http://rss.arxiv.org/rss/physics physics updates on the arXiv.org e-print archive. http://www.rssboard.org/rss-specification en-us Mon, 02 Feb 2026 05:00:07 +0000 rss-help@arxiv.org Mon, 02 Feb 2026 00:00:00 -0500 Sunday Saturday https://arxiv.org/abs/2601.22172 arXiv:2601.22172v1 Announce Type: new Abstract: The significance of wettability between solid and liquid substances in different fields encourages scientists to develop accurate models to estimate the resultant apparent contact angles. Surface free energy (SFE), which is principally defined for ideal (flat) surfaces, is not applicable to predict the wettability of real (rough) surfaces. This paper introduces a new parameter, namely normalized surface free energy (NSFE) as a combination of SFE and roughness, to predict the contact angle of liquids on non-ideal low-energy surfaces. The remarkable consistency of the predicted and measured contact angles of liquids on some rough surfaces also confirm the validity of the approach. oai:arXiv.org:2601.22172v1 physics.chem-ph cond-mat.mtrl-sci physics.app-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ 10.1016/j.porgcoat.2018.02.028 Progress in Organic Coatings, 119 (2018) 123-126 Majid Shaker, Erfan Salahinejad https://arxiv.org/abs/2601.22173 arXiv:2601.22173v1 Announce Type: new Abstract: X-ray absorption near edge structure (XANES) is an essential tool for elucidating the atomic-scale, local three-dimensional (3D) structure of given materials and molecules. The rapid computation of XANES based on molecular 3D structures constitutes a vital element of quantitative XANES analysis. Here, we present an XANES prediction model. It takes 3D structures as input and generates either unconvoluted XANES or convoluted spectra as output, demonstrating excellent generalizability across diverse instrumental broadening. This model has validated its predictive capability for both hard X-ray XAS (exemplified by K-edges of 3d 4d metals and lanthanides) and soft X-ray XAS (using S K-edge as examples). Adopting the model, XANES spectra of multiple elements can be predicted using a single unified model. A highly efficient 3D structure fitting algorithm based on this unconvoluted XANES prediction model, aiming to serve as an online data analysis method suitable for XAS beamlines. oai:arXiv.org:2601.22173v1 physics.chem-ph cond-mat.mtrl-sci Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Fei Zhan, Zhi Geng, Lirong Zheng, Haifeng Zhao https://arxiv.org/abs/2601.22180 arXiv:2601.22180v1 Announce Type: new Abstract: The biological effects of electromagnetic fields on proteins remain controversial beyond well-established thermal mechanisms, particularly with respect to frequency-dependent responses. Here, we propose that electromagnetic waves can modulate protein conformation through resonant coupling with intrinsic protein dynamics. Molecular dynamics simulations were employed to characterize spontaneous conformational fluctuations in the absence of external fields, and a tiered screening strategy combined with fast Fourier transform analysis was used to identify dominant intrinsic frequencies associated with periodically fluctuating non-covalent atom or residue pairs. Oscillating external electric fields were subsequently applied at resonant and off-resonant frequencies to evaluate conformational responses across diverse protein systems. The results demonstrate that resonant excitation induces significantly enhanced backbone conformational deviations compared to off-resonant conditions, with the effect becoming more pronounced in structurally flexible and multichain proteins. These findings provide atomistic evidence for frequency-specific resonance between electromagnetic fields and protein conformational dynamics, offering mechanistic insight into frequency-dependent electromagnetic effects and a computational framework for electromagnetic wave-based modulation of protein function. oai:arXiv.org:2601.22180v1 physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-sa/4.0/ Jiafei Chen, Yuanyuan Feng, Jingzhi Feng, Xinyun Zhang, Jinzhen Zhu, Qingmeng Xu https://arxiv.org/abs/2601.22186 arXiv:2601.22186v1 Announce Type: new Abstract: The accurate measurement of waves underpins marine energy resource characterization, device design, and project development. Datawell wave buoys are widely deployed around the world and have long served as a trusted standard for wave measurements. We quantify the measurement performance, including wave elevation and energy flux estimation, of a Datawell DWR-MkIII buoy using prescribed monochromatic heave motions on a large-amplitude six-degree-of-freedom motion platform at the National Laboratory of the Rockies, assuming the buoy behaves as an ideal wave follower. Commanded motions were validated with an optical motion tracking system while buoy elevation and raw acceleration were recorded. Wave elevations were propagated to wave energy flux estimation using four methods, including one frequency-domain method and three time-domain methods. The Bayesian optimization was applied for design of experiments, and records from three test sites were also applied and evaluated in the present study. Results show two error regions within the nominal period range of 1.6s to 30s}. For wave periods between 5s and 25s, the buoy provides accurate wave height measurements. For short periods less than 5s, the 1.28Hz sampling frequency induces sub-Nyquist artifacts