices are usually fabricated by complex, costly, multi-step processes that limit their size and volume scaling. These steps commonly involve UV or X-ray lithography, semiconductor selective etching and high-Z metal plating, usually Au, which require expensive tools and materials. Here we present a proof-of-concept fabrication via soft lithography and Hg infusion of microfluidic X-ray absorption gratings and their performance in biomedical imaging. Such fabrication technique requires fewer, less expensive, and more scalable processes using alternative and more sustainable materials, while showing comparable visibility with their conventional Au-based, solid equivalent. Our results constitute a promising shift in X-ray optics fabrication that could significantly lower barriers to commercialization and accelerate the practical deployment of X-ray Phase Contrast Imaging. - oai:arXiv.org:2512.07598v1 - physics.optics - physics.med-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Alessandro Rossi, Francesco Coccimiglio, Antonio Ferraro, Tiziana Ritacco, Alberto Astolfo, Michele Giocondo, Vincenzo Formoso, Raffaele Giuseppe Agostino, Francesco Iacoviello, Ioannis Papakonstantinou, Alessandro Olivo - - - Determination of nuclear quadrupole moments of $^{25}$Mg, $^{87}$Sr, and $^{135,137}$Ba via configuration-interaction plus coupled-cluster approach - https://arxiv.org/abs/2512.07603 - arXiv:2512.07603v1 Announce Type: new -Abstract: Using the configuration-interaction plus coupled-cluster approach, we calculate the electric-field gradients $q$ for the low-lying states of alkaline-earth atoms, including magnesium (Mg), strontium (Sr), and barium (Ba). These low-lying states specifically include the $3s3p~^3\!P_{1,2}$ states of Mg; the $5s4d~^1\!D_{2}$ and $5s5p~^3\!P_{1,2}$ states of Sr; as well as the $6s5d~^3\!D_{1,2,3}$, $6s5d~^1\!D_{2}$, and $6s6p~^1\!P_{1}$ states of Ba. By combining the measured electric quadrupole hyperfine-structure constants of these states, we accurately determine the nuclear quadrupole moments of $^{25}$Mg, $^{87}$Sr, and $^{135,137}$Ba. These results are compared with the available data. The comparison shows that our nuclear quadrupole moment of $^{25}$Mg is in perfect agreement with the result from the mesonic X-ray experiment. However, there are approximately 10\% and 4\% differences between our results and the currently adopted values [Pyykk$\rm \ddot{o}$, Mol. Phys. 116, 1328(2018)] for the nuclear quadrupole moments of $^{87}$Sr and $^{135,137}$Ba respectively. Moreover, we also calculate the magnetic dipole hyperfine-structure constants of these states, and the calculated results exhibit good agreement with the measured data. - oai:arXiv.org:2512.07603v1 - physics.atom-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Yong-Bo Tang - - - Efficient Simulation of Electron-Positron Pair Production in Foam Targets in the low \chi-Regime - https://arxiv.org/abs/2512.07605 - arXiv:2512.07605v1 Announce Type: new -Abstract: The generation of electron-positron pairs using direct laser-accelerated electrons and a cone-shaped reflector target for the generation of strong electromagnetic fields is investigated using particle-in-cell simulations. A newly implemented sub-sampling routine for the code vlpl is presented which allows for a better description of quantum electrodynamical processes which would otherwise come at a high computational cost. - oai:arXiv.org:2512.07605v1 - physics.plasm-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Oliver Mathiak, Lars Reichwein, Alexander Pukhov - - - Tensor Network Fluid Simulations in Structured Domains Using the Lattice Boltzmann Method - https://arxiv.org/abs/2512.07615 - arXiv:2512.07615v1 Announce Type: new -Abstract: High-fidelity fluid simulations are central to understanding transport phenomena, yet resolving large or geometrically complex systems remains computationally prohibitive with existing methods. Here we introduce a tensor-network formulation of the lattice Boltzmann method based on matrix product states (MPS), commonly known as a quantum-inspired approach, enabling compressed representations of structured flow fields with inherent error control. We demonstrate the generality of the method on flows through structured media and complex vascular geometries, establishing for the first time that tensor-network techniques can efficiently resolve fluid dynamics in complex, irregular domains. We show that in the presence of translational or approximate symmetries of the geometry, fluid states exhibit low effective complexity in MPS form, yielding compression ratios exceeding two orders of magnitude while preserving physical structure and dynamical fidelity. This reduction enables systematic numerical exploration of regimes that were previously intractable. Our results position tensor networks as a scalable paradigm for continuum mechanics. - oai:arXiv.org:2512.07615v1 - physics.flu-dyn - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Lukas Gross, David M. Wawrzyniak, Josef M. Winter, Nikolaus A. Adams, Elie Mounzer - - - Optimization for growth condition of ultrathin hexagonal boron nitride on dielectric substrates via LPCVD - https://arxiv.org/abs/2512.07640 - arXiv:2512.07640v1 Announce Type: new -Abstract: Hexagonal Boron Nitride (h-BN) is a highly intriguing candidate for heterostructure optoelectronic applications, such as Deep Ultraviolet photodetectors, UV sensing and communication systems and solar cells. This is primarily due to its unique properties, including a layer dependent wide energy bandgap, superior mechanical strength, high thermal conductivity, high band-edge absorption coefficient, and exceptional transparency in the UV region. The widely adopted synthesis method for h-BN thin films is Chemical Vapor Deposition (CVD) Method, which often utilizes catalytic substrates like copper (Cu) and Nickel (Ni). However, integrating the synthesized h-BN into device applications requires a subsequent transfer process to the target substrate. This transfer step introduces significant material damage, such as folding, cracking and polymer residues, which ultimately degrade the optoelectronic properties of the material and compromise device performance. To overcome this major challenge, there is a strong need to synthesize high-quality h-BN films directly onto dielectric substrates such as silicon (Si), SiO2, quartz, sapphire or AlN without the need for transfer. The primary difficulty in direct synthesis lies in achieving homogenous, high crystallinity films with controllable thickness due to the absence of a catalytic effect. In this work, we investigated the optimization of growth parameters for the direct synthesis of ultrathin h-BN films on non-catalytic quartz substrates, which are highly transparent in the UV region, using the Low-pressure Chemical Vapor Deposition (LPCVD) method. The optimal synthesis conditions were determined to be 1050oC for 60 min, achieved by the decomposition of 150 mg Ammonia Borane (AB) precursor at 80oC. This optimization is crucial for advancing large-scale, high-performance h-BN based DUV photodetector fabrication. - oai:arXiv.org:2512.07640v1 - physics.app-ph - cond-mat.mtrl-sci - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Meryem Bozkaya, Muhammet Nasuh Ar{\i}k, Ali Altuntepe, Hakan Ate\c{s}, Recep Zan - - - Fold catastrophe in breaking waves - https://arxiv.org/abs/2512.07644 - arXiv:2512.07644v1 Announce Type: new -Abstract: We present a dynamical-systems perspective on wave breaking for ideal incompressible free-surface flows. By tracking the most energetic hotspot on the wave surface, we find that near breaking the surface slope m evolves on a fast timescale governed by the small parameter epsilon = (partial_z u)^(-1), the inverse vertical velocity gradient at the hotspot, while the focusing parameter A = (U - Ce)/(U - Creq) varies slowly and adiabatically. Here U is the horizontal fluid velocity at the energetic point, Ce its propagation speed, and Creq the equivalent crest speed. This slow-fast structure reveals a fold catastrophe in the (m, A) space whose boundary forms the geometric skeleton organizing the dynamics near breaking. Finite-time blowup occurs when the trajectory crosses this boundary, marking the onset of breaking. - The inception of breaking is further characterized by crossing the slope threshold theta* = arctan(sqrt(2) - 1) = 22.5 degrees. This critical angle marks the maximum anisotropy that can be sustained between the Hessians of the velocity and pressure fields, reflecting an imbalance between kinetic and potential energy fluxes. The anisotropy of the velocity Hessian also gives rise to the classical 30-degree slope observed at the inflection point of steep waves near breaking inception. The crest height is limited by the maximum excess of kinetic over potential energy that the flow can sustain, beyond which breaking becomes inevitable. Wave breaking can also be interpreted as a gravity analogue of a collapsing black hole, with apparent and event horizons representing the onset and inception of breaking. - oai:arXiv.org:2512.07644v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Francesco Fedele - - - Collisional passing alpha energy transport in nearly quasisymmetric stellarators - https://arxiv.org/abs/2512.07675 - arXiv:2512.07675v1 Announce Type: new -Abstract: Recent advances in stellarator optimization have found nearly precise quasisymmetric configurations. These are expected to reduce the non-turbulent background plasma transport to acceptable neoclassical levels while removing nearly all collisionless direct orbit losses of alpha particles. Yet, alpha particles under resonant conditions can be very sensitive to collisions, causing concerning energy losses and damaging plasma facing components. For the passing alphas such resonances can happen near rational surfaces in the presence of helical error field departures from quasisymmetry that change the magnetic field direction and magnitude. The cancellation between streaming motion and tangential drift of the alphas enhances the effective collision frequency, allowing the formation of a collisional boundary layer and giving rise to a perturbed distribution function. We develop an analytical model to illustrate and evaluate the resonant plateau transport this mechanism causes by formulating a drift kinetic treatment. The results indicate the associated energy losses can become significant in the vicinity of rational surfaces at values of q=m/n when error fields with poloidal and toroidal numbers m and n are present. In addition, we investigate the validity of the quasilinear approximation to the energy flux to show that it imposes a restriction on the error field amplitude that can be considered. - oai:arXiv.org:2512.07675v1 - physics.plasm-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Miguel Calvo-Carrera, Peter J. Catto - - - Mapping Still Matters: Coarse-Graining with Machine Learning Potentials - https://arxiv.org/abs/2512.07692 - arXiv:2512.07692v1 Announce Type: new -Abstract: Coarse-grained (CG) modeling enables molecular simulations to reach time and length scales inaccessible to fully atomistic methods. For classical CG models, the choice of mapping, that is, how atoms are grouped into CG sites, is a major determinant of accuracy and transferability. At the same time, the emergence of machine learning potentials (MLPs) offers new opportunities to build CG models that can in principle learn the true potential of the mean force for any mapping. In this work, we systematically investigate how the choice of mapping influences the representations learned by equivariant MLPs by studying liquid hexane, amino acids, and polyalanine. We find that when the length scales of bonded and nonbonded interactions overlap, unphysical bond permutations can occur. We also demonstrate that correctly encoding species and maintaining stereochemistry are crucial, as neglecting either introduces unphysical symmetries. Our findings provide practical guidance for selecting CG mappings compatible with modern architectures and guide the development of transferable CG models. - oai:arXiv.org:2512.07692v1 - physics.chem-ph - q-bio.BM - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Franz G\"orlich, Julija Zavadlav - - - Conservative adaptive-precision interatomic potentials - https://arxiv.org/abs/2512.07693 - arXiv:2512.07693v1 Announce Type: new -Abstract: Adaptive precision molecular dynamics simulations have developed along energy- and force-coupling approaches, which allow for a continuous transition between different particle descriptions or interaction potentials. Most approaches consider different (fixed) spatial regions, which control the transition between the descriptions and consequently avoid a consistent momentum-conserving Hamiltonian description. We present here a new approach to fully integrate the coupling into a Hamiltonian, therefore allowing for a conservative description, which, by design, guarantees both energy and momentum conservation. By coupling a fast EAM potential to a highly accurate ACE potential, we verify numerically the conservation properties and show that one can achieve - dependent on both the potential and the atomistic system - a speedup of one or two orders of magnitude compared to a pure ACE simulation. - oai:arXiv.org:2512.07693v1 - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - David Immel, Ralf Drautz, Godehard Sutmann - - - Widefield pump-probe microscopy with coherent background subtraction by angle-compensated temporal shearing - https://arxiv.org/abs/2512.07779 - arXiv:2512.07779v1 Announce Type: new -Abstract: Pump-probe microscopy enables label-free imaging of structural and chemical features of samples. However, signals in pump-probe microscopy are typically small and often must be measured in the presence of large backgrounds. As a result, achieving measurements with a high signal-to-noise ratio is challenging, particularly when using sensors that are easily saturated, such as CMOS cameras. We present a method for enhancing signal-to-noise ratio while avoiding detector saturation. In this approach, temporally separated (sheared) reference and probe pulses transmit through a sample before and after the arrival of a pump pulse. The probe and reference pulses are then temporally recombined with opposing phases and nearly matched amplitudes, resulting in interferometric background subtraction. This recombining operation is performed by a novel common-path interferometer. Unlike previous techniques for temporal shearing, this interferometer demonstrates negligible phase and group delay dispersion with angle of incidence, allowing convenient widefield imaging. To our knowledge, this is the first common-path interferometer with such a property. We demonstrate the technique by measuring transient absorption signals in gold nanorod films with a signal-to-background ratio enhanced by over 100% and a signal-to-noise ratio enhanced by about 70%. - oai:arXiv.org:2512.07779v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Matthew Sheinman, Mark Polkovnikov, Luke Saunders, Pajo Vujkovic-Cvijin, Shyamsunder Erramilli, Lawrence D. Ziegler, Koustav Kundu, Ramprasath Rajagopal, Bingying Zhao, Christopher McMahon, Mi K. Hong, Jerome Mertz - - - Spatio-temporal equilibrium thermodynamics of guided optical waves at positive and negative temperatures - https://arxiv.org/abs/2512.07784 - arXiv:2512.07784v1 Announce Type: new -Abstract: Optical thermalization has been recently studied theoretically and experimentally in the 2D spatial evolution of (quasi-)monochromatic light waves propagating in multimode fibers. In this work, we investigate the spatio-temporal equilibrium properties of incoherent multimode optical waves through the analysis of the (2+1)D Bose-Einstein thermal distribution and the corresponding classical Rayleigh-Jeans approximation. In the anomalous dispersion regime, the spatio-temporal equilibrium is characterized by positive temperatures. In this regime, we show that as the number of modes of the waveguide increases, the fundamental spatial mode becomes macroscopically populated, while its temporal spectrum undergoes significant narrowing, ultimately leading to complete (2+1)D spatio-temporal condensation in the thermodynamic limit. In the normal dispersion regime, the spatio-temporal equilibrium is characterized by negative temperature states that exhibit a hybrid character: the spatial equilibrium displays an inverted modal population, whereas the temporal spectrum remains peaked around the fundamental (carrier) optical frequency. In this regime, we predict that spatio-temporal light waves exhibit a phase transition to Bose-Einstein condensation at negative temperatures, which occurs by increasing the temperature above a negative critical value. Our work opens new avenues for future research, including the possibility for a dual spatio-temporal beam cleaning through full spatio-temporal light condensation, and lay the groundwork for the development of spatio-temporal optical thermodynamics. - oai:arXiv.org:2512.07784v1 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Lucas Zanaglia, Josselin Garnier, Claire Michel, Val\'erie Doya, Mario Ferraro, Stefan Wabnitz, Iacopo Carusotto, Antonio Picozzi - - - Automating High Energy Physics Data Analysis with LLM-Powered Agents - https://arxiv.org/abs/2512.07785 - arXiv:2512.07785v1 Announce Type: new -Abstract: We present a proof-of-principle study demonstrating the use of large language model (LLM) agents to automate a representative high energy physics (HEP) analysis. Using the Higgs boson diphoton cross-section measurement as a case study with ATLAS Open Data, we design a hybrid system that combines an LLM-based supervisor-coder agent with the Snakemake workflow manager. In this architecture, the workflow manager enforces reproducibility and determinism, while the agent autonomously generates, executes, and iteratively corrects analysis code in response to user instructions. We define quantitative evaluation metrics including success rate, error distribution, costs per specific task, and average number of API calls, to assess agent performance across multi-stage workflows. To characterize variability across architectures, we benchmark a representative selection of state-of-the-art LLMs spanning the Gemini and GPT-5 series, the Claude family, and leading open-weight models. While the workflow manager ensures deterministic execution of all analysis steps, the final outputs still show stochastic variation. Although we set the temperature to zero, other sampling parameters (e.g., top-p, top-k) remained at their defaults, and some reasoning-oriented models internally adjust these settings. Consequently, the models do not produce fully deterministic results. This study establishes the first LLM-agent-driven automated data-analysis framework in HEP, enabling systematic benchmarking of model capabilities, stability, and limitations in real-world scientific computing environments. The baseline code used in this work is available at https://huggingface.co/HWresearch/LLM4HEP. This work was accepted as a poster at the Machine Learning and the Physical Sciences (ML4PS) workshop at NeurIPS 2025. The initial submission was made on August 30, 2025. - oai:arXiv.org:2512.07785v1 - physics.data-an - hep-ex - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Eli Gendreau-Distler, Joshua Ho, Dongwon Kim, Luc Tomas Le Pottier, Haichen Wang, Chengxi Yang - - - Analytic First Derivatives of Aufbau Suppressed Coupled Cluster Theory and their Perturbative Accuracy - https://arxiv.org/abs/2512.07804 - arXiv:2512.07804v1 Announce Type: new -Abstract: We derived and implemented analytic first derivatives for Aufbau suppressed coupled cluster theory to calculate the one-body reduced density matrix, from which excited state natural orbitals and one-body properties, like atomic populations and dipole moments, are obtained. We utilized the natural orbitals to refine the ASCC solution for simple valence and Rydberg systems, exploring the process of repeatedly solving the ASCC equations in successive natural orbital bases to achieve independence from the starting molecular orbitals. For dipole moments in small molecules where high-level comparison data is available, we find that the accuracy of ASCC essentially matches that of linear response and equation-of-motion coupled cluster as long as care is taken to preserve the response's perturbative completeness. - oai:arXiv.org:2512.07804v1 - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Conor Bready, Harrison Tuckman, Eric Neuscamman - - - Integral constraints on the linear instability of stratified flow with planar shear at an arbitrary angle to the vertical - https://arxiv.org/abs/2512.07817 - arXiv:2512.07817v1 Announce Type: new -Abstract: Integral constraints on the linear instability of stratified parallel flow with planar shear at an arbitrary angle to the vertical are derived using the analytical approach of Miles and Howard, for perturbations with 2D spatial structure, which are thought to be the most unstable. The general stability formulation reproduces the Miles-Howard stability criterion for vertical shear, but yields no stability condition for non-vertical shear, confirming expectations from earlier studies. This study also extends Howard's semicircle theorem to non-vertical planar shear, and derives a new expression for the upper bound of the instability growth rate (extending that obtained by Howard), which is consistent with published numerical results. - oai:arXiv.org:2512.07817v1 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - new - http://creativecommons.org/licenses/by/4.0/ - Miguel A. C. Teixeira, Mohamed Foudad, Paul D. Williams - - - Wealth Thermalization Hypothesis and Social Networks - https://arxiv.org/abs/2506.17720 - arXiv:2506.17720v3 Announce Type: cross -Abstract: In 1955 Fermi, Pasta, Ulam and Tsingou performed first numerical studies with the aim to obtain the thermalization in a chain of nonlinear oscillators from dynamical equations of motion. This model happend to have several specific features and the dynamical thermalization was established only later in other studies. In this work we study more generic models based on Random Matrix Theory and social networks with a nonlinear perturbation leading to dynamical thermalization above a certain chaos border. These systems have two integrals of motion being total energy and norm so that the theoretical Rayleigh-Jeans thermal distribution depends on temperature and chemical potential. We introduce the wealth thermalization hypothesis according to which the society wealth is associated with energy in the Rayleigh-Jeans distribution. At relatively small values of total wealth or energy there is a formation of the Rayleigh-Jeans condensate, well studied in physical systems such as multimode optical fibers. This condensation leads to a huge fraction of poor households at low wealth and a small oligarchic fraction which monopolizes a dominant fraction of total wealth thus generating a strong inequality in human society. We show that this thermalization gives a good description of real data of Lorenz curves of US, UK, the whole world and capitalization of companies at Stock Exchange of New York SE (NYSE), London and Hong Kong. It is also shown that above a chaos border the dynamical Rayleigh-Jeans thermalization takes place also in social networks with the Lorenz curves being similar to those of wealth distribution in world countries. Possible actions for inequality reduction are briefly discussed. - oai:arXiv.org:2506.17720v3 - cond-mat.stat-mech - physics.soc-ph - q-fin.ST - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Klaus M. Frahm, Dima L. Shepelyansky - - - Bidirectional Photoinduced Carrier Transfer in Fluorinated Quasi-2D Perovskites Governing Enhanced Photocurrent Generation - https://arxiv.org/abs/2510.22640 - arXiv:2510.22640v1 Announce Type: cross -Abstract: Quasi-two-dimensional (quasi-2D) metal halide perovskites exhibit rich phase heterogeneity that profoundly influences light-matter interactions and charge transport. However, the fundamental mechanisms governing carrier transfer across distinct phases remain poorly understood. Here, we demonstrate effective electron-hole separation in fluorinated multilayered quasi-2D perovskite films nominally prepared for three layers, using femtosecond transient absorption spectroscopy. The films are revealed to comprise a heterogeneous phase distribution (with 1, 2, 3 layers and bulk) naturally stacked along the growth direction. Our ultraviolet photoelectron spectroscopy (UPS) measurements, show the type-two band alignment between the small-n (layer number) phases and the bulk. This alignment drives charge separation via both direct and sequential carrier transfer mechanisms, whereby electrons preferentially migrate into the bulk domains while holes accumulate in the small-n layers, extending even to single layer phase-a process only rarely observed in previous studies. The nearly symmetric transfer times of electrons and holes yield an efficient and balanced spatial separation of carriers. Global target analysis employing a carrier transfer model quantitatively reproduces the spectral evolution, providing a rigorous validation of the mechanism. Nonetheless, we found photocurrent enhancement in the diode devices of this quasi-2D perovskite as a consequence of the efficient transfer of photocarriers in the opposite directions. This work delivers a comprehensive picture of interphase charge transfer in fluorinated quasi-2D perovskites and highlights strategies to engineer directional separation pathways for high-performance photovoltaic, optoelectronic, and quantum devices. - oai:arXiv.org:2510.22640v1 - cond-mat.mtrl-sci - physics.app-ph - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Soumya Halder, Koushik Gayen, Nagendra S. Kamath, Suman Kalyan Pal - - - Quantifying the irregularity of a time series - https://arxiv.org/abs/2512.05975 - arXiv:2512.05975v1 Announce Type: cross -Abstract: We introduce circulance, a scalar measure for classifying time series of dynamical systems. Circulance captures the extent of temporal regularity or irregularity that is encoded in the topology of a directed ordinal pattern transition network derived from a time series. We demonstrate numerically that circulance sensitively and robustly positions time series of canonical model systems, representative of preset dynamical regimes, along a continuous spectrum from regularity to randomness. Analyzing empirical data from long-term observations of high-dimensional, complex systems -- human brain and the Sun -- reveals that circulance aids in elucidating different dynamical regimes. - oai:arXiv.org:2512.05975v1 - nlin.CD - physics.data-an - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Max Potratzki, Manuel Adams, Timo Br\"ohl, Klaus Lehnertz - - - Solver-in-the-Loop Applications in Astrophysical (Magneto)hydrodynamics - https://arxiv.org/abs/2512.05999 - arXiv:2512.05999v1 Announce Type: cross -Abstract: We present two promising applications of training machine learning models inside a differentiable astrophysical (magneto)hydrodynamics simulator. First, we address the problem of slow convergence in hydrodynamical simulations of wind-blown bubbles with radiative cooling. We demonstrate that a learned cooling function can recover high-resolution dynamics in low-resolution simulations. Secondly, we train a convolutional neural network to correct 2D magnetohydrodynamics simulations of a specific blast wave problem. These case studies pave the way for the principled application of more general machine learning models inside astrophysical simulators. The code is available open source under https://github.com/leo1200/eurips25corr. - oai:arXiv.org:2512.05999v1 - astro-ph.IM - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Leonard Storcks, Tobias Buck - - - Neural reconstruction of 3D ocean wave hydrodynamics from camera sensing - https://arxiv.org/abs/2512.06024 - arXiv:2512.06024v1 Announce Type: cross -Abstract: Precise three-dimensional (3D) reconstruction of wave free surfaces and associated velocity fields is essential for developing a comprehensive understanding of ocean physics. To address the high computational cost of dense visual reconstruction in long-term ocean wave observation tasks and the challenges introduced by persistent visual occlusions, we propose an wave free surface visual reconstruction neural network, which is designed as an attention-augmented pyramid architecture tailored to the multi-scale and temporally continuous characteristics of wave motions. Using physics-based constraints, we perform time-resolved reconstruction of nonlinear 3D velocity fields from the evolving free-surface boundary. Experiments under real-sea conditions demonstrate millimetre-level wave elevation prediction in the central region, dominant-frequency errors below 0.01 Hz, precise estimation of high-frequency spectral power laws, and high-fidelity 3D reconstruction of nonlinear velocity fields, while enabling dense reconstruction of two million points in only 1.35 s. Built on a stereo-vision dataset, the model outperforms conventional visual reconstruction approaches and maintains strong generalization in occluded conditions, owing to its global multi-scale attention and its learned encoding of wave propagation dynamics. - oai:arXiv.org:2512.06024v1 - cs.CV - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Jiabin Liu, Zihao Zhou, Jialei Yan, Anxin Guo, Alvise Benetazzo, Hui Li - - - From orbital analysis to active learning: an integrated strategy for the accelerated design of TADF emitters - https://arxiv.org/abs/2512.06029 - arXiv:2512.06029v1 Announce Type: cross -Abstract: Thermally Activated Delayed Fluorescence (TADF) emitters must satisfy two competing requirements: small singlet-triplet energy gaps for thermal upconversion and sufficient spin-orbit coupling for fast reverse intersystem crossing. Predicting these properties accurately demands expensive calculations. We address this using a validated semi-empirical protocol (GFN2-xTB geometries, sTDA/sTD-DFT-xTB excited states) on 747 molecules, combined with charge-transfer descriptors from Natural Transition Orbital analysis. The hole-electron spatial overlap She emerges as a key predictor, accounting for 21% of feature importance for the triplet state alone. Our best model (Support Vector Regression) reaches MAE = 0.024 eV and R2 = 0.96 for $\Delta E_{ST}$. Active learning reduces the data needed to reach target accuracy by approximately 25% compared to random sampling. Three application domains are explored: NIR-emitting probes for bioimaging, photocatalytic sensitizers, and fast-response materials for photodetection. - oai:arXiv.org:2512.06029v1 - cond-mat.mtrl-sci - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Jean-Pierre Tchapet Njafa, Steve Cabrel Teguia Kouam, Patrick Mvoto Kongo, Serge Guy Nana Engo - - - Tractatus Quanticum - https://arxiv.org/abs/2512.06034 - arXiv:2512.06034v1 Announce Type: cross -Abstract: This is a re-editing, which takes quantum mechanics into account, of Wittgenstein's famous Tractatus. The operation has a playful side in the form, but is a serious attempt to capture possible philosophical implications of the Relational Interpretation of Quantum Mechanics, and formalize the naturalistic third-way between realism and instrumentalism explored by this interpretation. - oai:arXiv.org:2512.06034v1 - quant-ph - physics.hist-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Niccol\`o Covoni, Carlo Rovelli - - - Ferromagnetic Phase Transition of DPPH Induced by a Magic Angle Helical Magnetic Field - https://arxiv.org/abs/2512.06053 - arXiv:2512.06053v1 Announce Type: cross -Abstract: We report the results and unique instrument configuration of a novel experiment in which we successfully transitioned a DPPH sample from its natural paramagnetic state and essentially a non-magnetic material to a ferromagnetic state at room temperature. This was achieved using a specifically applied helical flux magnetic field. The DPPH sample (2,2-diphenyl-1-picrylhydrazyl) remained ferromagnetic for at least one hour after the experiment, indicating that a transformation in the material was induced by the external field rather than being merely a temporary magnetic phase transition observed only during the experiment. The external magnetic field used had a helical pitch angle of approximately $54.7{\deg}$, known mathematically as the Magic Angle, relative to the +z-axis, which is aligned with the normal S to N external field's magnetic moment vector. Based on the phenomenology of the experiment, we infer that this specific magic angle corresponding to the known quantization precession spin angle of free electrons under a homogeneous straight flux magnetic field potentially enhances the percentage of unpaired valence electrons within the DPPH material, allowing them to align in parallel with the applied external field. Typically, in paramagnetic materials, the distribution of unpaired electrons' quantum spins relative to an external field is nearly random, showing roughly a 50% chance of either parallel or antiparallel alignment. Only a slight majority preference exists in one alignment direction due to the Boltzmann thermal distribution, which contributes to the paramagnetic nature of these materials. In our measurements, we found that the induced ferromagnetism of the DPPH sample resulted in an abnormal thousand-fold decimal value increase in relative magnetic permeability at ${\mu}{\approx}1.4$, compared to its typical paramagnetic value of $1.0001$ for this material. - oai:arXiv.org:2512.06053v1 - cond-mat.mtrl-sci - physics.app-ph - physics.ins-det - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Emmanouil Markoulakis, John Chatzakis, Antonios Konstantaras, Iraklis Rigakis, Emmanuel Antonidakis - - - Measuring the Potential of Scientific Literature: A Network-Based Approach to Identifying Paradigm-Shifting Research - https://arxiv.org/abs/2512.06054 - arXiv:2512.06054v1 Announce Type: cross -Abstract: This study introduces the Disruption Index as a superior citation-based metric. This index quantitatively assesses the degree to which a publication redirects subsequent scholarly attention away from its preceding literature, thus measuring its novelty and disruptive impact. We tested the D metric's efficacy using a rigorous dataset comprising seminal publications by Nobel Prize winners across Physics, Chemistry, and Physiology or Medicine, benchmarked against control papers with comparable citation counts but non-transformative influence. Our analysis conclusively demonstrates that the D metric effectively distinguishes these prize-worthy, field-redefining works from highly cited but merely incremental research. Furthermore, we explore two contextual variables associated with high disruptive potential: (i) the scale of collaboration (author team size) and (ii) the linguistic structure of the article's title and summary text. The results reveal a strong positive correlation between larger collaborative teams and elevated average D scores, suggesting that extensive collaboration may be a facilitator for generating paradigm shifts. Additionally, publications with high D values tend to feature more expansive titles and greater density of specialized, technical jargon in their abstracts. These findings validate the D metric as a reliable and scalable instrument for both historical and predictive identification of transformative research. They also furnish empirical evidence concerning the team structures and communication patterns that optimize for the production of groundbreaking scientific knowledge. - oai:arXiv.org:2512.06054v1 - cs.DL - physics.soc-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Sarah James - - - Deep learning recognition and analysis of Volatile Organic Compounds based on experimental and synthetic infrared absorption spectra - https://arxiv.org/abs/2512.06059 - arXiv:2512.06059v1 Announce Type: cross -Abstract: Volatile Organic Compounds (VOCs) are organic molecules that have low boiling points and therefore easily evaporate into the air. They pose significant risks to human health, making their accurate detection the crux of efforts to monitor and minimize exposure. Infrared (IR) spectroscopy enables the ultrasensitive detection at low-concentrations of VOCs in the atmosphere by measuring their IR absorption spectra. However, the complexity of the IR spectra limits the possibility to implement VOC recognition and quantification in real-time. While deep neural networks (NNs) are increasingly used for the recognition of complex data structures, they typically require massive datasets for the training phase. Here, we create an experimental VOC dataset for nine different classes of compounds at various concentrations, using their IR absorption spectra. To further increase the amount of spectra and their diversity in term of VOC concentration, we augment the experimental dataset with synthetic spectra created via conditional generative NNs. This allows us to train robust discriminative NNs, able to reliably identify the nine VOCs, as well as to precisely predict their concentrations. The trained NN is suitable to be incorporated into sensing devices for VOCs recognition and analysis. - oai:arXiv.org:2512.06059v1 - cs.LG - physics.app-ph - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Andrea Della Valle, Annalisa D'Arco, Tiziana Mancini, Rosanna Mosetti, Maria Chiara Paolozzi, Stefano Lupi, Sebastiano Pilati, Andrea Perali - - - Generalized tension metrics for multiple cosmological datasets - https://arxiv.org/abs/2512.06086 - arXiv:2512.06086v1 Announce Type: cross -Abstract: We introduce a novel estimator to quantify statistical tensions among multiple cosmological datasets simultaneously. This estimator generalizes the Difference-in-Means statistic, $Q_{\rm DM}$, to the multi-dataset regime. Our framework enables the detection of dominant tension directions in the shared parameter space. It further provides a geometric interpretation of the tension for the two- and three-dataset cases in two dimensions. According to this approach, the previously reported increase in tension between DESI and Planck from $1.9\sigma$ (DR1) to $2.3\sigma$(DR2) is reinterpreted as a more modest shift from $1.18\sigma^{\rm eff}$ (DR1) to $1.45\sigma^{\rm eff}$ (DR2). These new tools may also prove valuable across research fields where dataset discrepancies arise. - oai:arXiv.org:2512.06086v1 - astro-ph.CO - astro-ph.IM - hep-ex - hep-ph - physics.data-an - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Mat\'ias Leizerovich, Susana J. Landau, Claudia G. Sc\'occola - - - High-Performance Labyrinth Circular Bragg Grating Design for Charge and Stark-Tunable Quantum Light Sources Spanning Visible to Telecom Wavelengths - https://arxiv.org/abs/2512.06117 - arXiv:2512.06117v1 Announce Type: cross -Abstract: Semiconductor quantum dots embedded in circular Bragg gratings (CBGs) are among the most efficient integrated single-photon sources. However, the fully etched rings of conventional CBGs restrict the implementation of charge and Stark tuning via electrical contacts. To overcome this limitation, a labyrinth CBG geometry with four bridges has been proposed, yet the added bridges significantly degraded optical performance. In this work, we numerically demonstrate that a periodic labyrinth CBG design preserves both high coupling efficiency and strong Purcell enhancement while enabling electrical integration if optimized after introducing the bridges. We show three optimized designs at emission wavelengths of 780 nm, 930 nm, and 1550 nm, because these wavelengths are among the most relevant for quantum dots and show the general applicability of our approach. At all three wavelengths collection efficiencies exceeding 90% into a numerical aperture of 0.7 and Purcell factors greater than 25 are achieved. Furthermore, we propose a device layout incorporating a barrier layer that separates p- and n-doped semiconductor regions, which is incorporated to prevent tunneling of one of the charge carriers for selective charging. Also this design can be reoptimized to retain the performance of a device without tunnel barrier. These results establish labyrinth CBGs as a platform for electrically tunable quantum dot single-photon sources with high efficiency and scalability. - oai:arXiv.org:2512.06117v1 - quant-ph - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Rohit Prasad, Quirin Buchinger, Fei Chi Kristy Yuen, Yorick Reum, Sven H\"ofling, Tobias Huber-Loyola - - - Polarons from first principles - https://arxiv.org/abs/2512.06176 - arXiv:2512.06176v1 Announce Type: cross -Abstract: This article reviews recent theoretical developments in the ab initio study of polarons in materials. The polaron is an emergent quasiparticle that arises from the interaction between electrons and phonons in solids, and consists of an electron or a hole accompanied by a distortion of the crystal lattice. Recent advances in experiments, theory, and computation have made it possible to investigate these quasiparticles with unprecedented detail, reigniting the interest in this classic problem of condensed matter physics. Recent theoretical and computational advances include ab initio calculations of polaron spectral functions, wavefunctions, lattice distortions, and transport and optical properties. These developments provide new insight into polaron physics, but they have evolved somewhat independently from the earlier effective Hamiltonian approaches that laid the foundation of the field. This article aims to bridge these complementary perspectives by placing them within a single unified conceptual framework. To this end, we start by reviewing effective Hamiltonians of historical significance in polaron theory, ab initio techniques based on density functional theory, and many-body first-principles approaches to polarons. After this survey, we outline a general field-theoretic framework that bridges between these diverse approaches to polaron physics. For completeness, we also review recent progress in the study of exciton polarons and self-trapped excitons and their relations to polarons. Beyond the methodology, we discuss recent applications to several classes of materials that attracted attention in the context of polaron physics. - oai:arXiv.org:2512.06176v1 - cond-mat.mtrl-sci - physics.app-ph - physics.comp-ph - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zhenbang Dai, Jon Lafuente-Bartolome, Feliciano Giustino - - - Protocol to evaluate the viscoelastic response of a polymer suspension to an active agent via oscillatory shear rheometry - https://arxiv.org/abs/2512.06233 - arXiv:2512.06233v1 Announce Type: cross -Abstract: Microorganisms inhabit viscoelastic environments, where their locomotion can deform polymers and trigger local complex viscoelastic responses. However, a systematic approach to quantify such responses remains lacking. Here, we propose a protocol that maps the shear effect induced by an active agent to oscillatory shear rheometry. The central idea is to establish a correspondence between the mean shear rate generated by swimming and that produced by an oscillating plate. In this mapping, the swimming velocity and active stress are translated into an effective oscillation frequency and strain amplitude. The resulting viscoelastic response can then be evaluated by standard oscillatory rheometry. The protocol is validated using lattice Boltzmann simulations of a squirmer embedded in polymer solutions. Our framework is generic and can be naturally extended to active microrheology, providing a pathway to quantify swimmer-induced viscoelasticity. - oai:arXiv.org:2512.06233v1 - cond-mat.soft - physics.bio-ph - physics.comp-ph - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/publicdomain/zero/1.0/ - Kai Qi, Qingzhi Zou, Ignacio Pagonabarraga - - - Robust AC vector sensing at zero magnetic field with pentacene - https://arxiv.org/abs/2512.06272 - arXiv:2512.06272v1 Announce Type: cross -Abstract: Quantum sensors based on electronic spins have emerged as powerful probes of microwave-frequency fields. Among other solid-state platforms, spins in molecular crystals offer a range of advantages, from high spin density to functionalization via chemical tunability. Here, we demonstrate microwave vector magnetometry using the photoexcited spin triplet of pentacene molecules, operating at zero external magnetic field and room temperature. We achieve full three-dimensional microwave field reconstruction by detecting the Rabi frequencies of anisotropic spin-triplet transitions associated with two crystallographic orientations of pentacene in deuterated naphthalene crystals. We further introduce a phase alternated protocol that extends the rotating-frame coherence time by an order of magnitude and enables sensitivities of approximately $1~\mu\mathrm{T}/\sqrt{\mathrm{Hz}}$ with sub-micrometer spatial resolution. These results establish pentacene-based molecular spins as a practical and high-performance platform for microwave quantum sensing in addition to demonstrating control techniques broadly applicable to other molecular and solid-state spin systems. - oai:arXiv.org:2512.06272v1 - cond-mat.mes-hall - physics.app-ph - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Boning Li, Garrett Heller, Jungbae Yong, Alexander Ungar, Hao Tang, Guoqing Wang, Patrick Hautle, Yifan Quan, Paola Cappellaro - - - Spin-photon Qubits for Scalable Quantum Network - https://arxiv.org/abs/2512.06285 - arXiv:2512.06285v1 Announce Type: cross -Abstract: Solid-state quantum light sources offer a scalable pathway for interfacing stationary spin qubits with flying photonic qubits, forming the backbone of future quantum networks. Telecom-band spin-photonic qubits, operating in the 1260-1675 nm wavelength range, are particularly well-suited for long-distance quantum communication due to minimal loss in standard optical fibers. Achieving scalability, however, hinges on fulfilling several stringent criteria: coherent spin-state control, deterministic and indistinguishable single-photon emission, and integration with nanophotonic structures that enhance radiative properties, such as lifetime, coherence, and photon indistinguishability. This study explores the state-of-the-art spin-photonic qubits across solid-state platforms, including diamond color centers, silicon carbide defect centers, quantum dots, and two-dimensional materials. Special attention is given to silicon-based emitters, particularly G, T, C- and Ci-centers, which promise monolithic integration with complementary metal-oxide-semiconductor (CMOS) technology and telecom-band operation. We classify these systems based on spin-photon interface availability, CMOS process compatibility, and emitter scalability. We also discuss recent advances in cavity quantum electrodynamics (cQED), including Purcell enhancement and quality factor engineering in integrated photonic (circuits) environments. The work highlights emerging demonstrations of quantum networking over metropolitan scales and outlines the trajectory toward chip-scale quantum photonic integrated circuits (QPICs). It combines deterministic emitter creation, coherent spin manipulation, and quantum information processing. These developments pave the way for global quantum networks, enabling secure communication, distributed quantum computing, and quantum-enhanced sensing. - oai:arXiv.org:2512.06285v1 - quant-ph - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Md Sakibul Islam, Kuldeep Singh, Yunhe Zhao, Nitesh Singh, Wayesh Qarony - - - On Spavieri's conundrum or the shadow of the twin paradox -- A submission to the One-Way Linear Effect (OWLE) Award - https://arxiv.org/abs/2512.06382 - arXiv:2512.06382v1 Announce Type: cross -Abstract: We deal with a problem concerning a supposed inconsistency in the special relativistic treatment of the so-called linear Sagnac effect. It is shown that, under modern clothes, the root of the difficulty perceived by some authors lies in their uneasiness with the standard solution of the twin paradox. In particular, since the linear Sagnac effect is an absolute effect, no tinkering with conventionality of simultaneity, so far as it preserves the physical content of special