that bias elevation and can drive maximum energy flux estimation errors above 100%. For long periods exceeding 25s, the buoy reported elevation is underpredicted with error depending on period but relatively independent of wave height, with maximum wave height and wave energy flux errors reaching 64% and 87%, respectively. The analysis of field data also indicates that the currently recommended method for estimating wave energy flux may underestimate the wave energy flux. oai:arXiv.org:2601.22186v1 physics.ins-det physics.flu-dyn Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Xuepeng Fu, Frederick Driscoll, Rebecca Fao, Calum Kenny, Kevin Patrick Griffin, Mark Murphy, Scott Lambert https://arxiv.org/abs/2601.22188 arXiv:2601.22188v1 Announce Type: new Abstract: Quantum mechanics provides extraordinarily accurate probabilistic predictions, yet the framework remains silent on what distinguishes quantum systems from definite measurement outcomes. This paper develops a measurement-theoretic framework for projective gating. The central object is the $\beta$-bound, an inequality that controls how much probability assignments can drift when gating and measurement fail to commute. For a density operator $\rho$, projector $F$, and effect $E$, with gate-passage probability $s = {\rm Tr}(\rho F)$ and commutator norm $\varepsilon = \|[F, E]\|$, the symmetric partial-gating drift satisfies $|\Delta p_F(E)| \leq 2 \sqrt{(1 - s)/s} \cdot \varepsilon$. The constant 2 is sharp. We introduce two diagnostic quantities: the coherence witness $W(\rho, F) = \|F \rho (I - F)\|_1$, measuring cross-boundary coherence, and the record fidelity gap $\Delta_T(\rho_F, R)$, measuring expectation-value change under symmetrisation. Three experimental vignettes demonstrate falsifiability: Hong--Ou--Mandel interferometry, atomic energy-basis dephasing, and decoherence-induced classicality. The framework is operational and interpretation-neutral, compatible with Everettian, Bohmian, QBist, and collapse approaches. It provides quantitative structure that any interpretation must accommodate, along with a template for experimental tests. oai:arXiv.org:2601.22188v1 physics.hist-ph quant-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Jonathon Sendall https://arxiv.org/abs/2601.22192 arXiv:2601.22192v1 Announce Type: new Abstract: The regeneration of oral and craniofacial bone defects ranging from minor periodontal and peri-implant defects to large and critical lesions imposes a substantial global health burden. Conventional therapies are associated with several limitations, highlighting the development of a unique treatment strategy, such as tissue engineering. A well-designed scaffold for bone tissue engineering should possess biocompatibility, biodegradability, mechanical strength, and osteoconductivity. For this purpose, mesoporous silica nanoparticles (MSNs) were synthesized and incorporated at different ratios (10, 20, and 30%) into alginate/chitosan (Alg/Chit)-based porous composite scaffolds fabricated through the freeze-drying method. The MSN incorporation significantly improved the mechanical strength of the scaffolds while showing a negligible decreasing effect on the porosity. All of the samples showed desirable swelling behaviors, which is beneficial for cell attachment and proliferation. The MSN-containing scaffolds indicated a decreased hydrolytic degradation in an MSN percentage-dependent manner. The fabricated scaffolds did not depict cytotoxic characteristics. The Alg/Chit/MSN30 scaffolds not only showed noncytotoxic properties, but also increased the cell viability significantly compared to the control group. The biomineralization properties of the MSN-containing nanocomposite scaffolds were significantly higher than the Alg/Chit composite, suggesting the potential of these nanoparticles for bone tissue engineering applications. Taken together, it is concluded that the Alg/Chit/ MSN30 scaffolds are considerable substances for bone tissue regeneration, and MSN has a great tissue engineering potential in addition to its extensive biomedical applications. oai:arXiv.org:2601.22192v1 physics.med-ph cond-mat.mtrl-sci physics.app-ph physics.bio-ph physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ 10.1007/s40097-022-00507-z Journal of Nanostructure in Chemistry, 13 (2023) 389-403 Satar Yousefiasl, Hamed Manoochehri, Pooyan Makvandi, Saeid Afshar, Erfan Salahinejad, Pegah Khosraviyan, Massoud Saidijam, Sara Soleimani Asl, Esmaeel Sharifi https://arxiv.org/abs/2601.22233 arXiv:2601.22233v1 Announce Type: new Abstract: We address the problem of how individuals can integrate efficiently their private behavior with information provided by others within a group. To this end, we consider the model of collective search introduced in [https://doi.org/10.1103/PhysRevE.102.012402], under a minimal setting with no olfactory information. Agents combine a private exploratory behavior and a social imitation consisting in aligning to their neighbors, and weigh the two contributions with a single ``trust" parameter that controls their relative influence. We find that an optimal trust parameter exists even in the absence of olfactory information, as was observed in the original model. Optimality is dictated by the need to explore the minimal region of space that contains the target. An optimal trust parameter emerges from this constraint because it it tunes imitation, which induces a