relativity, would get us out of the supposed trouble. - oai:arXiv.org:2512.06382v1 - gr-qc - physics.class-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Marco Mamone-Capria - - - Mitigating the Transition of SiV$^-$ in Diamond to an Optically Dark State - https://arxiv.org/abs/2512.06389 - arXiv:2512.06389v1 Announce Type: cross -Abstract: Negatively charged silicon vacancy centers in diamond (SiV$^-$) are promising for quantum photonic technologies. However, when subject to resonant optical excitation, they can inadvertently transfer into a zero-spin optically dark state. We show that this unwanted change of charge state can be quickly reversed by the resonant laser itself in combination with static electric fields. By defining interdigitated metallic contacts on the diamond surface, we increase the steady-state SiV$^-$ photoluminescence under resonant excitation by a factor $\ge3$ for most emitters, making it practically constant for certain individual emitters. We electrically activate single \sivs near the positively biased electrode, which are entirely dark without applying local electric fields. Using time-resolved 3-color experiments, we show that the resonant laser not only excites the SiV$^-$, but also creates free holes that convert SiV$^{2-}$ to SiV$^-$ on a timescale of milliseconds. Through analysis of several individual emitters, our results show that the degree of electrical charge state controllability differs between individual emitters, indicating that their local environment plays a key role. Our proposed electric-field-based stabilization scheme enhances deterministic charge state control in group-IV color centers and improves its understanding, offering a scalable path toward quantum applications such as entanglement generation and quantum key distribution. - oai:arXiv.org:2512.06389v1 - quant-ph - cond-mat.mes-hall - cond-mat.mtrl-sci - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Manuel Rieger, Rubek Poudel, Tobias Waldmann, Lina M. Todenhagen, Stefan Kresta, Nori N. Chavira Leal, Viviana Villafa\~ne, Martin S. Brandt, Kai M\"uller, Jonathan J. Finley - - - Measuring the buried interphase between solid electrolytes and lithium metal using neutrons - https://arxiv.org/abs/2512.06397 - arXiv:2512.06397v1 Announce Type: cross -Abstract: Interfaces are the key to next generation high energy batteries including solid state Li metal batteries. In solid state batteries, the buried nature of solid solid electrolyte electrode interfaces makes studying them difficult. Neutrons have significant potential to non destructively probe these buried solid solid interfaces. This work presents a comparative study using both neutron depth profiling (NDP) and neutron reflectometry (NR) to study a model lithium metal-lithium phosphorus oxynitride (LiPON) solid electrolyte system. In the NDP data, no distinct interphase is observed at the interface. NR shows a difference between electrodeposited, and vapor deposited LiPON -Li interfaces but finds both are gradient interphases that are less than 30 nm thick. Additional simulations of the LiPON-Li2O-Li system demonstrate that NDP has an excellent resolution in the 50 nm-1 mm regime while NR has an ideal resolution from 0.1 - 200 nm with different sample requirements. Together NDP and NR can provide a complementary understanding of interfaces between Li metal and solid electrolytes across relevant length scales. - oai:arXiv.org:2512.06397v1 - cond-mat.mtrl-sci - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - 10.1039/d5ta05758b - Journal of Materials Chemistry A 13.41 (2025): 35435-35446 - Andrew S. Westover, Katie L. Browning, Antonino Cannavo, Ralph Gilles, Jiri Vacik, James F. Browning, Neelima Paul, Giovanni Ceccio, Vasyl Lavrentiev - - - GENIUS: An Agentic AI Framework for Autonomous Design and Execution of Simulation Protocols - https://arxiv.org/abs/2512.06404 - arXiv:2512.06404v1 Announce Type: cross -Abstract: Predictive atomistic simulations have propelled materials discovery, yet routine setup and debugging still demand computer specialists. This know-how gap limits Integrated Computational Materials Engineering (ICME), where state-of-the-art codes exist but remain cumbersome for non-experts. We address this bottleneck with GENIUS, an AI-agentic workflow that fuses a smart Quantum ESPRESSO knowledge graph with a tiered hierarchy of large language models supervised by a finite-state error-recovery machine. Here we show that GENIUS translates free-form human-generated prompts into validated input files that run to completion on $\approx$80% of 295 diverse benchmarks, where 76% are autonomously repaired, with success decaying exponentially to a 7% baseline. Compared with LLM-only baselines, GENIUS halves inference costs and virtually eliminates hallucinations. The framework democratizes electronic-structure DFT simulations by intelligently automating protocol generation, validation, and repair, opening large-scale screening and accelerating ICME design loops across academia and industry worldwide. - oai:arXiv.org:2512.06404v1 - cs.AI - cond-mat.mtrl-sci - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Mohammad Soleymanibrojeni, Roland Aydin, Diego Guedes-Sobrinho, Alexandre C. Dias, Maur\'icio J. Piotrowski, Wolfgang Wenzel, Celso Ricardo Caldeira R\^ego - - - Thermodynamic description of world GDP distribution over countries - https://arxiv.org/abs/2512.06420 - arXiv:2512.06420v1 Announce Type: cross -Abstract: We apply the concept of Rayleigh-Jeans thermalization of classical fields for a description of the world Gross Domestic Product (GDP) distribution over countries. The thermalization appears due to a variety of interactions between countries with conservation of two integrals being total GDP and probability (norm). In such a case there is an emergence of Rayleigh-Jeans condensation at states with low GDP. This phenomenon has been studied theoretically and experimentally in multimode optical fibers and we argue that it is at the origin of emergence of poverty and oligarchic phases for GDP of countries. A similar phenomenon has been discussed recently in the framework of the Wealth Thermalization Hypothesis to explain the high inequality of wealth distribution in human society and companies at Stock Exchange markets. We show that the Rayleigh-Jeans thermalization well describes the GDP distribution during the last 50 years. - oai:arXiv.org:2512.06420v1 - cond-mat.stat-mech - physics.soc-ph - q-fin.ST - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Klaus M. Frahm, Dima L. Shepelyansky - - - Hybrid qubit-oscillator module with motional states of two trapped interacting atoms - https://arxiv.org/abs/2512.06429 - arXiv:2512.06429v1 Announce Type: cross -Abstract: We propose the use of motional states of two interacting atoms trapped in a potential stroboscopically engineered by an optical tweezer as a means to implement a qubit-oscillator system, in analogy to those implemented in circuit quantum electrodynamics and trapped ions. In our setting, the center of mass degree of freedom of the atoms plays the role of a photon or phonon mode, while the interacting, relative mode acts as a qubit. No internal state is involved in our system, which makes this motional qubit robust to spin-dependent noise. We show that a universal set of bosonic operations, including displacement, rotation, squeezing, and the corresponding set of gates controlled by the qubit, can be implemented through precise temporal modulation of the optical tweezers. We numerically check that these gates can be generated with high fidelity, and discuss possible schemes for initial state preparation and final state readout. While we restrict the discussion to a single qubit-oscillator module, scalability can be achieved by coupling arrays of atoms via dipolar or Rydberg-dressed interactions. - oai:arXiv.org:2512.06429v1 - quant-ph - physics.atom-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Jaeyong Hwang, Tianrui Xu, Sean R. Muleady, Steven Pampel, Gur Lubin, Dawson Hewatt, Cindy A. Regal, Ana Maria Rey - - - Phase-Factor-Controlled Surface Spirals in the Magnetic Conical Phase: The Role of In-Plane Directionality - https://arxiv.org/abs/2512.06465 - arXiv:2512.06465v1 Announce Type: cross -Abstract: In chiral magnets, the magnetic textures surrounding domain walls exhibit a rich variety of structures, offering insights into fundamental physics and potential applications in spintronic devices. Conical spirals and related structures possess intrinsic in-plane directionalities governed by phase factors $\phi_0$, which are often obscured in long spirals due to cylindrical symmetry but become prominent in short spirals or thin films. Using micromagnetic simulations, we systematically studied magnetic textures at ferromagnetic-conical interfaces (FCI), including 1D and 2D FCIs with various shapes. Surface spirals (SS) emerge adjacent to these FCIs, closely linked to the cone's in-plane reorientation. In 1D FCIs, reorientation controls the presence, shape, and topological charge of the SS, with a discontinuity point observed where spirals with opposite charges form on opposite sides. In 2D FCIs, eyebrow-like SS are evident. The reorientation angle between top and bottom SS is controlled by the film thickness, similar to stacked spirals reported previously. We further demonstrate that SSs form at the facets of skyrmion clusters within the conical phase, as confirmed by both simulations and Lorentz transmission electron microscopy observations in Co$_8$Zn$_{10}$Mn$_2$ thin films. The experiments specifically reveal two distinct formation pathways: thermally activated co-growth and field-driven transformation from residual helices. These findings establish $\phi_0$ as a fundamental control parameter for magnetic states, enabling promising spintronic functionalities such as multi-state memory through SS polymorphism and energy-efficient neuromorphic computing via controlled topological transitions. - oai:arXiv.org:2512.06465v1 - cond-mat.mes-hall - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - 10.1103/jdls-dpyq - Phys. Rev. Applied 24, 064023 (2025) - Haijun Zhao, Tae-Hoon Kim, Lin Zhou, Liqin Ke - - - Detrended cross-correlations and their random matrix limit: an example from the cryptocurrency market - https://arxiv.org/abs/2512.06473 - arXiv:2512.06473v1 Announce Type: cross -Abstract: Correlations in complex systems are often obscured by nonstationarity, long-range memory, and heavy-tailed fluctuations, which limit the usefulness of traditional covariance-based analyses. To address these challenges, we construct scale and fluctuation-dependent correlation matrices using the multifractal detrended cross-correlation coefficient $\rho_r$ that selectively emphasizes fluctuations of different amplitudes. We examine the spectral properties of these detrended correlation matrices and compare them to the spectral properties of the matrices calculated in the same way from synthetic Gaussian and $q$Gaussian signals. Our results show that detrending, heavy tails, and the fluctuation-order parameter $r$ jointly produce spectra, which substantially depart from the random case even under absence of cross-correlations in time series. Applying this framework to one-minute returns of 140 major cryptocurrencies from 2021-2024 reveals robust collective modes, including a dominant market factor and several sectoral components whose strength depends on the analyzed scale and fluctuation order. After filtering out the market mode, the empirical eigenvalue bulk aligns closely with the limit of random detrended cross-correlations, enabling clear identification of structurally significant outliers. Overall, the study provides a refined spectral baseline for detrended cross-correlations and offers a promising tool for distinguishing genuine interdependencies from noise in complex, nonstationary, heavy-tailed systems. - oai:arXiv.org:2512.06473v1 - q-fin.ST - cs.CE - physics.data-an - stat.AP - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - 10.3390/e27121236 - Entropy 2025, 27(12), 1236 - Stanis{\l}aw Dro\.zd\.z, Pawe{\l} Jarosz, Jaros{\l}aw Kwapie\'n, Maria Skupie\'n, Marcin W\k{a}torek - - - Convective Viscous Cahn-Hilliard/Allen-Cahn Equation with memory effects - https://arxiv.org/abs/2512.06508 - arXiv:2512.06508v1 Announce Type: cross -Abstract: The combination of the well-known Cahn-Hilliard and Allen-Cahn equations is used to describe surface processes, such as simultaneous adsorption/desorption and surface diffusion. In the present paper we have considered the convective-viscous Cahn-Hilliard/Allen-Cahn equation complemented by memory effects. Exact solutions are obtained and the combined action of the applied field, dissipation and memory are discussed. - oai:arXiv.org:2512.06508v1 - cond-mat.stat-mech - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - P. O. Mchedlov-Petrosyan, L. N. Davydov - - - Statistical physics for artificial neural networks - https://arxiv.org/abs/2512.06518 - arXiv:2512.06518v1 Announce Type: cross -Abstract: The 2024 Nobel Prize in Physics was awarded for pioneering contributions at the intersection of artificial neural networks (ANNs) and spin-glass physics, underscoring the profound connections between these fields. The topological similarities between ANNs and Ising-type models, such as the Sherrington-Kirkpatrick model, reveal shared structures that bridge statistical physics and machine learning. In this perspective, we explore how concepts and methods from statistical physics, particularly those related to glassy and disordered systems like spin glasses, are applied to the study and development of ANNs. We discuss the key differences, common features, and deep interconnections between spin glasses and neural networks while highlighting future directions for this interdisciplinary research. Special attention is given to the synergy between spin-glass studies and neural network advancements and the challenges that remain in statistical physics for ANNs. Finally, we examine the transformative role that quantum computing could play in addressing these challenges and propelling this research frontier forward. - oai:arXiv.org:2512.06518v1 - cond-mat.dis-nn - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Zongrui Pei - - - Hierarchical geometric deep learning enables scalable analysis of molecular dynamics - https://arxiv.org/abs/2512.06520 - arXiv:2512.06520v1 Announce Type: cross -Abstract: Molecular dynamics simulations can generate atomically detailed trajectories of complex systems, but analyzing these dynamics can be challenging when systems lack well-established quantitative descriptors (features). Graph neural networks (GNNs) in which messages are passed between nodes that represent atoms that are spatial neighbors promise to obviate manual feature engineering, but the use of GNNs with biomolecular systems of more than a few hundred residues has been limited in the context of analyzing dynamics by both difficulties in capturing the details of long-range interactions with message passing and the memory and runtime requirements associated with large graphs. Here, we show how local information can be aggregated to reduce memory and runtime requirements without sacrificing atomic detail. We demonstrate that this approach opens the door to analyzing simulations of protein-nucleic acid complexes with thousands of residues on single GPUs within minutes. For systems with hundreds of residues, for which there are sufficient data to make quantitative comparisons, we show that the approach improves performance and interpretability. - oai:arXiv.org:2512.06520v1 - cs.LG - cond-mat.stat-mech - physics.comp-ph - physics.data-an - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Zihan Pengmei, Spencer C. Guo, Chatipat Lorpaiboon, Aaron R. Dinner - - - High-harmonic generation driven by temporal-mode quantum states of light - https://arxiv.org/abs/2512.06602 - arXiv:2512.06602v1 Announce Type: cross -Abstract: We develop a theoretical framework for high-harmonic generation (HHG) driven by quantum states of light based on a temporal-mode expansion of the electromagnetic field. This approach extends previous single plane-wave mode treatments to realistic pulse configurations, resolving conceptual inconsistencies arising from non-normalizable infinite plane waves and establishing consistency between analytical and numerical methods. We derive a correction factor that quantifies deviations from the single-mode approximation and show that it remains below $10^{-4}$ for intensities typical of HHG ($\sim 10^{14}~$W/cm$^2$). This result confirms that free-space HHG driven by any quantum state of light is accurately described by averaging semi-classical calculations over the Husimi distribution, with no observable genuine quantum effects. The absence of such effects is attributed to the large photon numbers ($\sim 10^{11}$) required to reach HHG intensities in free space, which render quantum fluctuations negligible. We discuss nanophotonic environments with ultrasmall mode volumes as potential platforms where few-photon strong-field processes could exhibit genuine quantum signatures. - oai:arXiv.org:2512.06602v1 - quant-ph - physics.atom-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Juan M. Gonz\'alez-Monge, Johannes Feist - - - Fault-Tolerant Information Processing with Quantum Weak Measurement - https://arxiv.org/abs/2512.06619 - arXiv:2512.06619v1 Announce Type: cross -Abstract: Noise is an important factor that influences the reliability of information acquisition, transmission, processing, and storage. In order to suppress the inevitable noise effects, a fault-tolerant information processing approach via quantum weak measurement is proposed, where pairwise orthogonal postselected measurement bases with various tiny angles and optimal compositions of measured results are chosen as a decoding rule. The signal to be protected can be retrieved with a minimal distortion after having been transmitted through a noisy channel. Demonstrated by typical examples of encoding signal on two-level superposition state or Einstein-Podolsky-Rossen state transmitted through random telegraph noise and decoherence noises channel, the mean squared error distortion may be close to $0$ and the fault-tolerant capability could reach $1$ with finite quantum resources. To verify the availability of the proposed approach, classic coherent light and quantum coherent state are used for encoding information in the experiment. Potentially, the proposed approach may provide a solution for suppressing noise effects in long-distance quantum communication, high-sensitivity quantum sensing, and accurate quantum computation. - oai:arXiv.org:2512.06619v1 - quant-ph - physics.app-ph - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Qi Song, Hongjing Li, Chengxi Yu, Jingzheng Huang, Ding Wang, Peng Huang, Guihua Zeng - - - Compression-driven jamming in porous cohesive aggregates - https://arxiv.org/abs/2512.06624 - arXiv:2512.06624v1 Announce Type: cross -Abstract: I investigate the compression-driven jamming behavior of two-dimensional porous aggregates composed of cohesive, frictionless disks. Three types of initial aggregates are prepared using different aggregation procedures, namely, reaction-limited aggregation (RLA), ballistic particle-cluster aggregation (BPCA), and diffusion-limited aggregation (DLA), to elucidate the influence of aggregate morphology. Using distinct-element-method simulations with a shrinking circular boundary, I numerically obtain the pressure as a function of the packing fraction $\phi$. For the densest RLA and the intermediate BPCA aggregates, a clear jamming transition is observed at a critical packing fraction $\phi_{\rm J}$, below which the pressure vanishes and above which a finite pressure emerges; the transition is less distinct for the most porous DLA aggregates. The jamming threshold depends on the initial structure and, when extrapolated to infinite system size, approaches $\phi_{\rm J} = 0.765 \pm 0.004$ for RLA, $0.727 \pm 0.004$ for BPCA, and $0.602 \pm 0.023$ for DLA, where the errors denote the standard error. Above $\phi_{\rm J}$, the pressure follows $P \approx A {( \phi - \phi_{\rm J} )}^{2}$, which implies that the bulk modulus $K$ of jammed aggregates is proportional to $\phi - \phi_{\rm J}$. Rigid-cluster analysis of jammed aggregates shows that the average coordination number within the largest rigid cluster increases linearly with $\phi - \phi_{\rm J}$. Taken together, these relations suggest that the elastic response of compressed porous aggregates is analogous to that of random spring networks. - oai:arXiv.org:2512.06624v1 - cond-mat.soft - cond-mat.dis-nn - physics.ao-ph - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Sota Arakawa - - - Freestanding Thin-Film Materials - https://arxiv.org/abs/2512.06637 - arXiv:2512.06637v1 Announce Type: cross -Abstract: Freestanding thin films, a class of low-dimensional materials capable of maintaining structural integrity without substrates, have emerged as a forefront research focus. Their unique advantages-circumventing substrate clamping, liberating intrinsic material properties, and enabling cross-platform heterogeneous integration-underpin this prominence. This review systematically summarizes core fabrication techniques, including physical delamination (e.g., laser lift-off, mechanical exfoliation) and chemical etching, alongside associated transfer strategies. It further explores the induced strain modulation mechanisms, extreme mechanical properties and interface decoupling effects enabled by these films. Representative case studies demonstrate breakthrough applications in flexible/ultrathin electronics, ultrahigh-sensitivity sensors and the exploration of novel quantum states. Critical challenges regarding scalable fabrication, precise interface control, and long-term stability are analyzed, concluding with prospects for emerging applications in bio-inspired intelligent devices, quantum precision sensing, and brain-inspired neural networks. - oai:arXiv.org:2512.06637v1 - cond-mat.mtrl-sci - cond-mat.mes-hall - cond-mat.supr-con - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/publicdomain/zero/1.0/ - 10.1016/j.mattod.2025.11.035 - Li Liu, Peixin Qin, Guojian Zhao, Zhiyuan Duan, Jingyu Li, Sixu Jiang, Xiaoyang Tan, Xiaoning Wang, Ziang Meng, Zhiqi Liu - - - Full Electrical Switching of a Freestanding Ferrimagnetic Metal for Energy-Efficient Bipolar Neuromorphic Computing - https://arxiv.org/abs/2512.06669 - arXiv:2512.06669v1 Announce Type: cross -Abstract: Flexible electronics and neuromorphic computing face key challenges in material integration and function retention. In particular, freestanding membranes suffer from slow sacrificial layer removal and interfacial strain, while neuromorphic hardware often relies on area-intensive dual-device schemes for bipolar synaptic weights. Here, we present a universal strategy based on water-soluble Sr4Al2O7 sacrificial layers, enabling the rapid release of freestanding ferrimagnetic metal membranes, which exhibit deterministic spin-orbit torque switching characteristics with well-preserved perpendicular magnetic anisotropy and are potential for next-generation ultrafast information technology. Extending this approach, we realize single-device ferrimagnetic synapses exhibiting intrinsic bipolar resistive switching. When implemented in a ResNet-18 architecture, these devices achieve 92% accuracy on CIFAR-10 - comparable to floating-point software models - while halving device counts relative to differential-pair implementations. These results establish a scalable platform linking flexible spintronics with compact, high-performance neuromorphic systems, offering foundational advances for next-generation electronics and brain-inspired hardware. - oai:arXiv.org:2512.06669v1 - cond-mat.mes-hall - cond-mat.mtrl-sci - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/publicdomain/zero/1.0/ - 10.1021/acs.nanolett.5c04033 - Nano Letters, 25, 14213 (2025) - Li Liu, Peixin Qin, Xiang Wang, Xiaobo She, Shaoxuan Zhang, Xiaoning Wang, Hongyu Chen, Guojian Zhao, Zhiyuan Duan, Ziang Meng, Qinghua Zhang, Qiong Wu, Yu Liu, Zhiqi Liu - - - Learning Thermoelectric Transport from Crystal Structures via Multiscale Graph Neural Network - https://arxiv.org/abs/2512.06697 - arXiv:2512.06697v1 Announce Type: cross -Abstract: Graph neural networks (GNNs) are designed to extract latent patterns from graph-structured data, making them particularly well suited for crystal representation learning. Here, we propose a GNN model tailored for estimating electronic transport coefficients in inorganic thermoelectric crystals. The model encodes crystal structures and physicochemical properties in a multiscale manner, encompassing global, atomic, bond, and angular levels. It achieves state-of-the-art performance on benchmark datasets with remarkable extrapolative capability. By combining the proposed GNN with \textit{ab initio} calculations, we successfully identify compounds exhibiting outstanding electronic transport properties and further perform interpretability analyses from both global and atomic perspectives, tracing the origins of their distinct transport behaviors. Interestingly, the decision process of the model naturally reveals underlying physical patterns, offering new insights into computer-assisted materials design. - oai:arXiv.org:2512.06697v1 - cond-mat.mtrl-sci - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Yuxuan Zeng, Wei Cao, Yijing Zuo, Fang Lyu, Wenhao Xie, Tan Peng, Yue Hou, Ling Miao, Ziyu Wang, Jing Shi - - - A Fast, Parallelized, GPU-Accelerated Photochemical Model, XODIAC, with Built-in Equilibrium Chemistry and Multiple Chemical Networks for Exoplanetary Atmospheres - https://arxiv.org/abs/2512.06729 - arXiv:2512.06729v1 Announce Type: cross -Abstract: The launch of the James Webb Space Telescope (JWST) has delivered high-quality atmospheric observations and expanded the known chemical inventory of exoplanetary atmospheres, opening new avenues for atmospheric chemistry modeling to interpret these data. Here, we present XODIAC, a fast, GPU-accelerated, one-dimensional photochemical model with a built-in equilibrium chemistry solver, an updated thermochemical database, and three chemical reaction networks. This framework enables comparative atmospheric chemistry studies, including the newly developed XODIAC-2025 network, a state-of-the-art C-H-O-N-P-S-Metals network, linking 594 species through 7,720 reactions. The other two are existing, publicly available C-H-O-N-S and C-H-O-N-S-Metals networks, from the established photochemical models VULCAN and ARGO, respectively, which are commonly used in the community. The XODIAC model has been rigorously benchmarked on the well-studied hot Jupiter HD 189733 b, with results compared against these two models. Benchmarking shows excellent agreement and demonstrates that, when the same chemical network and initial conditions are used, the numerical scheme for solving atmospheric chemistry does not significantly affect the results. We also revisited the atmospheric chemistry of HD 189733 b and performed a comparative analysis across the three networks. Sulfur chemistry shows the least variation across networks, carbon chemistry shows slightly more, and phosphorus chemistry varies the most, primarily due to the introduction of unique PHO and PN pathways comprising 390 reactions in the XODIAC-2025 network. These findings highlight XODIAC's capability to advance exoplanetary atmospheric chemistry and provide a robust framework for comparative exoplanetology. - oai:arXiv.org:2512.06729v1 - astro-ph.EP - astro-ph.IM - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Priyankush Ghosh, Sambit Mishra, Shubham Dey, Debayan Das, Paul B. Rimmer, Liton Majumdar - - - Nanocrystals Heterostructures based on Halide Perovskites and Metal Sulfides - https://arxiv.org/abs/2512.06764 - arXiv:2512.06764v1 Announce Type: cross -Abstract: We report the synthesis of nanocrystal heterostructures composed of CsPbCl3 and PbS domains sharing an epitaxial interface. We were able to promote the growth of a PbS domain (in competition with the more commonly observed Pb4S3Cl2 one) on top of the CsPbCl3 domain by employing Mn2$^+$ ions, the latter acting most likely as scavengers of Cl$^-$ ions. Complete suppression of the Pb4S3Cl2 domain growth was then achieved by additionally selecting an appropriate sulfur source (bis(trimethylsilyl)sulfide, which also acted as scavenger of Cl$^-$ ions), and reaction temperature. In the heterostructures, emission from the perovskite domain was quenched, while emission from the PbS domain was observed, pointing to a type-I band alignment, as confirmed by calculations. These heterostructures in turn could be exploited to prepare second-generation heterostructures through selective ion exchange on the individual domains (halide ion exchange on CsPbCl3, cation exchange on PbS). We demonstrate the cases of Cl$^-$ to Br$^-$ and Pb2$^+$ to Cu$^+$ exchanges, which deliver CsPbBr3@PbS and CsPbCl3@Cu2-xS epitaxial heterostructures, respectively. - oai:arXiv.org:2512.06764v1 - cond-mat.mtrl-sci - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Nikolaos Livakas, Juliette Zito, Yurii P. Ivanov, Clara Otero Mart\'inez, Giorgio Divitini, Ivan Infante, Liberato Manna - - - Halide Perovskite-Chalcohalide Nanocrystal Heterostructures as a Platform for the Synthesis and Investigation of the CsPbCl3-CsPbI3 Epitaxial Interface - https://arxiv.org/abs/2512.06766 - arXiv:2512.06766v1 Announce Type: cross -Abstract: Halide exchange in lead-based halide perovskites has been studied extensively. While mixed Cl-Br or Br-I alloy compositions can be formed with no miscibility gaps, this is precluded for mixed Cl-I compositions, due to the large difference in Cl and I ionic radii. Here, we exploit perovskite-chalcohalide CsPbCl3-Pb4S3Cl2 heterostructures to study the Cl-I exchange and isolate new types of intermediate structures. The epitaxial interface between the Pb4S3Cl2 chalcohalide and the CsPbCl3 perovskite domain significantly influences the intermediate stages of halide exchange in the perovskite domain, leading to coexisting CsPbCl3 and CsPbI3 domains, thereby delivering segmented CsPbI3-CsPbCl3-Pb4S3Cl2 energetically favorable heterostructures, with partial iodide alloying of the CsPbCl3 domain and at the perovskite-chalcohalide interface. The I:CsPbCl3 domain between CsPbI3 and Pb4S3Cl2 enables a gradual lattice expansion across the heterostructure. This design accommodates interfacial strain, with a 5.6% mismatch at the CsPbCl3-CsPbI3 interface and a 3.4% mismatch at the perovskite-chalcohalide interface. Full halide exchange leads to CsPbI3-Pb4S3Cl2 heterostructures. Both in intermediate and fully exchanged heterostructures, the CsPbI3 domain is emissive. In the intermediate structures, the band alignment between the two perovskite domains is type-I, with carriers photogenerated in the CsPbCl3 domain quickly transferring to the CsPbI3 domain, where they can recombine radiatively. - oai:arXiv.org:2512.06766v1 - cond-mat.mtrl-sci - physics.class-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Nikolaos Livakas, Irina Skvortsova, Juliette Zito, Yurii P. Ivanov, Aswin Asaithambi, Andrea Toma, Annick De Backer, Muhammad Imran, Sandra Van Aert, Giorgio Divitini, Ivan Infante, Sara Bals, Liberato Manna - - - Polaron-Driven Spin Funneling through Rashba-Split Bands in Mixed-Phase Quasi-Two-Dimensional Ruddlesden-Popper Perovskites - https://arxiv.org/abs/2512.06773 - arXiv:2512.06773v1 Announce Type: cross -Abstract: Metal halide perovskites (MHPs) exhibit pronounced spin-orbit coupling (SOC) as a result of their heavy metal constituents, leading to distinctive electronic properties such as Rashba type band splitting which make them promising candidates for next generation spintronic applications. Here, using circularly polarized luminescence (CPL) and polarization dependent pump-probe spectroscopy, we found that spin polarization is present across all phases of our two-dimensional (2D) Ruddlesden-Popper (RP) mixed-phase perovskites, (C6H7SNH3)2 (CH3NH3)n-1PbnI3n+1 (n=1-4), irrespective of the number of inorganic layers. The origin of these spin polarized bands is attributed to the Rashba effect. Interestingly, the highly disordered nature of this system facilitates remarkably efficient ultrafast funneling of photoexcited spin-polarized excitons from the pure 2D phase (n=1) to higher-n phases at room temperature. We demonstrate that significant polaron formation due to the inherent soft crystal lattice and higher exciton-phonon interaction is responsible for the observed spin funneling effect in mixed-phase 2D RP perovskites. Polaron act as a protective mechanism for spin-polarized excitons, preserving their spin information through the screening of omnipresent phonon-induced momentum scattering. These findings not only offer valuable guidance for the design of 2D RP perovskites with pronounced Rashba effects but also unveil a compelling class of solution-processed perovskites capable of efficient spin-preserving energy transport at room temperature. - oai:arXiv.org:2512.06773v1 - cond-mat.mtrl-sci - physics.chem-ph - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Sushovan Sarkar, Koushik Gayen, Ashish Soni, Suman Kalyan Pal - - - Effective Electromagnetic Degrees of Freedom in Backscatter MIMO Systems - https://arxiv.org/abs/2512.06799 - arXiv:2512.06799v1 Announce Type: cross -Abstract: While the definition of the effective electromagnetic degrees of freedom (EEMDOFs) of a static linear multiple-input multiple-output (MIMO) system is well established, the counterpart for a backscatter MIMO (BS-MIMO) system is so far missing. A BS-MIMO system encodes the input information into the loads of backscatter elements. Due to mutual coupling, the mapping from load configuration to observed fields is fundamentally non-linear, which complicates the analysis of BS-EEMDOFs. We introduce a definition of BS-EEMDOFs based on the Jacobian of the observed fields with respect to the load configuration. We derive a closed-form expression from multiport network theory which demonstrates that the number of BS-EEMDOFs is fundamentally a distributed variable, whose distribution depends on the mutual coupling between the backscatter elements and the coherent illumination. The modes associated with BS-EEMDOFs lie in the column space of the end-to-end channel matrix from backscatter array ports to receiver ports, but the number of BS-EEMDOFs is generally different from the number of benchmark EEMDOFs associated with the same array being coherently fed rather than tunably terminated. The dependence on the coherent illumination yields optimized coherent illumination as a control knob for the number of BS-EEMDOFs. We present numerical and experimental results for the evaluation and optimization of the number of BS-EEMDOFs in different radio environments with reconfigurable intelligent surfaces. - oai:arXiv.org:2512.06799v1 - eess.SP - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Philipp del Hougne - - - Observation of Stable Bimeron Transport Driven by Spoof Surface Acoustic Waves on Chiral Metastructures - https://arxiv.org/abs/2512.06891 - arXiv:2512.06891v1 Announce Type: cross -Abstract: Topological quasiparticles, such as merons and bimerons, are characterized by non-trivial textures that exhibit remarkably robust transport against deformation, offering significant potential for information processing. While these phenomena have been explored in various systems, acoustic realizations remain challenging. Here, we report that acoustic meron topological textures were successfully realized using designed Archimedeanlike square spiral metastructures via the excitation of spoof surface acoustic waves (SSAWs). By applying mirror-symmetric combinatorial operations to the unit structures, we further construct composite chiral metastructures that enable both one-dimensional and two-dimensional stable transport of acoustic bimerons. It is further revealed that bimeron transport originates from the locked opposite phase differences of SSAWs, induced by the handedness of the cavity resonant modes. The intrinsic robustness of the meron textures against structural defects is confirmed through the calculation of their topological charge. Our findings establish stable acoustic bimeron transport as a topologically resilient foundation for future acoustic information processing and storage technologies. - oai:arXiv.org:2512.06891v1 - cond-mat.mtrl-sci - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Huaijin Ma, Te Liu, Jiachen Sheng, Kaiyan Cao, Jinpeng Yang, Jian Wang - - - Geometry protected probabilistic structure in many-body dynamics - https://arxiv.org/abs/2512.06894 - arXiv:2512.06894v1 Announce Type: cross -Abstract: Insomuch as statistical mechanics circumvents the formidable task of addressing many-body dynamics, it remains a challenge to derive macroscopic properties from a solution to Hamiltonian equations for microscopic motion of an isolated system. Launching new attacks on this long-standing problem -- part of Hilbert's sixth problem -- is urgently important, for focus of statistical phenomena is shifting from a fictitious ensemble to an individual member, i.e. a mechanically isolated system. Here we uncover a common probabilistic structure, the concentration of measure, in Hamiltonian dynamics of two families of systems, the Fermi-Pasta-Ulam-Tsingou (FPUT) model which is finite-dimensional and (almost) ergodic, and the Gross-Pitaevskii equation (GPE) which is infinite-dimensional and suffers strong ergodicity breaking. That structure is protected by the geometry of phase space and immune to ergodicity breaking, leading to counterintuitive phenomena. Notably, an isolated FPUT behaves as a thermal ideal gas even for strong modal interaction, with the thermalization time analogous to the Ehrenfest time in quantum chaos, while an isolated GPE system, without any quantum inputs, escapes the celebrated ultraviolet catastrophe through nonlinear wave localization in the mode space, and the Rayleigh-Jeans equilibrium sets in the localization volume. Our findings may have applications in nonlinear optics and cold-atom dynamics. - oai:arXiv.org:2512.06894v1 - cond-mat.stat-mech - nlin.CD - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Yue Liu, Chushun Tian, Dahai He - - - Single Flux Quantum Circuit Operation at Millikelvin Temperatures - https://arxiv.org/abs/2512.06895 - arXiv:2512.06895v1 Announce Type: cross -Abstract: As quantum computing processors increase in size, there is growing interest in developing cryogenic electronics to overcome significant challenges to system scaling. Single flux-quantum (SFQ) circuits offer a promising alternative to remote, bulky, and power-hungry room temperature electronics. To meet the need for digital qubit control, readout, and co-processing, SFQ circuits must be adapted to operate at millikelvin temperatures near quantum processors. SEEQC's SFQuClass digital quantum management approach proximally places energy-efficient SFQ (ERSFQ) circuits and qubits in a multi-chip module. This enables extremely low power dissipation, compatible with a typical dilution cryostat's limited cooling power, while maintaining high processing speed and low error rates. We report on systematic testing from 4 K to 10 mK of a comprehensive set of ERSFQ cells, as well as more complex circuits such as programmable counters and demultiplexers used in digital qubit control. We compare the operating margins and error rates of these circuits and find that, at millikelvin, bias margins decrease and the center of the margins (i.e., the optimal bias current value) increases by ~15%, compared to 4.2 K. The margins can be restored by thermal annealing by reducing Josephson junction (JJ) critical current Ic. To provide guidance for how circuit parameters vary from 4.2 K to millikelvin, relevant analog process control monitors (PCMs) were tested in the temperature range of interest. The measured JJ critical current (of the PCM JJ arrays) increases by ~15% when decreasing temperature from 4.2 K to millikelvin, in good agreement with both theory and the empirically measured change in the center of bias margins for the tested digital circuits. - oai:arXiv.org:2512.06895v1 - quant-ph - cond-mat.supr-con - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Jason Walter, Adam C. Weis, Kan-Ting Tsai, Meng-Ju Yu, Naveen Katam, Alex F. Kirichenko, Oleg A. Mukhanov, Shu-Jen Han, Igor V. Vernik - - - PARIS: Pruning Algorithm via the Representer theorem for Imbalanced Scenarios - https://arxiv.org/abs/2512.06950 - arXiv:2512.06950v1 Announce Type: cross -Abstract: The challenge of \textbf{imbalanced regression} arises when standard Empirical Risk Minimization (ERM) biases models toward high-frequency regions of the data distribution, causing severe degradation on rare but high-impact ``tail'' events. Existing strategies uch as loss re-weighting or synthetic over-sampling often introduce noise, distort the underlying distribution, or add substantial algorithmic complexity. - We introduce \textbf{PARIS} (Pruning Algorithm via the Representer theorem for Imbalanced Scenarios), a principled framework that mitigates imbalance by \emph{optimizing the training set itself}. PARIS leverages the representer theorem for neural networks to compute a \textbf{closed-form representer deletion residual}, which quantifies the exact change in validation loss caused by removing a single training point \emph{without retraining}. Combined with an efficient Cholesky rank-one downdating scheme, PARIS performs fast, iterative pruning that eliminates uninformative or performance-degrading samples. - We use a real-world space weather example, where PARIS reduces the training set by up to 75\% while preserving or improving overall RMSE, outperforming re-weighting, synthetic oversampling, and boosting baselines. Our results demonstrate that representer-guided dataset pruning is a powerful, interpretable, and computationally efficient approach to rare-event regression. - oai:arXiv.org:2512.06950v1 - stat.ML - cs.LG - physics.space-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Enrico Camporeale - - - Probing Anharmonic Lattice Dynamics and Thermal Transport in Layered Perovskite LiYTiO4 Anode - https://arxiv.org/abs/2512.06954 - arXiv:2512.06954v1 Announce Type: cross -Abstract: Layered perovskite lithium yttrium titanate ($\rm LiYTiO_4$) has recently emerged as a promising low-potential, ultrahigh-rate intercalation-type anode material for lithium-ion batteries; however, its lattice dynamics and thermal transport properties remain poorly understood, limiting a complete evaluation of its practical potential. Here, we combine experimental measurements with theoretical modeling to systematically investigate the anharmonic lattice dynamics and heat transport in $\rm LiYTiO_4$. We employ a neural evolution potential (NEP)-based framework that integrates the temperature-dependent effective potential method with the Wigner thermal transport (WTT) formalism, explicitly including both diagonal and off-diagonal terms of the heat-flux operator. Zero-temperature phonon calculations reveal dynamical instabilities associated with $\rm TiO_6$ octahedral rotation, which are stabilized at finite temperatures through anharmonic renormalization. Using the WTT approach with contributions from phonon propagation and coherence contributions, we predict a room-temperature lattice thermal conductivity ($\kappa_{\rm L}$) of 3.8 $\rm Wm^{-1}K^{-1}$ averaged over all crystal orientations, in close agreement with the measured value of 3.2 \pm 0.08 $\rm Wm^{-1}K^{-1}$ for polycrystalline samples. To further examine the possible influence of ionic motion on high-temperature thermal transport, we compute $\kappa_{\rm L}$ using a Green-Kubo equilibrium molecular dynamics approach based on the same NEP, which yields consistent results with both experiment and WTT predictions, confirming the negligible role of Li-ion mobility in heat conduction. Our study not only identifies the ultralow thermal conductivity of $\rm LiYTiO_4$ as a key limitation for its practical application but also establishes a reliable computational framework for studying thermal properties in battery materials. - oai:arXiv.org:2512.06954v1 - cond-mat.mtrl-sci - cond-mat.mes-hall - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Lin Zhang, Wen Liu, Mingquan He, Jun Huang - - - Parametric Design of a Cable-Driven Coaxial Spherical Parallel Mechanism for Ultrasound Scans - https://arxiv.org/abs/2512.06995 - arXiv:2512.06995v1 Announce Type: cross -Abstract: Haptic interfaces play a critical role in medical teleoperation by enabling surgeons to interact with remote environments through realistic force and motion feedback. Achieving high fidelity in such systems requires balancing performance trade-off among workspace, dexterity, stiffness, inertia, and bandwidth, particularly in applications demanding pure rotational motion. This paper presents the design methodology and kinematic analysis of a Cable-Driven Coaxial Spherical Parallel Mechanism (CDC-SPM) developed to address these challenges. The proposed cable-driven interface design allows for reducing the mass placed at the robot arm end-effector, thereby minimizing inertial loads, enhancing stiffness, and improving dynamic responsiveness. Through parallel and coaxial actuation, the mechanism achieves decoupled rotational degrees of freedom with isotropic force and torque transmission. Simulation and analysis demonstrate that the CDC-SPM provides accurate, responsive, and safe motion characteristics suitable for high-precision haptic applications. These results highlight the mechanism's potential for medical teleoperation tasks such as ultrasound imaging, where precise and intuitive manipulation is essential. - oai:arXiv.org:2512.06995v1 - cs.RO - physics.class-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Maryam Seraj, Mohammad Hossein Kamrava, Carlo Tiseo - - - Symmetry, Invariant Manifolds and Flow Reversals in Active Nematic Turbulence - https://arxiv.org/abs/2512.07047 - arXiv:2512.07047v1 Announce Type: cross -Abstract: We investigate how symmetry, exact coherent structures (ECSs), and their invariant manifolds organize spontaneous flow reversals in a 2D active nematic confined to a periodic channel. In minimal flow units commensurate with the intrinsic active vortex scale, we use equivariant bifurcation theory to trace the origin of dynamically relevant ECSs via a sequence of symmetry-constrained local and global bifurcations. At low activity level, we identify relative periodic orbits, created via a sequence of SNIPER, homoclinic and heteroclinic bifurcations, whose invariant manifolds provide robust heteroclinic pathways between left- and right-flowing nearly uniaxial states. These result in several symmetry-dictated reversal mechanisms in the preturbulent regime, with and without vortex-lattice intermediate states. In the active turbulent regime, this ECS skeleton persists and organizes chaotic attractors exhibiting persistent two-way reversals. By classifying ECSs through their symmetry signatures, we relate a small set of ECSs embedded in turbulence back to the preturbulent branches, and show that typical turbulent trajectories repeatedly shadow these ECSs and their unstable manifolds, resulting in near-heteroclinic transitions between opposite-flow states. Our results establish that channel confined active nematic turbulence is organized by a low-dimensional, symmetry-governed network of invariant solutions and their manifolds, and identify dynamical mechanisms that could be exploited to design, promote, or suppress flow reversals in active matter microfluidic devices. - oai:arXiv.org:2512.07047v1 - cond-mat.soft - math.DS - nlin.CD - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Angel Naranjo, Rumayel Pallock, Caleb Wagner, Piyush Grover - - - Machine Learning-based Unfolding for Cross Section Measurements in the Presence of Nuisance Parameters - https://arxiv.org/abs/2512.07074 - arXiv:2512.07074v1 Announce Type: cross -Abstract: Statistically correcting measured cross sections for detector effects is an important step across many applications. In particle physics, this inverse problem is known as \textit{unfolding}. In cases with complex instruments, the distortions they introduce are often known only implicitly through simulations of the detector. Modern machine learning has enabled efficient simulation-based approaches for unfolding high-dimensional data. Among these, one of the first methods successfully deployed on experimental data is the \textsc{OmniFold} algorithm, a classifier-based Expectation-Maximization procedure. In practice, however, the forward model is only approximately specified, and the corresponding uncertainty is encoded through nuisance parameters. Building on the well-studied \textsc{OmniFold} algorithm, we show how to extend machine learning-based unfolding to incorporate nuisance parameters. Our new algorithm, called Profile \textsc{OmniFold}, is demonstrated using a Gaussian example as well as a particle physics case study using simulated data from the CMS Experiment at the Large Hadron Collider. - oai:arXiv.org:2512.07074v1 - stat.AP - hep-ex - hep-ph - physics.data-an - stat.ML - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Huanbiao Zhu, Krish Desai, Mikael Kuusela, Vinicius Mikuni, Benjamin Nachman, Larry Wasserman - - - Wigner's Frame - https://arxiv.org/abs/2512.07101 - arXiv:2512.07101v1 Announce Type: cross -Abstract: This article suggests that thinking about the role of reference frames can provide new insight into Extended Wigner's Friend scenarios. This involves appealing to symmetries to make a principled distinction between properties of a system which are meaningful only relative to an external reference system and properties which are meaningful without further relativization. Thus we may propose that there are always well-defined facts about what observers have observed, but there are not necessarily well-defined facts about the relations between their reference frames, so there will not always exist a joint distribution over their outcomes which can meaningfully be compared to the predictions of quantum mechanics. In addition, this approach also offers a general argument against the idea that there should be a regress of relativization. - oai:arXiv.org:2512.07101v1 - quant-ph - physics.hist-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Emily Adlam - - - Single-cell identification with quantum-enhanced nuclear magnetic resonance - https://arxiv.org/abs/2512.07307 - arXiv:2512.07307v1 Announce Type: cross -Abstract: Identification of individual cells within heterogeneous populations is essential for biomedical research and clinical diagnostics. Conventional labeling-based sorting methods, such as fluorescence-activated cell sorting and magnetic-activated cell sorting, enable precise sorting when reliable markers are available. However, their applicability is limited in cells lacking defined markers or sensitive to labeling, as labeling can compromise cellular viability and function. We present a single-cell identification approach using quantum-enhanced NMR with diamond nitrogen-vacancy centers for label-free detection of intracellular proton ($^1$H) signals. Using this method, we distinguish two human tumor cell lines by their proton spin-lattice ($T_1$) relaxation times, which serve as a cell-intrinsic physicochemical signature. It lays the groundwork for label-free sorting applications in rare cell analysis, personalized medicine, and single-cell diagnostics. - oai:arXiv.org:2512.07307v1 - quant-ph - physics.bio-ph - physics.med-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zhiyuan Zhao, Qian Shi, Shaoyi Xu, Xiangyu Ye, Mengze Shen, Jia Su, Ya Wang, Tianyu Xie, Qingsong Hu, Fazhan Shi, Jiangfeng Du - - - Dispersive readout with two orthogonal modes of a dielectric cavity - https://arxiv.org/abs/2512.07356 - arXiv:2512.07356v1 Announce Type: cross -Abstract: Nitrogen-vacancy color centers in diamond have proven themselves as a good, sensitive element for the measurement of magnetic fields. While the mainstream of magnetometers based on NV centers uses so-called optically detected magnetic resonance, there has recently been a suggestion to use dispersive readout of a dielectric cavity to enhance the sensitivity of magnetometers. Here, we demonstrate that the dispersive readout approach can be significantly improved if a two-channel scheme is considered. - oai:arXiv.org:2512.07356v1 - quant-ph - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - A. M. Kozodaev, I. S. Cojocaru, S. M. Drofa, P. G. Vilyuzhanina, A. Chernyavskiy, V. G. Vins, A. N. Smolyaninov, S. Ya. Kilin, S. V. Bolshedvorskii, V. V. Soshenko, A. V. Akimov - - - Non-Intrusive Data-Free Parametric Reduced Order Model for Geometrically Nonlinear Structures - https://arxiv.org/abs/2512.07366 - arXiv:2512.07366v1 Announce Type: cross -Abstract: We present a fully non-intrusive parametric reduced-order modeling (PROM) framework for geometrically nonlinear structures subject to geometric variations. The method builds upon equation-driven Galerkin ROMs constructed from vibration modes and modal-derivative companion vectors, while nonlinear reduced tensors are identified from standard finite element outputs. A database of such ROMs is generated over a set of training samples, and all reduced operators-including the linear stiffness matrix, the quadratic and cubic nonlinear tensors, the Rayleigh damping parameters, and the reduction basis-are interpolated using Radial Basis Functions (RBFs). A global reduced basis is obtained through a two-level POD compression, combined with a MAC-guided reordering strategy to ensure parametric smoothness. The resulting PROM preserves the symmetry and polynomial structure of the reduced equations, enabling robust and efficient adaptation to new parameter values. Analytical parameter sensitivities follow directly from the interpolation model. The approach is demonstrated on a parametrically curved panel and a wing-box with geometric variations, showing excellent agreement with high-fidelity simulations and enabling substantial reductions in computational cost for parametric analyses. - oai:arXiv.org:2512.07366v1 - math.NA - cs.NA - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Alexander Saccani, Paolo Tiso - - - Bridging CORDEX and CMIP6: Machine Learning Downscaling for Wind and Solar Energy Droughts in Central Europe - https://arxiv.org/abs/2512.07429 - arXiv:2512.07429v1 Announce Type: cross -Abstract: Reliable regional climate information is essential for assessing the impacts of climate change and for planning in sectors such as renewable energy; yet, producing high-resolution projections through coordinated initiatives like CORDEX that run multiple physical regional climate models is both computationally demanding and difficult to organize. Machine learning emulators that learn the mapping between global and regional climate fields offer a promising way to address these limitations. Here we introduce the application of such an emulator: trained on CMIP5 and CORDEX simulations, it reproduces regional climate model data with sufficient accuracy. When applied to CMIP6 simulations not seen during training, it also produces realistic results, indicating stable performance. Using CORDEX data, CMIP5 and CMIP6 simulations, as well as regional data generated by two machine learning models, we analyze the co-occurrence of low wind speed and low solar radiation and find indications that the number of such energy drought days is likely to decrease in the future. Our results highlight that downscaling with machine learning emulators provides an efficient complement to efforts such as CORDEX, supplying the higher-resolution information required for impact assessments. - oai:arXiv.org:2512.07429v1 - stat.AP - physics.ao-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Nina Effenberger, Maxim Samarin, Maybritt Schillinger, Reto Knutti - - - Non-Hermitian off-diagonal disordered optical lattices - https://arxiv.org/abs/2512.07435 - arXiv:2512.07435v1 Announce Type: cross -Abstract: Within the framework of non-Hermitian photonics, we investigate the spectral and dynamical properties of one- and two-dimensional non-Hermitian off-diagonal disordered optical lattices, where randomness is applied to the couplings rather than to the on-site potential terms. We analyze eigenvalue distributions and the localization properties of the eigenmodes, comparing them with those of the corresponding Hermitian lattices. Furthermore, we study their transport behavior under single-channel excitation and identify unconventional phenomena such as jumps between distant lattice regions in systems with a purely real spectrum, as well as complex spectrum-induced Anderson jumps, reported here for the first time in two dimensions. Our results establish a reference framework for non-Hermitian off-diagonal disorder and open new directions for future studies of localization phenomena. - oai:arXiv.org:2512.07435v1 - cond-mat.dis-nn - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - E. T. Kokkinakis, I. Komis, K. G. Makris, E. N. Economou - - - Prediction and inference in complex networks: a brief review and perspectives - https://arxiv.org/abs/2512.07439 - arXiv:2512.07439v1 Announce Type: cross -Abstract: Inference and prediction are fundamental to the study of complex systems, where network data are often incomplete, inaccurate or obtained indirectly. In this paper, we review recent advances in network sampling and comparison, as well as in link prediction and network reconstruction from time series. We summarise key methodological developments and emerging approaches that integrate statistical and machine learning perspectives. We also outline promising research directions for enhancing the inference and prediction of complex networked systems. - oai:arXiv.org:2512.07439v1 - cond-mat.stat-mech - physics.soc-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Europhysics Letters (EPL), 2026 - Francisco A. Rodrigues - - - The influence of Parker spiral on the reflection-driven turbulence - https://arxiv.org/abs/2512.07446 - arXiv:2512.07446v1 Announce Type: cross -Abstract: The solar wind is observed to undergo substantial heating as it expands through the heliosphere, with measured temperature profiles exceeding those expected from adiabatic cooling. A plausible source of this heating is reflection-driven turbulence (RDT), in which gradients in the background Alfv\'en speed partially reflect outward-propagating Alfv\'en waves, seeding counter-propagating fluctuations that interact and dissipate via turbulence. Previous RDT models assume a radial background magnetic field, but at larger radii the interplanetary field is known to be twisted into the Parker Spiral (PS). Here, we generalize RDT phenomenology to include a PS, using three-dimensional expanding-box magnetohydrodynamic (MHD) simulations to test the ideas and compare the resulting turbulence to the radial-background-field case. We argue that the underlying RDT dynamics remain broadly similar with a PS, but the controlling scales change: as the azimuthal field grows it "cuts across" perpendicularly stretched, pancake-like eddies, producing outer scales perpendicular to the magnetic field that are much smaller than in the radial-background case. Consequently, the outer-scale nonlinear turnover time increases more slowly with heliocentric distance in PS geometry, weakening the tendency (seen in radial-background models) for the cascade to 'freeze' into quasi-static, magnetically dominated structures. This allows the system to dissipate a larger fraction of the fluctuation energy as heat, also implying that the turbulence remains strongly imbalanced (with high normalized cross-helicity) out to larger heliocentric distances. We complement our heating results with a detailed characterization of the turbulence (e.g., spectra, switchbacks, and compressive fractions) providing a set of concrete predictions for comparison with spacecraft observations. - oai:arXiv.org:2512.07446v1 - astro-ph.SR - physics.plasm-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Khurram Abbas, Jonathan Squire - - - Improving the Stability of Colloidal CsPbBr3 Nanocrystals with an Alkylphosphonium Bromide as Surface Ligand Pair - https://arxiv.org/abs/2512.07447 - arXiv:2512.07447v1 Announce Type: cross -Abstract: In this study, we synthesised a phosphonium-based ligand, trimethyl(tetradecyl)phosphonium bromide (TTP-Br), and employed it in the post-synthesis surface treatment of Cs-oleate-capped CsPbBr3 NCs. The photoluminescence quantum yield (PLQY) of the NCs increased from 60% to more than 90%, as a consequence of replacing Cs-oleate with TTP-Br ligand pairs. Density functional theory calculations revealed that TTP+ ions bind to the NC surface by occupying Cs+ surface sites and orienting one of their P-CH3 bonds perpendicular to the surface, akin to quaternary ammonium passivation. Importantly, TTP-Br-capped NCs exhibited higher stability in air compared to didodecyldimethylammonium bromide-capped CsPbBr3 NCs (which is considered a benchmark system), retaining 90% of their PLQY after six weeks of air exposure. Light-emitting diodes fabricated with TTP-Br-capped NCs achieved a maximum external quantum efficiency of 17.2 %, demonstrating the potential of phosphonium-based molecules as surface ligands for CsPbBr3 NCs in optoelectronic applications. - oai:arXiv.org:2512.07447v1 - cond-mat.mtrl-sci - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Meenakshi Pegu, Hossein Roshan, Clara Otero-Martinez, Luca Goldoni, Juliette Zito, Nikolaos Livakas, Pascal Rusch, Francesco De Boni, Francesco Di Stasio, Ivan Infante, Luca De Trizio, Liberato Manna - - - Generalized density functional theory framework for the non-linear density response of quantum many-body systems - https://arxiv.org/abs/2512.07457 - arXiv:2512.07457v1 Announce Type: cross -Abstract: A density functional theory (DFT) framework is presented that links functional derivatives of free-energy functionals to non-linear static density response functions in quantum many-body systems. Within this framework, explicit expressions are derived for various higher-order response functions of systems that are homogeneous on average, including the first theoretical result for the cubic response at the first harmonic $\chi_0^{(1,3)}(\vec{q})$. Specifically, our framework includes hitherto neglected mode-coupling effects that are important for the non-linear density response even in the presence of a single harmonic perturbation. We compare these predictions for $\chi_0^{(1,3)}(\vec{q})$ to new Kohn-Sham DFT simulations, leading to excellent agreement between theory and numerical results. Exact analytical expressions are also obtained for the long-wavelength limits of the ideal quadratic and cubic response functions. Particular emphasis is placed on the connections between the third- and fourth-order functional derivatives of the non-interacting free-energy functional $F_s[n]$ and the ideal quadratic and cubic response functions of the uniform electron gas, respectively. These relations provide exact constraints that may prove useful for the future construction of improved approximations to $F_s[n]$, in particular for warm dense matter applications at finite temperatures. Here, we use this framework to assess several commonly employed approximations to $F_s[n]$ through orbital-free DFT simulations of the harmonically perturbed ideal electron gas. The results are compared with Kohn-Sham DFT calculations across temperatures ranging from the ground state to the warm dense regime. Additionally, we analyze in detail the temperature- and wavenumber-dependent non-monotonic behavior of the ideal quadratic and cubic response functions. - oai:arXiv.org:2512.07457v1 - cond-mat.stat-mech - physics.chem-ph - physics.plasm-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zhandos A. Moldabekov, Cheng Ma, Xuecheng Shao, Sebastian Schwalbe, Pontus Svensson, Panagiotis Tolias, Jan Vorberger, Tobias Dornheim - - - Long-wavelength UV-LEDs and charge management in the detection of gravitational waves in space - https://arxiv.org/abs/2512.07546 - arXiv:2512.07546v1 Announce Type: cross -Abstract: For the charge management system in gravitational wave detection missions, a continuous discharge strategy is considered by continuously illuminating a test mass (TM) with weak light in such a way to strike a balance between the charging and discharging rates and at the same time avoids the requirement for frequent activation of charge measurements. Built on experiments by one of us based on a simple parallel plate model for inertial sensor, in the present work a more sophisticated inertial sensor model that mimics the surface properties and work function of a cubical TM of an inertial sensor in space (like that of the LISA Pathfinder) is employed to study bipolar charge management system that utilizes UV-LEDs with peak wavelengths of 269 nm, 275 nm, 280 nm, and 295 nm that are longer than the standard 255 nm commonly employed for direct TM illumination. Experimental results indicate that the 275 nm UV-LED achieves optimal performance, maintaining the TM potential closer to zero and at the same time accommodates both rapid discharge and continuous discharge strategies. The present work provides useful input in the future study of system design and optimization for the charge management system. - oai:arXiv.org:2512.07546v1 - gr-qc - astro-ph.IM - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/publicdomain/zero/1.0/ - Yuandong Jia, Yinbowen Zhang, Suwen Wang, Guozhi Chai, Zemin Zhang, Yi Zhang, Hongxin Li, Shuanglin Huang, Hongqing Huo, Zongfeng Li, Yun Kau Lau - - - Spin-Texture Spin-valve with a van der Waals Magnet - https://arxiv.org/abs/2512.07559 - arXiv:2512.07559v1 Announce Type: cross -Abstract: All-electrical methods for nucleating, detecting, and manipulating spin textures in two-dimensional (2D) van der Waals (vdW) magnets can serve as fundamental building blocks for multi-state spintronic memory, logic, and neuromorphic computing applications. Unlike conventional ferromagnets, vdW ferromagnets such as Fe5GeTe2 with strong Dzyaloshinskii-Moriya interactions stabilize nanoscale chiral spin textures, including skyrmions and stripe domains. However, the sub-100 nm size of these spin textures has limited their study to sophisticated microscopy techniques. Here, we demonstrate all-electrical detection of spin textures in vdW itinerant ferromagnet Fe5GeTe2 using pure spin transport in a lateral graphene spin-valve device at room temperature. By engineering nanoscale constrictions or notches in Fe5GeTe2, we create spin textures that inject distinct spin polarizations into the graphene channel, where they are nonlocally sensed by a reference conventional ferromagnetic detector at room temperature. This enables the observation of anomalous multi-level spin-valve switching and Hanle spin precession signals, which are due to unique spin textures in Fe5GeTe2 and in sharp contrast to single-domains and conventional magnet-based devices. This all-electrical approach can provide direct access to the spin textures on an integrated 2D spintronic circuit without the need for ex-situ microscopic characterizations. - oai:arXiv.org:2512.07559v1 - cond-mat.mes-hall - cond-mat.mtrl-sci - cond-mat.str-el - physics.app-ph - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Bing Zhao, Roselle Ngaloy, Lars Sj\"ostr\"om, Saroj P. Dash - - - Mid-infrared intraband transitions in InAs colloidal quantum dots - https://arxiv.org/abs/2512.07600 - arXiv:2512.07600v1 Announce Type: cross -Abstract: III-V colloidal quantum dots are widely studied for their applications as detectors and emitters from visible to short-wave infrared. They might also be used in the mid-infrared if they can be stably n-doped to access their intraband transitions. Mid-infrared intraband transitions are therefore studied for InAs, InAs/InP, and InAs/ZnSe colloidal quantum dots with an energy gap at 1.4 micron. Using electrochemistry, the quantum dot films show state-resolved mobility, state-resolved electron filling, and intraband absorption in the 3-8 micron range. The InAs/ZnSe films need a more reducing potential than InAs, but the InAs/InP films need a lower reduction potential. As a result, we found that dry films of InAs/InP dots show stable n-doping of the 1Se state, with a steady-state intraband absorption in the 3-5 micron range, and intraband luminescence at 5 micron. low-toxicity, high thermal stability, and stable n-doping, InAs quantum dots become an interesting material for mid-infrared applications. - oai:arXiv.org:2512.07600v1 - cond-mat.mtrl-sci - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Shraman Kumar Saha, Philippe Guyot-Sionnest - - - Enhanced charging power in nonreciprocal quantum battery by reservoir engineering - https://arxiv.org/abs/2512.07626 - arXiv:2512.07626v1 Announce Type: cross -Abstract: We propose a scheme to achieve a nonreciprocal quantum battery (QB) in the non-Hermitian (NH) system, which can overcome the intrinsic dissipation and reverse flow constraints. The design is based on a charger and a battery, which are coherently coupled and jointly interact with a bad cavity. By introducing the auxiliary bad cavity and exploiting the nonreciprocal condition, this model can harness the environmental dissipation to suppress the reverse energy transfer. Under resonant conditions, we have achieved a four ratio of the battery energy to the charger energy; in contrast, this ratio is significantly reduced under large detuning. Through damping optimization, high efficiency of the short-time charging power is attained. In comparison to the fully nonreciprocal scheme, the QB operating at the exceptional point (EP) exhibits greater resilience to parameter fluctuations. These findings highlight the potential of NH quantum engineering for advancing QB technology, particularly in regimes involving directional energy transfer, controlled dissipation, and entropy management in open quantum systems. - oai:arXiv.org:2512.07626v1 - quant-ph - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Qi-Yin Lin, Guang-Zheng Ye, Can Li, Wan-Jun Su, Huai-Zhi Wu - - - Magnonics of time-varying media: Giant amplification via phase-transition-driven temporal interfaces - https://arxiv.org/abs/2512.07713 - arXiv:2512.07713v1 Announce Type: cross -Abstract: Gilbert damping-the primary obstacle limiting spin-wave propagation in magnonic devices-can be transformed from an adversary into an asset. Here we demonstrate 175-fold spin-wave amplitude amplification in ultrathin films with perpendicular magnetic anisotropy at temporal interfaces associated with a field-driven transition between a uniform in-plane state and a stripe-domain state, exceeding existing parametric and spin-torque schemes (10-50-fold) without a continuous power supply. When the in-plane bias field is swept through a critical value in the presence of finite Gilbert damping, the spin-wave dispersion undergoes dramatic softening, and the eigenfrequency crosses zero and acquires a positive imaginary part that drives exponential growth. We identify this as a damping-induced instability operating near an exceptional point-a non-Hermitian degeneracy where, counterintuitively, increased Gilbert damping enhances amplification. This mechanism exploits ingredients specific to these magnetic films: the interplay of Gilbert damping, Dzyaloshinskii-Moriya-interaction-induced nonreciprocity, and field-driven phase transitions-a combination that, to our knowledge, has no direct counterpart in photonic or acoustic time-varying platforms. Our analytical framework provides explicit design rules, while micromagnetic simulations capture the full nonlinear dynamics, including stripe-domain formation. This work establishes temporal magnonics as a new paradigm for reconfigurable, lithography-free spin-wave control. - oai:arXiv.org:2512.07713v1 - cond-mat.mes-hall - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://creativecommons.org/licenses/by/4.0/ - Krzysztof Sobucki, Pawel Gruszecki - - - Statistical properties of quantum jumps between macroscopic states of light: reading an operational coherence record - https://arxiv.org/abs/2512.07754 - arXiv:2512.07754v1 Announce Type: cross -Abstract: We propose an experimental apparatus to reveal the quantum coherence manifested in downward quantum jumps of amplitude bistability. The underlying coherent superposition of macroscopic quantum states is translated into the statistical properties of the integrated charge deposited in the detector circuit of a mode-matched heterodyne/homodyne detection scheme. At first, the dynamical evolution of a signal transmitted from an auxiliary cavity is employed to pinpoint a macroscopic switching event in a bistable main cavity subject to direct photodetection. Once the decision is made on the occurrence of a downward switch, the main cavity mode is let to freely decay to the vacuum, monitored to the production of an integrated charge. In the long-time limit, the charge distribution over an identical collection of pure states generated during the jumps converges to the Q function (heterodyne detection) or marginals of the Wigner function (homodyne detection) dictated by the phase of the local oscillator. When fluctuations over the ensemble step in, we connect the statistical properties of several switching events and the ensuing production of current records, to the cavity field correlations associated with the breakdown of photon blockade. - oai:arXiv.org:2512.07754v1 - quant-ph - cond-mat.mes-hall - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Th. K. Mavrogordatos - - - Trapped Fermions Through Kolmogorov-Arnold Wavefunctions - https://arxiv.org/abs/2512.07800 - arXiv:2512.07800v1 Announce Type: cross -Abstract: We investigate a variational Monte Carlo framework for trapped one-dimensional mixture of spin-$\frac{1}{2}$ fermions using Kolmogorov-Arnold networks (KANs) to construct universal neural-network wavefunction ans\"atze. The method can, in principle, achieve arbitrary accuracy, limited only by the Monte Carlo sampling and was checked against exact results at sub-percent precision. For attractive interactions, it captures pairing effects, and in the impurity case it agrees with known results. We present a method of systematic transfer learning in the number of network parameters, allowing for efficient training for a target precision. We vastly increase the efficiency of the method by incorporating the short-distance behavior of the wavefunction into the ans\"atz without biasing the method. - oai:arXiv.org:2512.07800v1 - nucl-th - cond-mat.dis-nn - cond-mat.quant-gas - physics.comp-ph - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Paulo F. Bedaque, Jacob Cigliano, Hersh Kumar, Srijit Paul, Suryansh Rajawat - - - The impossibility of expanding the square root of the electron density as a linear combination of elements of a complete set of basis functions - https://arxiv.org/abs/1804.00252 - arXiv:1804.00252v2 Announce Type: replace -Abstract: In orbital-free density functional theory (OFDFT), an equation exists for $\psi = \sqrt n$, the square root of the ground state electron density $n$. We show that $\psi$ cannot be expanded as a linear combination of elements of a complete set of basis functions except in the case of one or two electron systems. This is unlike the case for the ground state of a system of identical bosons in which the square root of the ground state bosonic density can have an expansion as a linear combination of elements of a complete set of basis functions. - oai:arXiv.org:1804.00252v2 - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Omololu Akin-Ojo - - - Radiation pattern and source size of particles in nanoplasmonic fusion - https://arxiv.org/abs/2309.05156 - arXiv:2309.05156v5 Announce Type: replace -Abstract: For the angular radiation patterns of proton, deuteron or alpha emission we present a way using particle-in-cell simulation of laser induced nanoplasmonic fusion. The differential Hanbury-Brown and Twiss analysis is widely used in astrophysics and in relativistic heavy ion physics to determine the source size of emitted particles. Here, we show how this method could be adopted for inertial confinement fusion. This method aims to determine the parameters of emitted nuclei after the fusion target ignition. In addition to spatial volume, the method can detect specific space-time correlation patterns connected to the collective flow post-ignition. In the NAPLIFE project our aim is to avoid thermalization and fluidization as much as possible at each stage of the fusion process. As the original laser beam is non-thermal and not equilibrated in any way it is obvious that we can minimize energy loss if we exploit the initial available energy in a non-thermal way. The detailed dynamics of deuterium and alpha production is not aimed at and not addressed by this paper. - oai:arXiv.org:2309.05156v5 - physics.plasm-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1142/S0218301326420012 - International Journal of Modern Physics E (2026) 2642001 - L. P. Csernai, T. Cs\"org\H{o}, I. Papp, K. Tamosiunas, M. Csete, A. Szenes, D. Vass, T. S. Bir\'o, N. Kro\'o - - - Anatomical basis of sex differences in the electrocardiogram identified by three-dimensional torso-heart imaging reconstruction pipeline - https://arxiv.org/abs/2312.13976 - arXiv:2312.13976v4 Announce Type: replace -Abstract: The electrocardiogram (ECG) is used for diagnosis and risk stratification in myocardial infarction (MI). Women have a higher incidence of missed MI diagnosis and complications following infarction, and to address this we aim to provide quantitative information on sex-differences in ECG and torso-ventricular anatomical features and their interdependence. A novel computational automated pipeline is presented enabling the three-dimensional reconstruction of torso-ventricular anatomies for 425 post-MI subjects and 1051 healthy controls from UK Biobank clinical images. Regression models were created relating torso-ventricular and ECG parameters. We found that female hearts were positioned more posteriorly and superiorly than male, and in MI hearts were oriented more horizontally, especially for women. Post-MI women exhibited less QRS prolongation, requiring 27% more prolongation than men to exceed 120ms. Only half of the sex difference in QRS duration was associated with smaller female cavities. Lower STj amplitude in women was striking, associated with smaller ventricles, but also more superior and posterior cardiac position. Post-MI, T wave amplitude and R axis deviations were more strongly associated with posterior and horizontal cardiac positioning in women than in men. Our study highlights the need to quantify sex differences in anatomical features, their implications in ECG interpretation, and the application of clinical ECG thresholds in post-MI. - oai:arXiv.org:2312.13976v4 - physics.med-ph - cs.AI - cs.CG - eess.IV - q-bio.QM - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Hannah J. Smith, Blanca Rodriguez, Yuling Sang, Marcel Beetz, Robin P. Choudhury, Vicente Grau, Abhirup Banerjee - - - Modeling diffusion in networks with communities: a multitype branching process approach - https://arxiv.org/abs/2408.04456 - arXiv:2408.04456v2 Announce Type: replace -Abstract: The dynamics of diffusion in complex networks are widely studied to understand how entities, such as information, diseases, or behaviors, spread in an interconnected environment. Complex networks often present community structure, and tools to analyze diffusion processes on networks with communities are needed. In this paper, we develop theoretical tools using multi-type branching processes to model and analyze diffusion processes, following a simple contagion mechanism, across a broad class of networks with community structure. We show how, by using limited information about the network -- the degree distribution within and between communities -- we can calculate standard statistical characteristics of propagation dynamics, such as the extinction probability, hazard function, and cascade size distribution. These properties can be estimated not only for the entire network but also for each community separately. - Furthermore, we estimate the probability of spread crossing from one community to another where it is not currently spreading. We demonstrate the accuracy of our framework by applying it to two specific examples: the Stochastic Block Model and a log-normal network with community structure. We show how the initial seeding location affects the observed cascade size distribution on a heavy-tailed network and that our framework accurately captures this effect. - oai:arXiv.org:2408.04456v2 - physics.soc-ph - stat.OT - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.1103/PhysRevE.111.034310 - Alina Dubovskaya, Caroline B. Pena, David J. P. O'Sullivan - - - A new theory of tensor-scalar gravity coupled to Aharonov-Bohm electrodynamics - https://arxiv.org/abs/2408.05230 - arXiv:2408.05230v3 Announce Type: replace -Abstract: Tensor-scalar theories of gravitation are commonly employed as extensions of General Relativity that allow to describe a much wider phenomenology. They are also naturally generated as low energy limit of higher-dimensional or unified theories, and the gravitational scalar components can represent quantum corrections to the Einstein theory. The coupling of the scalars to an e.m. field does not introduce any relevant new physics if the e.m. action has the usual Maxwell form, implying a vanishing trace of the e.m. energy-momentum tensor. In the case of the extended Aharonov-Bohm electrodynamics some interesting new situations are possible, which in this work are analyzed in the gravitational weak-field approximation and for a basic version of tensor-scalar gravity involving only a Brans-Dicke field plus another scalar. Since the Aharonov-Bohm theory differs from Maxwell theory only in the presence of anomalous sources with local violation of charge conservation, which is thought to be possible only at a quantum level, the resulting formal framework can be useful to model interactions between gravitation and physical systems with macroscopic quantization. The theory contains some unknown parameters, the most important being the VEV $\psi_0$ of the second gravitational scalar and the level $\gamma$ of violation of local charge conservation in the e.m. sector. An attempt is done to relate these parameters to some experimental constraints. However, there is presently much space left for uncertainty. - oai:arXiv.org:2408.05230v3 - physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.1142/S0217732325500233 - Modern Physics Letters A Vol. 40, No. 09n10, 2550023 (2025) - F. Minotti, G. Modanese - - - Sea ice floe segmentation in close-range optical imagery using active contour and foundation models - https://arxiv.org/abs/2409.06641 - arXiv:2409.06641v5 Announce Type: replace -Abstract: The size of sea ice floes in the marginal ice zone (MIZ) is a key factor influencing ice coverage, albedo, wave propagation, and ocean--atmosphere energy exchanges. Floe size can be observed by processing visual-range imagery from ships, aircraft, or satellites. However, autonomously capturing floe boundaries remains challenging, particularly due to sea ice heterogeneity, which impairs boundary definition and reduces image clarity. This study evaluates the accuracy of sea ice floe segmentation using the gradient vector flow (GVF) active contour method, the deep learning-based Segment Anything Model (SAM), and a hybrid approach combining GVF and SAM. Methods are evaluated on a representative subset of a large dataset of close-range, high-resolution imagery collected from cameras aboard an icebreaker during an Antarctic winter expedition. Spanning a wide range of ice conditions and image clarity in the MIZ, the subset provides a rigorous segmentation test bed. Performance is assessed in terms of floe detection accuracy, size distribution, and ice concentration, with results compared against a manually segmented benchmark. Results indicate SAM, in prompt-driven mode, offers the best balance between accuracy and computational efficiency. Its strong performance in estimating sea ice concentration and detecting floes, while maintaining close agreement with benchmark floe size distributions, makes it suitable for real-time applications and scalable analyses of large imagery datasets. Compared with SAM, the combined SAM-GVF method provides more accurate floe boundary delineation, although at much higher computational cost, and is therefore better suited for analyses requiring precise floe shapes. - oai:arXiv.org:2409.06641v5 - physics.ao-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Giulio Passerotti, Alberto Alberello, Marcello Vichi, Luke G. Bennetts, James Bailey, Alessandro Toffoli - - - Machine learning of the Ising model on a spherical Fibonacci lattice - https://arxiv.org/abs/2410.12007 - arXiv:2410.12007v3 Announce Type: replace -Abstract: We investigate the Ising model on a spherical surface, utilizing a Fibonacci lattice to approximate uniform coverage. This setup poses challenges in achieving consistent lattice distribution across the sphere for comparison with planar models. We employ Monte Carlo simulations, principal component analysis (PCA), graph convolutional networks (GCNs) to study spin configurations across a range of temperatures and to determine phase transition temperatures. The Fibonacci lattice, despite its uniformity, contains irregular sites that influence spin behavior. In the ferromagnetic case, sites with fewer neighbors exhibit a higher tendency for spin flips at low temperatures, though this effect weakens as temperature increases, leading to a higher phase transition temperature than in the planar Ising model. In the antiferromagnetic case, lattice irregularities induce geometric frustration, resulting in highly degenerate ground states and the phase transition temperature lower than the planar square lattice. Phase transition temperatures are derived through specific heat, magnetic susceptibility analysis and GCNs predictions, yielding $T_c$ values for both ferromagnetic and antiferromagnetic scenarios. This work emphasizes the impact of the Fibonacci lattice's geometric properties-namely curvature and connectivity-on spin interactions in non-planar systems, with relevance to microgravity environments. - oai:arXiv.org:2410.12007v3 - physics.comp-ph - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1088/1367-2630/ae21fc - New J. Phys. 27 124601(2025) - Zheng Zhou, Chen-Hui Song, Xu-Yang Hou, Hao Guo - - - Distributed network of smartphone sensors: a new tool for scientific field measurements - https://arxiv.org/abs/2501.04886 - arXiv:2501.04886v4 Announce Type: replace -Abstract: Smartphones sensors are now commonly used by a worldwide audience thanks to their availability, high connectivity, and versatility. Here, we present a methodology to use a collection of smartphones, namely a fleet, as a distributed network of time-synchronized mechanical sensors. We first present the mechanical tests we develop to evaluate the smartphone sensor accuracy. We then describe how to use efficiently a distributed network of smartphones as autonomous sensors. We use a combination of an Android application hosted on each phone (Gobannos), and a server application (Phonefleet) on a controlling host to perform the tasks in parallel remotely. We implement in particular a time synchronization protocol based on UDP communication. We achieved an accuracy of the smartphone clock synchronisation of 60 microseconds. Using two test cases in realistic outdoor conditions, we eventually prove the reliability of a smartphone fleet to measure mechanical wave measurements in field conditions. - oai:arXiv.org:2501.04886v4 - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Forces at the scale of the cell + https://arxiv.org/abs/2512.08311 + arXiv:2512.08311v1 Announce Type: cross +Abstract: The importance of molecular-scale forces in sculpting biological form and function has been acknowledged for more than a century. Accounting for forces in biology is a problem that lies at the intersection of soft condensed matter physics, statistical mechanics, computer simulations and novel experimental methodologies, all adapted to a cellular context. This review surveys how forces arise within the cell. We provide a summary of the relevant background in basic biophysics, of soft-matter systems in and out of thermodynamic equilibrium, and of various force measurement methods in biology. We then show how these ideas can be incorporated into a description of cell-scale processes where forces are involved. Our examples include polymerization forces, motion of molecular motors, the properties of the actomyosin cortex, the mechanics of cell division, and shape changes in tissues. We show how new conceptual frameworks are required for understanding the consequences of cell-scale forces for biological function. We emphasize active matter descriptions, methodological tools that provide ways of incorporating non-equilibrium effects in a systematic manner into conceptual as well as quantitative descriptions. Understanding the functions of cells will necessarily require integrating the role of physical forces with the assimilation and processing of information. This integration is likely to have been a significant driver of evolutionary change. + oai:arXiv.org:2512.08311v1 + cond-mat.soft + cond-mat.stat-mech + physics.bio-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - J. Zhang, N. Mokus, J. Casoli, A. Eddi, S. Perrard - - - Reinforcement learning-based adaptive time-integration for nonsmooth dynamics - https://arxiv.org/abs/2501.08934 - arXiv:2501.08934v2 Announce Type: replace -Abstract: Numerical time integration is fundamental to the simulation of initial and boundary value problems. Traditionally, time integration schemes require adaptive time-stepping to ensure computational speed and sufficient accuracy. Although these methods are based on mathematical derivations related to the order of accuracy for the chosen integrator, they also rely on heuristic development to determine optimal time steps. In this work, we use an alternative approach based on Reinforcement Learning (RL) to select the optimal time step for any time integrator method, balancing computational speed and accuracy. To explore the potential of our RL-based adaptive time-stepping approach, we choose a challenging model problem involving set-valued frictional instabilities at various spatiotemporal scales. This problem demonstrates the robustness of our strategy in handling nonsmooth problems, which present a demanding scenario for numerical integration. Specifically, we apply RL to the simulation of a seismic fault with Coulomb friction. Our findings indicate that RL can learn an optimal strategy for time integration, achieving up to a fourfold speed-up. Our RL-based adaptive integrator offers a new approach for time integration in various other problems in mechanics. - oai:arXiv.org:2501.08934v2 - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-sa/4.0/ - David Michael Riley, Alexandros Stathas, Diego Guti\'errez-Oribio, Ioannis Stefanou + K. Vijay Kumar, Mandar M. Inamdar, Pramod A. Pullarkat, Gautam I. Menon - Ultrafast neural sampling with spiking nanolasers - https://arxiv.org/abs/2501.14446 - arXiv:2501.14446v2 Announce Type: replace -Abstract: Owing to their significant advantages in terms of bandwidth, power efficiency, and latency, optical neuromorphic systems have arisen as interesting alternatives to digital electronic devices. Recently, photonic crystal nanolasers with excitable behavior were first demonstrated. Depending on the pumping strength, they emit short optical pulses -- spikes -- at various intervals on a nanosecond timescale. In this theoretical work, we show how networks of such photonic spiking neurons can be used for Bayesian inference through sampling from learned probability distributions. We provide a detailed derivation of translation rules from conventional sampling networks, such as Boltzmann machines, to photonic spiking networks and demonstrate their functionality across a range of generative tasks. Finally, we provide estimates of processing speed and power consumption, for which we expect improvements of several orders of magnitude over current state-of-the-art neuromorphic systems. - oai:arXiv.org:2501.14446v2 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Joint economic and epidemiological modelling of alternative pandemic response strategies + https://arxiv.org/abs/2512.08355 + arXiv:2512.08355v1 Announce Type: cross +Abstract: In an emerging pandemic, policymakers need to make important decisions with limited information, for example choosing between a mitigation, suppression or elimination strategy. These strategies may require trade-offs to be made between the health impact of the pandemic and the economic costs of the interventions introduced in response. Mathematical models are a useful tool that can help understand the consequences of alternative policy options on the future dynamics and impact of the epidemic. Most models have focused on direct health impacts, neglecting the economic costs of control measures. Here, we introduce a model framework that captures both health and economic costs. We use this framework to compare the expected aggregate costs of mitigation, suppression and elimination strategies, across a range of different epidemiological and economic parameters. We find that for diseases with low severity, mitigation tends to be the most cost-effective option. For more severe diseases, suppression tends to be most cost effective if the basic reproduction number $R_0$ is relatively low, while elimination tends to be more cost-effective if $R_0$ is high. We use the example of New Zealand's elimination response to the Covid-19 pandemic in 2020 to anchor our framework to a real-world case study. We find that parameter estimates for Covid-19 in New Zealand put it close to or above the threshold at which elimination becomes more cost-effective than mitigation. We conclude that our proposed framework holds promise as a decision-support tool for future pandemic threats, although further work is needed to account for population heterogeneity and other factors relevant to decision-making. + oai:arXiv.org:2512.08355v1 + q-bio.PE + physics.soc-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - 10.1038/s41467-025-66818-1 - Ivan K. Boikov, Alfredo de Rossi, Mihai A. Petrovici + M J Plank, M Sushames, T Fisher-Taylor, R N Thompson, A Hurford, S C Hendy - A Methodology for Process Design Kit Re-Centering Using TCAD and Experimental Data for Cryogenic Temperatures - https://arxiv.org/abs/2502.02685 - arXiv:2502.02685v2 Announce Type: replace -Abstract: In this work, we describe and demonstrate a novel Technology Computer Aided Design (TCAD) driven methodology to re-center room-temperature Process Design Kits (PDKs) for cryogenic operation using a limited set of experimental measurements. Unlike previous approaches that relied on direct fitting of sparse measurements, our technique accounts for process-induced deviations by calibrating TCAD models to both room-temperature and cryogenic data. Compact models for all process corners are extracted from TCAD-generated target characteristics, enabling accurate cryogenic modeling without dedicated foundry support. This scalable, technology-independent method provides a practical path for cryogenic circuit design. - oai:arXiv.org:2502.02685v2 - physics.app-ph + An extended low-frequency noise compact model for single-layer graphene FETs including correlated mobility fluctuations effect + https://arxiv.org/abs/2512.08388 + arXiv:2512.08388v1 Announce Type: cross +Abstract: Correlated mobility fluctuations are considered in the physics-based carrier number fluctuation deltaN low-frequency noise (LFN) compact model of single-layer graphene field effect transistors (GFET) in the present study. Trapped charge density and Coulomb scattering coefficient deltaN LFN parameters are obtained after applying a parameter extraction methodology, adapted from conventional silicon technologies, to the linear ambipolar regions of GFETs. Appropriate adjustments are considered in the method according to GFETs physical characteristics. Afterwards, Hooge mobility as well as series resistance fluctuations LFN parameters can be extracted. The updated