collective mechanism of inertia affecting the size and path of the swarm. We predict the optimal trust parameter for cohesive groups where all agents interact with one another. We show how optimality depends on the initialization of the agents and the unknown location of the target, in close agreement with numerical simulations. Our results may be leveraged to optimize the design of swarm robotics or to understand information integration in organisms with decentralized nervous systems such as cephalopods. oai:arXiv.org:2601.22233v1 physics.bio-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Francesco Boccardo, Simone Di Marino, Agnese Seminara https://arxiv.org/abs/2601.22261 arXiv:2601.22261v1 Announce Type: new Abstract: We report a time-domain optical coherence tomography (TD-OCT) system operating in the 2 $\mu\mathrm{m}$ spectral region, enabled by a GaSb-based superluminescent diode (SLD). The spectrum emitted by the SLD exhibits a full-width half-maximum (FWHM) of $\sim$80 nm centred near 2.1 $\mu\mathrm{m}$. For OCT operation, stable amplified spontaneous emission with low spectral ripple ($<20\%$) is maintained at drive currents below 150 mA. The SLD is fiber coupled and integrated into a fiber-based Michelson interferometer. In the OCT system, the measured coherence envelope yields an axial resolution of approximately 300 $\mu$m in air and enables depth-resolved imaging of scattering paint-based coating samples. In contrast to OCT implementations at 2 $\mu\mathrm{m}$ wavelength region that commonly rely on supercontinuum sources, the use of GaSb-based SLDs offers a compact practical alternative, leveraging the maturity and scalability of electrically driven semiconductor light sources packaged in a standard "butterfly" module. This report represents the first demonstration of TD-OCT imaging at 2 $\mu\mathrm{m}$ using a GaSb-based SLD source and establishes its suitability for compact and scalable mid-IR OCT instrumentation targeting non-biological, low-water-content materials. oai:arXiv.org:2601.22261v1 physics.optics physics.app-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Ifte Khairul Aam Bhuiyan, Alejandro Martinez Jimenez, Ramona Cernat, Adrian Fernandez Uceda, Joonas Hilska, Markus Peil, Manuel Jorge Marques, George Dobre, Jukka Viheriala, Adrian Podoleanu, Mircea Guina https://arxiv.org/abs/2601.22293 arXiv:2601.22293v1 Announce Type: new Abstract: A packed community of exponentially proliferating microbes will spread in size exponentially. However, due to nutrient depletion, mechanical constraints, or other limitations, exponential proliferation is not indefinite, and the spreading slows. Here, we theoretically explore a fundamental question: is it possible to infer the dominant limitation type from the spreading dynamics? Using a continuum active fluid model, we consider three limitations to cell proliferation: intrinsic growth arrest (e.g., due to sporulation), pressure from other cells, and nutrient access. We find that memoryless growth arrest still results in superlinear (accelerating) spreading, but at a reduced rate. In contrast, pressure-limited growth results in linear (constant-speed) spreading in the long-time limit. We characterize how the expansion speed depends on the maximum growth rate, the limiting pressure value, and the effective fluid friction. Interestingly, nutrient-limited growth results in a phase transition: depending on the nutrient supply and how efficiently nutrient is converted to biomass, the spreading can be either superlinear or sublinear (decelerating). We predict the phase boundary in terms of these parameters and confirm with simulations. Thus, our results suggest that when an expansion slowdown is observed, its dominant cause is likely nutrient depletion. More generally, our work suggests that cell-level growth limitations can be inferred from population-level dynamics, and it offers a methodology for connecting these two scales. oai:arXiv.org:2601.22293v1 physics.bio-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Meiyi Yao, Joshua M. Jones, Joseph W. Larkin, Andrew Mugler https://arxiv.org/abs/2601.22300 arXiv:2601.22300v1 Announce Type: new Abstract: While software implementations of neural networks have driven significant advances in computation, the von Neumann architecture imposes fundamental limitations on speed and energy efficiency. Neuromorphic networks, with structures inspired by the brain's architecture, offer a compelling solution with the potential to approach the extreme energy efficiency of neurobiological systems. Photonic neuromorphic networks (PNNs) are particularly attractive because they leverage the inherent advantages of light, namely high parallelism, low latency, and exceptional energy efficiency. Previous PNN demonstrations have largely focused on device-level functionalities or system-level implementations reliant on supervised learning and inefficient optical-electrical-optical (OEO) conversions. Here, we introduce a purely photonic deep PNN architecture that enables online, unsupervised learning. We propose a local feedback mechanism operating entirely in the optical domain that implements a Hebbian learning rule using non-volatile phase-change material synapses. We experimentally demonstrate this approach on a non-trivial letter recognition task using a commercially available fiber-optic platform and achieve a 100 percent recognition rate, showcasing an all-optical