LFN model is validated with experimental data from various long and short-channel GFETs at an extended range of gate and drain bias conditions. + oai:arXiv.org:2512.08388v1 cond-mat.mes-hall - cs.SY - eess.SY - Tue, 09 Dec 2025 00:00:00 -0500 - replace + physics.app-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Tapas Dutta, Fikru Adamu-Lema, Djamel Bensouiah, Asen Asenov - - - Recorded Versus Synthetic Spectral-compatible Ground Motions: A Comparative Analysis of Structural Seismic Responses - https://arxiv.org/abs/2502.19549 - arXiv:2502.19549v2 Announce Type: replace -Abstract: This paper presents a comparative analysis of structural seismic responses under two types of ground motion inputs: (i) synthetic motions generated by stochastic spectral-compatible ground motion models and (ii) recorded motions from an earthquake database. Both ground motion datasets are calibrated to a shared target response spectrum to ensure consistent spectral median, variance, and correlation structure. Five key stochastic response metrics-probability distributions, statistical moments, correlations, tail indices, and variance-based global sensitivity indices-are systematically evaluated for two representative structures: a medium-period building and a limiting case of a long-period tower. The comparison accounts for uncertainties both from ground motion and structural parameters. The results reveal that synthetic motions closely replicate recorded motions in terms of global response behavior-including distributions, mean and variance, correlation structure, and dominant uncertainty sources-indicating their suitability for routine seismic design and parametric studies. However, substantial differences emerge in response extremes for long-period structures, particularly in metrics governed by rare events, such as higher-order moments and tail behavior. These differences, which often exceed 50%, can be attributed to the non-Gaussian features and complex characteristics inherent in recorded motions, which are less pronounced in synthetic datasets. The findings support the use of synthetic ground motions for evaluating global seismic response characteristics, while highlighting their limitations in capturing rare-event behavior and long-period structural dynamics. - oai:arXiv.org:2502.19549v2 - physics.geo-ph - stat.AP - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Jungho Kim, Maijia Su, Ziqi Wang, Marco Broccardo + 10.1109/TED.2025.3640600 + IEEE Transactions on Electron Devices 2025 + Nikolaos Mavredakis, Anibal Pacheco-Sanchez, David Jimenez - Non-Hermitian Linear Electro-Optic Effect Through Interactions of Free and Bound Charges - https://arxiv.org/abs/2503.09274 - arXiv:2503.09274v2 Announce Type: replace -Abstract: In recent years, there has been growing interest in non-Hermitian phenomena in low-symmetry conductors, particularly optical gain driven by electro-optic effects. Conventional semiclassical treatments typically attribute these effects to nonlinear interactions associated with the anomalous velocity of Bloch electrons. Here, we present a phenomenological microscopic model that not only recovers these anomalous-velocity contributions, but also incorporates interband effects that become significant at higher frequencies. Our model captures a wide range of nonlinear interactions while remaining consistent with passivity and microscopic reversibility. Using this broader framework, we study the nonlinear interactions between free and bound electrons as an alternative mechanism for optical gain. - We show that, under non-equilibrium conditions in low-symmetry conductors, the linearized electromagnetic response can exhibit both nonreciprocity and gain, even without anomalous velocity contributions. Finally, we analyze the stability of electrically biased systems and highlight potential applications such as optical isolators and traveling-wave amplifiers. - oai:arXiv.org:2503.09274v2 - physics.optics - cond-mat.mes-hall - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Practical protein-pocket hydration-site prediction for drug discovery on a quantum computer + https://arxiv.org/abs/2512.08390 + arXiv:2512.08390v1 Announce Type: cross +Abstract: Demonstrating the practical utility of Noisy Intermediate-Scale Quantum (NISQ) hardware for recurrent tasks in Computer-Aided Drug Discovery is of paramount importance. We tackle this challenge by performing three-dimensional protein pockets hydration-site prediction on a quantum computer. Formulating the water placement problem as a Quadratic Unconstrained Binary Optimization (QUBO), we use a hybrid approach coupling a classical three-dimensional reference-interaction site model (3D-RISM) to an efficient quantum optimization solver, to run various hardware experiments up to 123 qubits. Matching the precision of classical approaches, our results reproduced experimental predictions on real-life protein-ligand complexes. Furthermore, through a detailed resource estimation analysis, we show that accuracy can be systematically improved with increasing number of qubits, indicating that full quantum utility is in reach. Finally, we provide evidence that advantageous situations could be found for systems where classical optimization struggles to provide optimal solutions. The method has potential for assisting simulations of protein-ligand complexes for drug lead optimization and setup of docking calculations. + oai:arXiv.org:2512.08390v1 + quant-ph + physics.bio-ph + physics.chem-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Sylvain Lanneb\`ere, Nader Engheta, M\'ario G. Silveirinha + Daniele Loco, Kisa Barkemeyer, Andre R. R. Carvalho, Jean-Philip Piquemal - Flexible BiSel/NiO-based X-ray synapses bridging the functions of detection and memory - https://arxiv.org/abs/2503.14005 - arXiv:2503.14005v2 Announce Type: replace -Abstract: Currently, the X-ray detectors are widely used in medical imaging, industrial inspection, aerospace, and other fields, as the market demand for high-efficiency, flexible, and low-power detectors is increased. Although the traditional inorganic X-ray detection materials have achieved great success and effectiveness, they have their own limitations and let alone flexibility/bendability and memory function. In this study, we present the design of a BiSeI/NiO-based X-ray synaptic detector and its application in the simulation of biological synaptic processes. Herein, the BiSeI, a quasi-1D inorganic semiconductor, stands out as an ideal choice for the X-ray detectors, especially for flexible and portable devices due to its large atomic number, large photoelectric absorption coefficient, and mechanical plasticity. Meanwhile, the NiO-based materials provide the memory function required for the intelligent detection systems. Moreover, our devices offer notable advantages in terms of low power consumption, compared with traditional X-ray detectors. The BiSeI/NiO detectors demonstrate advanced features with an ultrahigh sensitivity, an ultralow detection limit, and include the paired-pulse facilitation (PPF) and the transition from short- to long-term memory, maintaining the functionality on flexible substrates. This design represents a significant step toward the development of intelligent and flexible X-ray detectors. - oai:arXiv.org:2503.14005v2 - physics.ins-det - cond-mat.mtrl-sci - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Many interacting particles in solution. I. Screening-ranged expansions of electrostatic potential and energy + https://arxiv.org/abs/2512.08407 + arXiv:2512.08407v1 Announce Type: cross +Abstract: We present an analytical many-body formalism for systems of spherical particles carrying arbitrary free charge distributions and interacting in a polarizable electrolyte solution, that we model within the linearized Poisson--Boltzmann framework. Building on the detailed spectral analysis of the associated nonstandard Neumann--Poincar\'e-type operators developed in our companion study~\cite{supplem_pre_math}, we construct exact explicit expansions of the electrostatic potential and energy in ascending orders of Debye screening thereby obtaining systematic "screening-ranged" series for potentials and energies. These screening-ranged expansions provide a unified and tractable description of many-body electrostatics. We demonstrate the versatility of the approach by showing how it generalizes and improves upon both classical and modern methods, enabling rigorous treatment of heterogeneously charged systems (such as Janus particles) and accurate modeling of higher-order phenomena (such as asymmetric dielectric screening, opposite-charge repulsion, like-charge attraction) as well as yielding many-body generalizations to analytical explicit results previously known only in the two-body setting. + oai:arXiv.org:2512.08407v1 + cond-mat.soft + math-ph + math.MP + physics.bio-ph + physics.chem-ph + physics.comp-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Qiao Wang, Pengfei Li, Yushou Song, Jalu Li, Haiying Xiao, Yuqing Wang, Guoliang Ma, Hsu-Sheng Tsai, Ping-An Hu - - - EnsAI: An Emulator for Atmospheric Chemical Ensembles - https://arxiv.org/abs/2504.16024 - arXiv:2504.16024v2 Announce Type: replace -Abstract: Ensemble-based methods for data assimilation and emission inversions are a popular way to encode flow-dependency within the model error covariance. While most ensemble methods do not require the use of an adjoint model, the need to repeatedly run a geophysical model to generate the ensemble can be a significant computational burden. In this paper, we introduce EnsAI, a new AI-based ensemble generation system for atmospheric chemical constituents. When trained on an existing ensemble for ammonia generated by the GEM-MACH air quality model, it was shown that the ensembles produced by EnsAI can accurately reproduce the meteorology-dependent features of the original ensemble, while generating the ensemble 3,300 times faster than the original GEM-MACH ensemble. While EnsAI requires an upfront cost for generating an ensemble used for training, as well as the training itself, the long term computational savings can greatly exceed these initial computational costs. When used in an emissions inversion system, EnsAI produced similar inversion results to those in which the original GEM-MACH ensemble was used while using significantly less computational resources. - oai:arXiv.org:2504.16024v2 - physics.ao-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Michael Sitwell - - - Discovery of a Physically Interpretable Data-Driven Wind-Turbine Wake Model - https://arxiv.org/abs/2505.00522 - arXiv:2505.00522v2 Announce Type: replace -Abstract: This study presents a compact data-driven Reynolds-averaged Navier-Stokes (RANS) model for wind turbine wake prediction, built as an enhancement of the standard \(k\)-\(\varepsilon\) formulation. Several candidate models were discovered using the symbolic regression framework Sparse Regression of Turbulent Stress Anisotropy (SpaRTA), trained on a single Large Eddy Simulation (LES) dataset of a standalone wind turbine. The leading model was selected by prioritizing simplicity while maintaining reasonable accuracy, resulting in a novel linear eddy viscosity model. This selected leading model reduces eddy viscosity in high-shear regions, particularly in the wake, to limit turbulence mixing and delay wake recovery. This addresses a common shortcoming of the standard \(k\)-\(\varepsilon\) model, which tends to overpredict mixing, leading to unrealistically fast wake recovery. Moreover, the formulation of the leading model closely resembles that of the established \(k\)-\(\varepsilon\)-\(f_P\) model. Consistent with this resemblance, the leading and \(k\)-\(\varepsilon\)-\(f_P\) models show nearly identical performance in predicting velocity fields and power output, but they differ in their predictions of turbulent kinetic energy. In addition, the generalization capability of the leading model was assessed using three unseen six-turbine configurations with varying spacing and alignment. Despite being trained solely on a standalone turbine case, the model produced results comparable to LES data. These findings demonstrate that data-driven methods can yield interpretable, physically consistent RANS models that are competitive with traditional modeling approaches while maintaining simplicity and achieving generalizability. - oai:arXiv.org:2505.00522v2 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - 10.1007/s10494-025-00679-y - Flow, Turbulence and Combustion, Vol. 115, pp. 1181-1207, 2025 - Kherlen Jigjid, Ali Eidi, Nguyen Anh Khoa Doan, Richard P. Dwight + Sergii V. Siryk, Walter Rocchia - Parameter estimation for land-surface models using Neural Physics - https://arxiv.org/abs/2505.02979 - arXiv:2505.02979v2 Announce Type: replace -Abstract: The Neural Physics approach is used to determine the parameters of a simple land-surface model using PyTorch's backpropagation engine to carry out the optimisation. In order to test the inverse model, a synthetic dataset is created by running the model in forward mode with known parameter values to create soil temperature time series that can be used as observations for the inverse model. We show that it is not possible to obtain a reliable parameter estimation using a time series of soil temperature observed at a single depth. Using measurements at two depths, reliable parameter estimates can be obtained although it is not possible to differentiate between latent and sensible heat fluxes. We apply the inverse model to urban flux tower data in Phoenix, United States, and show that the thermal conductivity, volumetric heat capacity and the combined sensible-latent heat transfer coefficient can be reliably estimated using an observed value for the effective surface albedo. The resulting model accurately predicts the outgoing longwave radiation, conductive soil fluxes and the combined sensible-latent heat fluxes. - oai:arXiv.org:2505.02979v2 - physics.ao-ph - cs.LG - Tue, 09 Dec 2025 00:00:00 -0500 - replace + High-OAM Deep Ultraviolet Twisted Light Generation for RF-Photoinjector Applications + https://arxiv.org/abs/2512.08442 + arXiv:2512.08442v1 Announce Type: cross +Abstract: We report on the generation and characterization of ultraviolet (wavelength 266 nm) twisted light with high orbital angular momentum (OAM) using three types of fabricated diffractive optical elements (DOEs): a reflective fork grating, a high-charge spiral phase plate (SPP), and binary axicons. All elements were integrated into a drive-laser beamline of an electron RF-photoinjector, enabling direct evaluation under accelerator-relevant conditions. + The SPP produced a high-purity Laguerre-Gaussian mode with OAM l = 64 and a measured conversion efficiency of approximately 80\%. Binary axicons generated quasi-Bessel twisted light with topological charges up to m = 10, exhibiting low divergence and stable multi-lobe ring structures. The fork grating reliably produced lower-order modes, l = 2-8, with good agreement between simulations and cylindrical-lens diagnostics. + These results constitute, to our knowledge, the first comprehensive experimental demonstration of deep-UV high-OAM beams generated with fabricated DOEs and validated through mode-conversion measurements. The demonstrated techniques are compatible with high-power UV laser systems used in RF-photoinjectors and offer a practical route toward structured photocathode illumination and the generation of relativistic vortex electrons at a particle accelerator facility. + oai:arXiv.org:2512.08442v1 + quant-ph + physics.acc-ph + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Ruiyue Huang, Claire E. Heaney, Maarten van Reeuwijk + A. S. Dyatlov, D. M. Dolgintsev, V. V. Gerasimov, V. V. Kobets, V. P. Nazmov, M. A. Nozdrin, A. N. Sergeev, D. S. Shokin, K. E. Yunenko, D. V. Karlovets - Bennett Vorticity: A family of nonlinear Shear-Flow Stabilized Z-pinch equilibria - https://arxiv.org/abs/2506.05727 - arXiv:2506.05727v5 Announce Type: replace -Abstract: The Bennett profile is a classic form for the plasma number density of an equilibrium Z-pinch that has been studied for almost a century by plasma physicists interested in nonlinear plasma pinch science, and fusion energy. By transferring the nonlinearity entirely from the number density to the plasma flow velocity the current density of the resulting flowing Z-pinch equilibrium remains unchanged whilst now being defined by a vortical flow which previously did not exist in the classic case. Due to the positive-definite structure of the nonlinearity's first derivative, in the ideal limit this equilibrium conforms globally to the validity criterion for a shear-flow stabilized Z-pinch when the form of the temperature profile satisfies certain constraints. For a cubic temperature the equilibrium has an analytic solution which is investigated. - oai:arXiv.org:2506.05727v5 - physics.plasm-ph - nlin.SI - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Photon Dynamics and Collision Risks in Relativistic Spaceflight: A Comparative Study of Methods and Implications + https://arxiv.org/abs/2512.08447 + arXiv:2512.08447v1 Announce Type: cross +Abstract: This dissertation explores the dynamics of relativistic spaceflight, focusing on the risks associated with collisions and photon interactions as a spacecraft approaches velocities near the speed of light. The study emphasizes two primary collision types: (1) collisions with interstellar dust and particles, and (2) interactions with cosmic molecules, specifically hydrogen. Using principles of energy conservation and relativistic mechanics, the energy transfer from these collisions is calculated, showing that even small particles can impart massive energy at relativistic speeds. The dissertation also examines the impact of the cosmic microwave background (CMB) radiation, particularly its blue-shifting effect at high velocities, which influences photon interactions with the spacecraft. Additionally, the Schwinger limit, which sets an upper bound on the electromagnetic field strength for sustained relativistic travel, is discussed in the context of photon-induced pair production. Lastly, advanced photon interactions, such as Compton scattering, are analyzed for their role in thermal management and spacecraft design. The findings highlight the importance of shielding, thermal regulation, and collision avoidance strategies in the design of spacecraft for interstellar travel, offering insights into the potential challenges and solutions for achieving relativistic spaceflight. + oai:arXiv.org:2512.08447v1 + astro-ph.HE + gr-qc + physics.space-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Matt Russell + Li Kai Wen, Joao Rodrigues - Ion Track Formation via Electric-Field-Enhanced Energy Deposition - https://arxiv.org/abs/2506.12884 - arXiv:2506.12884v4 Announce Type: replace -Abstract: High-energy ion irradiation deposits extreme energy in a narrow range (1-10 nm) along ion trajectories in solid through electronic energy loss, producing unique irradiation effects such as ion tracks. However, intrinsic velocity effects impose an upper limit on electronic energy loss that cannot be overcome by adjusting irradiation parameters. We introduce a method using electric fields during irradiation to enhance nanoscale energy deposition by accelerating ion-excited electrons within sub-picosecond timescales.Our extended thermal spike model quantitatively describes this enhancement and predicts a significant reduction in the electronic energy loss required for ion track formation in amorphous SiO2, which is in excellent agreement with experimental observations. This work provides a new approach to control energy deposition during irradiation and boosts the wide application of ion tracks in material modification and nanoengineering to much broader extents. - oai:arXiv.org:2506.12884v4 - physics.app-ph + Single-Particle X-ray Scattering Reveals a High Local Supersaturation of Precursors as the Origin of CoO Assembly Formation + https://arxiv.org/abs/2512.08488 + arXiv:2512.08488v1 Announce Type: cross +Abstract: Single-particle small-angle X-ray scattering (SP-SAXS) enables quantitative morphological analysis by recording diffraction snapshots from isolated particles using X-ray free-electron laser (XFEL) pulses. Unlike conventional X-ray techniques, which average over the entire illuminated sample volume, SP-SAXS resolves low-contrast, less abundant, or transient species within heterogeneous particle populations that would otherwise remain hidden. Here, we apply SP-SAXS to investigate the solvothermal formation of CoO nanocrystal assemblies from a Co(acac)$_3$ precursor in benzyl alcohol. The single-particle data reveal amorphous, uniform-density Co(acac)$_2$ spheres as transient intermediates that directly crystallize into cavernous CoO nanocrystal assemblies, which explains why CoO forms as hierarchical aggregates rather than as isolated nanocrystals. These results demonstrate that SP-SAXS provides a powerful framework for disentangling morphological heterogeneity in nanoparticle formation processes. + oai:arXiv.org:2512.08488v1 cond-mat.mes-hall - Tue, 09 Dec 2025 00:00:00 -0500 - replace + cond-mat.mtrl-sci + physics.data-an + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zikang Ge, Jinhao Hu, Shengyuan Peng, Wei Kang, Xiaofei Shen, Yanbo Xie, Jianming Xue + Sani Y. Harouna-Mayer, Lars Klemeyer, Cecilia A. Zito, Johan Bielecki, Xuemei Cheng, Davide Derelli, Armando D. Estillore, Tjark L. R. Groene, Lukas V. Haas, Romain Letrun, Chan Kim, Jayanath C. P. Koliyadu, Abhishek Mall, Parichita Mazumder, Diogo V. M. Melo, Adam R. Round, Amit K. Samanta, Abhisakh Sarma, Zhou Shen, Xiao Sun, Patrik Vagovic, Tamme Wollweber, Richard Bean, Jochen K\"upper, Henry N. Chapman, Dorota Koziej, Kartik Ayyer - Three-Wave Interaction Grating Coupler with Sub-Decibel Insertion Loss at Normal Incidence - https://arxiv.org/abs/2506.19242 - arXiv:2506.19242v2 Announce Type: replace -Abstract: We report the design, fabrication in a commercial foundry, and experimental results of high-efficiency, normal incidence grating couplers for silicon photonics. We observe a maximum coupling efficiency of 85.4% (-0.69 dB) with a 1 dB bandwidth of 20 nm at a central wavelength of 1546 nm. These experimental results verify earlier theoretical and simulation results and pave the way for the use of perfectly vertical grating couplers, as an alternative to edge coupling, in silicon photonics applications that are sensitive to input coupling loss. Further, these results enable the use of grating couplers for vertically oriented elements, such as multicore fibers and VCSELs, and address challenges associated with coupling to free space beams. - oai:arXiv.org:2506.19242v2 + Tunable passive squeezing of squeezed light through unbalanced double homodyne detection + https://arxiv.org/abs/2512.08540 + arXiv:2512.08540v1 Announce Type: cross +Abstract: The full characterization of quantum states of light is a central task in quantum optics and information science. Double homodyne detection provides a powerful method for the direct measurement of the Husimi Q quasi-probability distribution, offering a complete state representation in a simple experimental setting and a limited time frame. Here, we demonstrate that double homodyne detection can serve as more than a passive measurement apparatus. By intentionally unbalancing the input beamsplitter that splits the quantum signal, we show that the detection scheme itself performs an effective squeezing or anti-squeezing transformation on the state being measured. The resulting measurement directly samples the Q function of the input state as if it were acted upon by a squeezing operator whose strength is a tunable experimental parameter : the beamsplitter's reflectivity. We experimentally realize this technique using a robust polarization-encoded double homodyne detection to characterize a squeezed vacuum state. Our results demonstrate the controlled deformation of the measured Q function's phase-space distribution, confirming that unbalanced double homodyne detection is a versatile tool for simultaneous quantum state manipulation and characterization. + oai:arXiv.org:2512.08540v1 + quant-ph physics.optics - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Carson G. Valdez, Simon A. Bongarz, Anne R. Kroo, Anna J. Miller, Michel J. F. Digonnet, David A. B. Miller, Olav Solgaard + Niels Tripier-Mondancin, David Barral, Gana\"el Roeland, Ra\'ul Leonardo Rincon Celis, Yann Bouchereau, Nicolas Treps - Fast prediction of plasma instabilities with sparse-grid-accelerated optimized dynamic mode decomposition - https://arxiv.org/abs/2507.03245 - arXiv:2507.03245v2 Announce Type: replace -Abstract: Parametric data-driven reduced-order models (ROMs) that embed dependencies in a large number of input parameters are crucial for enabling many-query tasks in large-scale problems. These tasks, including design optimization, control, and uncertainty quantification, are essential for developing digital twins in real-world applications. However, standard grid-based data generation methods are computationally prohibitive due to the curse of dimensionality. This paper investigates efficient training of parametric data-driven ROMs using sparse grid interpolation with (L)-Leja points, specifically targeting scenarios with higher-dimensional input parameter spaces. (L)-Leja points are nested and exhibit slow growth, resulting in sparse grids with low cardinality in low-to-medium dimensional settings, making them ideal for large-scale, computationally expensive problems. Focusing on gyrokinetic simulations of plasma micro-instabilities in fusion experiments as a representative real-world application, we construct parametric ROMs for the full 5D gyrokinetic distribution function via optimized dynamic mode decomposition (optDMD) and sparse grids based on (L)-Leja points. We perform detailed experiments in two scenarios: First, the Cyclone Base Case benchmark assesses optDMD ROM prediction capabilities beyond training time horizons and across variations in the binormal wave number. Second, for a real-world electron-temperature-gradient-driven micro-instability simulation with six input parameters, we demonstrate that a predictive parametric optDMD ROM that is up to three orders of magnitude cheaper to evaluate can be constructed using only 28 high-fidelity gyrokinetic simulations, enabled by the use of sparse grids. In the broader context of fusion research, these results demonstrate the potential of sparse grid-based parametric ROMs to enable otherwise intractable many-query tasks. - oai:arXiv.org:2507.03245v2 - physics.comp-ph - cs.CE - cs.NA - math.NA - physics.plasm-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Transcript-based estimators for characterizing interactions + https://arxiv.org/abs/2512.08570 + arXiv:2512.08570v1 Announce Type: cross +Abstract: The concept of transcripts was introduced in 2009 as a means to characterize various aspects of the functional relationship between time series of interacting systems. Based on this concept that utilizes algebraic relations between ordinal patterns derived from time series, estimators for the strength, direction, and complexity of interactions have been introduced. These estimators, however, have not yet found widespread application in studies of interactions between real-world systems. Here, we revisit the concept of transcripts and showcase the usage of transcript-based estimators for a time-series-based investigation of interactions between coupled paradigmatic dynamical systems of varying complexity. At the example of a time-resolved analysis of multichannel and multiday recordings of ongoing human brain dynamics, we demonstrate the potential of the methods to provide novel insights into the intricate spatial-temporal interactions in the human brain underlying different vigilance states. + oai:arXiv.org:2512.08570v1 + nlin.CD + physics.data-an + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Kevin Gill, Ionut-Gabriel Farcas, Silke Glas, Benjamin J. Faber + Manuel Adams, Jos\'e M. Amig\'o, Klaus Lehnertz - Deep Feature-specific Imaging - https://arxiv.org/abs/2508.01981 - arXiv:2508.01981v5 Announce Type: replace -Abstract: Modern photon-counting sensors are increasingly dominated by Poisson noise, yet conventional Feature-Specific Imaging (FSI) is optimized for additive Gaussian noise, leading to suboptimal performance and a loss of its advantages under Poisson noise. To address this, we introduce DeepFSI, a novel end-to-end optical-electronic framework. DeepFSI "unfreezes" traditional FSI masks, enabling a deep neural network to learn globally optimal measurement masks by computing gradients directly under realistic Poisson and additive noise conditions. Our simulations demonstrate DeepFSI's superior feature fidelity and task performance compared to conventional FSI with predefined masks, especially in Poisson-Noise-dominant environments. DeepFSI also exhibits enhanced robustness to design choices and performs well under additive Gaussian noise, representing a significant advance for noise-robust computational imaging in photon-limited applications. - oai:arXiv.org:2508.01981v5 + $\mathcal{PT}$-symmetric cavity magnomechanics with gain-assisted transparency and amplification + https://arxiv.org/abs/2512.08612 + arXiv:2512.08612v1 Announce Type: cross +Abstract: We investigate magnomechanically induced transparency in a parity-time-symmetric cavity magnomechanical system with traveling-field-induced non-Hermiticity. The setup consists of a microwave cavity mode coupled to magnons in a single-crystal yttrium iron garnet sphere, which in turn are hybridized with a vibrational mechanical mode through magnetostrictive interaction. In the Hermitian regime, strong photon-magnon coupling generates a single transparency window in the cavity transmission, which splits into a doublet when the magnon is coherently hybridized with the mechanical mode via magnomechanical coupling. This establishes a versatile platform in which the transparency spectrum can be engineered from single- to multi-window response using experimentally accessible, scaled magnomechanical interactions. When a non-Hermitian coupling is introduced, the system enters a parity-time-broken regime in which the transparency ceases to be purely passive and becomes gain assisted, leading to asymmetric transmission with amplification on one side of the resonance and enhanced absorption on the other. By tuning the cavity detuning, we convert magnomechanical transparency into Fano-type line shapes with strongly non-Lorentzian phase dispersion and map their deformation into asymmetric, gain-assisted Fano ridges in the joint space of probe and magnon detunings. Finally, we analyze the associated group delay and show that both slow- and fast-light behavior can be widely tuned by varying the photon-magnon and magnomechanical couplings together with the non-Hermitian strength, highlighting parity-time-symmetric cavity magnomechanics as a promising platform for reconfigurable quantum signal processing and enhanced sensing. + oai:arXiv.org:2512.08612v1 + quant-ph + math-ph + math.MP physics.optics - eess.IV - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Yizhou Lu, Andreas Velten + Cham Oumie, Wu-Ming Liu, Kashif Ammar Yasir - Numerical and Experimental Evaluation of Chip Evacuation and Lubricant Flow using Optimized Drill Heads for Ejector Deep Hole Drilling - https://arxiv.org/abs/2508.02333 - arXiv:2508.02333v2 Announce Type: replace -Abstract: Ejector deep hole drilling offers great potential to utilize the typical advantages of deep hole drilling processes on conventional machining centers in a cost-effective and resource-efficient manner. However, maintaining reliable chip evacuation and stable process conditions often relies on high flow volumes of metalworking fluid, resulting in considerable energy consumption in industrial settings. Therefore, to analyze the highly sophisticated chip evacuation dynamics of the process, two flow-optimized drill heads and a reference drill head were evaluated with smoothed particle hydrodynamics simulation using experimentally obtained chip shapes. In addition, modified drill heads were additively manufactured and experimentally investigated to validate the numerical results and to determine the positive effect on the necessary fluid flow for a stable ejector drilling process. The modifications aim to improve chip evacuation by reducing vortex formation and optimizing flow conditions near the cutting zone. Therefore, the minimum volume flow required for a stable drilling process without chip clogging is reduced, leading to an energy-efficient sustainable ejector drilling process. - oai:arXiv.org:2508.02333v2 - physics.flu-dyn + Nonequilibrium Photocarrier and Phonon Dynamics from First Principles: a Unified Treatment of Carrier-Carrier, Carrier-Phonon, and Phonon-Phonon Scattering + https://arxiv.org/abs/2512.08618 + arXiv:2512.08618v1 Announce Type: cross +Abstract: We develop a first-principles many-body framework to describe the dynamics of photocarriers and phonons in semiconductors following ultrafast excitation. Our approach incorporates explicit ab initio light-matter coupling and first-principles collision integrals for carrier-carrier, carrier-phonon, and phonon-phonon scattering. It also yields time-dependent quasiparticle and phonon frequency renormalizations, along with light-induced coherent atomic motion. The equations of motion are solved in a maximally localized Wannier basis, ensuring gauge-consistent scattering integrals and ultradense momentum sampling, thereby enabling direct comparison with pump-probe experiments. The method can be coupled to constrained density-functional theory to access light-induced structural phase transitions at longer times after the light pulse. We showcase the capabilities and predictive power of this framework on MoS$_2$ and h-BN monolayers. For MoS$_2$, we resolve photoinduced renormalizations of electronic and lattice properties, ultrafast carrier relaxation, hot-phonon dynamics, and displacive coherent atomic motion. Including carrier-carrier scattering is crucial to obtain realistic photocarrier equilibration times, while omitting phonon-phonon scattering leads to incorrect long-time lattice thermalization and a factor of two larger A$_{1g}$ coherent phonon damping time. For h-BN, we quantify photoinduced changes in the electronic, optical, and lattice responses in quasi-equilibrium, demonstrating a fluence-dependent enhancement of screening and melting of excitonic features. + oai:arXiv.org:2512.08618v1 + cond-mat.mtrl-sci physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Nuwan Rupasinghe, Sebastian Michel, Andreas Baumann, Julian Gerken, Samuel G\"ulde, Dirk Biermann, Peter Eberhard + Stefano Mocatti, Giovanni Marini, Giulio Volpato, Pierluigi Cudazzo, Matteo Calandra - Spatiotemporal wall pressure forecast of a rectangular cylinder with physics-aware DeepU-Fourier neural network - https://arxiv.org/abs/2508.03183 - arXiv:2508.03183v2 Announce Type: replace -Abstract: The wall pressure is of great importance in understanding the forces and structural responses induced by fluid. Recent works have investigated the potential of deep learning techniques in predicting mean pressure coefficients and fluctuating pressure coefficients, but most of existing deep learning frameworks are limited to predicting a single snapshot using full spatial information. To forecast spatiotemporal wall pressure of flow past a rectangular cylinder, this study develops a physics-aware DeepU-Fourier neural Network (DeepUFNet) deep learning model. DeepUFNet comprises the UNet structure and the Fourier neural network, with physical high-frequency loss control embedded in the model training stage to optimize model performance. Wind tunnel testing was performed to collect wall pressures on two-dimensional rectangular cylinders using high-frequency pressure scanning, thereby constructing a database for DeepUFNet training and testing. The DeepUFNet model is found capable of forecasting spatiotemporal wall pressure information with high accuracy on the rectangular cylinder with side ratio 1.5. The comparison between forecast results and experimental data presents agreement in statistical information and physical interpretation. It is also found that embedding a physical high-frequency loss control coefficient b in the DeepUFNet model can significantly improve model performance in forecasting spatiotemporal wall pressure information, particularly, high-order frequency fluctuation and wall pressure variance. Furthermore, the DeepUFNet extrapolation capability is tested with sparse spatial information input, and the model presents a satisfactory extrapolation ability. Last, the DeepUFNet is tested for generalization in unseen cases, rectangular cylinders with side ratio 4 and 3.75, and the model presents satisfactory generalization ability. - oai:arXiv.org:2508.03183v2 - physics.flu-dyn - cs.AI - cs.CE - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Strain sensitivity enhancement in a Grover-Michelson interferometer + https://arxiv.org/abs/2512.08638 + arXiv:2512.08638v1 Announce Type: cross +Abstract: The Michelson interferometric phase detection resolution can be enhanced by replacing conventional beam splitters with novel directionally unbiased four-port scatterers, such as Grover coins. We present a quantitative analysis of the noise-to-signal ratio of sideband frequencies generated by gravitational wave-induced phase perturbations in a Grover-Michelson interferometer (GMI). We discuss the principles of GMI signal enhancement and demonstrate how combining this configuration with additional light-recycling arrangements further enhances the performance. + oai:arXiv.org:2512.08638v1 + quant-ph + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - 10.1063/5.0298947 - Junle Liu, Chang Liu, Yanyu Ke, Wenliang Chen, Kihing Shum, Tim K. T. Tse, Gang Hu + 10.1103/8h71-w8tt + Manni, A., Schwarze, C., Simon, D., Ndao, A., & Sergienko, A. (2025). Strain sensitivity enhancement in a Grover-Michelson interferometer. Phys. Rev. D, 112, 122002 + Anthony D. Manni, Christopher R. Schwarze, David S. Simon, Abdoulaye Ndao, Alexander V. Sergienko - How to simulate L\'evy flights in a steep potential: An explicit splitting numerical scheme - https://arxiv.org/abs/2508.07339 - arXiv:2508.07339v3 Announce Type: replace -Abstract: We propose an effective explicit numerical scheme for simulating solutions of stochastic differential equations with confining superlinear drift terms, driven by multiplicative heavy-tailed L\'evy noise. The scheme is designed to prevent explosion and accurately capture all finite moments of the solutions. - In the purely Gaussian case, it correctly reproduces moments of sub-Gaussian tails of the solutions. - This method is particularly well-suited for approximating statistical moments and other probabilistic characteristics of L\'evy flights in steep potential landscapes. - oai:arXiv.org:2508.07339v3 - physics.comp-ph - cond-mat.stat-mech - math.PR - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Ilya Pavlyukevich, Olga Aryasova, Alexei Chechkin, Oleksii Kulyk + Perfect continuous-variable quantum microcombs + https://arxiv.org/abs/2512.08650 + arXiv:2512.08650v1 Announce Type: cross +Abstract: Quantum microcombs generated in high-Q microresonators provide compact, multiplexed sources of entangled modes for continuous-variable (CV) quantum information processing. While deterministic generation of CV states via Kerr-induced two-mode squeezing has been demonstrated, achieving spectrally uniform squeezing remains challenging because of asymmetry and anomalies in the dispersion profile. Here we overcome these limitations by combining a microresonator with an engineered mode spectrum and optimized pump conditions. We realize a CV quantum microcomb comprising 14 independent two-mode squeezed states, each exhibiting more than 4 dB of raw squeezing (up to 4.3 dB) across a 0.7 THz bandwidth. This uniform, high-performance quantum resource represents a key step toward scalable, integrated CV quantum technologies operating beyond classical limits. + oai:arXiv.org:2512.08650v1 + quant-ph + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Kangkang Li, Yue Wang, Ze Wang, Xin Zhou, Jincheng Li, Yinke Cheng, Binyan Wu, Qihuang Gong, Bei-Bei Li, Qi-Fan Yang - Transition to the ultimat regime of turbulent convection in stratified inclined duct flow - https://arxiv.org/abs/2508.10571 - arXiv:2508.10571v3 Announce Type: replace -Abstract: The stratified inclined duct (SID) flow provides a canonical model for sustained, buoyancy-driven exchange between two reservoirs of different density, and emerges as a new paradigm in geophysical fluid dynamics. Yet, the flow dynamics remain unclear in the highly turbulent regime; laboratory experiments can access this regime but they lack resolution, while direct numerical simulations (DNS) at realistically high Prandtl number $\mathrm{Pr}=7$ (for heat in water) have not achieved sufficiently high Reynolds numbers $\mathrm{Re}$. We conduct three-dimensional DNS up to $\mathrm{Re}= 8000$ and observe the transition to the so-called ultimate regime of turbulent convection as evidenced by the Nusselt number scaling $\mathrm{Nu} \sim \mathrm{Ra}^{1/2}$, i.e., considerably enhanced transport. At the transition the shear Reynolds number, a key parameter characterizing boundary layer (BL) dynamics, exceeds the threshold range of 420 for turbulent kinetic BLs with the emergence of logarithmic velocity profiles. The nature of the transition towards ultimate SID flow is of nonlinear-normal nature, i.e., subcritical and hysteretic, as typical for the transition to fully turbulent shear flows. Our work connects SID flow with the broader class of wall-bounded turbulent convection flows and gives insight into mixing in the vigorously turbulent regimes in oceanography and industry. - oai:arXiv.org:2508.10571v3 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Spectroscopic readout of chiral photonic topology in a single-cavity spin-orbit-coupled Bose-Einstein condensate + https://arxiv.org/abs/2512.08662 + arXiv:2512.08662v1 Announce Type: cross +Abstract: Topological photonic phases are typically identified through band reconstruction, steady-state transmission, or real-space imaging of edge modes. In this work, we present a framework for spectroscopic readout of chiral photonic topology in a single driven optical cavity containing a spin-orbit-coupled Bose-Einstein condensate. We demonstrate that the cavity transmission power spectral density provides a direct and measurable proxy for a momentum- and frequency-resolved photonic Chern marker, enabling topological characteristics to be inferred from spectral data without the need for bulk-band tomography. In the loss-dominated regime, where cavity decay exceeds atomic dissipation, the power spectral density exhibits Dirac-like gapped hybrid modes with a vanishing Chern marker, indicating a trivial phase. When the dissipation imbalance is reversed, a bright, gap-spanning spectral ridge emerges, co-localized with peaks in both the Chern marker and Berry curvature. The complex spectrum reveals parity-time symmetric coalescences and gain-loss bifurcations, marking exceptional points and enabling chiral, gap-traversing transport. By linking noise spectroscopy to geometric and non-Hermitian topology in a minimal cavity-QED architecture, this work provides a framework for spectroscopic detection of topological order in driven quantum systems. This approach offers a pathway to compact, tunable topological photonics across a broad range of light-matter platforms, providing a method for the study and control of topological phases in hybrid quantum systems. + oai:arXiv.org:2512.08662v1 + quant-ph + cond-mat.quant-gas + physics.app-ph + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://creativecommons.org/licenses/by/4.0/ - Rundong Zhou, Adrien Lefauve, Roberto Verzicco, Detlef Lohse + Kashif Ammar Yasir, Gao Xianlong - From real-time calibrations to smart HV tuning for FAIR - https://arxiv.org/abs/2509.17653 - arXiv:2509.17653v2 Announce Type: replace -Abstract: Real-time data processing of the next generation of experiments at FAIR requires reliable event reconstruction and thus depends heavily on in-situ calibration procedures. Previously, we developed a neural-network-based approach that predicts calibration parameters from continuously available environmental and operational data and validated it on the HADES Multiwire Drift Chambers (MDCs), achieving fast predictions as accurate as offline calibrations. In this work, we introduce several methodological improvements that enhance both accuracy and the ability to adapt to new data. These include changes to the input features, better offline calibration and trainable normalizations. Furthermore, by combining beam-time and cosmic-ray datasets, we demonstrate that the learned dependencies can be transferred between very different data-taking scenarios. This enables the network not only to provide real-time calibration predictions, but also to infer optimal high-voltage settings, thus establishing a practical framework for a real-time detector control during data acquisition process. - oai:arXiv.org:2509.17653v2 - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by/4.0/ - Valentin Kladov, Johan Messchendorp, James Ritman + Many interacting particles in solution. II. Screening-ranged expansion of electrostatic forces + https://arxiv.org/abs/2512.08682 + arXiv:2512.08682v1 Announce Type: cross +Abstract: We present a fully analytical integration of the Maxwell stress tensor and derive exact relations for interparticle forces in systems of multiple dielectric spheres immersed in a polarizable ionic solvent, within the framework of the linearized Poisson--Boltzmann theory. Building upon the screening-ranged (in ascending orders of Debye screening) expansions of the potentials developed and rigorously analyzed in the accompanying works \cite{supplem_pre,supplem_pre_math,supplem_prl}, we construct exact screening-ranged many-body expansions for electrostatic forces in explicit analytical form. These results establish a rigorous foundation for evaluating screened electrostatic interactions in complex particle systems and provide direct analytical connections to, and systematic improvements upon, various earlier approximate or limited-case formulations available in the literature, both at zero and finite ionic strength. + oai:arXiv.org:2512.08682v1 + cond-mat.soft + math-ph + math.MP + physics.bio-ph + physics.chem-ph + physics.comp-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Sergii V. Siryk, Walter Rocchia - A flux bounce-back scheme for the filtered Spectral Element Lattice Boltzmann Method - https://arxiv.org/abs/2509.19171 - arXiv:2509.19171v2 Announce Type: replace -Abstract: We develop a spectral element lattice Boltzmann method (SELBM) with the flux bounce-back (FBB) scheme, to enable accurate simulations of single-phase fluid dynamics in unstructured mesh. We adopt an Eulerian description of the streaming process in place of the perfect shift in the regular LBM. The spectral element method is used to spatially discretize the convective term, while the strong stability-preserving Runge-Kutta (SSPRK) method is used for time integration. To increase stability, we investigate the use of an explicit filter, particularly in the context of the sensitive double shear layer problem. The results indicate that by using the high-order polynomial, we can effectively eliminate the small vortices around the neck region. We introduce the flux bounce-back scheme to enable the current scheme to handle complex boundaries. The proposed scheme and flux boundary method are validated through benchmark simulations, including the unsteady Couette flow and the planar Poiseuille flow. Further validation is provided through the Taylor-Green vortex problem, demonstrating the accuracy and convergence of the scheme for isotropic turbulence. Finally, we consider a fully developed turbulent flow within a cylindrical pipe and correctly predict the turbulent boundary layer profile. - oai:arXiv.org:2509.19171v2 - physics.flu-dyn + Many interacting particles in solution. III. Spectral analysis of the associated Neumann--Poincar\'e-type operators + https://arxiv.org/abs/2512.08684 + arXiv:2512.08684v1 Announce Type: cross +Abstract: The interaction of particles in an electrolytic medium can be calculated by solving the Poisson equation inside the solutes and the linearized Poisson--Boltzmann equation in the solvent, with suitable boundary conditions at the interfaces. Analytical approaches often expand the potentials in spherical harmonics, relating interior and exterior coefficients and eliminating some coefficients in favor of others, but a rigorous spectral analysis of the corresponding formulations is still lacking. Here, we introduce composite many-body Neumann--Poincar\'e-type operators and prove that they are compact with spectral radii strictly less than one. These results provide the foundation for systematic screening-ranged expansions, in powers of the Debye screening parameters, of electrostatic potentials, interaction energies, and forces, and establish the analytical framework for the accompanying works~\cite{supplem_prl,supplem_pre,supplem_pre_force}. + oai:arXiv.org:2512.08684v1 + cond-mat.soft + math-ph + math.MP + physics.bio-ph + physics.chem-ph physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Chunheng Zhao, Saumil Patel, Hai Lu Lin, Misun Min, Taehun Lee + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Sergii V. Siryk, Walter Rocchia - First Electron Acceleration in a Tunable-Velocity Laser Wakefield - https://arxiv.org/abs/2509.21098 - arXiv:2509.21098v2 Announce Type: replace -Abstract: We present the first experimental confirmation that a laser-wakefield accelerator produced by a flying focus pulse is able to maintain the coherent structures necessary to accelerate electrons to relativistic energies. Through a combination of spatio-temporal near-field shaping of the beam and focusing with an axiparabola - a long-focal-depth mirror that produces a quasi-Bessel beam - the propagation velocity of the wakefield is tuned to control the maximum electron energy achievable. The experimental data are supported by advanced optical and particle-in-cell simulations and are aligned with a simplified analytical model. Together, the results significantly strengthen the case for the flying-focus wakefield as a strategy for mitigating dephasing in laser-wakefield acceleration. - oai:arXiv.org:2509.21098v2 - physics.acc-ph - physics.optics - physics.plasm-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace + Two-phase hydrodynamic model of active colloid motion + https://arxiv.org/abs/2512.08744 + arXiv:2512.08744v1 Announce Type: cross +Abstract: The paper presents a two-phase hydrodynamic model for the numerical simulation of collective motion in a thin layer of active colloids containing spherical microswimmers. The model accounts for three fundamental mechanisms governing the dynamics of the active colloid: the random motion of the microswimmers, their mutual collisions, and their interaction with the surrounding fluid phase. The accurate resolution of the characteristic time scales associated with each mechanism is crucial for reproducing the different dynamic modes. The model reproduces two primary modes of motion: Brownian and collective, as well as the transition between them. It is demonstrated that hydrodynamic interactions begin to play a significant role when the microswimmer velocity exceeds a critical threshold. At this point, the kinetic energy transferred to the fluid phase is sufficient to generate a noticeable feedback effect on the swimmers' motion. Conversely, a further increase in microswimmers' velocity enhances the role of collisions, causing the system to revert from a collective mode back to a Brownian-like state. A similar transition occurs at higher volume fractions of microswimmers within the colloid. + oai:arXiv.org:2512.08744v1 + cond-mat.soft + physics.flu-dyn + Wed, 10 Dec 2025 00:00:00 -0500 + cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Aaron Liberman, Anton Golovanov, Slava Smartsev, Anda-Maria Talposi, Sheroy Tata, Victor Malka + A. Kiverin, S. Luguev, I. Yakovenko - EnScale: Temporally-consistent multivariate generative downscaling via proper scoring rules - https://arxiv.org/abs/2509.26258 - arXiv:2509.26258v2 Announce Type: replace -Abstract: The practical use of future climate projections from global circulation models (GCMs) is often limited by their coarse spatial resolution, requiring downscaling to generate high-resolution data. Regional climate models (RCMs) provide this refinement, but are computationally expensive. To address this issue, machine learning models can learn the downscaling function, mapping coarse GCM outputs to high-resolution fields. Among these, generative approaches aim to capture the full conditional distribution of RCM data given coarse-scale GCM data, which is characterized by large variability and thus challenging to model accurately. We introduce EnScale, a generative machine learning framework that emulates the full GCM-to-RCM map by training on multiple pairs of GCM and corresponding RCM data. It first adjusts large-scale mismatches between GCM and coarsened RCM data, followed by a super-resolution step to generate high-resolution fields. Both steps employ generative models optimized with the energy score, a proper scoring rule. Compared to state-of-the-art ML downscaling approaches, our setup reduces computational cost by about one order of magnitude. EnScale jointly emulates multiple variables -- temperature, precipitation, solar radiation, and wind -- spatially consistent over an area in Central Europe. In addition, we propose a variant EnScale-t that enables temporally consistent downscaling. We establish a comprehensive evaluation framework across various categories including calibration, spatial structure, extremes, and multivariate dependencies. Comparison with diverse benchmarks demonstrates EnScale's strong performance and computational efficiency. EnScale offers a promising approach for accurate and temporally consistent RCM emulation. - oai:arXiv.org:2509.26258v2 - physics.ao-ph - physics.data-an - stat.AP - stat.ML - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-sa/4.0/ - Maybritt Schillinger, Maxim Samarin, Xinwei Shen, Reto Knutti, Nicolai Meinshausen + Resource and population dynamics in an agent-environment interaction model + https://arxiv.org/abs/2512.08762 + arXiv:2512.08762v1 Announce Type: cross +Abstract: In any ecosystem, the conditions of the environment and the characteristics of the species that inhabit it are entangled, co-evolving in space and time. We introduce a model that couples active agents with a dynamic environment, interpreted as a nutrient source. Agents are persistent random walkers that gather food from the environment and store it in an inner energy depot. This energy is used for self-propulsion, metabolic expenses, and reproduction. The environment is a two-dimensional surface divided into patches, each of them producing food. Thus, population size and resource distribution become emergent properties of the system. Combining simulations and analytical framework to analyze limiting cases, we show that the system exhibits distinct phases separating quasi-static and highly motile regimes. We observe that, in general, population sizes are inversely proportional to the average energy per agent. Furthermore, we find that, counter-intuitively, reduced access to resources or increased metabolic expenditure can lead to a larger population size. The proposed theoretical framework provides a link between active matter and movement ecology, allowing to investigate short vs long-term strategies to resource exploitation and rationing, as well as sedentary vs wandering strategy. The introduced approach may serve as a tool to describe real-world ecological systems and to test environmental strategies to prevent species extinction. + oai:arXiv.org:2512.08762v1 + q-bio.PE + physics.bio-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by-nc-nd/4.0/ + G. Briozzo, G. J. Sibona, F. Peruani - Resultant Delta-V Estimation from EDR Data Recorded in Automobiles that have Undergone Impact-Induced Yaw Rate - https://arxiv.org/abs/2510.00077 - arXiv:2510.00077v2 Announce Type: replace -Abstract: There are several references in the public literature that discuss the effect impact-induced yaw motion has on the measurement of acceleration, vis-\`a-vis accelerometers, in automobile collisions [1], [2], [3], [4]. It is well-understood that direct integration of accelerometer data does not provide accurate velocity components for a vehicle undergoing appreciable rotational motion whether the accelerometers are installed at the vehicle center of gravity or not. Direct integration of accelerometer data is, nonetheless, how event data recorders (EDRs) calculate Delta-V components and care must be taken on the part of the analyst in interpreting this information when the vehicle from which it came was known to have experienced significant yaw motion. As such, in this paper we set out to: (1) examine whether the correct resultant Delta-V at the center of gravity can be determined from the directly-integrated EDR Delta-V components, and (2) to assess what useful Delta-V information can be readily gotten from EDRs that are typically not installed at the vehicle center of gravity. - oai:arXiv.org:2510.00077v2 - physics.class-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Micky Marine + Commissioning of an experiment for thermodynamic and spectroscopic studies of hydrogen isotopologues at cryogenic conditions + https://arxiv.org/abs/2512.08788 + arXiv:2512.08788v1 Announce Type: cross +Abstract: To study thermodynamic properties and dynamic phase space behavior of hydrogen isotopologues (Q$_2$) at cryogenic temperatures and at high density, the Tritium Absorption InfraRed Spectroscopy 2 (T$_2$ApIR) experiment has been set up and commissioned at Tritium Laboratory Karlsruhe (TLK). In the frame of the experiment, Q$_2$ behavior in different phases, ortho/para states, temperatures (10 K - 300 K) and pressures (up to 2.5 bar a) will be investigated with optical methods, infrared and Raman spectroscopy. The facility consists of a fully tritium compatible cryostat, which includes an optical cell, ortho/para converter and windows for optical and spectroscopic studies. The cryostat can be cooled below the H$_2$ triple point by a two-stage cryocooler and contains openings in the cryogenic shielding for the optical access. The challenge of combining these scientific requirements in a design with high amounts of tritium (14 g), in a limited space, all while maintaining the TLK safety philosophy was solved by the presented design. The experiment is ready to be fully integrated into the TLK closed loop tritium infrastructure. This contribution reports a comprehensive overview of the commissioning phase of the experimental facility and the results of the first commissioning experiments, including cryogenic performance tests, commissioning experiments with non-radioactive gases, and tests of the analytical instruments. + oai:arXiv.org:2512.08788v1 + cond-mat.stat-mech + physics.atm-clus + physics.chem-ph + physics.ins-det + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by-sa/4.0/ + Joshua Kohpei{\ss} (Karlsruhe Institute of Technology), Dominic Batzler (Karlsruhe Institute of Technology), Beate Bornschein (Karlsruhe Institute of Technology), Lutz Bornschein (Karlsruhe Institute of Technology), Robin Gr\"o{\ss}le (Karlsruhe Institute of Technology), Daniel Kurz (Karlsruhe Institute of Technology), Ralph Lietzow (Karlsruhe Institute of Technology), Alexander Marsteller (Karlsruhe Institute of Technology), Michael Sturm (Karlsruhe Institute of Technology), Stefan Welte (Karlsruhe Institute of Technology) - Learning from the electronic structure of molecules across the periodic table - https://arxiv.org/abs/2510.00224 - arXiv:2510.00224v2 Announce Type: replace -Abstract: Machine-Learned Interatomic Potentials (MLIPs) require vast amounts of atomic structure data to learn forces and energies, and their performance continues to improve with training set size. Meanwhile, the even greater quantities of accompanying data in the Hamiltonian matrix H behind these datasets has so far gone unused for this purpose. Here, we provide a recipe for integrating the orbital interaction data within H towards training pipelines for atomic-level properties. We first introduce HELM ("Hamiltonian-trained Electronic-structure Learning for Molecules"), a state-of-the-art Hamiltonian prediction model which bridges the gap between Hamiltonian prediction and universal MLIPs by scaling to H of structures with 100+ atoms, high elemental diversity, and large basis sets including diffuse functions. To accompany HELM, we release a curated Hamiltonian matrix dataset, 'OMol_CSH_58k', with unprecedented elemental diversity (58 elements), molecular size (up to 150 atoms), and basis set (def2-TZVPD). Finally, we introduce 'Hamiltonian pretraining' as a method to extract meaningful descriptors of atomic environments even from a limited number atomic structures, and repurpose this shared embedding space to improve performance on energy-prediction in low-data regimes. Our results highlight the use of electronic interactions as a rich and transferable data source for representing chemical space. - oai:arXiv.org:2510.00224v2 - physics.chem-ph - cond-mat.mtrl-sci - cs.LG - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Manasa Kaniselvan, Benjamin Kurt Miller, Meng Gao, Juno Nam, Daniel S. Levine + Space-time discretization for barotropic flow stemming from a multisymplectic variational formulation + https://arxiv.org/abs/2512.08841 + arXiv:2512.08841v1 Announce Type: cross +Abstract: This study proposes and analyses a novel higher-order, structure preserving discretization method for inviscid barotropic flows from a Lagrangian perspective. The method is built on a multisymplectic variational principle discretized over a full space-time domain. Flow variables are encoded on a staggered space-time mesh, leveraging the principles of mimetic spectral element discretization. Unlike standard Lagrangian methods, which are prone to mesh distortion, this framework computes fluid deformations in a fixed reference configuration and systematically maps them to the physical domain via the Piola-Kirchhoff stress. Further, the structure preserving design ensures that the discrete analogues of the fundamental conservation laws for mass, momentum, and energy are satisfied up to machine precision. The formulation also inherently handles low-Mach number flows without specialized preconditioning. Numerical experiments on expansion and compression flows confirm the accuracy, stability, and exact conservation properties of the discretization. + oai:arXiv.org:2512.08841v1 + math.NA + cs.NA + physics.flu-dyn + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by/4.0/ + Mukthesh Mahadev, Marc Gerritsma - Double-pair Coulomb and Breit photon correction to the correlated relativistic energy - https://arxiv.org/abs/2510.04571 - arXiv:2510.04571v2 Announce Type: replace -Abstract: The simplest, algebraic quantum-electrodynamical corrections, due to the double-negative energy subspace and instantaneous interactions, are computed to the no-pair energy of two-spin-1/2-fermion systems. Numerical results are reported for two-electron atoms with a clamped nucleus and positronium-like genuine two-particle systems. The Bethe-Salpeter equation provides the theoretical framework, and numerical methods have been developed for its equal-time time-slice. In practice, it requires solving a sixteen-component eigenvalue equation with a two-particle Dirac Hamiltonian, including the appropriate interaction. The double-pair corrections can either be included in the interaction part of the eigenvalue equation or treated as a perturbation to the no-pair Hamiltonian. The numerical results have an $\alpha$ fine-structure constant dependence that is in excellent agreement with the known $\alpha^3E_\mathrm{h}\$-order double-pair correction of non-relativistic quantum electrodynamics. - oai:arXiv.org:2510.04571v2 - physics.chem-ph - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1103/dv76-8rkt - P\'eter Jeszenszki, Edit M\'atyus + A mathematical model of \textit{Culex} population abundance and the impact of vector control interventions in a patchy environment + https://arxiv.org/abs/2512.08842 + arXiv:2512.08842v1 Announce Type: cross +Abstract: Recent mosquito-borne outbreaks have revealed vulnerabilities in our abatement programmes, raising concerns about how abatement-districts should choose optimal future control strategies. Spatial dissemination of vector-borne disease is strongly shaped by the movement of both hosts and mosquitoes, creating substantial overlap between vector activity and pathogen spread. We developed a mathematical model for Culex mosquito dynamics in a patchy landscape, integrating entomological observations, weather-driven factors, and the vector control practices of the Northwest Mosquito Abatement District (NWMAD) in Cook County, Illinois. By coupling a temperature-driven multi-patch ODE model with NWMAD's adulticide and larvicide interventions, we investigated how spatial heterogeneity and control timing influence mosquito abundance. We also evaluated how mosquito dispersal modifies intervention effectiveness by comparing single-patch and two-patch model outcomes. Our results showed that models ignoring spatial connectivity can substantially overestimate the impact of interventions or misidentify the thresholds of vector persistence. Through numerical simulations, we analysed continuous and pulsatile control approaches under varying spatial and temporal configurations. These findings provide insight into optimal strategies for managing Culex populations and mitigating mosquito-borne disease risk in weather-driven, spatially connected environments across Cook County, Illinois. + oai:arXiv.org:2512.08842v1 + q-bio.PE + physics.bio-ph + Wed, 10 Dec 2025 00:00:00 -0500 + cross + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Suman Bhowmick, Patrick Irwin, Kristina Lopez, Megan Lindsay Fritz, Rebecca Lee Smith - Bidirectional Nonlinear Optical Tomography: Unbiased Characterization of Off- and On-Chip Coupling Efficiencies - https://arxiv.org/abs/2510.13110 - arXiv:2510.13110v2 Announce Type: replace -Abstract: Accurate evaluation of nonlinear photonic integrated circuits requires separating input and output coupling efficiencies (i.e., $\eta_1$ and $\eta_2$), yet the conventional linear-transmission calibration method recovers only their product (i.e., $\eta_1\,\eta_2$) and therefore introduces systematic bias when inferring on-chip performance from off-chip data. We present bidirectional nonlinear optical tomography (BNOT), a direction-aware metrology that uses forward and backward pumping of complementary nonlinear probes, with process-appropriate detection, to break the ``degeneracy'' of $\eta_1\,\eta_2$ and estimate individual interface efficiencies with tight confidence intervals. The method links off-chip measurements to on-chip quantities through a compact observation model that explicitly incorporates pump fluctuations and detector noise, and it frames efficiency extraction as a joint constrained optimization. Monte Carlo studies show unbiased convergence of the estimated efficiencies to ground truth with low error across realistic operating regimes. Using these efficiency estimates to reconstruct on-chip nonlinear figures of merit yields distributions centered on the true values with reduced variance, whereas conventional ``degenerate'' calibration is biased and can substantially misestimate on-chip performance. BNOT is hardware-compatible and platform-agnostic, and provides unbiased characterization of off- and on-chip coupling efficiencies across nonlinear processes, enabling reproducible, coupling-resolved benchmarking for scalable systems in quantum optics, frequency conversion, and precision metrology. - oai:arXiv.org:2510.13110v2 + Quantum-Plasmonic Dynamics Modeled via a Modified Langevin Noise Formalism: Numerical Studies of Single-Photon Emission and Two-Photon Interference + https://arxiv.org/abs/2205.03388 + arXiv:2205.03388v2 Announce Type: replace +Abstract: Recent studies have established and rigorously validated a modified Langevin noise formalism that enables first-principles quantization of electromagnetic fields in open and dissipative environments [1,2,3]. Building on this foundation, a fully quantum-mechanical multimode Jaynes-Cummings framework has been developed and verified, providing an accurate description of atom--field interactions in lossy and radiative systems [4]. In this work, we explore the potential of this formalism for nanophotonic applications by modeling representative quantum-plasmonic dynamics. In particular, we present detailed numerical examples for (i) two-photon interference mediated by a quantum plasmonic beam splitter, and (ii) non-Markovian dynamics of an atom located in plasmonic antennas and directional control of out-coupled single-photon fields. These results demonstrate that the proposed modeling approach can be directly used to guide the design and optimization of plasmonic single-photon sources and beam-splitting structures. Moreover, the framework is broadly applicable to the analysis of linear optical components and cavity quantum electrodynamics problems in open and dissipative photonic integrated circuits. + oai:arXiv.org:2205.03388v2 physics.optics - nlin.AO quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Bo-Han Wu, Mahmoud Jalali Mehrabad, Dirk Englund + Jisang Seo, Hyunwoo Choi, Thomas E Roth, Jie Zhu, Weng C Chew, Dong-Yeop Na - The Neuroticism Paradox: How Emotional Instability Fuels Collective Feelings - https://arxiv.org/abs/2510.16046 - arXiv:2510.16046v2 Announce Type: replace -Abstract: Collective emotions shape organizations, communities, and societies, yet the traits that determine who drives them remain unknown. Conventional wisdom holds that stable, extraverted individuals act as emotional leaders, calming and coordinating the feelings of others. Here we challenge this view by analyzing a 30.5-month longitudinal dataset of daily emotions from 38 co-located professionals (733,534 records). Using Granger-causality network reconstruction, we find that emotionally unstable individuals -- those high in neuroticism (r = 0.478, p = 0.002) and low in conscientiousness (r = -0.512, p = 0.001) -- are the true "emotional super-spreaders," while extraversion shows no effect (r = 0.238, p = 0.150). This "Neuroticism Paradox" reveals that emotional volatility, not stability, drives contagion. Emotions propagate with a reproduction rate (R_0 = 15.58) comparable to measles, yet the system avoids collapse through high clustering (C = 0.705) that creates "emotional quarantine zones." Emotional variance increased 22.9% over time, contradicting homeostasis theories and revealing entropy-driven dynamics. We propose an Affective Epidemiology framework showing that collective emotions are governed by network position and volatility rather than personality stability -- transforming how we understand emotional leadership in human systems. - oai:arXiv.org:2510.16046v2 + Observing network dynamics through sentinel nodes + https://arxiv.org/abs/2408.00045 + arXiv:2408.00045v3 Announce Type: replace +Abstract: A fundamental premise of statistical physics is that the particles in a physical system are interchangeable, and hence the state of each specific component is representative of the system as a whole. This assumption breaks down for complex networks, in which nodes may be extremely diverse, and no single component can truly represent the state of the entire system. It seems, therefore, that to observe the dynamics of social, biological or technological networks, one must extract the dynamic states of a large number of nodes -- a task that is often practically prohibitive. Theoretical tools are also highly restrictive, given the analytically impenetrable combination of complex heterogeneous networks with nonlinear, often hidden, dynamics. To overcome this challenge, we use machine learning techniques to detect the network's sentinel nodes, a set of network components whose combined states can help approximate the average dynamics of the entire network. The method allows us to assess the equilibrium state of a large complex system by tracking just a small number of carefully selected nodes. We find that the sentinels are mainly determined by the network structure such that they can be extracted even with little knowledge of the system's specific interaction dynamics. Therefore, the network's sentinels offer a natural probe by which to observe the system's dynamic states. Intriguingly, sentinels tend to avoid the highly central nodes such as the hubs. + oai:arXiv.org:2408.00045v3 physics.soc-ph - cs.CY - cs.SI - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Xiao Sun + 10.1038/s41467-025-64975-x + Neil G. MacLaren, Baruch Barzel, Naoki Masuda - Perturbation-assisted Observation of the Lowest Vibrational Level of the $\mathrm{b}^{3}\Pi_{0}$ State of Ultracold LiK Molecules - https://arxiv.org/abs/2510.17166 - arXiv:2510.17166v3 Announce Type: replace -Abstract: The narrow transition from the lowest rovibrational level of the $\mathrm{X}^{1}\Sigma^{+}$ electronic ground state to the lowest vibrational level of the $\mathrm{b}^{3}\Pi_{0}$ potential provides opportunities for achieving magic-wavelength trapping of ultracold bialkali molecules for enhancing their rotational coherence times. Guided by existing spectroscopic data of several perturbed and deeply-bound rovibrational states of the $\mathrm{A}^{1}\Sigma^{+}$ potential [Grochola et al., Chem. Phys. Lett., 2012, 535, 17-20], we conducted a targeted spectroscopic search and report the first observation of the lowest vibrational level of the $\mathrm{b}^{3}\Pi_{0}$ state in $^{6}\mathrm{Li}^{40}\mathrm{K}$. The transition frequency from $|\mathrm{X}^{1}\Sigma^{+},\,v=0,\,J=0>$ to $|\mathrm{b}^{3}\Pi_{0},\,v'=0,\,J'=1>$ is determined to be 314,230.5(5)GHz. Assisted by microwave spectroscopy, we resolved the rotational structure of $|\mathrm{b}^{3}\Pi_{0},\,v'=0>$ and extracted a rotational constant of $h\times8.576(44)$ GHz for the $\mathrm{b}^{3}\Pi_{0}$ state. From this, we deducted an energy separation between $|\mathrm{b}^{3}\Pi_{0},v'=0,J'=0>$ and $|\mathrm{X}^{1}\Sigma^{+},v=0,J=0>$ of $hc\times$10,481.03(2) $\mathrm{cm}^{-1}$. Our work provides timely and precise information on the deeply-bound region of the $\mathrm{b}^{3}\Pi_{0}$ triplet excited potential of LiK, and benefits future applications of ultracold LiK isotopologues in quantum simulation and quantum computation that demand long coherence times. - oai:arXiv.org:2510.17166v3 - physics.atom-ph - cond-mat.quant-gas - Tue, 09 Dec 2025 00:00:00 -0500 + Surface acoustic waves to monitor active THz metagrating based on VO2 + https://arxiv.org/abs/2412.01210 + arXiv:2412.01210v2 Announce Type: replace +Abstract: We theoretically propose a new approach to in-situ monitor the altered states of pixels in VO2 based active THz amplitude metagrating by using surface acoustic waves (SAWs) generated in LiNbO3 substrate. A single broadband RF response of the SAW device consists of N narrowband frequency channels which code the feedback information on the current pixels states. This way the resistance alteration due to metal-to-insulator transition of all VO2 based pixels of the active THz grating is monitored in advance even without incident radiation. The method provides important new options of monitoring a metasurface aging as well as incorrect switching related to technological defects. Using of the SAW device in all-electrically addressed VO2 based binary grating with tunable period as well as advanced gradient type gratings are modeled. + oai:arXiv.org:2412.01210v2 + physics.optics + physics.app-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Anbang Yang, Xiaoyu Nie, Hao Lin Yu, Yiming Liu, Victor Avalos, Canming He, Jacek Klos, Svetlana Kotochigova, Kai Dieckmann + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + G. Y. Karapetyan, M. V. Ochkurov, V. E. Kaydashev - Water wave scattering by a surface-mounted rectangular anisotropic elastic plate - https://arxiv.org/abs/2510.17872 - arXiv:2510.17872v2 Announce Type: replace -Abstract: This paper considers the problem of water wave scattering by a rectangular anisotropic elastic plate mounted on the ocean surface, with either free or clamped edges. The problem is obtained as an expansion over the dry modes of the elastic plate, which are computed using a Rayleigh--Ritz method. In turn, the component diffraction and radiation problems are solved by formulating a boundary integral equation and solving numerically using a constant panel method. The results are presented to highlight the resonant responses of the plate under different forcing scenarios. In particular, we illustrate how the excitation of certain modes can be forbidden due to symmetry. - oai:arXiv.org:2510.17872v2 + Wave induced fracture of a sea ice analog + https://arxiv.org/abs/2501.04824 + arXiv:2501.04824v2 Announce Type: replace +Abstract: We study at the laboratory scale the rupture of thin floating sheets made of a brittle material under a wave-induced mechanical forcing. We show that the rupture occurs where the curvature is maximum and the break-up threshold strongly depends on the wave properties. We observe that the critical stress for fracture depends on the forcing wavelength. Hence our observations are incompatible with a critical stress criterion for fracture. Instead, our measurements can be rationalized as an energy criterion: a fracture propagates when the material surface energy is lower than the released elastic energy, which depends on the forcing geometry. In light of these findings, it may be worthwhile to revisit current numerical models of sea ice fracture by ocean waves. + oai:arXiv.org:2501.04824v2 physics.flu-dyn - cond-mat.mtrl-sci - physics.class-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Ben Wilks, Michael H. Meylan, Zachary J. Wegert, Vivien J. Challis, Ngamta Thamwattana - - - In vivo evidence of blood flow slippage: failure of the no-slip boundary condition assumption - https://arxiv.org/abs/2510.18107 - arXiv:2510.18107v2 Announce Type: replace -Abstract: The assumption that blood adheres to vessel walls, the ``no-slip'' boundary condition, is an essential premise of cardiovascular fluid dynamics. Yet, whether it holds true \emph{in vivo} has not been established. Using 4D flow magnetic resonance imaging of the human thoracic aorta and modeling blood as a Navier--Stokes fluid, we quantify the velocity of blood at the wall. We find tangential wall velocities of about 30--80\% of the mean luminal velocity, providing clear evidence of blood slippage. To our knowledge, this is the first demonstration that the no-slip condition does not apply to blood flow \emph{in vivo}. This finding challenges a fundamental assumption in cardiovascular modeling and directly affects key blood flow characteristics such as pressure drop, vorticity, wall shear stress, and energy dissipation, all of which play important roles across a wide range of cardiovascular conditions. - oai:arXiv.org:2510.18107v2 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Alena Jarol\'imov\'a, Jaroslav Hron, Karel T\r{u}ma, Josef M\'alek, Radom\'ir Chabiniok, Keshava Rajagopal - - - Direct Measurement of the $5s5p\,{}^1P_1 \to 5s4d\,{}^1D_2$ Decay Rate in Strontium - https://arxiv.org/abs/2510.22184 - arXiv:2510.22184v2 Announce Type: replace -Abstract: We investigate the decay process $5s5p\,{}^1P_1 \to 5s4d\,{}^1D_2 \to 5s5p\,{}^3P_2$ in a magneto-optical trap of Sr atoms operating on the $461\,\mathrm{nm}$ ($5s^2\,{}^1S_0 - 5s5p\,{}^1P_1$) transition by irradiating the trapped atoms with laser light resonant with the $448\,\mathrm{nm}$ ($5s4d\,{}^1D_2 - 5s8p\,{}^1P_1$) transition and observing the transient response of atom fluorescence. We measure, for the first time, the branching ratio of the $5s4d\,{}^1D_2 \to 5s5p\,{}^3P_2$ transition to be $0.177(4)$, which significantly deviates from the widely cited theoretical value of $0.322$ [C. W. Bauschlicher Jr. et al., J. Phys. B 18, 1523 (1985)]. Moreover, we determine the decay rate of the $5s5p\,{}^1P_1 \to 5s4d\,{}^1D_2$ transition to be $5.3(5)\times10^3\,\mathrm{s^{-1}}$, consistent within uncertainty with the widely cited experimental value [L. R. Hunter et al., Phys. Rev. Lett. 56, 823 (1986)], but substantially lower than the recent theoretical value of $9.25(40)\times10^3\,\mathrm{s^{-1}}$ [A. Cooper et al., Phys. Rev. X 8, 041055 (2018)]. These findings have significant implications for laser cooling of Sr and fluorescence detection of single atoms in optical tweezers. They also call for a reevaluation of the previous theoretical frameworks used to calculate the decay rates of the $5s5p\,{}^1P_1 \to 5s4d\,{}^1D_2$ and $5s4d\,{}^1D_2 \to 5s5p\,{}^3P_{1,2}$ transitions. - oai:arXiv.org:2510.22184v2 - physics.atom-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Naohiro Okamoto, Takatoshi Aoki, Yoshio Torii - - - Structural Stress as a Predictor of the Rate and Spatial Location of Aortic Growth in Uncomplicated Type B Aortic Dissection - https://arxiv.org/abs/2511.03287 - arXiv:2511.03287v2 Announce Type: replace -Abstract: Accurate prediction of aortic expansion in uncomplicated type B aortic dissection (TBAD) can help identify patients who may benefit from timely thoracic endovascular aortic repair. This study investigates associations between biomechanical predictors derived from reduced-order fluid-structure interaction (FSI) analysis and aortic growth outcomes. Baseline and follow-up CT images from 30 patients with uncomplicated TBAD were obtained. For each patient, a reduced-order FSI analysis using the forward penalty stress computation method was performed on the baseline geometry. Aortic growth was quantified by registering baseline and follow-up surfaces using nonrigid registration. Mixed-effects linear and logistic regression analyses were performed to assess relationships between structural stress, wall shear stress (WSS), pressure and growth rate while accounting for inter-patient variability. Group comparison analyses were performed to evaluate spatial distributions of these biomechanical variables along the dissected aorta between patient groups categorized by optimal medical therapy (OMT) and aortic growth outcomes. Linear regression revealed a positive association between structural stress and aortic growth rate (p = 0.0003) and a negative association for WSS (p = 0.0227). Logistic regression yielded area under the receiver operator characteristic curve (AUCs) of 0.7414, 0.5953, 0.4991, and 0.6845 for structural stress, WSS, pressure, and aortic diameter, respectively. Group comparisons showed significant regional differences in structural stress, but not in diameter, WSS, or pressure, between groups defined by aortic growth and OMT outcomes. These results indicate that structural stress is a promising predictor of both the rate and location of aortic growth in uncomplicated TBAD, which supports its use in risk stratification models to identify patients at higher risk of TBAD progression. - oai:arXiv.org:2511.03287v2 - physics.med-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Yuhang Du (Department of Mechanical Engineering, Texas Tech University, Lubbock, TX), Yuxuan Wu (Mercer University School of Medicine, Macon, GA), Hannah L. Cebull (Department of Radiology & Imaging Science, Emory University, Atlanta, GA), Bangquan Liao (Department of Mechanical Engineering, Texas Tech University, Lubbock, TX), Rishika Agarwal (The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA), Alan Meraz (Department of Mechanical Engineering, Texas Tech University, Lubbock, TX), Hai Dong (Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA), Asanish Kalyanasundaram (Aortic Institute at Yale-New Haven Hospital, Yale University School of Medicine, New Haven, CT), John N. Oshinski (Department of Radiology & Imaging Science, Emory University, Atlanta, GA, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA), Rudolph L. Gleason Jr (The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, The George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA), John A. Elefteriades (Aortic Institute at Yale-New Haven Hospital, Yale University School of Medicine, New Haven, CT), Bradley G. Leshnower (Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine, Atlanta, GA), Minliang Liu (Department of Mechanical Engineering, Texas Tech University, Lubbock, TX) + Baptiste Auvity, Laurent Duchemin, Antonin Eddi, St\'ephane Perrard - Non-Gravitational Acceleration in 3I ATLAS: Constraints on Exotic Volatile Outgassing in Interstellar Comets - https://arxiv.org/abs/2511.07450 - arXiv:2511.07450v2 Announce Type: replace -Abstract: The interstellar comet 3I/ATLAS displayed a small but statistically significant non-gravitational acceleration during its passage through the inner Solar System. Using a thermophysical model coupled with stochastic sampling of jet configurations, we investigate whether standard volatile-driven activity can account for the observed acceleration. The model includes diurnal and obliquity-averaged energy balance, empirical vapour-pressure relations, and collimated outflow from localized active areas. We find that CO-dominated activity can reproduce the magnitude of the acceleration inferred from the Marsden non-gravitational parameters for nucleus radii between 0.5 and 3 km with active-area fractions that are substantial but thermodynamically plausible. Less volatile species, including NH_3 and CH_4, contribute less efficiently and cannot provide the required recoil when acting alone, while CO_2 remains radiatively dominated and dynamically ineffective over the heliocentric-distance range relevant to the observations. These results show that the measured acceleration of 3I/ATLAS is consistent with ordinary CO-driven outgassing and does not require unusual physical properties. The analysis delineates the thermophysical conditions under which interstellar comets can exhibit measurable deviations from purely gravitational motion. - oai:arXiv.org:2511.07450v2 - physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Residual-based Chebyshev filtered subspace iteration for sparse Hermitian eigenvalue problems tolerant to inexact matrix-vector products + https://arxiv.org/abs/2503.22652 + arXiv:2503.22652v4 Announce Type: replace +Abstract: Chebyshev Filtered Subspace Iteration (ChFSI) has emerged as a robust alternative to Krylov eigensolvers for extracting a small subset of extremal eigenpairs from large sparse matrices, particularly in situations where these eigenpairs must be computed repeatedly as the system matrix evolves within an outer iteration. In this work, we propose R-ChFSI, a residual based reformulation of ChFSI designed to exhibit strong convergence properties even when the matrix-vector products are computed inexactly. We derive convergence guarantees under matrix-vector product approximations, providing a rigorous foundation for the method in large-scale eigenvalue computations. The tolerance of R-ChFSI to inexact matrix-vector products enables an efficient treatment of generalized Hermitian definite eigenproblems of the form $\textbf{A} \textbf{x} = \lambda \textbf{B} \textbf{x}$ where exact factorizations or high-accuracy iterative solves for evaluating $\textbf{B}^{-1}$ are often prohibitively expensive. Moreover, R-ChFSI naturally accommodates low-precision arithmetic for both standard and generalized eigenproblems, making it well-suited for modern hardware accelerators optimised for mixed-precision computation. To demonstrate the effectiveness of the approach, extensive numerical experiments are conducted on finite-element discretized eigenproblems with millions of degrees of freedom, solving for thousands of eigenpairs arising in \emph{ab initio} material modelling using Kohn-Sham density functional theory. For generalized eigenproblems employing approximate $\textbf{B}^{-1}$, R-ChFSI achieves desired residual norms orders of magnitude smaller than those obtained with standard ChFSI. In addition, R-ChFSI reliably reaches target residual tolerances (e.g., 10$^{-8}$) even with FP32 and TF32 arithmetic, significantly outperforming standard ChFSI in similar settings. + oai:arXiv.org:2503.22652v4 + physics.comp-ph + cs.NA + math.NA + Wed, 10 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by/4.0/ - Florian Neukart + http://creativecommons.org/publicdomain/zero/1.0/ + Nikhil Kodali, Kartick Ramakrishnan, Phani Motamarri - Quantum Phase Gradient Imaging Using a Nonlocal Metasurface System - https://arxiv.org/abs/2511.09922 - arXiv:2511.09922v4 Announce Type: replace -Abstract: Quantum phase imaging enables the analysis of transparent samples with thickness and refractive index variations in scenarios requiring precise measurements under low-light conditions. Here, we present a compact quantum phase-gradient imaging system integrating a lithium niobate (LiNbO3) metasurface for generating spatially entangled photon pairs and a silicon (Si) metasurface for phase gradient extraction. By leveraging nonlocal resonances, the LiNbO3 metasurface enables efficient spontaneous parametric down-conversion (SPDC) with all-optically angularly tunable emission, while the Si metasurface provides a nearly linear optical transfer function (OTF) that differentiates the photon wavefunction and extracts phase gradients.Experimental proof-of-concept results demonstrate the imaging of up to 25~rad/mm phase gradients, achieving 89% similarity with the reference values. The pixel resolution of the system can be potentially enhanced by orders of magnitude by increasing the metasurface dimensions and resonance quality factor.Our work showcases the application of metasurfaces in both generating and detecting quantum states and establishes a new paradigm for portable quantum phase-gradient imaging, with potential applications in quantum sensing, microscopy, and LiDAR technology. - oai:arXiv.org:2511.09922v4 - physics.optics - quant-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Modelling Lateral Spread in Wire Flat Rolling + https://arxiv.org/abs/2504.06300 + arXiv:2504.06300v2 Announce Type: replace +Abstract: A mathematical model for wire rolling is developed, focusing on predicting the lateral spread. This provides, for the first time, an analytic model of lateral spread without any fitting parameters. The model is derived directly from the governing equations, assuming a rigid, perfectly plastic material and exploiting the thinness of the wire (in thickness and width) relative to the roller size. Results are compared against experiments performed on stainless steel wire using 100mm diameter rolls, demonstrating accurate predictions of lateral spread across a wide range of wire diameters (2.96mm-7.96mm) and reduction ratios (20%-60%), all without the need for fitting parameters. Since the model requires only seconds to compute, the model's valid range is explored for varying roll diameter, wire diameter, and reduction ratio, and their effects on the resulting lateral spread characterized. The model can serve as a robust tool for validating FE results, guiding process design, and laying the foundation for future improved models. Matlab code to evaluate the model is provided in the supplementary material. + oai:arXiv.org:2504.06300v2 + physics.class-ph + cond-mat.mtrl-sci + Wed, 10 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Jinliang Ren, Jinyong Ma, Katsuya Tanaka, Lukas Wesemann, Ann Roberts, Frank Setzpfandt, Andrey A. Sukhorukov + Mozhdeh Erfanian, Carl D. Slater, Edward James Brambley - A microscopic model for the self-inductance of an ideal solenoid - https://arxiv.org/abs/2511.10677 - arXiv:2511.10677v2 Announce Type: replace -Abstract: We derive the formula for the self-inductance of an ideal solenoid by calculating the total kinetic energy associated with the drift velocity of the conduction electrons. - oai:arXiv.org:2511.10677v2 - physics.gen-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Climate impacts of forced equatorial superrotation in an idealized GCM + https://arxiv.org/abs/2504.06909 + arXiv:2504.06909v3 Announce Type: replace +Abstract: While it is expected that the large-scale tropical circulation should undergo some changes in a warmer climate, it remains an open question whether its characteristic features, such as the Hadley cell, the intertropical convergence zone, or the weak surface easterlies, could take a completely different shape. As an example, it has been hypothesized that the Earth's atmosphere may have experienced equatorial superrotation -- i.e. westerly winds at the equator -- during its history. The possibility of equatorial superrotation has been studied in a range of planetary atmospheres, including Earth-like ones, with the objective of understanding the underlying dynamical processes. However, the broader impact that this dramatic circulation change would have on the climate system is practically unexplored. This is the question we address here. We perform idealized GCM simulations with an imposed equatorial torque to investigate how a forced superrotating atmosphere affects surface temperature and the water cycle. We show that these effects are quite large and directly related to the global circulation changes, which extend beyond the tropical atmosphere. Using tools including a forcing/feedback analysis and a moist energy balance model, we argue that the dominant mechanism is changes in atmospheric energy transport, driven in particular by the collapse of the meridional overturning circulation, and to a smaller extent by the appearance of an equatorial jet, and the concomitant redistribution of moisture in the tropics, leading to a much weaker relative humidity gradient which has strong radiative effects. + oai:arXiv.org:2504.06909v3 + physics.ao-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Calin Galeriu + Tim Marino, Michael P. Byrne, Corentin Herbert - GRANITE: Mechanical Characterization and Optical Inspection of Large-Area TPC Electrodes - https://arxiv.org/abs/2511.11400 - arXiv:2511.11400v3 Announce Type: replace -Abstract: Next-generation dual-phase time projection chambers (TPCs) for rare event searches will require large-scale, high-precision electrodes. To meet the stringent requirements for mechanical stability and high-voltage performance of such an experiment, we have developed a scanning setup for electrode quality assurance called GRANITE: Granular Robotic Assay for Novel Integrated TPC Electrodes. GRANITE is built around a gantry robot on top of a $2.5\,\text{m}\times1.8\,\text{m}$ granite table, equipped with a suite of non-contact metrology devices. - We demonstrate the setup's capabilities in two key areas: first, using laser scanners, we characterize wire tension, and in an independent measurement wire deflection due to gravity and electrostatic forces is determined. The setup achieves a precision of $20\,\mu\text{m}$ for the relative measurement of only electrostatic displacement. Furthermore, GRANITE can measure gravitational sag down to $200\,\mu\text{m}$ in an absolute measurement; this precision improves to $50\,\mu\text{m}$ when applying model-based corrections for systematic effects. The performance achieved exceeds the needs for the characterisation of the electrode sagging in future experiments, which typically aims to ensure a maximal sag on the order of $500\,\mu\text{m}$. - Second, we use GRANITE's high resolution camera to image all wires of XENON1T's cathode grid. Subsets of these images are then hand sorted and used to train an autoencoder, to reliably classify wire images as either pristine wires or images containing severe anomalous features. These anomalies appear e.g. as staining and may be potential defects. The interpretation of the classification results is complicated by the fact that most wire segments are not spotless, but show a varying amount of anomalous features. Follow-up studies are needed to identify the exact nature of such features on wires. - oai:arXiv.org:2511.11400v3 - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 + Identifying the approach of a major earthquake + https://arxiv.org/abs/2504.19431 + arXiv:2504.19431v4 Announce Type: replace +Abstract: By analyzing the seismicity in natural time and studying the evolution of the fluctuations of the entropy change of seismicity under time reversal for various scales of different length i (number of events), we can identify the approach of a major earthquake (EQ) occurrence. The current investigation is extended from 1984 until 2025 for the seismicity in Japan. + oai:arXiv.org:2504.19431v4 + physics.geo-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Alexander Deisting, Jan Lommler, Shumit A. Mitra, Uwe Oberlack, Fabian Piermaier, Quirin Weitzel, Daniel Wenz + Panayiotis A. Varotsos, Nicholas V. Sarlis, Toshiyasu Nagao - Discrete Contact Angles and Electric Field Singularity in Electrowetting: A Multi-Scale Complex Potential Analysis - https://arxiv.org/abs/2511.11556 - arXiv:2511.11556v2 Announce Type: replace -Abstract: This study constructed a multi-scale theoretical framework to resolve the electric field singularity at the Triple Contact Point in electrowetting. Utilizing conformal transformation and complex analysis, we established the structure for both the global potential and local field solutions, complementing the analysis with numerical methods. Our primary finding is that the contact angle $\theta$ is not continuously adjustable but is restricted to a discrete set of values, constrained by the characteristic exponent $\lambda$. Analysis of the complex potential established $\text{Re}[\lambda] \ge 1$ as the critical condition for a non-singular electric field; conversely, singular solutions ($\text{Re}[\lambda] < 1$) are localized exclusively in the acute-angle regime ($\theta < \pi/2$). The high-order solution region exhibits a degeneracy phenomenon at specific angles, implying the local field structure is geometrically stable and universally applicable for a wide range of permittivity ratios $k$. Furthermore, we determined that the onset of electric field oscillation requires the simultaneous satisfaction of two critical conditions: the geometry must approach a flat boundary ($\theta \to \pi$) and the dielectric ratio must approach homogeneity ($k \to 1$). These findings provide a solid theoretical basis for designing non-singular electric fields and mitigating the common contact angle saturation phenomenon. - oai:arXiv.org:2511.11556v2 - physics.flu-dyn - math-ph - math.CV - math.MP - Tue, 09 Dec 2025 00:00:00 -0500 + Surface Waves and Axoplasmic Pressure Waves in Action Potential Propagation: Fundamentally Different Physics or Two Sides of the Same Coin? + https://arxiv.org/abs/2505.24580 + arXiv:2505.24580v2 Announce Type: replace +Abstract: In this commentary, we argue that El Hady and Machta's "surface wave" model for mechanical waves accompanying action potential (AP) propagation describes the same underlying process as the "axoplasmic pressure wave" model introduced earlier by Rvachev. Both models describe mechanical modes that store potential energy in the elastic components of the axon (axonal membrane, cytoskeleton, bulk axoplasmic deformation), with kinetic energy carried by the axoplasmic fluid and axoplasmic viscosity playing a significant role. The "surface wave" model quantitatively considers driving by the traveling electrical depolarization wave of the AP, whereas the "axoplasmic pressure wave" model qualitatively considers driving not only by the AP's electrical depolarization but also by other mechanisms, such as cytoskeletal actomyosin contractility. In addition, the "axoplasmic pressure wave" model considers mechanisms for synchronizing the depolarization wave and the pressure wave. Although derived using different approaches, the two models yield identical dependencies for the mechanical modes in key limits. The confusion in the literature, which treats these models as describing distinct processes, needs to be resolved to improve comprehensive understanding of the AP phenomenon and to guide future research. + oai:arXiv.org:2505.24580v2 + physics.bio-ph + q-bio.NC + Wed, 10 Dec 2025 00:00:00 -0500 replace - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Dhairya Shah, Yuan Liu, Samuel Brzezicki + http://creativecommons.org/licenses/by-nc-nd/4.0/ + 10.1142/S1793048025500055 + Marat M. Rvachev, Benjamin Drukarch - Molecular mechanism of heterogeneous ice nucleation in the atmosphere - https://arxiv.org/abs/2511.13402 - arXiv:2511.13402v2 Announce Type: replace -Abstract: Mineral dust aerosols strongly influence Earth's climate by acting as ice-nucleating particles (INPs). Feldspar minerals, particularly K-feldspar, are recognized as dominant INPs, and a previous study attributed this behavior to (100) surfaces exposed at defects. Using machine-learning molecular dynamics simulations, we systematically investigate ice nucleation on all K-feldspar surfaces. We identify the (110) surface, exposed at defects such as steps, as the most active plane for ice formation. This surface uniquely structures interfacial water into an arrangement resembling that on the (110) surface of cubic ice, providing an optimal template for nucleation. Using advanced sampling, we directly observe the formation of clusters with cubic-ice structure and their orientation agrees with experiment. These results provide a molecular-level explanation of how ice forms in our planet's atmosphere. - oai:arXiv.org:2511.13402v2 - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Stochastic modeling of deterministic laser chaos using generator extended dynamic mode decomposition + https://arxiv.org/abs/2506.05798 + arXiv:2506.05798v3 Announce Type: replace +Abstract: Recently, chaotic phenomena in laser dynamics have attracted much attention to its applied aspects, and a synchronization phenomenon, leader-laggard relationship, in time-delay coupled lasers has been used in reinforcement learning. In the present paper, we discuss the possibility of capturing the essential stochasticity of the leader-laggard relationship; in nonlinear science, it is known that coarse-graining allows one to derive stochastic models from deterministic systems. We derive stochastic models with the aid of the Koopman operator approach, and we clarify that the low-pass filtered data is enough to recover the essential features of the original deterministic chaos, such as peak shifts in the distribution of being the leader and a power-law behavior in the distribution of switching-time intervals. We also confirm that the derived stochastic model works well in reinforcement learning tasks, i.e., multi-armed bandit problems, as with the original laser chaos system. + oai:arXiv.org:2506.05798v3 + physics.app-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Wanqi Zhou, Pablo M. Piaggi + Kakutaro Fukushi, Jun Ohkubo - Deep-Learning Based Super-Resolution Functional Ultrasound Imaging of Transient Brain-Wide Neurovascular Activity on a Microscopic Scale - https://arxiv.org/abs/2511.14071 - arXiv:2511.14071v2 Announce Type: replace -Abstract: Transient brain-wide neuroimaging on a microscopic scale is pivotal for brain research, yet current modalities face challenges in meeting such spatiotemporal requirements. Functional ultrasound (fUS) enables transient neurovascular imaging through red blood cell backscattering, but suffers from diffraction-limited spatial resolution. We hypothesize that deep learning-based super-resolution reconstruction can break through this limitation, introducing super-resolution functional ultrasound (SR-fUS) which leverages ultrasound localization microscopy (ULM) data to achieve super-resolution reconstruction of red blood cell dynamics. By incorporating red blood cell radial fluctuations with uncertainty-driven loss, SR-fUS enables mapping ultrasound Doppler frames to super-resolution blood flow images, achieving 25-{\mu}m spatial and 0.2-s temporal resolution. SR-fUS was applied to image transient hemodynamic responses induced by pain stimulation in rat brains. SR-fUS accuracy in cortical microvasculature during whisker stimulation was further validated by a comparative study with two-photon microscopy. - oai:arXiv.org:2511.14071v2 - physics.med-ph - eess.SP - Tue, 09 Dec 2025 00:00:00 -0500 + Inference of a time delay in stochastic systems + https://arxiv.org/abs/2507.10429 + arXiv:2507.10429v2 Announce Type: replace +Abstract: Time delay is ubiquitous in many experimental and real-world situations. It is often unclear whether time delay plays a significant role in observed phenomena, and if it does, how long the time lag really is. This would be invaluable knowledge when analyzing and modeling such systems. Hitherto, no universal method is available by which the time delay can be inferred. To address this problem, we propose and demonstrate two different methods to infer time delay in overdamped Langevin systems with delayed feedback. In the first part, we focus on the power spectral density based on the positional data and use a characteristic signature of the time delay to infer the delay time. In limiting cases, we establish a direct relation of the observations made for nonlinear time-delayed feedback forces to analytical results obtained for the linear system. In other situations despite the absence of this direct relation, the characteristic signature remains and can be exploited by a semiautomatic method to infer the delay time. Furthermore, it may not always desirable or possible to observe a system for a long time to infer dependencies and parameters. Thus, in the second part, we propose for the first time a probing method combined with a neural network to infer the delay time, which requires only short observation time series. These proposed methods for inferring time delays in stochastic systems may prove to be valuable tools for gaining deeper insight into the role of delay across a wide range of applications -- from the behavior of individual colloidal particles under feedback control to emergent collective phenomena such as flocking and swarming. + oai:arXiv.org:2507.10429v2 + physics.data-an + cond-mat.soft + cond-mat.stat-mech + Wed, 10 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yang Cai, Shaoyuan Yan, Long Xu, Yanfeng Zhu, Bo Li, Kailiang Xu - - - End-to-end deep learning for superoscillatory subtraction imaging - https://arxiv.org/abs/2511.16115 - arXiv:2511.16115v2 Announce Type: replace -Abstract: Breaking the diffraction limit in optical imaging is crucial for resolving subwavelength details in a wide range of applications, where superoscillatory imaging and subtraction imaging are two common strategies for surpassing conventional resolution limits. We propose an end-to-end deep learning framework that integrates superoscillatory focusing and subtraction imaging into a single jointly-optimized vectorial Debye integral neural network pipeline, eliminating the traditional two-step acquisition and manual weighting process. With this end-to-end neural network, we further improve the focusing capability of the system to the sub-100-nm regime, enabling deep-subwavelength imaging resolution. - oai:arXiv.org:2511.16115v2 - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Zhongwei Jin, Keyi Chen, Qiuyu Ren, Zhigang Dai, Ruoping Yao, Zhi Hong, Bin Fang, Fangzhou Shu, Shengtao Mei, Yiping Lu - - - Calibration Plan for the SBC 10-kg Liquid Argon Detector with 100 eV Target Threshold - https://arxiv.org/abs/2511.19817 - arXiv:2511.19817v2 Announce Type: replace -Abstract: The Scintillating Bubble Chamber (SBC) Collaboration is designing a new generation of low background, noble liquid bubble chamber experiments with sub-keV nuclear recoil threshold. These experiments combine the electronic recoil blindness of a bubble chamber with the energy resolution of noble liquid scintillation, and maintain electron recoil discrimination at higher degrees of superheat (lower nuclear recoil thresholds) than Freon-based bubble chambers. A 10-kg liquid argon bubble chamber has the potential to set world leading limits on the dark matter nucleon cross-section for $O(\mathrm{GeV}/c^{2})$ masses, and to perform a high statistics coherent elastic neutrino nuclear scattering measurement with reactor neutrinos. This work presents a detailed calibration plan to measure the detector response of these experiments, combining photoneutron scattering with two new techniques to induce sub-keV nuclear recoils: nuclear Thomson scattering and thermal neutron capture. - oai:arXiv.org:2511.19817v2 - physics.ins-det - hep-ex - nucl-ex - Tue, 09 Dec 2025 00:00:00 -0500 + 10.1103/7hsc-mmzc + Robin A. Kopp, Sabine H. L. Klapp, Deepak Gupta + + + Three-dimensional numerical study on hydrogen bubble growth at electrode + https://arxiv.org/abs/2507.15582 + arXiv:2507.15582v3 Announce Type: replace +Abstract: Three-dimensional direct numerical simulation of electrolysis is applied to investigate the growth and detachment of bubbles at electrodes. + The moving gas-liquid interface is modeled employing the VOF-based method. To ensure the accuracy of the simulations, + a mesh-independence study has been performed. + The simulations include the growth phase of the bubbles, followed by their detachment from the electrode surface + and the results are validated with analytical models and experimental data. + The bubble growth is diffusion-controlled, leading to the scaling \(R = 2\beta t^{1/2}\), but our simulation overpredicts the growth exponent during the initial stage. + We further demonstrate that the number of nucleation sites significantly affects gas transport, as quantified by the Sherwood number. + The influences of contact angle and nucleation site on bubble detachment are also examined. + The predicted detachment radius varies linearly with contact angle, consistent with the well-known relation + \( R_{det}=0.6 \theta \sqrt{\sigma/(\rho_c-\rho_d)g}\) between the volume-equivalent radius and contact angle, confirming that the surface tension is the dominant attachment force. + Finally, as the nucleation sites increase, the induced bubble coalescence accelerates the bubble detachment. Taken together, + these findings give us valuable insights into improving gas bubble removal and enhancing overall electrolysis efficiency. + oai:arXiv.org:2507.15582v3 + physics.flu-dyn + Wed, 10 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by/4.0/ - E. Alfonso-Pita, D. Baxter, E. Behnke, J. Corbett, M. Crisler, C. E. Dahl, K. Dering, A. de St. Croix, D. Durnford, P. Giampa, J. Hall, O. Harris, H. Hawley-Herrera, L. Joseph, A. Kucich, N. Lamb, M. Laurin, I. Levine, W. H. Lippincott, B. Mitra, R. Neilson, O. Nicholson, M. -C. Piro, G. Putnam, D. Pyda, Z. Sheng, G. Sweeney, O. Vald\'es-Mart\'inez, E. V\'azquez-J\'auregui, S. Westerdale, T. J. Whitis, S. Windle, A. Wright, E. Wyman, R. Zhang + http://creativecommons.org/licenses/by-sa/4.0/ + Wei Qin, Tian Long, Jacob Maarek, St\'ephane Zaleski - Correlation-Weighted Communicability Curvature as a Structural Driver of Dengue Spread: A Bayesian Spatial Analysis of Recife (2015-2024) - https://arxiv.org/abs/2512.00315 - arXiv:2512.00315v2 Announce Type: replace -Abstract: We investigate whether the structural connectivity of urban road networks helps explain dengue incidence in Recife, Brazil (2015--2024). For each neighborhood, we compute the average \emph{communicability curvature}, a graph-theoretic measure capturing the ability of a locality to influence others through multiple network paths. We integrate this metric into Negative Binomial models, fixed-effects regressions, SAR/SAC spatial models, and a hierarchical INLA/BYM2 specification. Across all frameworks, curvature is the strongest and most stable predictor of dengue risk. In the BYM2 model, the structured spatial component collapses ($\phi \approx 0$), indicating that functional network connectivity explains nearly all spatial dependence typically attributed to adjacency-based CAR terms. The results show that dengue spread in Recife is driven less by geographic contiguity and more by network-mediated structural flows. - oai:arXiv.org:2512.00315v2 - physics.soc-ph - math.PR - q-bio.PE - stat.AP - Tue, 09 Dec 2025 00:00:00 -0500 + Waves in a shear flow: transition between the KH, Holmboe and Miles instability + https://arxiv.org/abs/2507.20166 + arXiv:2507.20166v2 Announce Type: replace +Abstract: We investigate shear driven wave generation at the interface between two immiscible fluids, using an exponential velocity profile with a sharp density interface representing stable stratification. At low Froude and high Bond numbers, conditions relevant to geophysical and astrophysical flows, we identify a novel transition in the fastest growing mode: from Kelvin Helmholtz (KH) instability at high density ratio (delta = 0.9), to Holmboe (H) instability as delta approaches 0.5, and ultimately to the Miles (1957) critical layer instability as delta approaches 0.001, representative of the air water system. Remarkably, the Miles mode, characterized by a sharp jump in inviscid Reynolds stress (tau) at the critical layer, persists up to delta = 0.01, i.e., ten times the air water value. As delta increases, the vertical variation of tau undergoes a qualitative change, from a sharp jump at the critical layer for delta much less than 1 to a smooth transition through it for delta greater than or equal to 0.5. A theoretical explanation is provided. In the moderate to high density ratio regime, comparison with a piecewise-linear (PL) velocity profile confirms the presence of both H and KH instabilities in the exponential profile. Nonlinear simulations of the incompressible Euler equations with gravity and surface tension show excellent agreement with linear theory for delta = 0.01 up to five wave periods. At delta = 0.1, waves saturate into finite-amplitude structures with capillary ripples, while at delta = 0.5, the waves develop sheared cusps and emit spume, resembling asymmetric Holmboe waves observed experimentally. At delta = 0.9, the waves rapidly evolve into classic KH spirals. Comparisons with the PL profile highlight the role of background curvature and the critical layer. This work presents, for the first time, all three canonical instabilities within a single background state. + oai:arXiv.org:2507.20166v2 + physics.flu-dyn + Wed, 10 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Marc\'ilio Ferreira dos Santos, Cleiton de Lima Ricardo, Andreza dos Santos Rodrigues de Melo + Anil Kumar, S. Ravichandran, Ratul Dasgupta - Linearized instability of Couette flow in stress-power law fluids - https://arxiv.org/abs/2512.00404 - arXiv:2512.00404v2 Announce Type: replace -Abstract: This paper examines the linearized stability of plane Couette flow for stress-power law fluids, which exhibit non-monotonic stress-strain rate behavior. The constitutive model is derived from a thermodynamic framework using a non-convex rate of dissipation potential. Under velocity boundary conditions, the system may admit three steady-state solutions. Linearized stability analysis reveals that the two solutions on ascending constitutive branches are unconditionally stable, while the solution on the descending branch is unconditionally unstable. For mixed traction-velocity boundary conditions, the base state is unique. Stability depends solely on whether the prescribed traction lies on an ascending (stable) or descending (unstable) branch of the constitutive curve. The results demonstrate that flow stability in these complex fluids is fundamentally governed by both boundary conditions and constitutive non-monotonicity. - oai:arXiv.org:2512.00404v2 - physics.flu-dyn - cond-mat.soft - math-ph - math.MP - Tue, 09 Dec 2025 00:00:00 -0500 + In-vivo 6D heart motion analysis for emerging self-powered cardiac implants + https://arxiv.org/abs/2507.21263 + arXiv:2507.21263v2 Announce Type: replace +Abstract: Self-powered intracardiac implant devices show great promise for future clinical applications due to their extended operational lifespan and the potential to reduce the need for high-risk repeat surgeries. This study investigates the feasibility of harvesting energy from cardiac motion through in vivo testing of intracardiac devices. Comprehensive three-dimensional translational and rotational cardiac motions are captured in a porcine model using a miniaturized 9-degree-of-freedom motion sensor implanted at six strategic epicardial sites. Kinematic criteria are developed to evaluate the energy harvesting potential of each implant site based on the available kinetic energy, acceleration, and jerk factors. The recorded heart motion signals are analyzed and applied to a conceptual energy harvester proposed to identify the optimal implant site. The results reveal that the left ventricular apex emerges as a preferable site for energy harvesting, particularly at moderate heart rates. These findings offer valuable insights into optimizing self-powered intracardiac implants, reducing dependency on battery replacements, and enhancing long-term patient safety. + oai:arXiv.org:2507.21263v2 + physics.med-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by-nc-nd/4.0/ - Krishna Kaushik Yanamundra (Department of Mechanical Engineering, Texas A&M University, College Station, TX, USA), Lorenzo Fusi (Dipartimento di Matematica e Informatica "U. Dini'', Universit\`a degli Studi di Firenze, 50134, Firenze, Italy) + Milad Hasani, John Huber, Benedict Kjaergaard, Tomas Zaremba, Alireza Rezania, Sam Riahi - Large/small eddy simulations: A posteriori analysis in high Reynolds number isotropic turbulence - https://arxiv.org/abs/2512.00554 - arXiv:2512.00554v2 Announce Type: replace -Abstract: While direct numerical simulations (DNS) are the most accurate method for studying turbulence, their large computational cost restricts their use to idealized configurations and to Reynolds numbers well below those found in practical systems. A recently proposed method, Large/Small Eddy Simulation (L/SES), aims to overcome this limitation while still providing the solution fidelity comparable to that of DNS. L/SES represents a pair of coupled calculations: a lower-fidelity Large Eddy Simulation (LES), which captures the large-scale flow structure, and a high-fidelity Small-Eddy Simulation (SES) targeting a sub-region of interest of the LES, in which the small-scale dynamics is fully resolved. In this study, we demonstrate the accuracy and performance of L/SES in large Reynolds-number homogeneous isotropic turbulence (HIT) up to Taylor-scale Reynolds number approximately 600. Turbulence properties obtained with L/SES are shown to be in close agreement with the literature, both in terms of global characteristics, such as kinetic energy spectra and dissipative anomaly, as well as small-scale properties, such as higher-order moments of the velocity gradients up to the 10th order and probability density functions of the intermittent quantities. Also using simulations of HIT, we systematically investigate various method parameters and determine their optimal converged values. Finally, we discuss the computational cost of L/SES and demonstrate that it is approximately 3 orders of magnitude lower than for a traditional DNS at the highest Reynolds number considered here. This highlights the potential of L/SES as a discovery tool, which brings high-fidelity simulations of realistic flows into the realm of feasibility. - oai:arXiv.org:2512.00554v2 + Unsteady aerodynamic theory and experiments of hovering membrane wings + https://arxiv.org/abs/2509.00666 + arXiv:2509.00666v2 Announce Type: replace +Abstract: We investigate the unsteady lift response of compliant membrane wings in hovering kinematics by combining analytical inviscid theory with experimental results. An unsteady aerodynamic model is derived for a compliant thin aerofoil immersed in incompressible inviscid flow of variable freestream velocity at high angles of attack. The model, representing a spanwise section of a hovering membrane wing, assumes small membrane deformation and attached flow. These assumptions are supported by experiments showing that passive membrane deformation suppresses flow separation when hovering at angles of attack up to $55^\circ$. An analytically derived expression is obtained for the unsteady lift response, incorporating the classical Wagner and Theodorsen functions and the membrane dynamic response. This theoretical expression is validated against experimental water-tank measurements that are performed on hovering membrane wings at angles of attack of $35^\circ$ and $55^\circ$. Data from membrane deformation measurements is applied to the theoretical lift expression, providing the theoretical lift response prediction for each of the available experimental scenarios. Results of the comparison show that the proposed theory accurately predicts unsteady lift contributions from membrane deformation at high angles of attack, provided the deformation remains small and the flow is attached. This agreement between inviscid theory and experimental measurements suggests that when flow separation is suppressed, the unsteady aerodynamic theory is valid well beyond the typical low angle of attack regime. + oai:arXiv.org:2509.00666v2 physics.flu-dyn - astro-ph.IM - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by-nc-sa/4.0/ - Chang Hsin Chen, Arnab Moitro, Alexei Y. Poludnenko + http://creativecommons.org/licenses/by/4.0/ + Sonya Tiomkin, Alexander Gehrke - A data-driven framework to identify restenosis-prone regions in femoral arteries from geometric and inflow waveform parameters - https://arxiv.org/abs/2512.01024 - arXiv:2512.01024v2 Announce Type: replace -Abstract: Haemodynamic indices derived from Computational Fluid Dynamics (CFD), such as Time-averaged Wall Shear Stress (TAWSS) and Oscillatory Shear Index (OSI), are closely associated with restenosis risk in Peripheral Arterial Disease (PAD). However, translating these insights into clinical practice may require computationally efficient approaches such as Reduced Order Model (ROM) or Machine Learning (ML). In this work, we developed an ML-ROM framework to predict critical, restenosis-prone, haemodynamic regions accounting for both vessel geometries and inlet flow waveforms. We generated 500 synthetic femoral-artery geometries parameterised by six geometric parameters, and created physiologically realistic inflow waveforms via Principal Component Analysis (PCA) of patient data. CFD was used to obtain the Wall Shear Stress (WSS) distribution, from which TAWSS and OSI were computed. Critical regions were then defined by applying threshold-based criteria to the TAWSS and OSI. Four critical-region definitions were considered: two with vessel-specific relative thresholds (TAWSS< 33rd percentile and OSI> 66nd percentile) and two with absolute thresholds (TAWSS< 0.5 Pa and OSI> 0.2). Proper orthogonal decomposition (POD) was then applied to these high-dimensional critical-region data to obtain ROMs; These were then used to train ML models from which the critical region regions could be reconstructed. Three ML architectures were explored: a Fourier-based architecture, a Long Short-term Memory (LSTM) architecture, and a Convolutional Neural Network (CNN) architecture. The Fourier models achieved the highest performance, with the median values of Balanced Accuracy (BA) exceeding 0.92 across all critical-region definitions. The ML-ROM framework also offered a substantial speed-up ratio, about nine orders of magnitude faster than traditional CFD. - oai:arXiv.org:2512.01024v2 - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 + A Probabilistic Framework for Predicting Spatiotemporal Intensity and Variability of Outdoor Thermal Comfort + https://arxiv.org/abs/2509.09468 + arXiv:2509.09468v2 Announce Type: replace +Abstract: Thermal conditions in the urban canopy exhibit stochastic variability driven by varied radiative fluxes and turbulent wind fields, requiring probabilistic rather than deterministic prediction methods. This study presents a probabilistic framework for predicting the spatial and temporal intensity and variability of outdoor thermal comfort in tropical urban environments. The framework integrates ground-measured meteorological data and remote sensing urban morphological data to calculate Physiological Equivalent Temperature (PET), and applies K-means, XGBoost, and Monte Carlo simulations on PET training and inference. The prediction model achieved strong performance, with R2, RMSE, and SMAPE values of 0.93, 0.81 degC, and 1.34% for PET_mean, and 0.85, 0.38 degC, and 10.44% for PET_std, respectively. A case study showed clear spatial heterogeneity of outdoor thermal comfort. Locations with dense tree canopies and vegetated surfaces displayed a normalized percentage of acceptable thermal comfort (NATC) up to 65%, whereas built-up zones dominated by impervious surfaces, such as industrial estates and high-density residential areas, recorded NATC below 30%. Greenery was found to mitigate both the intensity of heat stress and its variability, producing a stable and comfortable microclimate. Daytime PET_std ranged from 4.0-4.5 degC in built-up areas to 1.5-2.0 degC in greenery-covered zones, while nighttime PET_std decreased to 2.2-2.4 degC and 1.2-1.4 degC, respectively. These findings emphasize the critical role of greenery in mitigating thermal variability and enhancing outdoor thermal comfort, while revealing the stochastic nature of thermal comfort across different urban morphologies. + oai:arXiv.org:2509.09468v2 + physics.app-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by-nc-nd/4.0/ - Chotirawee Chatpattanasiri, Federica Ninno, Vanessa D{\i}az-Zuccarini, Stavroula Balabani + 10.1016/j.buildenv.2025.114102 + Chen, Shisheng, et al. "A Probabilistic Framework for Predicting Spatiotemporal Intensity and Variability of Outdoor Thermal Comfort." Building and Environment (2025): 114102 + Shisheng Chen, Ruohan Xu, Nyuk Hien Wong, Shanshan Tong, Jiashuo Wang, Matthaios Santamouris - Calibrating Geophysical Predictions under Constrained Probabilistic Distributions - https://arxiv.org/abs/2512.03081 - arXiv:2512.03081v2 Announce Type: replace -Abstract: Machine learning (ML) has shown significant promise in studying complex geophysical dynamical systems, including turbulence and climate processes. Such systems often display sensitive dependence on initial conditions, reflected in positive Lyapunov exponents, where even small perturbations in short-term forecasts can lead to large deviations in long-term outcomes. Thus, meaningful inference requires not only accurate short-term predictions, but also consistency with the system's long-term attractor that is captured by the marginal distribution of state variables. Existing approaches attempt to address this challenge by incorporating spatial and temporal dependence, but these strategies become impractical when data are extremely sparse. In this work, we show that prior knowledge of marginal distributions offers valuable complementary information to short-term observations, motivating a distribution-informed learning framework. We introduce a calibration algorithm based on normalization and the Kernelized Stein Discrepancy (KSD) to enhance ML predictions. The method here employs KSD within a reproducing kernel Hilbert space to calibrate model outputs, improving their fidelity to known physical distributions. This not only sharpens pointwise predictions but also enforces consistency with non-local statistical structures rooted in physical principles. Through synthetic experiments-spanning offline climatological CO2 fluxes and online quasi-geostrophic flow simulations-we demonstrate the robustness and broad utility of the proposed framework. - oai:arXiv.org:2512.03081v2 - physics.ao-ph - cs.LG - stat.ML - Tue, 09 Dec 2025 00:00:00 -0500 + Soft x-ray ptychography with SOPHIE: Guide and instrumentation + https://arxiv.org/abs/2509.18805 + arXiv:2509.18805v2 Announce Type: replace +Abstract: Soft x-ray ptychography is becoming a key synchrotron microscopy technique in the fields of condensed matter physics, chemistry, and environmental and life sciences. Its attractiveness across broad disciplinary fields is owed to the favorable combination of high spatial resolution and strong contrast mechanisms. The SOft X-ray Ptychography Highly Integrated Endstation (SOPHIE) at the Swiss Light Source (SLS) was developed to accommodate soft x-ray ptychography experiments requiring high spatial resolution, in addition to high chemical and ferroic sensitivities. An introduction to soft x-ray ptychography with SOPHIE aimed at prospective users is provided. Furthermore, an overview of the instrumentation of SOPHIE is given along with an example of the imaging capabilities, which demonstrate the achievement of a sub-10 nm spatial resolution at a photon energy of 706 eV. + oai:arXiv.org:2509.18805v2 + physics.ins-det + cond-mat.mes-hall + Wed, 10 Dec 2025 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Zhewen Hou, Jiajin Sun, Subashree Venkatasubramanian, Peter Jin, Shuolin Li, Tian Zheng + 10.1063/5.0303529 + Rev. Sci. Instrum. 96, 123704 (2025) Rev. Sci. Instrum. 96, 123704 (2025) Rev. Sci. Instrum. 96, 123704 (2025) + Tim A. Butcher, Simone Finizio, Lars Heller, Nicholas W. Phillips, Blagoj Sarafimov, Carlos A. F. Vaz, Armin Kleibert, Benjamin Watts, Mirko Holler, J\"org Raabe - A novel multiscale modelling for the hemodynamics in retinal microcirculation with an analytic solution for the capillary-tissue coupled system - https://arxiv.org/abs/2512.03446 - arXiv:2512.03446v2 Announce Type: replace -Abstract: Mathematical modelling of the microcirculatory hemodynamics in the retina is an essential tool for understanding various diseases of the retina, yet remains challenging due to the multiscale nature of the retinal vasculature and its coupling to surrounding tissue. To address this, we develop a multiscale model that couples retinal vasculature across scales with interstitial tissue. Our model combines the one-dimensional (1D) model for arteries and veins with the coupled Darcy equations for capillaries and tissue. The model uses an analytic solution for capillary-tissue coupled system that provides a simple interpretation of the results along with much faster computation. The analytic solution implies a dynamic coupling condition that links the capillary bed with upstream arterial and downstream venous flows. The model is mathematically robust, demonstrated through analysis of the solution's truncation error and convergence. Its predictive accuracy is verified against experimental data and other models, making it useful in interpreting experimental results. Finally, the role of various parameters in controlling retinal hemodynamics is explored. - oai:arXiv.org:2512.03446v2 - physics.bio-ph - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 + Optimised neural networks for online processing of ATLAS calorimeter data on FPGAs + https://arxiv.org/abs/2510.11469 + arXiv:2510.11469v2 Announce Type: replace +Abstract: A study of neural network architectures for the reconstruction of the energy deposited in the cells of the ATLAS liquid-argon calorimeters under high pile-up conditions expected at the HL-LHC is presented. These networks are designed to run on the FPGA-based readout hardware of the calorimeters under strict size and latency constraints. Several architectures, including Dense, Recurrent (RNN), and Convolutional (CNN) neural networks, are optimised using a Bayesian procedure that balances energy resolution against network size. The optimised Dense, CNN, and combined Dense+RNN architectures achieve a transverse energy resolution of approximately 80 MeV, outperforming both the optimal filtering (OF) method currently in use and RNNs of similar complexity. A detailed comparison across the full dynamic range shows that Dense, CNN, and Dense+RNN accurately reproduce the energy scale, while OF and RNNs underestimate the energy. Deep Evidential Regression is implemented within the Dense architecture to address the need for reliable per-event energy uncertainties. This approach provides predictive uncertainty estimates with minimal increase in network size. The predicted uncertainty is found to be consistent, on average, with the difference between the true deposited energy and the predicted energy. + oai:arXiv.org:2510.11469v2 + physics.ins-det + Wed, 10 Dec 2025 00:00:00 -0500 replace - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Chang Lin, Zilong Song, Robert Eisenberg, Shixin Xu, Huaxiong Huang + http://creativecommons.org/licenses/by/4.0/ + Georges Aad, Raphael Bertrand, Lauri Laatu, Emmanuel Monnier, Arno Straessner, Nairit Sur, Johann C. Voigt - Structured Light at the Extreme: Harnessing Spatiotemporal Control for High-Field Laser-Matter Interactions - https://arxiv.org/abs/2512.05042 - arXiv:2512.05042v2 Announce Type: replace -Abstract: This review charts the emerging paradigm of intelligent structured light for high-field laser-matter interactions, where the precise spatiotemporal and vectorial control of light is a critical degree of freedom. We outline a transformative framework built upon three synergistic pillars. First, we survey the advanced electromagnetic toolkit, moving beyond conventional spatial light modulators to include robust static optics and the promising frontier of plasma light modulators. Second, we detail the optimization engine for this high-dimensional design space, focusing on physics-informed digital twins and AI-driven inverse design to automate the discovery of optimal light structures. Finally, we explore the groundbreaking applications enabled by this integrated approach, including programmable electron beams, orbital-angular-momentum-carrying {\gamma}-rays, compact THz accelerators, and robust communications. The path forward necessitates overcoming grand challenges in material science, real-time adaptive control at MHz rates, and the extension of these principles to the quantum realm. This review serves as a call to action for a coordinated, interdisciplinary effort to command, rather than merely observe, light-matter interactions at the extreme. - oai:arXiv.org:2512.05042v2 - physics.optics - math-ph - math.MP - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Latent Spaces for Langevin Dynamics + https://arxiv.org/abs/2510.25773 + arXiv:2510.25773v2 Announce Type: replace +Abstract: In the field of machine learning coarse-grained potentials in molecular dynamics, many propagators require that the effective Hamiltonian is quadratic in momentum, thus limiting the family of coarse-graining functions. In this paper, we derive a general family of coarse-graining embedding functions for which Langevin dynamics samples correctly. These equations have significant implications for molecular simulations and pave the way for Langevin dynamics on non-geometric coarse-graining representations, such as those provided by principal components of component analysis or latent embeddings of molecules obtained from neural networks. + oai:arXiv.org:2510.25773v2 + physics.chem-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ - Sergio Carbajo, Seung-Whan Bahk, Justin Baker, Andrea Bertozzi, Abhimanyu Borthakur, Antonino Di Piazza, Andrew Forbes, Spencer Gessner, Jack Hirschman, Maciej Lewenstein, Yuhang Li, Inhyuk Nam, Eileen Otte, James Rozensweig, Yijie Shen, Liwei Song, Ye Tian, Yu Wang, Yuntian Wang, Logan Wright, Xiaojun Wu, Hao Zhang + Andy Bruce, Alexander Aghili, Razvan Marinescu, Daniel Sabo - Ensemble Learning of Machine Learning Force Fields - https://arxiv.org/abs/2403.17507 - arXiv:2403.17507v2 Announce Type: replace-cross -Abstract: Machine learning force fields (MLFFs) are a promising approach to balance the accuracy of quantum mechanics with the efficiency of classical potentials, yet selecting an optimal model amid increasingly diverse architectures that delivers reliable force predictions and stable simulations remains a core pratical challenge. Here we introduce EL-MLFFs, an ensemble learning framework that uses a stacking methodology to integrate predictions from diverse base MLFFs. Our approach constructs a graph representation where a graph neural network (GNN) acts as a meta-model to refine the initial force predictions. We present two meta-model architectures: a computationally efficient direct fitting model and a physically-principled conservative model that ensures energy conservation. The framework is evaluated on a diverse range of systems, including single molecules (methane), surface chemistry (methanol/Cu(100)), molecular dynamics benchmarks (MD17), and the MatPES materials dataset. Results show that EL-MLFFs improves predictive accuracy across these domains. For molecular systems, it reduces force errors and improves the simulation stability compared to base models. For materials, the method yields lower formation energy errors on the WBM test set. The EL- MLFFs framework offers a systematic approach to address challenges of model selection and the accuracy-stability trade-off in molecular and materials simulations. - oai:arXiv.org:2403.17507v2 - cs.LG + Adiabatic Electron Transfer in the Barrierless and Marcus-Inverted Regimes + https://arxiv.org/abs/2511.01909 + arXiv:2511.01909v3 Announce Type: replace +Abstract: Here it is shown that in the adiabatic limit of condensed-phase electron transfer, the onset of barrierless transition occurs at a lower driving force than predicted by the non-adiabatic Marcus formulation. Furthermore, in the adiabatic limit of the Marcus-inverted region, the standard mechanism of electron transfer becomes topologically forbidden. This behavior arises from a topological change in the mapping between the adiabatic and diabatic electronic surfaces, emerging precisely at the onset of the Marcus-inverted region. In this case, alternative mechanisms such as tunneling and non-radiative decay may dominate the rate, typically orders of magnitude slower than the rate calculated from Marcus theory. + oai:arXiv.org:2511.01909v3 physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Bangchen Yin, Yue Yin, Yuda W. Tang, Hai Xiao - - - Turbulence and far-from-equilibrium equation of state of Bogoliubov waves in Bose-Einstein Condensates - https://arxiv.org/abs/2408.15163 - arXiv:2408.15163v3 Announce Type: replace-cross -Abstract: Bogoliubov waves are fundamental excitations of Bose-Einstein Condensates (BECs). They emerge from a perturbed ground state and interact nonlinearly, triggering turbulent cascades. Here, we study turbulent BECs theoretically and numerically using the 3D Gross-Pitaevskii model and its associated wave-kinetic equations. We derive a new Kolmogorov-like stationary spectrum for short Bogoliubov waves and find a complete analytical expression for the spectrum in the long-wave acoustic regime. We then use our predictions to explain the BEC equation of state reported in [Dora et al. Nature 620,521 (2023)], and to suggest new experimental settings. - oai:arXiv.org:2408.15163v3 - cond-mat.quant-gas - nlin.CD - physics.atom-ph - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Ying Zhu, Giorgio Krstulovic, Sergey Nazarenko - - - Compressing multivariate functions with tree tensor networks - https://arxiv.org/abs/2410.03572 - arXiv:2410.03572v2 Announce Type: replace-cross -Abstract: Tensor networks are a compressed format for multi-dimensional data. One-dimensional tensor networks -- often referred to as tensor trains (TT) or matrix product states (MPS) -- are increasingly being used as a numerical ansatz for continuum functions by ``quantizing'' the inputs into discrete binary digits. Here we demonstrate the power of more general tree tensor networks for this purpose. We provide direct constructions of a number of elementary functions as generic tree tensor networks and interpolative constructions for more complicated functions via a generalization of the tensor cross interpolation algorithm. For a range of multi-dimensional functions we show how more structured tree tensor networks offer a significantly more efficient ansatz than the commonly used tensor train. We demonstrate an application of our methods to solving multi-dimensional, non-linear Fredholm equations, providing a rigorous bound on the rank of the solution which, in turn, guarantees exponentially scaling accuracy with the size of the tree tensor network for certain problems. - oai:arXiv.org:2410.03572v2 - quant-ph - cs.NA - math.NA - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Joseph Tindall, E. Miles Stoudenmire, Ryan Levy - - - Intrinsically chiral exciton polaritons in an atomically-thin semiconductor - https://arxiv.org/abs/2412.17266 - arXiv:2412.17266v2 Announce Type: replace-cross -Abstract: Photonic bound states in the continuum (BICs) have emerged as a versatile tool for enhancing light-matter interactions by strongly confining light fields. Chiral BICs are photonic resonances with a high degree of circular polarisation, which hold great promise for spin-selective applications in quantum optics and nanophotonics. Here, we demonstrate a novel application of a chiral BIC for inducing strong coupling between the circularly polarised photons and spin-polarised (valley) excitons (bound electron-hole pairs) in atomically-thin transition metal dichalcogenide crystals (TMDCs). By placing monolayer WS$_2$ onto the BIC-hosting metasurface, we observe the formation of intrinsically chiral, valley-selective exciton polaritons, evidenced by circularly polarised photoluminescence (PL) at two distinct energy levels. The PL intensity and degree of circular polarisation of polaritons exceed those of uncoupled excitons in our structure by an order of magnitude. Our microscopic model shows that this enhancement is due to folding of the Brillouin zone creating a direct emission path for high-momenta polaritonic states far outside the light cone, thereby providing a shortcut to thermalisation (energy relaxation) and suppressing depolarisation. Moreover, while the polarisation of the upper polariton is determined by the valley excitons, the lower polariton behaves like an intrinsic chiral emitter with its polarisation fixed by the BIC. Therefore, the spin alignment of the upper and lower polaritons ($\uparrow\downarrow$ and $\uparrow \uparrow$) can be controlled by $\sigma^+$ and $\sigma^-$ polarised optical excitation, respectively. Our work introduces a new type of chiral light-matter quasi-particles in atomically-thin semiconductors and provides an insight into their energy relaxation dynamics. - oai:arXiv.org:2412.17266v2 cond-mat.mes-hall - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross + cond-mat.mtrl-sci + quant-ph + Wed, 10 Dec 2025 00:00:00 -0500 + replace http://creativecommons.org/licenses/by/4.0/ - Matthias J. Wurdack, Ivan Iorsh, Sarka Vavreckova, Tobias Bucher, Mateusz Kr\'ol, Zlata Fedorova, Eliezer Estrecho, Sebastian Klimmer, Larionette P. L. Mawlong, Huachun Deng, Qinghai Song, Timothy van der Laan, Giancarlo Soavi, Thomas Pertsch, Falk Eilenberger, Isabelle Staude, Yuri Kivshar, Elena. A. Ostrovskaya + Ethan Abraham - Observation of quantum free fall and the consistency with the equivalence principle - https://arxiv.org/abs/2502.14535 - arXiv:2502.14535v4 Announce Type: replace-cross -Abstract: The unification of quantum theory and the general theory of relativity - describing gravity, is one of the most important challenges in science. Einstein's general theory of relativity is based on the principle of equivalence, and has been confirmed to great accuracy for large bodies. However, in the quantum domain the equivalence principle has been predicted to take a unique form involving a gauge phase, equal to the quantum phase of a free-falling object. To measure this phase, we realize a novel cold-atom interferometer in which one wave-packet stays static in the laboratory frame while the other is in free fall. The observed relative-phase of the wave-packets confirms the predicted phase of a free-falling object, and shows that in our low energy regime, the equivalence principle may be applied to the quantum domain. Our observation constitutes a fundamental test of the interface between quantum theory and gravity. The new interferometer also opens the door for further probing of the latter interface, as well as to searches for new physics. - oai:arXiv.org:2502.14535v4 - quant-ph - cond-mat.quant-gas - gr-qc - hep-th - physics.atom-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross + Report on the Scoping Workshop on AI in Science Education Research 2025 + https://arxiv.org/abs/2511.14318 + arXiv:2511.14318v3 