solution for efficient, real-time information processing. This work unlocks the potential of photonic computing for complex artificial intelligence applications by enabling direct, high-throughput processing of optical information without intermediate OEO signal conversions. oai:arXiv.org:2601.22300v1 physics.optics cond-mat.dis-nn Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Xi Li, Disha Biswas, Peng Zhou, Wesley H. Brigner, Anna Capuano, Joseph S. Friedman, Qing Gu https://arxiv.org/abs/2601.22330 arXiv:2601.22330v1 Announce Type: new Abstract: GPS mobility data is a valuable source of behavioral measurement which is subject to systematic biases including the over- or under-representation of demographic groups, and variations in the quality of location sampling across time. In this paper, we address the challenge of temporal bias in mobility data, which can skew the representation of mobility behaviors due to the event-based nature of location data sampling. We use the American Time Use Survey (ATUS) to assess the accuracy of a place-based measure of economic segregation drawn from large-scale mobility data across 11 U.S. cities. We show that comparisons with high quality time use surveys such as the ATUS can validate behavioral insights from mobility data, while quantifying uncertainty and highlighting areas of relative instability in analytical findings. We also propose a temporal re-weighting method that can complement existing bias-mitigation techniques to improve the accuracy of conclusions drawn from GPS-based mobility data. oai:arXiv.org:2601.22330v1 physics.soc-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Sarah A. Sanchez, Hamish Gibbs, Takahiro Yabe, Daniel T. O'Brien, Esteban Moro https://arxiv.org/abs/2601.22342 arXiv:2601.22342v1 Announce Type: new Abstract: X-ray calorimetric sample platforms combining specific heat and synchrotron x-ray measurements provide a powerful means to investigate fundamental material properties. Calorimeter cell designs featuring a compact heater and thermometer arranged in a sidecar geometry, with the sample positioned directly above the heater at the center of a silicon nitride membrane, are presented. High-yield, wafer-level batch fabrication of precision calorimetric sensor chips, beamline and laboratory cryostat plugins with sensor mounting and packaging are described. Using our calorimetric sensors, we present specific heat measurements on samples with masses ranging from 4 {\mu}g to 145 {\mu}g. The sample and reference cells are characterized with relaxation and ac steady-state measurements. The thermal response is captured using lock-in detection at carefully optimized measurement frequencies, with phase-lag correction ensuring precise extraction of heat capacity. The reference cell's background heat capacity was measured to be under 320 nJ/K at 300 K, decreasing to just 0.4 nJ/K at 0.7 K. The calorimeter performance is illustrated by studying the specific heat of small samples of superconducting Nb and a 4 {\mu}g piece of superconducting Al under different magnetic field strengths. The determination of fundamental thermodynamic quantities from low-temperature electronic and lattice specific heat measurements is discussed. These versatile, high-throughput sample platforms are engineered for small-sample calorimetry across a broad cryogenic temperature range, and they support scalable integration with a wide range of cryostats, including beamline cryostats at the Advanced Photon Source. They accommodate multimodal geometries and enable operation under ultra-high vacuum, millikelvin temperatures, magnetic fields, and x-ray illumination. oai:arXiv.org:2601.22342v1 physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ U. Patel, H. Zheng, J. L. McChesney, U. Welp, Z. Islam, A. Miceli https://arxiv.org/abs/2601.22360 arXiv:2601.22360v1 Announce Type: new Abstract: Motivated by the needs of atomic tritium sources for neutrino mass experiments, we present calculations of energy-dependent elastic scattering cross sections of hydrogen isotopes (H, D and T) on helium isotopes ($^3$He and $^4$He) in the temperature range 1~mK to 300~K. The tritium-on-helium cross sections are found to be enhanced over their hydrogen-on-helium counterparts by a near-threshold resonant s-wave bound state at low energy, similar to that predicted in the triplet T-T system. While the energy-dependent cross sections span a wide range at low energy due to this s-wave enhancement, they tend toward a common value at high energy where the scattering becomes effectively geometric in nature. oai:arXiv.org:2601.22360v1 physics.atom-ph nucl-ex Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ B. J. P. Jones https://arxiv.org/abs/2601.22377 arXiv:2601.22377v1 Announce Type: new Abstract: Wearable devices are widely used for heart rate (HR) monitoring, yet their accuracy across diverse body compositions and skin tones remains uncertain. This study evaluated four wrist worn devices (Apple, Fitbit, Samsung, Garmin) in 58 Hispanic adults with Fitzpatrick skin types III to V during a cycling protocol alternating moderate (0.64 to 0.76 HRmax) and vigorous (0.77 to 0.95 HRmax) intensities. Criterion HR was obtained using a Polar H10 ECG, and accuracy was assessed using mean absolute error, mean absolute percentage error (MAPE), bias, and intraclass correlation coefficients. All devices showed significant deviation from criterion measures. Apple