Announce Type: replace +Abstract: This report summarizes the outcomes of a two-day international scoping workshop on the role of artificial intelligence (AI) in science education research. As AI rapidly reshapes scientific practice, classroom learning, and research methods, the field faces both new opportunities and significant challenges. The report clarifies key AI concepts to reduce ambiguity and reviews evidence of how AI influences scientific work, teaching practices, and disciplinary learning. It identifies how AI intersects with major areas of science education research, including curriculum development, assessment, epistemic cognition, inclusion, and teacher professional development, highlighting cases where AI can support human reasoning and cases where it may introduce risks to equity or validity. The report also examines how AI is transforming methodological approaches across quantitative, qualitative, ethnographic, and design-based traditions, giving rise to hybrid forms of analysis that combine human and computational strengths. To guide responsible integration, a systems-thinking heuristic is introduced that helps researchers consider stakeholder needs, potential risks, and ethical constraints. The report concludes with actionable recommendations for training, infrastructure, and standards, along with guidance for funders, policymakers, professional organizations, and academic departments. The goal is to support principled and methodologically sound use of AI in science education research. + oai:arXiv.org:2511.14318v3 + physics.ed-ph + cs.CY + Wed, 10 Dec 2025 00:00:00 -0500 + replace http://creativecommons.org/licenses/by-nc-nd/4.0/ - Or Dobkowski, Barak Trok, Peter Skakunenko, Yonathan Japha, David Groswasser, Maxim Efremov, Chiara Marletto, Ivette Fuentes, Roger Penrose, Vlatko Vedral, Wolfgang P. Schleich, Ron Folman - - - First passage time properties of diffusion with a broad class of stochastic diffusion coefficients - https://arxiv.org/abs/2502.20705 - arXiv:2502.20705v3 Announce Type: replace-cross -Abstract: Diffusion in a heterogeneous environment or diffusion of a particle that shows conformational fluctuations can be described by Brownian motions with stochastic diffusion coefficients (sDCs). In this study, we investigate first passage time (FPT) properties of diffusion with a broad class of non-zero sDCs. We show that for diffusion in one-dimensional semi-infinite domain with an absorbing boundary, particles will eventually reach the boundary with probability one, and that diffusion with a sDC exhibits higher transport efficiency in an early arrival of particles at the boundary than would be expected under diffusion whose DC is the ensemble average (EA) of the sDC. When particles begin to reach an absorbing boundary before the change in a sDC occurs, diffusion with a sDC with a larger supremum exhibits a more efficient transport in an early arrival of particles at the boundary even if the EAs of sDCs are the same. For ergodic DCs, the mean FPT is infinite. In addition, if particles take a long time to reach an absorbing boundary, higher transport efficiency in an early arrival at the boundary almost disappears and the FPT distribution can be approximated by the L\'evy-Smirnov distribution. We show that these three properties result from the convergence of the time average of the DC to the EA and the convergence speed is determined by the time scale of fluctuations in the DC. We finally discuss the similarities and differences of FPT properties between three-dimensional diffusion outside a spherical absorbing boundary and the one-dimensional diffusion. Our results indicate that fluctuations in DCs may need to be non-Markov and/or non-ergodic to allow efficient transport of particles to distant targets. Our results also suggest that fluctuations in a DC play an important role, for example, in diffusion-limited reactions triggered by single molecules in physics, chemistry, or biology. - oai:arXiv.org:2502.20705v3 - cond-mat.stat-mech - physics.bio-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Go Uchida, Hiromi Miyoshi, Hitoshi Washizu - - - Thermodynamic bounds on energy use in quasi-static Deep Neural Networks - https://arxiv.org/abs/2503.09980 - arXiv:2503.09980v3 Announce Type: replace-cross -Abstract: The rapid growth of deep neural networks (DNNs) has brought increasing attention to their energy use during training and inference. Here, we establish the thermodynamic bounds on energy consumption in quasi-static analog DNNs by mapping modern feedforward architectures onto a physical free-energy functional. This framework provides a direct statistical-mechanical interpretation of quasi-static DNNs. As a result, inference can proceed in a thermodynamically reversible manner, with vanishing minimal energy cost, in contrast to the Landauer limit that constrains digital hardware. Importantly, inference corresponds to relaxation to a unique free-energy minimum with F_{\min}=0, allowing all constraints to be satisfied without residual stress. By comparison, training overconstrains the system: simultaneous clamping of inputs and outputs generates stresses that propagate backward through the architecture, reproducing the rules of backpropagation. Parameter annealing then relaxes these stresses, providing a purely physical route to learning without an explicit loss function. We further derive a universal lower bound on training energy, E< 2NDkT, which scales with both the number of trainable parameters and the dataset size. - oai:arXiv.org:2503.09980v3 - cond-mat.stat-mech - cs.LG - physics.data-an - q-bio.NC - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Alexei V. Tkachenko + Marcus Kubsch, Marit Kastaun, Peter Wulff, Nicole Graulich, Moriah Ariely, Alexander Bergmann-Gering, Sebastian Gombert, Bor Gregorcic, Hendrik H\"artig, Benedikt Heuckmann, Andrea Horbach, Christina Krist, Gerd Kortemeyer, Ben M\"unch, Samuel Pazicni, Joshua M. Rosenberg, Sascha Schanze, Gena Sbeglia, Vidar Skogvoll, Christophe Speroni, Christoph Thyssen, Lars-Jochen Thoms, Brandon J. Yik, Xiaoming Zhai - Using Wavelet Decomposition to Determine the Dimension of Structures from Projected Images - https://arxiv.org/abs/2503.23202 - arXiv:2503.23202v2 Announce Type: replace-cross -Abstract: Mesoscale structures can often be described as fractional dimensional across a wide range of scales. We consider a $\gamma$ dimensional measure embedded in an $N$ dimensional space and discuss how to determine its dimension, both in $N$ dimensions and projected into $D$ dimensions. - It is a highly non-trivial problem to decode the original geometry from lower dimensional projection of a high-dimensional measure. The projections are space-feeling, the popular box-counting techniques do not apply, and the Fourier methods are contaminated by aliasing effects. In the present paper we demonstrate that under the "Copernican hypothesis'' that we are not observing objects from a special direction, projection in a wavelet basis is remarkably simple: the wavelet power spectrum of a projected $\gamma$ dimensional measure is $P_j \propto 2^{-j\gamma}$. This holds regardless of the embedded dimension, $N$, and the projected dimension, $D$. This approach could have potentially broad applications in data sciences where a typically sparse matrix encodes lower dimensional information embedded in an extremely high dimensional field and often measured in projection to a low dimensional space. - Here, we apply this method to JWST and Chandra observations of the nearby supernova Cas A. We find that the emissions can be represented by projections of mesoscale substructures with fractal dimensions varying from $\gamma = 1.7$ for the warm CO layer observed by JWST, up to $\gamma = 2.5$ for the hot X-ray emitting gas layer in the supernova remnant. The resulting power law indicates that the emission is coming from a fractal dimensional mesoscale structure likely produced by magneto-hydrodynamical instabilities in the expanding supernova shell. - oai:arXiv.org:2503.23202v2 - astro-ph.HE - astro-ph.GA - math.AP - physics.data-an - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross + On the analytical behavior of the $k$--$\omega$ turbulence model in buoyant-driven thermal convection + https://arxiv.org/abs/2512.01308 + arXiv:2512.01308v3 Announce Type: replace +Abstract: The representation of buoyancy-driven turbulence in Reynolds-averaged Navier--Stokes models remains unresolved, with no widely accepted standard formulation. A key difficulty is the lack of analytical guidance for incorporating buoyant effects, particularly under unstable stratification. This study derives an analytical solution of the standard $k$--$\omega$ model for Rayleigh--B\'enard convection in an infinite layer, where turbulent kinetic energy is generated solely by buoyancy. The solution provides explicit scaling relations among the Rayleigh ($\mathit{Ra}$), Prandtl ($\mathit{Pr}$), and Nusselt ($\mathit{Nu}$) numbers that capture the simulation trends: $\mathit{Nu} \sim \mathit{Ra}^{1/3}\mathit{Pr}^{1/3}$ for $\mathit{Pr} \ll 1$ and $\mathit{Nu} \sim \mathit{Ra}^{1/3}\mathit{Pr}^{-0.415}$ for $\mathit{Pr} \gg 1$. This framework quantifies the discrepancies in the conventional buoyancy treatment and clarifies their origin. Informed by this analysis, the buoyancy-related modelling terms are reformulated to recover the measured $\mathit{Nu}$--$\mathit{Ra}$--$\mathit{Pr}$ trends. Only two dimensionless algebraic functions are introduced, which vanish in the absence of buoyancy, ensuring full compatibility with the standard closure. The corrected model is validated across a range of buoyancy-driven flows, including two-dimensional Rayleigh--B\'enard convection, internally heated convection in two configurations, unstably stratified Couette flow, and vertically heated natural convection with varying aspect ratios. Across all cases, it provides highly accurate predictions. + oai:arXiv.org:2512.01308v3 + physics.flu-dyn + Wed, 10 Dec 2025 00:00:00 -0500 + replace http://creativecommons.org/licenses/by/4.0/ - Svitlana Mayboroda, David N Spergel + Da-Sol Joo - A Behaviour and Disease Model of Testing and Isolation - https://arxiv.org/abs/2504.02488 - arXiv:2504.02488v2 Announce Type: replace-cross -Abstract: There has been interest in the interactions between infectious disease dynamics and behaviour for most of the history of mathematical epidemiology. This has included consideration of which mathematical models best capture each phenomenon, as well as their interaction, but typically in a manner that is agnostic to the exact behaviour in question. Here, we investigate interacting behaviour and disease dynamics specifically related to decisions around testing and isolation. To carry out our investigation we extend an existing "behaviour and disease" (BaD) model by incorporating the dynamics of symptomatic testing and isolation, including the influence of positive tests on perception of infection risk. We provide a dynamical systems analysis of the ordinary differential equations that define this model, providing theoretical results on its behaviour early in a new outbreak (particularly its basic reproduction number) and endemicity of the system (its steady states and associated stability criteria). We then supplement these findings with a numerical analysis to inform how temporal and cumulative outbreak metrics depend on the model parameter values for epidemic and endemic regimes. We observe novel model outputs such as epidemics that have more observed cases detected through increased testing, but are less objectively severe in terms of total number of infections. - oai:arXiv.org:2504.02488v2 - q-bio.PE - physics.soc-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross + Granite sliding on granite: friction, wear rates, surface topography, and the scale-dependence of rate-state effects + https://arxiv.org/abs/2512.01765 + arXiv:2512.01765v2 Announce Type: replace +Abstract: We study tribological granite-granite contacts as a model for tectonic faulting, combining experiments, theory, and molecular dynamics simulations. The high friction in this system is not dominated by particulate wear or plowing, as frequently assumed, but by cold welding within plastically deformed asperity junctions. We base this conclusion on the observation that wear is repeatedly high after cleaning contacts but decreases as gouge accumulates, while friction shows the opposite trend. Moreover, adding water reduces wear by a factor of ten but barely decreases friction. Thermal and rate-dependent effects - central to most earthquake models-are negligible: friction remains unchanged between -40{\deg}C and 20{\deg}C, across abrupt velocity steps, and after hours of stationary contact. The absence of rate-state effects in our macroscopic samples is rationalized by the scale-dependence of pre-slip. The evolution of surface topography shows that quartz grains become locally smooth, with height spectra isotropic for wavelength below 10 microns but anisotropic at longer wavelengths, similar to natural faults. The resulting gouge particles have the usual characteristic sizes near 100 nm. Molecular dynamics simulations of a rigid, amorphous silica tip sliding on {\alpha}-quartz reproduce not only similar friction coefficients near unity but also other experimentally observed features, including stress-introduced transitions to phases observed in post-mortem faults, as well as theoretical estimates of local flash temperatures. Additionally, they reveal a marked decrease of interfacial shear strength above 600{\deg}C. The overall correspondence between experiments, simulations, theory, and field observations indicates that our model system captures essential aspects of rock friction. + oai:arXiv.org:2512.01765v2 + physics.geo-ph + cond-mat.mtrl-sci + physics.comp-ph + Wed, 10 Dec 2025 00:00:00 -0500 + replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Matthew Ryan, Roslyn I. Hickson, Edward M. Hill, Thomas House, Valerie Isham, Dongni Zhang, Mick G. Roberts + Sergey V. Sukhomlinov, Martin H. M\"user, B. N. J. Persson - Learning Enhanced Ensemble Filters - https://arxiv.org/abs/2504.17836 - arXiv:2504.17836v3 Announce Type: replace-cross -Abstract: The filtering distribution in hidden Markov models evolves according to the law of a mean-field model in state-observation space. The ensemble Kalman filter (EnKF) approximates this mean-field model with an ensemble of interacting particles, employing a Gaussian ansatz for the joint distribution of the state and observation at each observation time. These methods are robust, but the Gaussian ansatz limits accuracy. Here this shortcoming is addressed by using machine learning to map the joint predicted state and observation to the updated state estimate. The derivation of methods from a mean field formulation of the true filtering distribution suggests a single parametrization of the algorithm that can be deployed at different ensemble sizes. And we use a mean field formulation of the ensemble Kalman filter as an inductive bias for our architecture. - To develop this perspective, in which the mean-field limit of the algorithm and finite interacting ensemble particle approximations share a common set of parameters, a novel form of neural operator is introduced, taking probability distributions as input: a measure neural mapping (MNM). A MNM is used to design a novel approach to filtering, the MNM-enhanced ensemble filter (MNMEF), which is defined in both the mean-field limit and for interacting ensemble particle approximations. The ensemble approach uses empirical measures as input to the MNM and is implemented using the set transformer, which is invariant to ensemble permutation and allows for different ensemble sizes. In practice fine-tuning of a small number of parameters, for specific ensemble sizes, further enhances the accuracy of the scheme. The promise of the approach is demonstrated by its superior root-mean-square-error performance relative to leading methods in filtering the Lorenz '96 and Kuramoto-Sivashinsky models. - oai:arXiv.org:2504.17836v3 - stat.ML - cs.LG - cs.SY - eess.SY - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Eviatar Bach, Ricardo Baptista, Edoardo Calvello, Bohan Chen, Andrew Stuart + Calendar Time Local Earthquake Forecasts from Earthquake Nowcasts: A Do-It-Yourself (DIY) Ensemble Method + https://arxiv.org/abs/2512.06572 + arXiv:2512.06572v2 Announce Type: replace +Abstract: A previous paper discussed a method that builds on local earthquake nowcasts to produce fixed natural time forecasts, where natural time represents counts of small earthquakes since the last large earthquake. In this second paper we extend the natural time forecast to calendar time forecasts using an ensemble approach. The Gutenberg-Richter (GR) magnitude-frequency relation, which was the basis for both methods, states that for every large target earthquake of magnitude greater than MT , there are on average NGR small earthquakes of magnitude MS. The only assumption in our method is that the statistics of the local region are the same as in the larger surrounding regions. The method has significant skill, as defined by the Receiver Operating Characteristic (ROC) test, which improves as time since the last major earthquake increases. The probability is conditioned on the number of small earthquakes n(t) that have occurred since the last large earthquake. We do not need to assume a probability model, the probability is instead computed directly as the Positive Predictive Value (PPV) associated with the ROC curve. We find that for short time intervals (months), the forecast shows strong main shock clustering, followed by a gradual buildup of probability over the following years leading to the next large earthquake ("elastic rebound"). We apply the method to the same local region as in our first paper around Los Angeles, California, following the January 17, 1994 magnitude M6.7 Northridge earthquake. + oai:arXiv.org:2512.06572v2 + physics.geo-ph + Wed, 10 Dec 2025 00:00:00 -0500 + replace + http://creativecommons.org/licenses/by/4.0/ + John B Rundle, Ian Baughmann, Andrea Donnellan, Lisa Grant Ludwig, Geoffrey C Fox, Kazuyoshi Nanjo - Microwave-field quantum metrology with inherent robustness against detection losses enabled by Rydberg interactions - https://arxiv.org/abs/2505.01506 - arXiv:2505.01506v2 Announce Type: replace-cross -Abstract: Quantum sensing and metrology present one of the most promising near-term applications in the field of quantum technologies, with quantum sensors enabling unprecedented precision in measurements of electric, magnetic or gravitational fields and displacements. Experimental loss at the detection stage remains one of the key obstacles to achieving a truly quantum advantage in many practical scenarios. Here, we combine the capabilities of Rydberg atoms to both sense external fields and be used for quantum information processing, thereby largely overcoming the issue of detection losses. While utilising the large dipole moments of Rydberg atoms in an ensemble to achieve a $\SI{39}{\nV\per\cm \hertz\tothe{-1/2}}$ sensitivity, we employ inter-atomic dipolar interactions to take advantage of an error-prevention protocol that protects information against conventional losses at the detection stage. Counterintuitively, the protocol's idea is based on introducing an additional non-linear, lossy quantum channel, which results in a 3.3-fold enhancement of Fisher information. The presented results pave the way for broader adoption of quantum-information-inspired enhancements enabled by intrinsic interactions present in a sensor system, and more broadly in practical quantum metrology and communication, without the need for a general-purpose quantum computer. - oai:arXiv.org:2505.01506v2 - quant-ph - physics.atom-ph - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross + A Capacitor Model of the Helical Deflector: Revisiting Shamaev's Proposal and the Model in the Book + https://arxiv.org/abs/2512.06651 + arXiv:2512.06651v2 Announce Type: replace +Abstract: A RF helical deflector is a type of electron and ion optics device that applies a time-dependent rotating transverse electric or magnetic field by means of time-dependent RF voltage applied on two opposite conducting helical structures (wires, ribbons or other) to deflect charged particles (a single, bunch or beam) in a circular or spiral path. It is a perspective indirect timing system being concurrent for reaching picosecond time resolution, and have promise being excellent candidate for high precision time-of-flight detection. As a timing system, it converts the temporal structure of an electron beam into a spatial pattern -- particularly, an ellipse in the case of a single-frequency RF voltage and continuous electron pencil beam. + I propose a capacitor model of a RF helical deflector and compare it with the existing model in the Book, interpret it and provide understanding of it. Furthermore, I analyze the latter, finding analytical formulas for the applied electric field, ellipse sizes (semi-axes) and rotation angle, lengths of the ellipse line, corresponding to the duration of electron pencil bunches or beams. The present article touches the topics of getting circle on resonance limit and of deflection sensitivity. + oai:arXiv.org:2512.06651v2 + physics.acc-ph + physics.app-ph + physics.class-ph + physics.ins-det + Wed, 10 Dec 2025 00:00:00 -0500 + replace http://creativecommons.org/licenses/by/4.0/ - Stanis{\l}aw Kurzyna, Bartosz Niewelt, Mateusz Mazelanik, Wojciech Wasilewski, Rafa{\l} Demkowicz-Dobrza\'nski, Micha{\l} Parniak + Hayk L. Gevorgyan - Interface Fragmentation via Horizontal Vibration: A Pathway to Scalable Monodisperse Emulsification - https://arxiv.org/abs/2506.07742 - arXiv:2506.07742v2 Announce Type: replace-cross -Abstract: We present a scalable method for producing monodisperse micro-scale emulsions in a rectangular container holding two stably stratified layers of immiscible liquids by applying horizontal vibration. This setup enables the excitation of a single line of ordered Faraday waves along each end wall when viscous forces dominate interfacial dynamics. Our experiments and theoretical modelling show that the critical non-dimensional acceleration for the breakup of the wave tips in a regular array of droplets scales as $N^{-1/2} \omega^{*3/2}$, where $N$ is the kinematic viscosity ratio and $\omega^{*}$ is the frequency of forcing on the viscous-capillary scale. The droplet diameter can be easily tuned by varying the forcing parameters, and the number of droplets generated per cycle is proportional to the width of the container. - oai:arXiv.org:2506.07742v2 - cond-mat.soft - physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - Linfeng Piao, Anne Juel + ExPUFFIN: Thermodynamic Consistent Viscosity Prediction in an Extended Path-Unifying Feed-Forward Interfaced Network + https://arxiv.org/abs/2512.06927 + arXiv:2512.06927v2 Announce Type: replace +Abstract: Accurate prediction of liquid viscosity is essential for process design and simulation, yet remains challenging for novel molecules. Conventional group-contribution models struggle with isomer discrimination, large molecules, and parameter availability, while purely data-driven graph neural networks (GNNs) demand large datasets and offer limited interpretability. Even when feasible to be applied, purely data-driven models lack thermodynamic consistency in their predictions and are not a reliable solution. This work introduces ExPUFFIN, an extended version of the Path-unifying Feed-Forward Interfaced Network, consisting of a hybrid GNN-based framework that directly predicts temperature-dependent viscosities of pure hydrocarbons from molecular graphs, while enforcing mechanistic inductive biases in the output layer to ensure thermodynamic consistency. Molecular information is given as graph structures, encoded as a graph convolutional network, and mapped to an inductive bias neuron based on two thermophysical correlations: a three-parameter Andrade-type equation and a four-parameter empirical viscosity-temperature relation. The accuracy of these models is compared with a solely data-driven prediction. The Andrade-based ExPUFFIN variant reduces RMSE compared to the purely data-driven baseline of 37 percent and yields smooth, physically consistent interpolation and extrapolation of viscosity-temperature curves, properties that are not observed in purely data-driven models. The empirical ExPUFFIN model provides comparable accuracy while retaining robust trends. Overall, embedding physics-based structure in GNN outputs improves accuracy, robustness, and transferability, enabling reliable viscosity predictions for complex hydrocarbon molecules. The approach is readily extendable to other properties and significantly broader chemical domains. + oai:arXiv.org:2512.06927v2 + physics.chem-ph + Wed, 10 Dec 2025 00:00:00 -0500 + replace + http://creativecommons.org/licenses/by-nc-sa/4.0/ + Carine Menezes Rebello, Ulderico Di Caprio, Jenny Steen-Hansen, Bruno Rodrigues, Erbet Almeida Costa, Anderson Rapello dos Santos, Flora Esposito, Mumin Enis Leblebici, Idelfonso B. R. Nogueira - Physical-Layer Machine Learning with Multimode Interferometric Photon Counting - https://arxiv.org/abs/2506.12309 - arXiv:2506.12309v2 Announce Type: replace-cross -Abstract: The learning of the physical world relies on sensing and data post-processing. When the signals are weak, multidimensional and correlated, the performance of learning is often bottlenecked by the quality of sensors, calling for integrating quantum sensing into the learning of such physical-layer data. An example of such a learning scenario is the stochastic quadrature displacements of electromagnetic fields, modeling optomechanical force sensing, radiofrequency photonic sensing, microwave cavity weak signal sensing, and other applications. We propose a unified protocol that combines machine learning with interferometric photon counting to reduce noise and reveal correlations. By applying variational quantum learning with multimode programmable quantum measurements, we enhance signal extraction. Our results show that multimode interferometric photon counting outperforms conventional homodyne detection proposed in prior works for tasks like principal component analysis (PCA) and cross-correlation analysis (CCA), even below vacuum noise levels. To further enhance the performance, we also integrate entanglement-enhanced modules, in the form of squeezed state distribution and anti-squeezing at detection, into the protocol. Combining multimode interferometric photon counting and multipartite entanglement, the proposed protocol provides a powerful toolbox for learning weak signals. - oai:arXiv.org:2506.12309v2 - quant-ph - physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1103/mft4-mbzc - Phys. Rev. Applied 24, 054050 (2025) - Jia-Jin Feng, Anthony J. Brady, Quntao Zhuang + Mapping Still Matters: Coarse-Graining with Machine Learning Potentials + https://arxiv.org/abs/2512.07692 + arXiv:2512.07692v2 Announce Type: replace +Abstract: Coarse-grained (CG) modeling enables molecular simulations to reach time and length scales inaccessible to fully atomistic methods. For classical CG models, the choice of mapping, that is, how atoms are grouped into CG sites, is a major determinant of accuracy and transferability. At the same time, the emergence of machine learning potentials (MLPs) offers new opportunities to build CG models that can in principle learn the true potential of the mean force for any mapping. In this work, we systematically investigate how the choice of mapping influences the representations learned by equivariant MLPs by studying liquid hexane, amino acids, and polyalanine. We find that when the length scales of bonded and nonbonded interactions overlap, unphysical bond permutations can occur. We also demonstrate that correctly encoding species and maintaining stereochemistry are crucial, as neglecting either introduces unphysical symmetries. Our findings provide practical guidance for selecting CG mappings compatible with modern architectures and guide the development of transferable CG models. + oai:arXiv.org:2512.07692v2 + physics.chem-ph + q-bio.BM + Wed, 10 Dec 2025 00:00:00 -0500 + replace + http://creativecommons.org/licenses/by/4.0/ + Franz G\"orlich, Julija Zavadlav - Quantum-Classical Hybrid Quantized Neural Network - https://arxiv.org/abs/2506.18240 - arXiv:2506.18240v4 Announce Type: replace-cross -Abstract: In this work, we introduce a novel Quadratic Binary Optimization (QBO) framework for training a quantized neural network. The framework enables the use of arbitrary activation and loss functions through spline interpolation, while Forward Interval Propagation addresses the nonlinearities and the multi-layered, composite structure of neural networks via discretizing activation functions into linear subintervals. This preserves the universal approximation properties of neural networks while allowing complex nonlinear functions accessible to quantum solvers, broadening their applicability in artificial intelligence. Theoretically, we derive an upper bound on the approximation error and the number of Ising spins required by deriving the sample complexity of the empirical risk minimization problem from an optimization perspective. A key challenge in solving the associated large-scale Quadratic Constrained Binary Optimization (QCBO) model is the presence of numerous constraints. To overcome this, we adopt the Quantum Conditional Gradient Descent (QCGD) algorithm, which solves QCBO directly on quantum hardware. We establish the convergence of QCGD under a quantum oracle subject to randomness, bounded variance, and limited coefficient precision, and further provide an upper bound on the Time-To-Solution. To enhance scalability, we further incorporate a decomposed copositive optimization scheme that replaces the monolithic lifted model with sample-wise subproblems. This decomposition substantially reduces the quantum resource requirements and enables efficient low-bit neural network training. We further propose the usage of QCGD and Quantum Progressive Hedging (QPH) algorithm to efficiently solve the decomposed problem. - oai:arXiv.org:2506.18240v4 - cs.LG - cs.AI + VO2 films grown on TiO2 sub-layer: influence of thickness on structural, electrical and optical properties + https://arxiv.org/abs/2411.14920 + arXiv:2411.14920v2 Announce Type: replace-cross +Abstract: Vanadium dioxide with metal-to-insulator transition (MIT) that is triggered by heat, current or light is a promising material for modern active THz/mid-IR metasurfaces and all-optical big data processing systems. Multilayer VO2-based active metasurfaces are urgently needed however several important issues related to VO2 properties in VO2/TiO2/Al2O3 films should be thoroughly examined first. We study electrical, optical and structural properties of VO2 films as well as their composition and switching characteristics as function of the VO2 layer thickness in VO2/TiO2 composites. XRD analysis revealed an epitaxial growth of films with deformation of the monoclinic VO2 lattice to hexagonal symmetry. Reduced VO2 layer thickness from 170 nm to 20 nm results in increased phase transition temperature while the width of the resistance versus temperature hysteresis loop R(T) remains constant at ~6C for all VO2 thicknesses in the range of 20-170 nm. The resistance alteration ratio is reduced from 4.2e3 to 2.7e2 in thinner films. Raman spectra reveal a significant shift of VO2 lattice vibration modes for films thinner than 30 nm claiming a great structural strain whereas modes position for thicker VO2 layers are similar to those in bulk structure. Composition of VO2 films has revealed only a minor alteration of VO2/V2O5 phases ratio from 1.6 to 1.8 when the film thickness has been increased from 20 nm to 50 nm. Investigation of surface elemental composition and valence states of VO2 films revealed that VO2/V2O5 ratio remains practically unchanged with thickness reduction. The study of electrical MIT dynamics revealed the switching time of a 50 nm VO2 film to be as low as 800 ns. + oai:arXiv.org:2411.14920v2 + cond-mat.mtrl-sci physics.optics - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Wenxin Li, Chuan Wang, Hongdong Zhu, Qi Gao, Yin Ma, Hai Wei, Kai Wen + M. E. Kutepov, V. E. Kaydashev, D. V. Stryukov, A. S. Konstantinov, A. V. Nikolskiy, A. T. Kozakov, A. D. Morozov, I. K. Domaratskiy, S. S. Zhukov, E. M. Kaidashev - Charge Regulation Effect on Nanoparticles Interaction Mediated by Polyelectrolyte - https://arxiv.org/abs/2507.00549 - arXiv:2507.00549v2 Announce Type: replace-cross -Abstract: The ability to precisely control surface charge using charged polymers is fundamental to many nanotechnology applications, enabling the design and fabrication of materials with tailored properties and functionalities. Here, we study the effect of charge regulation (CR) on the interaction between two nanoparticles (NPs) mediated by an oppositely charged polyelectrolyte (PE) in an electrolyte solution. To this end, we employ a hybrid CR Monte Carlo / molecular dynamics simulation framework to systematically explore the effects of pH, salt concentration, and polymer chain length on NP surface charge behavior. For comparison, we also conduct molecular simulations under constant charge (CC) conditions. Our results reveal that CR enhances PE adsorption onto NP surfaces compared to the CC case, where polymer bridging dominates across a wide range of NP intersurface separations. This enhanced adsorption under CR leads to a weak net repulsion driven by osmotic forces. In contrast, the CC model yields a stronger net attraction due to the bridging force. Furthermore, we find that the CR effects are more pronounced at low salt concentration, whereas at high salt concentration, counterion screening dominates in both CR and CC cases, diminishing the CR effect. These findings highlight the importance of incorporating charge regulation in characterizing nanoparticle interactions within a complex biochemical environment, particularly in low salt concentrations. - oai:arXiv.org:2507.00549v2 + Universal criterion for selective outcomes under stochastic resetting + https://arxiv.org/abs/2502.09127 + arXiv:2502.09127v2 Announce Type: replace-cross +Abstract: Resetting plays a pivotal role in optimizing the completion time of complex first passage processes with single or multiple outcomes/exit possibilities. While it is well established that the coefficient of variation -- a statistical dispersion defined as a ratio of the fluctuations over the mean of the first passage time -- must be larger than unity for resetting to be beneficial for any outcome averaged over all the possibilities, the same can not be said while conditioned on a particular outcome. The purpose of this letter is to derive a universal condition which reveals that two statistical metric -- the mean and coefficient of variation of the conditional times -- come together to determine when resetting can expedite the completion of a selective outcome, and furthermore can govern the biasing between preferential and non-preferential outcomes. The universality of this result is demonstrated for a one dimensional diffusion process subjected to resetting with two absorbing boundaries. + oai:arXiv.org:2502.09127v2 + cond-mat.stat-mech cond-mat.soft - physics.bio-ph - Tue, 09 Dec 2025 00:00:00 -0500 + math.PR + physics.chem-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - Vijay Yadav, Prabhat Kumar Jaiswal, Rudolf Podgornik, Sunita Kumari + 10.1103/p3yc-kmt1 + Phys. Rev. E 112, 034116, 2025 + Suvam Pal, Leonardo Dagdug, Dibakar Ghosh, Denis Boyer, Arnab Pal - A Hartree-Fock Analysis of the Finite Jellium Model - https://arxiv.org/abs/2507.05002 - arXiv:2507.05002v2 Announce Type: replace-cross -Abstract: A Hartree--Fock analysis of the ground-state electronic structure of the finite spherical jellium model is carried out for systems containing up to $520$ electrons in a positive background field with densities ranging from $10^{-3}$ to $1$. The study focuses on quantifying the effects of confinement on the local-density models of the exchange and kinetic energies used in orbital-free density-based quantum computation methods. Significant discrepancies are observed between the energies obtained from the Hartree--Fock approximation and those predicted by the local density approximation (LDA) and the Thomas--Fermi model (TF) evaluated at the computed electron densities, both in the inner region and on the surface of the system. To reconcile these differences, refined expressions for the local one-electron energy densities, parametrized by the system's size and background charge density, are proposed. These models are also compared with commonly used gradient-based energy functionals. - oai:arXiv.org:2507.05002v2 - cond-mat.mtrl-sci - physics.atm-clus - Tue, 09 Dec 2025 00:00:00 -0500 + Multivariable Behavioral Change Modeling of Epidemics in the Presence of Undetected Infections + https://arxiv.org/abs/2503.00982 + arXiv:2503.00982v3 Announce Type: replace-cross +Abstract: Epidemic models are invaluable tools to understand and implement strategies to control the spread of infectious diseases, as well as to inform public health policies and resource allocation. However, current modeling approaches have limitations that reduce their practical utility, such as the exclusion of human behavioral change in response to the epidemic or ignoring the presence of undetected infectious individuals in the population. These limitations became particularly evident during the COVID-19 pandemic, underscoring the need for more accurate and informative models. To address these challenges, we develop a novel Bayesian epidemic modeling framework to better capture the complexities of disease spread by incorporating behavioral responses and undetected infections. In particular, our framework makes three contributions: 1) leveraging additional data on hospitalizations and deaths in modeling the disease dynamics, 2) accounting for data uncertainty arising from the large presence of asymptomatic and undetected infections, and 3) allowing the population behavioral change to be dynamically influenced by multiple data sources (cases and deaths). We thoroughly investigate the properties of the proposed model via simulation, and illustrate its utility on COVID-19 data from Montreal and Miami. + oai:arXiv.org:2503.00982v3 + stat.ME + physics.soc-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross - http://creativecommons.org/licenses/by/4.0/ - Michael P\'iro, Jaroslav Hamrle + http://arxiv.org/licenses/nonexclusive-distrib/1.0/ + Caitlin Ward, Rob Deardon, Alexandra M. Schmidt - Continuous-time parametrization of neural quantum states for quantum dynamics - https://arxiv.org/abs/2507.08418 - arXiv:2507.08418v3 Announce Type: replace-cross -Abstract: Neural quantum states are a promising framework for simulating many-body quantum dynamics, as they can represent states with volume-law entanglement. As time evolves, the neural network parameters are typically optimized at discrete time steps to approximate the wave function at each point in time. Given the differentiability of the wave function stemming from the Schr\"odinger equation, here we impose a time-continuous and differentiable parameterization of the neural network by expressing its parameters as linear combinations of temporal basis functions with trainable, time-independent coefficients. We test this ansatz, referred to as the smooth neural quantum state (\textit{s}-NQS) with a loss function defined over an extended time interval, under a sudden quench of a non-integrable many-body quantum spin chain. We demonstrate accurate time evolution using a restricted Boltzmann machine as the instantaneous neural network architecture. We show that the parameterization enables accurate simulations with fewer variational parameters, independent of time-step resolution. Furthermore, the smooth neural quantum state also allows us to initialize and evaluate the wave function at times not included in the training set, both within and beyond the training interval. - oai:arXiv.org:2507.08418v3 - quant-ph - cond-mat.str-el + An empirical formulation of accelerated molecular dynamics for simulating and predicting microstructure evolution in materials + https://arxiv.org/abs/2503.14294 + arXiv:2503.14294v3 Announce Type: replace-cross +Abstract: Despite its widespread use in materials science, conventional molecular dynamics (MD) simulations are severely constrained by timescale limitations. To address this shortcoming, we propose an empirical formulation of accelerated MD method, adapted from a collective-variable-based extended system dynamics framework. While this framework is originally developed for efficient free energy sampling and reaction pathway determination of specific rare events in condensed matter, we have modified it to enable accelerated MD simulation and prediction of microstructure evolution of materials across a broad range of scenarios. In essence, the nearest neighbor off-centering absolute displacement (NNOAD), which quantifies the deviation of an atom from the geometric center of its nearest neighbors in materials, is introduced. We propose that the collection of NNOADs of all atoms can serve as a generalized reaction coordinate for various structural transitions in materials. The NNOAD of each atom, represented by its three components, is coupled with three additional dynamic variables assigned to the atom. Time evolution of the additional dynamic variables follows Langevin equation, while Nos\'e-Hoover dynamics is employed to thermostat the system. Through careful analysis and benchmark simulations, we established appropriate parameter ranges for the equations in our method. Application of this method to several test cases demonstrates its capability to accelerate MD simulations by several orders of magnitude while maintaining kinetic consistency and good accuracy in predicting long timescale microstructure evolutions of materials. We also provide some preliminary thoughts on theoretical justification of the method, offering insights into its underlying principles. + oai:arXiv.org:2503.14294v3 + cond-mat.mtrl-sci physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Dingzu Wang, Wenxuan Zhang, Xiansong Xu, Dario Poletti + Liang Wan, Qingsong Mei, Haowen Liu, Huafeng Zhang, Jun-Ping Du, Shigenobu Ogata, Wen Tong Geng - XiChen: An observation-scalable fully AI-driven global weather forecasting system with 4D variational knowledge - https://arxiv.org/abs/2507.09202 - arXiv:2507.09202v2 Announce Type: replace-cross -Abstract: Artificial intelligence (AI)-driven models have the potential to revolutionize weather forecasting, but still rely on initial conditions generated by costly Numerical Weather Prediction (NWP) systems. Although recent end-to-end forecasting models attempt to bypass NWP systems, these methods lack scalable assimilation of new types of observational data. Here, we introduce XiChen, an observation-scalable fully AI-driven global weather forecasting system, wherein the entire pipeline, from Data Assimilation (DA) to medium-range forecasting, can be accomplished within only 15 seconds. XiChen is built upon a foundation model that is pre-trained for weather forecasting and subsequently fine-tuned to serve as both observation operators and DA models, thereby enabling the scalable assimilation of conventional and raw satellite observations. Furthermore, the integration of Four-Dimensional Variational (4DVar) knowledge ensures XiChen to achieve DA and medium-range forecasting accuracy comparable to operational NWP systems, with skillful forecasting lead time beyond 8.75 days. A key feature of XiChen is its ability to maintain physical balance constraints during DA, enabling observed variables to correct unobserved ones effectively. In single-point perturbation DA experiments, XiChen exhibits flow-dependent characteristics similar to those of traditional 4DVar systems. These results demonstrate that XiChen holds strong potential for fully AI-driven weather forecasting independent of NWP systems. - oai:arXiv.org:2507.09202v2 + Elucidated Rolling Diffusion Models for Probabilistic Forecasting of Complex Dynamics + https://arxiv.org/abs/2506.20024 + arXiv:2506.20024v3 Announce Type: replace-cross +Abstract: Diffusion models are a powerful tool for probabilistic forecasting, yet most applications in high-dimensional complex systems predict future states individually. This approach struggles to model complex temporal dependencies and fails to explicitly account for the progressive growth of uncertainty inherent to the systems. While rolling diffusion frameworks, which apply increasing noise to forecasts at longer lead times, have been proposed to address this, their integration with state-of-the-art, high-fidelity diffusion techniques remains a significant challenge. We tackle this problem by introducing Elucidated Rolling Diffusion Models (ERDM), the first framework to successfully unify a rolling forecast structure with the principled, performant design of Elucidated Diffusion Models (EDM). To do this, we adapt the core EDM components-its noise schedule, network preconditioning, and Heun sampler-to the rolling forecast setting. The success of this integration is driven by three key contributions: (i) a novel loss weighting scheme that focuses model capacity on the mid-range forecast horizons where determinism gives way to stochasticity; (ii) an efficient initialization strategy using a pre-trained EDM for the initial window; and (iii) a bespoke hybrid sequence architecture for robust spatiotemporal feature extraction under progressive denoising. On 2D Navier-Stokes simulations and ERA5 global weather forecasting at 1.5-degree resolution, ERDM consistently outperforms key diffusion-based baselines, including conditional autoregressive EDM. ERDM offers a flexible and powerful general framework for tackling diffusion-based dynamics forecasting problems where modeling uncertainty propagation is paramount. + oai:arXiv.org:2506.20024v3 cs.LG cs.AI physics.ao-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Wuxin Wang, Weicheng Ni, Lilan Huang, Tao Hao, Ben Fei, Shuo Ma, Taikang Yuan, Yanlai Zhao, Kefeng Deng, Xiaoyong Li, Hongze Leng, Boheng Duan, Lei Bai, Weimin Zhang, Kaijun Ren, Junqiang Song - - - Look the Other Way: Designing 'Positive' Molecules with Negative Data via Task Arithmetic - https://arxiv.org/abs/2507.17876 - arXiv:2507.17876v2 Announce Type: replace-cross -Abstract: The scarcity of molecules with desirable properties (i.e., `positive' molecules) is an inherent bottleneck for generative molecule design. To sidestep such obstacle, here we propose molecular task arithmetic: training a model on diverse and abundant negative examples to learn 'property directions' - without accessing any positively labeled data - and moving models in the opposite property directions to generate positive molecules. When analyzed on 33 design experiments with distinct molecular entities (small molecules, proteins), model architectures, and scales, molecular task arithmetic generated more diverse and successful designs than models trained on positive molecules in general. Moreover, we employed molecular task arithmetic in dual-objective and few-shot design tasks. We find that molecular task arithmetic can consistently increase the diversity of designs while maintaining desirable complex design properties, such as good docking scores to a protein. With its simplicity, data efficiency, and performance, molecular task arithmetic bears the potential to become the de facto transfer learning strategy for de novo molecule design. - oai:arXiv.org:2507.17876v2 - cs.LG - physics.chem-ph - q-bio.BM - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - R{\i}za \"Oz\c{c}elik, Sarah de Ruiter, Francesca Grisoni - - - Effective permeability conditions for diffusive transport through impermeable membranes with gaps - https://arxiv.org/abs/2508.10694 - arXiv:2508.10694v4 Announce Type: replace-cross -Abstract: Membranes regulate transport in a wide variety of industrial and biological applications. The microscale geometry of the membrane can significantly affect overall transport through the membrane, but the precise nature of this multiscale coupling is not well characterised in general. Motivated by the application of transport across a bacterial membrane, in this paper we use formal multiscale analysis to derive explicit effective coupling conditions for macroscale transport across a two-dimensional impermeable membrane with periodically spaced gaps, and validate these with numerical simulations. We derive analytic expressions for effective macroscale quantities associated with the membrane, such as the permeability, in terms of the microscale geometry. Our results generalise the classic constitutive membrane coupling conditions to a wider range of membrane geometries and time-varying scenarios. Specifically, we demonstrate that if the exterior concentration varies in time, for membranes with long channels, the transport gains a memory property where the coupling conditions depend on the system history. By applying our effective conditions in the context of small molecule transport through gaps in bacterial membranes called porins, we predict that bacterial membrane permeability is primarily dominated by the thickness of the membrane. Furthermore, we predict how alterations to membrane microstructure, for example via changes to porin expression, might affect overall transport, including when external concentrations vary in time. These results will apply to a broad range of physical applications with similar membrane structures, from medical and industrial filtration to carbon capture. - oai:arXiv.org:2508.10694v4 - cond-mat.soft - math.AP - math.DS - physics.bio-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - Molly Brennan, Edwina F. Yeo, Philip Pearce, Mohit P. Dalwadi - - - Reconfiguration of a Magnetic Tunnel Junction as a Way to Turn It into a Field-Free Vortex Oscillator - https://arxiv.org/abs/2508.10739 - arXiv:2508.10739v2 Announce Type: replace-cross -Abstract: Magnetic tunnel junctions (MTJs) are key elements in practical spintronics, enabling not only conventional tasks such as data storage, transmission, and processing but also the implementation of compute-in-memory processing elements, facilitating the development of efficient hardware for neuromorphic computing. The functionality of an MTJ is determined by the properties of its free layer (FL) and reference layer (RL) with fixed magnetization, separated by an MgO tunnel barrier. This paper presents a mechanism for reconfiguring the RL, which is the upper layer of a pinned synthetic antiferromagnet, enabling a reversible transition from a single-domain state to a vortex magnetic state with different core positions. When the RL is in the vortex state, it generates a spin current with a vortex-like polarization distribution, enabling stable vortex oscillations in the FL even in the absence of external magnetic fields. This effect has been confirmed in MTJs with diameters ranging from 400 to 1000 nm. It is demonstrated, using experimental data with comparative micromagnetic simulation, that the pinning antiferromagnet retains a long term memory of previous reannealing states resulting in a deformation of the vortex polarised spin current, which in turn introduces a strong dynamical vortex core polarity symmetry breaking. The analogue reprogrammable nature of both the static and dynamic properties of the MTJ demonstrate different possible routes for the introduction of non-volatility into radiofrequency spintronic neuromorphic paradigms. - oai:arXiv.org:2508.10739v2 - cond-mat.other - physics.app-ph - Tue, 09 Dec 2025 00:00:00 -0500 + stat.ML + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - Maksim Stebliy, Alex Jenkins, Luana Benetti, Ricardo Ferreira + Advances in Neural Information Processing Systems (NeurIPS), 2025 + Salva R\"uhling Cachay, Miika Aittala, Karsten Kreis, Noah Brenowitz, Arash Vahdat, Morteza Mardani, Rose Yu - A Haldane-Anderson Hamiltonian Model for Hyperthermal Hydrogen Scattering from a Semiconductor Surface - https://arxiv.org/abs/2508.13360 - arXiv:2508.13360v2 Announce Type: replace-cross -Abstract: Collisions of atoms and molecules with metal surfaces create electronic excitations in the metal, leading to nonadiabatic energy dissipation, inelastic scattering, and sticking. Mixed quantum-classical molecular dynamics simulation methods, such as molecular dynamics with electronic friction, are able to capture nonadiabatic energy loss during dynamics at metal surfaces. Hydrogen atom scattering from semiconductors, on the other hand, exhibits strong adsorbate-surface energy transfer only when the projectile kinetic energy exceeds the bandgap of the substrate. Electronic friction fails to describe this effect. Here, we report a first-principles parameterization of a simple Haldane-Anderson Hamiltonian model of hydrogen atom gas-surface scattering on Ge(111)$c(2\times8)$, for which hyperthermal scattering experiments have been reported. We subsequently perform independent-electron surface hopping and Ehrenfest dynamics simulations on this model, and validate these results through numerically exact quantum-dynamical simulations using the hierarchical equation of motion approach. While mean-field dynamics yield weak nonadiabatic energy loss that is independent of the initial kinetic energy, independent electron surface hopping simulations qualitatively agree with the experimental observation that nonadiabatic energy dissipation only occurs if the initial kinetic energy exceeds the bandgap of the surface. - oai:arXiv.org:2508.13360v2 - cond-mat.mtrl-sci + A molecule with half-M\"obius topology + https://arxiv.org/abs/2507.03516 + arXiv:2507.03516v2 Announce Type: replace-cross +Abstract: Stereoisomers of C$_{13}$Cl$_2$ exhibiting helical orbitals around a ring of carbon atoms were synthesized by atom manipulation on NaCl surfaces. We resolved the enantiomeric geometries of the closed-shell singlet states by atomic force microscopy and mapped their helical orbital densities by scanning tunnelling microscopy. A ${\pi}$-orbital basis of the helical, non-planar singlets that twists by 90{\deg} in one circulation is consistent with a half-M\"obius topology. In such a topology, the ${\pi}$-orbital basis changes sign with respect to two circumnavigations and is periodic with respect to four circumnavigations. A quasiparticle on a ring with this boundary condition could be interpreted as carrying a Berry phase of ${\pi}$/2. We demonstrate reversible switching of the topology, between the two singlets of oppositely threaded half-M\"obius topology, and the planar, topologically trivial, triplet state. Multireference calculations, including large-scale sample-based ab initio calculations executed on quantum hardware, reveal that the switching is associated with a helical pseudo Jahn-Teller effect. + oai:arXiv.org:2507.03516v2 + cond-mat.mes-hall physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - Xuexun Lu, Nils Hertl, Sara Oregioni, Riley Preston, Samuel L. Rudge, Michael Thoss, Rocco Martinazzo, Reinhard J. Maurer + Igor Roncevic, Fabian Paschke, Yueze Gao, Leonard-Alexander Lieske, Lene A. G\"odde, Stefano Barison, Samuele Piccinelli, Alberto Baiardi, Ivano Tavernelli, Jascha Repp, Florian Albrecht, Harry L. Anderson, Leo Gross - Conditionally adaptive augmented Lagrangian method for physics-informed learning of forward and inverse problems - https://arxiv.org/abs/2508.15695 - arXiv:2508.15695v2 Announce Type: replace-cross -Abstract: We present several key advances to the Physics and Equality Constrained Artificial Neural Networks (PECANN) framework, substantially improving its capacity to solve challenging partial differential equations (PDEs). Our enhancements broaden the framework's applicability and improve efficiency. First, we generalize the Augmented Lagrangian Method (ALM) to support multiple, independent penalty parameters for enforcing heterogeneous constraints. Second, we introduce a constraint aggregation technique to address inefficiencies associated with point-wise enforcement. Third, we incorporate a single Fourier feature mapping to capture highly oscillatory solutions with multi-scale features, where alternative methods often require multiple mappings or costlier architectures. Fourth, a novel time-windowing strategy enables seamless long-time evolution without relying on discrete time models. Fifth, and critically, we propose a conditionally adaptive penalty update (CAPU) strategy for ALM that accelerates the growth of Lagrange multipliers for constraints with larger violations, while enabling coordinated updates of multiple penalty parameters. CAPU accelerates the growth of Lagrange multipliers for selectively challenging constraints, enhancing constraint enforcement during training. We demonstrate the effectiveness of PECANN-CAPU across diverse problems, including the transonic rarefaction problem, reversible scalar advection by a vortex, high-wavenumber Helmholtz and Poisson's equations, and inverse heat source identification. The framework achieves competitive accuracy across all cases when compared with established methods and recent approaches based on Kolmogorov-Arnold networks. Collectively, these advances improve the robustness, computational efficiency, and applicability of PECANN to demanding problems in scientific computing. - oai:arXiv.org:2508.15695v2 - cs.LG - math.OC - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Thermochemical models of outer core convection with heterogeneous core-mantle boundary heat flux + https://arxiv.org/abs/2507.03538 + arXiv:2507.03538v2 Announce Type: replace-cross +Abstract: Thermochemical convection in Earth's outer core is driven by the crystallisation of the inner core that releases latent heat and light elements. A key question in core dynamics is whether a stable layer exists just below the core-mantle boundary. Recent core convection simulations, accounting for CMB heterogeneities, propose locally stable regions (or regional inversion lenses, RILs) rather than a global layer, allowing both stable and unstable regions to coexist. In this study, we consider a suite of numerical simulations of thermal, chemical, and thermochemical convection models focussed on Ekman number ($E=10^{-5}$) with thermal and chemical flux Rayleigh numbers $\widetilde{Ra}_T=30-4000$ and $\widetilde{Ra}_C=30-100000$, and thermal and chemical Prandtl numbers $Pr_T=1$ and $Pr_\xi=10$. Analysis of purely chemical models reveals light element accumulation (LEA) below the CMB, resulting in either locally stable regions near the poles or global layers, depending on the strength of chemical forcing. These chemically stratified regions persist in our thermochemical models even if the thermal field is fully destabilising. The addition of a heterogeneous CMB heat flux leads to the formation of RILs driven by thermal stratification. Stable regions in these thermochemical models have varying locations, properties, and morphologies depending on whether thermal or chemical convection dominates. In the investigated parameter range, these RILs are O(100 km) thick, and their strength and thickness generally increase with the strength of thermal driving; they are comparatively less sensitive to the strength of chemical driving. Our simulations reveal a diverse range of possible stable regions and/or a global layer at the top of Earth's core, with a seismically plausible range of thickness and strength, which may also have a signature in geomagnetic observations. + oai:arXiv.org:2507.03538v2 + astro-ph.EP + physics.geo-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - Qifeng Hu, Shamsulhaq Basir, Inanc Senocak + Souvik Naskar, Jonathan E. Mound, Christopher J. Davies, Andrew T. Clarke - Quantum Seniority-based Subspace Expansion: Linear Combinations of Short-Circuit Unitary Transformations for the Electronic Structure Problem - https://arxiv.org/abs/2509.01061 - arXiv:2509.01061v2 Announce Type: replace-cross -Abstract: Quantum SENiority-based Subspace Expansion (Q-SENSE) is a hybrid quantum-classical algorithm that interpolates between the Variational Quantum Eigensolver (VQE) and Configuration Interaction (CI) methods. It constructs Hamiltonian matrix elements on a quantum device and solves the resulting eigenvalue problem classically. Unlike other expansion-based methods -- such as Quantum Subspace Expansion (QSE), Quantum Krylov Algorithms, and the Non-Orthogonal Quantum Eigensolver -- Q-SENSE introduces seniority operators as artificial symmetries to construct orthogonal basis states. This seniority-symmetry-based approach reduces one of the primary limitations of VQE on near-term quantum hardware -- circuit depth -- at the cost of measuring additional matrix elements. The artificial symmetries also reduce the number of Hamiltonian terms that must be measured, as only a small fraction of the terms couple basis states in different seniority subspaces. With all these merits, Q-SENSE offers a scalable and resource-efficient route to quantum advantage on near-term quantum devices and in the early fault-tolerant regime. - oai:arXiv.org:2509.01061v2 - quant-ph - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 + PET Image Reconstruction Using Deep Diffusion Image Prior + https://arxiv.org/abs/2507.15078 + arXiv:2507.15078v2 Announce Type: replace-cross +Abstract: Diffusion models have shown great promise in medical image denoising and reconstruction, but their application to Positron Emission Tomography (PET) imaging remains limited by tracer-specific contrast variability and high computational demands. In this work, we proposed an anatomical prior-guided PET image reconstruction method based on diffusion models, inspired by the deep diffusion image prior (DDIP) framework. The proposed method alternated between diffusion sampling and model fine-tuning guided by the PET sinogram, enabling the reconstruction of high-quality images from various PET tracers using a score function pretrained on a dataset of another tracer. To improve computational efficiency, the half-quadratic splitting (HQS) algorithm was adopted to decouple network optimization from iterative PET reconstruction. The proposed method was evaluated using one simulation and two clinical datasets. For the simulation study, a model pretrained on [$^{18}$F]FDG data was tested on [$^{18}$F]FDG data and amyloid-negative PET data to assess out-of-distribution (OOD) performance. For the clinical-data validation, ten low-dose [$^{18}$F]FDG datasets and one [$^{18}$F]Florbetapir dataset were tested on a model pretrained on data from another tracer. Experiment results show that the proposed PET reconstruction method can generalize robustly across tracer distributions and scanner types, providing an efficient and versatile reconstruction framework for low-dose PET imaging. + oai:arXiv.org:2507.15078v2 + eess.IV + cs.CV + physics.med-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Smik Patel, Praveen Jayakumar, Rick Huang, Tao Zeng, Artur F. Izmaylov + Fumio Hashimoto, Kuang Gong - An exact multiple-time-step variational formulation for the committor and the transition rate - https://arxiv.org/abs/2509.03539 - arXiv:2509.03539v2 Announce Type: replace-cross -Abstract: For a transition between two stable states, the committor is the probability that the dynamics leads to one stable state before the other. It can be estimated from trajectory data by minimizing an expression for the transition rate that depends on a lag time. We show that an existing such expression is minimized by the exact committor only when the lag time is a single time step, resulting in a biased estimate in practical applications. We introduce an alternative expression that is minimized by the exact committor at any lag time. The key idea is that, when trajectories enter the stable states, the times that they enter (stopping times) must be used for estimating the committor and transition rate instead of the lag time. Numerical tests on benchmark systems demonstrate that our committor and transition rate estimates are much less sensitive to the choice of lag time. We show how further accuracy for the transition rate can be achieved by combining results from two lag times. We also relate the transition rate expression to a variational approach for kinetic statistics based on the mean-squared residual and discuss further numerical considerations with the aid of a decomposition of the error into dynamic modes. - oai:arXiv.org:2509.03539v2 + Physical Constraints on the Rhythmicity of the Biological Clock + https://arxiv.org/abs/2507.20750 + arXiv:2507.20750v2 Announce Type: replace-cross +Abstract: Circadian rhythms in living organisms are temporal orders emerging from biochemical circuits driven out of equilibrium. Here, we study how the rhythmicity of KaiABC clock is generated from the underlying circuit. The phase diagram in terms of KaiC and KaiA concentrations reveals a narrowly bounded oscillatory phase. As dictated by the cost-precision trade-offs of the thermodynamic uncertainty relations, the presence of intrinsic noise, amplified in small systems, demands higher energy cost to achieve greater rhythmic precision. The cost-minimizing condition giving rise to $\sim$21-hr rhythm is identified close enough to entrain the system to 24-hr environmental signals. An optimal level of intrinsic noise can induce oscillations beyond the Hopf bifurcation, effectively expanding the oscillatory phase. Our study clarifies how the physical factors, such as energy cost, stochastic noise, and regulatory mechanism, contribute to the operation of biological clocks. + oai:arXiv.org:2507.20750v2 cond-mat.stat-mech - cs.LG - physics.comp-ph - physics.data-an - Tue, 09 Dec 2025 00:00:00 -0500 + physics.bio-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - Chatipat Lorpaiboon, Jonathan Weare, Aaron R. Dinner + YeongKyu Lee, Changbong Hyeon - Evidential Physics-Informed Neural Networks for Scientific Discovery - https://arxiv.org/abs/2509.14568 - arXiv:2509.14568v3 Announce Type: replace-cross -Abstract: We present the fundamental theory and implementation guidelines underlying Evidential Physics-Informed Neural Network (E-PINN) -- a novel class of uncertainty-aware PINN. It leverages the marginal distribution loss function of evidential deep learning for estimating uncertainty of outputs, and infers unknown parameters of the PDE via a learned posterior distribution. Validating our model on two illustrative case studies -- the 1D Poisson equation with a Gaussian source and the 2D Fisher-KPP equation, we found that E-PINN generated empirical coverage probabilities that were calibrated significantly better than Bayesian PINN and Deep Ensemble methods. To demonstrate real-world applicability, we also present a brief case study on applying E-PINN to analyze clinical glucose-insulin datasets that have featured in medical research on diabetes pathophysiology. - oai:arXiv.org:2509.14568v3 - cs.LG + A Non-Local Orientation Field Phase-Field Model for Misorientation- and Inclination- Dependent Grain Boundaries + https://arxiv.org/abs/2508.01688 + arXiv:2508.01688v3 Announce Type: replace-cross +Abstract: We propose to incorporate grain boundary (GB) anisotropy in phase-field modeling by extending the standard partial differential equations formulation to include a non-local functional of an orientation field. Regardless of the number of grains in the simulation, the model uses a single orientation field and incorporates grain misorientation and inclination information obtained from sampling the orientation field at optimized locations in the vicinity of the grain boundary. The formalism enables simple and precise tuning of GB energy anisotropy while avoiding an extensive fitting procedure. The functional includes an explicit GB anisotropy function to control the GB energy as a function of both misorientation and inclination. The model is validated by reproducing the linear grain growth rate, Wulff shapes with varying misorientations and anisotropic coefficients, and analytical equilibrium dihedral angles at triple junctions. Polycrystalline simulations demonstrate grain growth, coalescence, triple junction behavior, and the influence of anisotropy on grain morphology. + oai:arXiv.org:2508.01688v3 + cond-mat.mtrl-sci physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - Hai Siong Tan, Kuancheng Wang, Rafe McBeth + Xiao Han, Axel van de Walle - Machine Learning for Event Reconstruction in the CMS Phase-2 High Granularity Calorimeter Endcap - https://arxiv.org/abs/2510.01851 - arXiv:2510.01851v2 Announce Type: replace-cross -Abstract: The high-luminosity era of the LHC will offer greatly increased number of events for more precise Standard Model measurements and Beyond Standard Model searches, but will also pose unprecedented challenges to the detectors. To meet these challenges, the CMS detector will undergo several upgrades, including the replacement of the current endcap calorimeters with a novel High-Granularity Calorimeter (HGCAL). To make optimal use of this innovative detector, new and original algorithms are being devised. A dedicated reconstruction framework, The Iterative Clustering (TICL), is being developed within the CMS Software (CMSSW). This new framework is designed to fully exploit the high spatial resolution and precise timing information provided by HGCAL. Several key ingredients of the object reconstruction chain already rely on Machine Learning (ML) techniques and their usage is expected to further develop in the future. The existing reconstruction strategies will be presented stressing the role played by ML techniques to exploit the information provided by the detector. The areas where ML techniques are expected to play a role in the future developments will be also discussed. - oai:arXiv.org:2510.01851v2 - hep-ex - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 + Random-phase Wave Splatting of Translucent Primitives for Computer-generated Holography + https://arxiv.org/abs/2508.17480 + arXiv:2508.17480v2 Announce Type: replace-cross +Abstract: Holographic near-eye displays offer ultra-compact form factors for VR/AR systems but rely on advanced computer-generated holography (CGH) algorithms to convert 3D scenes into interference patterns on spatial light modulators (SLMs). Conventional CGH typically generates smooth-phase holograms, limiting view-dependent effects and realistic defocus blur, while severely under-utilizing the SLM space-bandwidth product. + We propose Random-phase Wave Splatting (RPWS), a unified wave optics rendering framework that converts arbitrary 3D representations based on 2D translucent primitives into random-phase holograms. RPWS is fully compatible with modern 3D representations such as Gaussians and triangles, improves bandwidth utilization which effectively enlarges eyebox size, reconstructs accurate defocus blur and parallax, and leverages time-multiplexed rendering not as a heuristic for speckle suppression, but as a mathematically exact alpha-blending mechanism derived from first principles in statistics. At the core of RPWS are (1) a new wavefront compositing procedure and (2) an alpha-blending scheme for random-phase geometric primitives, ensuring correct color reconstruction and robust occlusion when compositing millions of primitives. + RPWS departs substantially from the recent primitive-based CGH algorithm, Gaussian Wave Splatting (GWS). Because GWS uses smooth-phase primitives, it struggles to capture view-dependent effects and realistic defocus blur and under-utilizes the SLM space-bandwidth product; moreover, naively extending GWS to random-phase primitives fails to reconstruct accurate colors. In contrast, RPWS is designed from the ground up for arbitrary random-phase translucent primitives, and through simulations and experimental validations we demonstrate state-of-the-art image quality and perceptually faithful 3D holograms for next-generation near-eye displays. + oai:arXiv.org:2508.17480v2 + cs.GR + cs.AR + eess.IV + eess.SP + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - Th\'eo Cuisset (on behalf of the CMS Collaboration) + Brian Chao, Jacqueline Yang, Suyeon Choi, Manu Gopakumar, Ryota Koiso, Gordon Wetzstein - On the Feasibility of Exact Unitary Transformations for Many-body Hamiltonians - https://arxiv.org/abs/2510.10957 - arXiv:2510.10957v2 Announce Type: replace-cross -Abstract: Exact unitary transformations play a central role in the analysis and simulation of many-body quantum systems, yet the conditions under which they can be carried out exactly and efficiently remain incompletely understood. We show that exact transformations arise whenever the adjoint action of a unitary's generator defines a linear map within a finite-dimensional operator space. In this regime, there exists a finite-degree polynomial that annihilates the adjoint map, rendering the Baker-Campbell-Hausdorff (BCH) expansion finite. We identify the role of Lie algebras and their modules in producing finite BCH expansions in all known cases. This perspective brings together previously disparate examples of exact transformations under a single unifying principle and clarifies how algebraic relations between generators and transformed operators determine the polynomial degree of the transformation. We illustrate this framework for previously known cases of efficient unitary transformations including unitary coupled-cluster and Pauli product generators. Using this framework, we propose a new class of fermionic generators that can be used for efficient transformations. The result establishes sufficient algebraic conditions for when exact unitary transformations are possible and provides new strategies for reducing their computational cost in quantum simulation and constructing feasible unitary transformations. - oai:arXiv.org:2510.10957v2 + Quantization of the electromagnetic fields from single atomic or molecular radiators + https://arxiv.org/abs/2509.07359 + arXiv:2509.07359v3 Announce Type: replace-cross +Abstract: A framework is introduced for expressing electromagnetic (EM) potentials and fields of single atomic or molecular emitters modeled as oscillating dipoles, which follows a recently proposed method for solving inhomogeneous wave equations for arbitrary, time-dependent distributions of charge. This framework is first used to evaluate the physical implications of simplifying assumptions made in the standard approach to quantization of the EM fields and the impact of such assumptions on the results of energy and momentum quantization. Then, the exact expressions for the EM potentials and fields, in relation to the oscillating (transition) dipoles properties, afforded by the present framework are used to quantize electromagnetic fields from single emitters and restore the agreement with the well-known classical dipole radiation pattern, while maintaining the quantum mechanical description of electromagnetic radiation in terms of the probability distribution of quantum modes. Contributions of the present analysis to the understanding of photon emission from excited atoms or molecules stimulated by light or vacuum field fluctuations are highlighted, and possible experimental tests and practical applications are proposed. + oai:arXiv.org:2509.07359v3 quant-ph - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 + physics.class-ph + physics.optics + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Praveen Jayakumar, Tao Zeng, Artur F. Izmaylov + http://creativecommons.org/licenses/by-nc-nd/4.0/ + Valerica Raicu - Space-time resonances in the spatiotemporal spectrum of nonlinear dispersive waves - https://arxiv.org/abs/2510.19828 - arXiv:2510.19828v2 Announce Type: replace-cross -Abstract: In weakly nonlinear dispersive wave systems, long-time dynamics are typically governed by time resonances, where wave phases evolve coherently due to exact frequency matching. Recent advances in spatio-temporal spectrum measurements, however, reveal prominent features that go beyond the predictions of time resonance theory. In this work, we develop a theoretical framework to interpret these signatures by identifying and characterizing an alternative mechanism: space resonances. These arise when wave packets share the same group velocity and remain co-located, leading to long-lived interactions. We further show that gauge-breaking terms in the Hamiltonian give rise to space resonances supported on negative frequencies. By combining sea-surface elevation data, numerical simulations, and analytical theory, we derive the leading-order spatio-temporal spectrum for weakly interacting water waves, providing a unified explanation for its observed features. - oai:arXiv.org:2510.19828v2 - nlin.PS - math-ph - math.MP - nlin.CD + Dynamics of Ideal Fluid Flows + https://arxiv.org/abs/2511.16254 + arXiv:2511.16254v2 Announce Type: replace-cross +Abstract: We will discuss various aspects of the incompressible Euler equation. We will discuss, in particular, problems related to the least action principle, the existence of special solutions, the problem of solvability, singularity formation, and asymptotic behavior. + oai:arXiv.org:2511.16254v2 + math.AP physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - Michal Shavit, Fabio Pusateri, Zhou Zhang, Yulin Pan, Davide Maestrini, Miguel Onorato, Jalal Shatah - - - HPC-Driven Modeling with ML-Based Surrogates for Magnon-Photon Dynamics in Hybrid Quantum Systems - https://arxiv.org/abs/2510.22221 - arXiv:2510.22221v2 Announce Type: replace-cross -Abstract: Simulating hybrid magnonic quantum systems remains a challenge due to the large disparity between the timescales of the two systems. We present a massively parallel GPU-based simulation framework that enables fully coupled, large-scale modeling of on-chip magnon-photon circuits. Our approach resolves the dynamic interaction between ferromagnetic and electromagnetic fields with high spatiotemporal fidelity. To accelerate design workflows, we develop a physics-informed machine learning surrogate trained on the simulation data, reducing computational cost while maintaining accuracy. This combined approach reveals real-time energy exchange dynamics and reproduces key phenomena such as anti-crossing behavior and the suppression of ferromagnetic resonance under strong electromagnetic fields. By addressing the multiscale and multiphysics challenges in magnon-photon modeling, our framework enables scalable simulation and rapid prototyping of next-generation quantum and spintronic devices. - oai:arXiv.org:2510.22221v2 - quant-ph - cs.LG - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Jialin Song, Yingheng Tang, Pu Ren, Shintaro Takayoshi, Saurabh Sawant, Yujie Zhu, Jia-Mian Hu, Andy Nonaka, Michael W. Mahoney, Benjamin Erichson, Zhi Yao - - - Mixed-State Measurement-Induced Phase Transitions in Imaginary-Time Dynamics - https://arxiv.org/abs/2511.04402 - arXiv:2511.04402v2 Announce Type: replace-cross -Abstract: Mixed-state phase transitions have recently attracted growing attention as a new frontier in nonequilibrium quantum matter and quantum information. In this work, we introduce the measurement-dressed imaginary-time evolution (MDITE) as a novel framework to explore mixed-state quantum phases and decoherence-driven criticality. In this setup, alternating imaginary-time evolution and projective measurements generate a competition between coherence-restoring dynamics and decoherence-inducing events. While reminiscent of monitored unitary circuits, MDITE fundamentally differs in that the physics is encoded in decoherent mixed states rather than in quantum trajectories. We demonstrate that this interplay gives rise to a novel class of mixed-state phase transitions, using numerical simulations of the one-dimensional transverse-field Ising model and the two-dimensional columnar dimerized Heisenberg model. Notably, the observed transitions do not fall into any previously established universality classes. Furthermore, we provide a diagrammatic representation of the evolving state, which naturally enables efficient studies of MDITE with quantum Monte Carlo and other many-body numerical methods, thereby extending investigations of mixed-state phase transitions to large-scale and higher-dimensional systems. In addition, the representation provides a natural interpretation of the phase transitions in terms of cluster formation within the simulations. Our results highlight MDITE as a powerful paradigm for investigating non-unitary dynamics and the fundamental role of decoherence in many-body quantum systems. - oai:arXiv.org:2511.04402v2 - quant-ph - cond-mat.stat-mech - cond-mat.str-el - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Yi-Ming Ding, Zenan Liu, Xu Tian, Zhe Wang, Yanzhang Zhu, Zheng Yan - - - A synchronization-free one-way ranging observable for detecting and characterizing coherent orbital-period systematics in GRACE-FO laser ranging data - https://arxiv.org/abs/2511.14782 - arXiv:2511.14782v3 Announce Type: replace-cross -Abstract: We present a synchronization-free differential observable for one-way inter-satellite laser ranging, designed to suppress first-order Doppler effects without requiring clock synchronization between spacecraft. The observable is constructed from successive pulse-interval differences, which isolate time-varying signatures while eliminating static and slowly varying biases. Applied to GRACE-FO Laser Ranging Interferometer (LRI) Level-1B data over four seasonal epochs in 2019, the method reveals a stable, spectrally narrow modulation at the orbital frequency. The amplitude and phase of the detected signature remain consistent across all datasets, demonstrating a deterministic, mission-internal origin. The detection is independently confirmed through synthetic-signal injection, shuffle-based significance testing, and cross-comparison with K-band ranging data. These results show that the proposed observable provides a sensitive diagnostic for identifying coherent orbital-period systematics that may remain hidden in conventional range-rate analysis. The method offers a pathway toward improved characterization of instrument and dynamical effects in current and future satellite gravity missions. - oai:arXiv.org:2511.14782v3 - gr-qc - astro-ph.IM - physics.data-an - physics.ins-det - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by/4.0/ - S. H. Wassegh + Tarek M. Elgindi - Projections of Earth's Technosphere: Strategies for Observing Technosignatures on Terrestrial Exoplanets - https://arxiv.org/abs/2511.20329 - arXiv:2511.20329v2 Announce Type: replace-cross -Abstract: The search for technosignatures--remotely detectable evidence of extraterrestrial technology--draws upon examples from the recent history of Earth as well as projections of Earth's technosphere. Facilities like the Habitable Worlds Observatory (HWO) will significantly advance the feasibility of characterizing the atmospheres of habitable exoplanets at visible and near-infrared wavelengths, while other future mission concepts could extend this search to mid-infrared wavelengths. We draw upon a recently developed set of 10 self-consistent scenarios for future Earth technospheres as analogs for extraterrestrial technospheres, which we use to outline a stepwise technosignature search strategy, beginning with HWO and followed by other missions. We find that HWO could reveal elevated abundances of a CO$_2$ + NO$_2$ pair on planets with combustion and other large-scale industry, which could be observable in up to eight of the 10 scenarios. Follow-up radio observations could reveal narrowband directed transmissions, as occur in two of the scenarios. Further study involving direct detections at mid-infrared wavelengths with the Large Interferometer for Exoplanets could reveal spectral features from industry, such as the combinations of CO$_2$ + CFC-11/12 in four scenarios and CO$_2$ + CFC-11/12 + CF$_4$ in one scenario; two of these also include the N$_2$O + CH$_4$ + NH$_3$ triple from large-scale agriculture. Other mission concepts, such as a solar-gravitational-lens mission, could reveal large-scale surface features in two scenarios that would otherwise show no detectable technosignatures, while an interplanetary flyby or probe mission would be the most conclusive way to reveal the presence of technology on terrestrial exoplanets. - oai:arXiv.org:2511.20329v2 + The Albedo Problem and Cloud Cover on Hot Jupiters + https://arxiv.org/abs/2511.18497 + arXiv:2511.18497v2 Announce Type: replace-cross +Abstract: Observations of transiting hot Jupiters have revealed a mismatch between the values of the Bond versus geometric albedos. In the planetary science literature, the ratio of these quantities is known as the phase integral. It has been extensively measured for the Solar System planets and shown to generally be non-unity in value. We use existing Cassini data of Jupiter to derive bandpass-integrated geometric albedos and phase integrals in the CHEOPS, TESS and Ariel bandpasses, demonstrating that these quantities vary markedly across these different wavelength ranges. By performing a population study of geometric albedos and phase integrals, we demonstrate that atmospheres with partial cloud cover may be identified using measurements of the phase integral if its measured uncertainty is $\sim 0.1$, which corresponds to an uncertainty of $\sim 3\%$ on the optical/visible secondary eclipse depth. The upcoming Ariel space mission will conduct an unprecedented statistical survey of cloud cover on hot Jupiters via the simultaneous measurement of $\sim 100$ infrared phase curves and optical secondary eclipses. Whenever available, the shape of optical phase curves of reflected light will directly constrain the phase integral, spherical albedo, degree of cloud cover and scattering asymmetry factor. + oai:arXiv.org:2511.18497v2 astro-ph.EP - astro-ph.IM - physics.pop-ph - physics.soc-ph - Tue, 09 Dec 2025 00:00:00 -0500 + physics.ao-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ - 10.3847/2041-8213/ae23c6 - The Astrophysical Journal Letters (2025) 995: L22 - Jacob Haqq-Misra, Ravi Kopparapu, George Profitiliotis - - - Microscopic Variability Alters Macroscopic Rotation Speed in Stochastic Spiral Waves - https://arxiv.org/abs/2511.21710 - arXiv:2511.21710v2 Announce Type: replace-cross -Abstract: We present a general theory for noise-induced corrections to the angular velocity of spiral waves. Stochasticity produces two second-order effects: an instantaneous term from heterogeneity that always slows rotation, and an orbital-drift term from temporal fluctuations that can either accelerate or decelerate it. For our parameters, orbital drift is weaker, producing a net slowdown. Analytical predictions match Barkley-model simulations with temporal noise. Examination of additional noise types in silico confirms angular velocity slowing. This mechanism provides a robust route by which stochasticity reshapes spiral dynamics in excitable media, with direct implications for arrhythmias and neural wave propagation. - oai:arXiv.org:2511.21710v2 - nlin.PS - math-ph - math.MP - physics.bio-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Jolien Kamphuis, Desmond Kabus, Hermen Jan Hupkes, Tim De Coster + Kevin Heng, Billy Edwards, Nicolas B. Cowan Onsager Condensation in Chiral Active Matter: Universality of Supersonic Topological Gas Dynamics https://arxiv.org/abs/2512.01884 - arXiv:2512.01884v4 Announce Type: replace-cross + arXiv:2512.01884v5 Announce Type: replace-cross Abstract: To explain how dissipative active turbulence sustains inertial cascades, we construct a chiral model mapping overdamped agents to supersonic topological gas dynamics. Here, Mach cones function as acoustic horizons, shielding defect cores from the sound radiation of shallow water flows. We show that disorder activates a topological heat pump driving an inverse cascade toward a negative-temperature Onsager dipole, unless arrested into a vortex glass by insufficient dispersion. This mapping identifies a universality class unifying active swarms with the statistical mechanics of classical inviscid fluids. - oai:arXiv.org:2512.01884v4 + oai:arXiv.org:2512.01884v5 cond-mat.soft cond-mat.stat-mech physics.flu-dyn - Tue, 09 Dec 2025 00:00:00 -0500 + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by-nc-sa/4.0/ Magnus F Ivarsen - Revealing Nanoscale Molecular Organization in Liquid Crystals via Cryogenic Atom Probe Tomography - https://arxiv.org/abs/2512.03734 - arXiv:2512.03734v2 Announce Type: replace-cross -Abstract: While liquid crystals (LCs) have been extensively studied, obtaining a comprehensive nanoscale picture of their molecular organization remains challenging, as conventional techniques face an intrinsic trade-off between spatial and chemical resolution. Here, cryogenic atom probe tomography (cryo-APT) is introduced as a new analytical approach for LC materials, using 4'-Pentyl-4-cyanobiphenyl (5CB) and 4'-Octyl-4-cyanobiphenyl (8CB) as representative model compounds. This was enabled by a tailored cryogenic focused ion beam (cryo-FIB) protocol optimized for small organic molecules. The method enables controlled field evaporation of both intact molecules and diagnostic fragments, achieving over 90% molecular retention while preserving four characteristic dissociation patterns. By spatially correlating these fragmentation profiles with the local electric field derived from the tip geometry, we reveal field-directed dissociation pathways of CB molecules. In parallel, the distribution of intact molecular ions enables nanoscale visualization of material structure: we resolve homogeneous mixing of 5CB and 8CB in the nematic phase and directly observe the sub-nanometer crystalline layering in a supercooled 8CB sample, with contrast to the surrounding amorphous matrix suggesting the presence of a solid-liquid interface. This work establishes cryo-APT as a new powerful analytical platform for LC research and reveals its broad potential for application in soft matter systems. - oai:arXiv.org:2512.03734v2 - cond-mat.mtrl-sci - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 + China Regional 3km Downscaling Based on Residual Corrective Diffusion Model + https://arxiv.org/abs/2512.05377 + arXiv:2512.05377v2 Announce Type: replace-cross +Abstract: A fundamental challenge in numerical weather prediction is to efficiently produce high-resolution forecasts. A common solution is applying downscaling methods, which include dynamical downscaling and statistical downscaling, to the outputs of global models. This work focuses on statistical downscaling, which establishes statistical relationships between low-resolution and high-resolution historical data using statistical models. Deep learning has emerged as a powerful tool for this task, giving rise to various high-performance super-resolution models, which can be directly applied for downscaling, such as diffusion models and Generative Adversarial Networks. This work relies on a diffusion-based downscaling framework named CorrDiff. In contrast to the original work of CorrDiff, the region considered in this work is nearly 40 times larger, and we not only consider surface variables as in the original work, but also encounter high-level variables (six pressure levels) as target downscaling variables. In addition, a global residual connection is added to improve accuracy. In order to generate the 3km forecasts for the China region, we apply our trained models to the 25km global grid forecasts of CMA-GFS, an operational global model of the China Meteorological Administration (CMA), and SFF, a data-driven deep learning-based weather model developed from Spherical Fourier Neural Operators (SFNO). CMA-MESO, a high-resolution regional model, is chosen as the baseline model. The experimental results demonstrate that the forecasts downscaled by our method generally outperform the direct forecasts of CMA-MESO in terms of MAE for the target variables. Our forecasts of radar composite reflectivity show that CorrDiff, as a generative model, can generate fine-scale details that lead to more realistic predictions compared to the corresponding deterministic regression models. + oai:arXiv.org:2512.05377v2 + cs.LG + cs.AI + physics.ao-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - Kuan Meng, Kang'an Wang, Sebastian Eich, Pierre Nacke, Johanna R. Bruckner, Patrick Stender, Frank Giesselmann, Guido Schmitz - - - Double Perovskites K2NbTaO6 and Rb2NbTaO6 from First-Principles: Towards Efficient Materials for Green Energy - https://arxiv.org/abs/2512.04134 - arXiv:2512.04134v2 Announce Type: replace-cross -Abstract: The structural flexibility and multifunctional nature of double perovskite oxides make them attractive for applications requiring coupled optical, mechanical, and thermal performance. Using first-principles computations, this study examines the structural, electronic, elastic, optical, and thermoelectric stability of K2NbTaO6 and Rb2NbTaO6. The two compounds combine to form a cubic double perovskite structure with ordered Nb$^{5+}$ and Ta$^{5+}$ cations. The calculated elastic constants satisfy the Born stability criteria, confirming mechanical stability; however, both K2NbTaO6 and Rb2NbTaO6 exhibit brittle behavior according to Pugh's ratio, reflecting limited ductility. Semiconducting behavior is revealed by band structure analysis with energy gaps of 2.79 eV for K2NbTaO6 and 2.63 eV for Rb2NbTaO6. Optical spectra show noticeable absorption in the high-energy region near the UV, indicating relevance for theoretical studies of optoelectronic and photocatalytic processes, without implying practical device efficiency. Therm - oai:arXiv.org:2512.04134v2 - cond-mat.mtrl-sci - physics.comp-ph - Tue, 09 Dec 2025 00:00:00 -0500 - replace-cross - http://creativecommons.org/licenses/by-nc-nd/4.0/ - Ouendadji Salima, Aissani Ali, El Haj Hassan Fouad, Benahmedi Lakhdar + Honglu Sun, Hao Jing, Zhixiang Dai, Sa Xiao, Wei Xue, Jian Sun, Qifeng Lu - Thermal stability originates the vanishing of the specific heats at the absolute zero - https://arxiv.org/abs/2512.05129 - arXiv:2512.05129v2 Announce Type: replace-cross -Abstract: The relationship between the vanishing of the heat capacities as $T\to0^+$ and the thermal stability is examined. The heat capacities vanish as fast as or faster than $T$ as $T\to0^+$ for states at the phase space boundary ($T=0$) to sustain the standard thermal stability criterion $U_{ss}>0$. Conversely, weakly vanishing heat capacities, which signify a loss of curvature in $U(S)$ at $T=0$, are the signature of a critical condition precisely at $T=0$, as exemplified in marginal Fermi liquids. Therefore, the vanishing of the specific heat should be viewed not as a new law but as a confirmatory result of the existing framework of thermodynamics. - oai:arXiv.org:2512.05129v2 - cond-mat.stat-mech - cond-mat.str-el - physics.chem-ph - Tue, 09 Dec 2025 00:00:00 -0500 + Towards agent-based-model informed neural networks + https://arxiv.org/abs/2512.05764 + arXiv:2512.05764v2 Announce Type: replace-cross +Abstract: In this article, we present a framework for designing neural networks that remain consistent with the underlying principles of agent-based models. We begin by highlighting the limitations of standard neural differential equations in modeling complex systems, where physical invariants (like energy) are often absent but other constraints (like mass conservation, information locality, bounded rationality) must be enforced. To address this, we introduce Agent-Based-Model informed Neural Networks (ABM-NNs), which leverage restricted graph neural networks and hierarchical decomposition to learn interpretable, structure-preserving dynamics. We validate the framework across three case studies of increasing complexity: (i) a generalized Generalized Lotka--Volterra system, where we recover ground-truth parameters from short trajectories in presence of interventions; (ii) a graph-based SIR contagion model, where our method outperforms state-of-the-art graph learning baselines (GCN, GraphSAGE, Graph Transformer) in out-of-sample forecasting and noise robustness; and (iii) a real-world macroeconomic model of the ten largest economies, where we learn coupled GDP dynamics from empirical data and demonstrate counterfactual analysis for policy interventions + oai:arXiv.org:2512.05764v2 + cs.LG + cs.SI + nlin.AO + physics.soc-ph + Wed, 10 Dec 2025 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ - 10.1088/1402-4896/ae22a5 - Physica Scripta 2025 100 125206 - Mart\'in-Olalla, Jos\'e Mar\'ia + Nino Antulov-Fantulin