and Garmin demonstrated the lowest error, whereas Fitbit and Samsung exhibited greater inaccuracies. Higher BMI and darker skin tones were associated with increased MAPE. These biases disproportionately affect higher risk populations, underscoring the need for improved algorithms to ensure equitable health monitoring. oai:arXiv.org:2601.22377v1 physics.med-ph physics.optics physics.soc-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Kostrna, Jason, Oparina, Ekaterina, Palacios, Cristina, Rodriguez, Andres J, Pei, JunZhu, Ajmal, Ajmal, Ramella-Roman, Jessica C https://arxiv.org/abs/2601.22389 arXiv:2601.22389v1 Announce Type: new Abstract: Techniques for detecting critical phenomena -- phase transitions where correlation length diverges and small perturbations have large effects -- have been developed across at least eight fields of application over nine decades. We document this convergence pattern. The physicist's correlation length $\xi$, the cardiologist's DFA scaling exponent $\alpha$, the financial analyst's Hurst exponent $H$, and the machine learning engineer's spectral radius $\chi$ all measure correlation decay rate, detecting the same critical signatures under different notation. Citation analysis reveals minimal cross-domain awareness during the formative period (1987--2010): researchers in biomedicine, finance, machine learning, power systems, and traffic flow developed equivalent techniques independently, each with distinct notation and terminology. We present Metatron Dynamics, a framework derived from distributed systems engineering, as a candidate ninth independent discovery -- strengthening the convergence pattern while acknowledging that as authors of both the framework and this analysis, external validation would strengthen this claim. Correspondence testing on the 2D Ising model confirms that measures from multiple frameworks correctly identify the critical regime at $T_c = 2.269$. We argue that repeated independent discovery establishes criticality mathematics as fundamental public knowledge, with implications for cross-disciplinary education and research accessibility. Because these findings affect fields beyond mathematics and physics, we include a plain-language summary in Appendix B for non-specialist readers. oai:arXiv.org:2601.22389v1 physics.soc-ph cond-mat.stat-mech Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Bruce Stephenson, Robin Macomber https://arxiv.org/abs/2601.22391 arXiv:2601.22391v1 Announce Type: new Abstract: Smartwatches are widely used to estimate caloric expenditure for weight management, clinical decision making, and public health monitoring. These devices combine photoplethysmography, accelerometry, and proprietary algorithms. However, prior studies report substantial error, and the influence of moderators such as skin tone and body fat percentage (BF) remains underexamined. This study tested whether smartwatch brand, BF, and Fitzpatrick skin type (III to V) predict caloric expenditure error relative to indirect calorimetry. Fifty eight Hispanic adults completed a single laboratory visit including a ten minute recumbent cycling protocol with alternating two minute moderate and vigorous intensity intervals, bracketed by rest and recovery. Participants wore four consumer devices: Apple Watch Series 8, Fitbit Sense 2, Samsung Galaxy Watch 5, and Garmin Forerunner 955. Energy expenditure was measured using a COSMED K5 metabolic system. After device specific data quality filtering, valid participant device pairings ranged from 44 to 52 per brand. One sample tests showed significant mean bias for three devices: Apple, Garmin, and Samsung. Fitbit showed no significant overall bias, although this depended on device specific outlier removal. Mean bias varied by brand, with Garmin and Samsung showing the largest overestimations. Mixed effects models revealed significant effects of device and BF, as well as a device by BF interaction, with physical activity energy expenditure error increasing as adiposity increased. Overall, common smartwatches substantially misestimate caloric expenditure compared with indirect calorimetry. Error varies by brand and worsens with higher body fat, highlighting limitations of current consumer wearables and the need for improved accuracy across diverse body types. oai:arXiv.org:2601.22391v1 physics.med-ph physics.optics physics.soc-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Jason Kostrna, Ekaterina Oparina, Andres J. Rodriguez, JunZhu Pei, Ajmal Ajmal, Cristina Palacios, Jessica C. Ramella-Roman https://arxiv.org/abs/2601.22428 arXiv:2601.22428v1 Announce Type: new Abstract: Improving student success in introductory physics remains a persistent challenge despite substantial progress from research-based instructional practices. Evidence from the Latin American context remains limited, where resources for instructional change are often constrained. This study reports a transparent benchmark of student passing outcomes in \textit{Elementary Mechanics I} at a large public university in M\'exico, comparing sections using Active Learning (AL) with those using Traditional Lecturing (TL). The labels AL and TL are operational, referring to section-level implementations by individual instructors rather than standardized protocols. Using aggregated counts from coordinator reports and common departmental assessments -- written by a committee independent of instructional modality -- we estimated pooled student-level pass probabilities for the first and second midterm exams, the global exam, and the final mark. Modality differences are summarized primarily by the risk difference, $RD_a=p_{\mathrm{AL},a}-p_{\mathrm{TL},a}$ (percentage points), with uncertainty quantified using Wilson confidence intervals and a Bayesian reference analysis with Jeffreys priors for binomial proportions. Across assessments, pooled pass rates were higher under AL than under TL, with the strongest separation observed for the global exam and the final mark. For these outcomes, the $95\%$ confidence intervals excluded zero, including under a random-intercept Bayesian model. We emphasize a constrained interpretation: the results provide a student-weighted benchmark of ``AL as implemented'' versus ``TL as implemented'' in this setting, without isolating the causal effect of individual instructional techniques. Implications are discussed for departmental decision-making and feasible next steps in evaluation, including improved student data collection and more robust qualitative analysis. oai:arXiv.org:2601.22428v1 physics.ed-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Isaac P\'erez Castillo, Lidia Jim\'enez Lara, Orlando Guzman, Juan Ernesto Chavero Amador, Juan Miguel Carrillo Gil, Luis Alberto Gonz\'alez Flores, Miguel Angel Morales Olvera, Oscar Enrique Bonfil Urbalejo, Eric Burkholder https://arxiv.org/abs/2601.22458 arXiv:2601.22458v1 Announce Type: new Abstract: Historical archives contain qualitative descriptions of climate events, yet converting these into quantitative records has remained a fundamental challenge. Here we introduce a paradigm shift: a generative AI framework that inverts the logic of historical chroniclers by inferring the quantitative climate patterns associated with documented events. Applied to historical Chinese archives, it produces the sub-annual precipitation reconstruction for southeastern China over the period 1368-1911 AD. Our reconstruction not only quantifies iconic extremes like the Ming Dynasty's Great Drought but also, crucially, maps the full spatial and seasonal structure of El Ni$\~n$o influence on precipitation in this region over five centuries, revealing dynamics inaccessible in shorter modern records. Our methodology and high-resolution climate dataset are directly applicable to climate science and have broader implications for the historical and social sciences. oai:arXiv.org:2601.22458v1 physics.ao-ph cs.AI cs.LG Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Sida He, Lingxi Xie, Xiaopeng Zhang, Qi Tian https://arxiv.org/abs/2601.22459 arXiv:2601.22459v1 Announce Type: new Abstract: Multiplex contagion dynamics display localization phenomena in which spreading activity concentrates on a subset of layers, as well as delocalized regimes where layers behave collectively. We investigate how these regimes are encoded in temporal correlations of node activity. By deriving a closed-form mean-field expression for node autocorrelations in a contact-based social contagion multiplex model and validating it through simulations, we show that lag-one autocorrelations act as sensitive indicators of both activation and localization transitions. Our results establish temporal correlations as lightweight, structure-agnostic probes of multiplex spreading dynamics, particularly valuable in partially observable systems. oai:arXiv.org:2601.22459v1 physics.soc-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Joan Hern\`andez Tey, Emanuele Cozzo https://arxiv.org/abs/2601.22506 arXiv:2601.22506v1 Announce Type: new Abstract: Metasurfaces emerged as a powerful tool for controlling thermal radiation, yet achieving coherent emission with opposite circular handednesses remains a highly challenging problem. Here, we demonstrate experimentally the Janus chiral thermal emission from metasurfaces with opposite circular handednesses on either side of a single device. We employ anisotropic metasurfaces supporting high-Q resonances with photonic flatbands enabling near-unity circular dichroism through in-plane symmetry control. Our experiments confirm the Janus coherent emission, and they are validated by the results of the coupled-mode theory. The flatband resonant metasurfaces enabling a control of chiral thermal emission provide an efficient platform for spin-controlled light-matter interaction. oai:arXiv.org:2601.22506v1 physics.optics Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Kaili Sun, Yangjian Cai, Maxim V. Gorkunov, Yuri Kivshar, Zhanghua Han https://arxiv.org/abs/2601.22540 arXiv:2601.22540v1 Announce Type: new Abstract: Global medium-range weather forecasts suffer occasional failures ("busts"), often linked to tropical cyclones (TCs). We systematically investigate the TC influences by clustering historical TC tracks and comparing skill of forecasts from a physics-based model (ECMWF-IFS) and an AI-physics hybrid model (Google-NGCM) initialized near TC genesis. Case analysis shows both models exhibit similar large-scale error growth in the extratropics, suggesting prediction skill bounded by similar limits despite model differences in spatial resolution and parameterized physics. Aggregated statistics reveal that low skill of Week-2 forecasts may occur after TC genesis, regardless of whether they recurve or not. While recurving tracks are established error sources, zonal-track clusters can be associated with similarly profound forecast degradation, acting through Rossby wave dynamics and remote moisture transport mechanisms. Furthermore, the stochastic NGCM generally outperforms its deterministic counterpart and suggests that TC-related forecast degradation is more pronounced for Europe than elsewhere in the Northern Hemisphere. oai:arXiv.org:2601.22540v1 physics.ao-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Gan Zhang https://arxiv.org/abs/2601.22552 arXiv:2601.22552v1 Announce Type: new Abstract: Plasmons, arising from the collective motion of electrons, can interact strongly with electromagnetic fields or photons; this capability has been exploited across a broad range of applications, from chemical reactivity to biosensing. Recently, there has been growing interest in plasmons for applications in quantum information processing. Electrons floating on liquid helium provide an exceptionally clean, disorder-free system and have emerged as a promising platform for this purpose. In this work, we establish this system as a tunable plasmon-photon hybrid platform. We demonstrate strong coupling between floating-electron plasmons and radio-frequency (RF) photons confined in an LC resonator. Time-resolved measurements reveal coherent oscillatory energy exchange between the plasmonic and photonic modes, providing direct evidence of their coherent coupling. These results represent a step towards cavity quantum electrodynamics with a floating-electron plasmon coupled to a resonator. Furthermore, the LC resonator serves as a sensitive probe of electron-on-helium physics, enabling the observation of the Wigner crystal transition and a quantitative study of the temperature-dependent plasmon decay arising from ripplon-induced scattering. oai:arXiv.org:2601.22552v1 physics.optics cond-mat.str-el Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Asher Jennings, Ivan Grytsenko, Thomas Giovansili, Itay Josef Barabash, Oleksiy Rybalko, Yiran Tian, Jun Wang, Hiroki Ikegami, Erika Kawakami https://arxiv.org/abs/2601.22564 arXiv:2601.22564v1 Announce Type: new Abstract: Species interactions through cross-feeding via leakage and uptake of chemicals are important in microbial communities, and play an essential role in the coexistence of diverse species. Here, we study a simple dynamical model of a microbial community in which species interact by competing for the uptake of common metabolites that are leaked by other species. The model includes coupled dynamics of species populations and chemical concentrations in the medium, allowing for a variety of uptake and leakage networks among species. Depending on the structure of these networks, the system exhibits different attractors, including fixed points, limit cycles, low-dimensional chaos, and high-dimensional chaos. In the fixed-point and limit-cycle cases, the number of coexisting species is bounded by the number of exchangeable chemicals, consistent with the well-known competitive exclusion principle. In contrast, in the low-dimensional chaotic regime, the number of coexisting species exhibits noticeable but limited excess over this limit. Remarkably, in the high-dimensional chaotic regime, a much larger number of species beyond this limit coexist persistently over time. In this case, the rank-abundance distribution is broader than exponential, as often observed in real ecosystems. The population dynamics displays intermittent switching among quasi-stationary states, while the chemical dynamics explore most of the high dimensions. We find that such high-dimensional chaos is ubiquitous when the number of uptake chemicals is moderately larger than the number of leaked chemicals. Our results identify high-dimensional chaos with intermittent switching as a generic dynamical mechanism that stabilizes coexistence in interacting systems. We discuss its relevance to sustaining diverse microbial communities with leak-uptake cross-feeding. oai:arXiv.org:2601.22564v1 physics.bio-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Takashi Shimada, Kunihiko Kaneko https://arxiv.org/abs/2601.22606 arXiv:2601.22606v1 Announce Type: new Abstract: The Martian brain terrain (MBT), characterized by its unique brain-like morphology, is a potential geological archive for finding hints of paleoclimatic conditions during its formation period. The morphological similarity of MBT to self-organized patterned ground on Earth suggests a shared formation mechanism. However, the lack of quantitative descriptions and robust physical modeling of self-organized stone transport jointly limits the study of the thermal and aqueous conditions governing MBT's formation. Here we established a specialized quantitative system for extracting the morphological features of MBT, taking a typical region located in the northern Arabia Terra as an example, and then employed a numerical model to investigate its formation mechanisms. Our simulation results accurately replicate the observed morphology of MBT, matching its key geometric metrics with deviations $<10\%$. Crucially, however, we find that the self-organized transport can solely produce relief $<0.5$ m, insufficient to explain the formation of MBT with average relief of $3.29 \pm 0.65$ m. We attribute this discrepancy to sculpting driven by late-stage sublimation, constraining cumulative subsurface ice loss in this region to $\sim 3$ meters over the past $\sim 3$ Ma. These findings demonstrate that MBT's formation is a multi-stage process: initial patterning driven by freeze-thaw cycles (implying liquid water) followed by vertical sculpting via sublimation (requiring a dry environment). This evolution provides physical evidence for the transition of the ancient Martian climate from a wetter period to a colder hyper-arid state. oai:arXiv.org:2601.22606v1 physics.geo-ph astro-ph.EP physics.comp-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Shenyi Zhang, Lei Zhang, Yutian Ke, Jinhai Zhang https://arxiv.org/abs/2601.22698 arXiv:2601.22698v1 Announce Type: new Abstract: Micro-scale cilia play a vital role in mucociliary clearance (MCC) in the human respiratory airways. In this numerical study, we examine fluid transport driven by the active beating of a single filament immersed in a three-dimensional two-phase flow. The cilium is modeled as an elastic filament actuated by a time-varying basal angle. The two-phase flow is resolved using the Shan-Chen model in a lattice Boltzmann solver, while the two-way coupling between the filament and the fluid is treated by the immersed boundary method. Pathological conditions such as cystic fibrosis and chronic obstructive pulmonary disease are associated with drastic alterations of MCC properties, including changes in periciliary layer (PCL) thickness and the viscosity ratio between the PCL and the mucus layer (ML). Here, we systematically investigate the effects of these parameters, along with filament bending stiffness, on the beating pattern and fluid transport. Within the parameter ranges investigated, a moderate PCL thickness and viscosity ratio, together with high bending stiffness, tend to yield higher net flow rate and transport efficiency. The underlying hydrodynamic mechanisms are characterized through analyses of the beating pattern, filament dynamics, energy partition, and flow-field evolution. Two competing mechanisms are identified: the drag-elastic force balance and the viscous diffusion of momentum. Furthermore, quantitative relationships are established between flow rate and beating pattern, expressed in terms of tip amplitude and beating asymmetry. oai:arXiv.org:2601.22698v1 physics.flu-dyn Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Qian Mao (M2P2), Umberto d'Ortona (M2P2), Julien Favier (M2P2) https://arxiv.org/abs/2601.22712 arXiv:2601.22712v1 Announce Type: new Abstract: We present a registration procedure for parametric model order reduction (MOR) in two- and three-dimensional bounded domains. In the MOR framework, registration methods exploit solution snapshots to identify a parametric coordinate transformation that improves the approximation of the solution set through linear subspaces. For each training parameter, optimization-based (or variational) registration methods minimize a target function that measures the alignment of the coherent structures of interest (e.g., shocks, shear layers, cracks) for different parameter values, over a family of bijections of the computational domain $\Omega$. We consider diffeomorphisms $\Phi$ that are vector flows of given velocity fields $v$ with vanishing normal component on $\partial \Omega$; we rely on a sensor to extract appropriate point clouds from the solution snapshots and we develop an expectation-maximization procedure to simultaneously solve the point cloud matching problem and to determine the velocity $v$ (and thus the bijection $\Phi$); finally, we combine our registration method with the nonlinear interpolation technique of [Iollo, Taddei, J. Comput. Phys., 2022] to perform accurate interpolations of fluid dynamic fields in the presence of shocks. Numerical results for a two-dimensional inviscid transonic flow past a NACA airfoil and a three-dimensional viscous transonic flow past an ONERA M6 wing illustrate the many elements of the methodology and demonstrate the effectiveness of nonlinear interpolation for shock-dominated fields. oai:arXiv.org:2601.22712v1 physics.flu-dyn cs.NA math.NA Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-sa/4.0/ Jon Labatut, Jean-Baptiste Chapelier, Angelo Iollo, Tommaso Taddei https://arxiv.org/abs/2601.22713 arXiv:2601.22713v1 Announce Type: new Abstract: A novel photodetector based on a MCP-PMT vacuum tube with encapsulated CMOS ASIC has been tested at the CERN SPS high energy hadron beam, allowing single photon Cherenkov detection operating at 10$^4$ gain and with timing resolution of about 280~ps. oai:arXiv.org:2601.22713v1 physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ G. Romolini, J. Alozy, R. Ballabriga, N. V. Biesuz, R. Bolzonella, M. Campbell, G. Cavallero, V. Cavallini, A. Cotta Ramusino, M. Fiorini, E. Franzoso, M. Guarise, X. Llopart Cudie, A. Saputi, D. Vincenzi https://arxiv.org/abs/2601.22723 arXiv:2601.22723v1 Announce Type: new Abstract: Accurate molecular geometries are a prerequisite for reliable quantum-chemical predictions, yet density functional theory (DFT) optimization remains a major bottleneck for high-throughput molecular screening. Here we present GeoOpt-Net, a multi-branch SE(3)-equivariant geometry refinement network that predicts DFT-quality structures at the B3LYP/TZVP level of theory in a single forward pass starting from inexpensive initial conformers generated at a low-cost force-field level. GeoOpt-Net is trained using a two-stage strategy in which a broadly pretrained geometric representation is subsequently fine-tuned to approach B3LYP/TZVP-level accuracy, with theory- and basis-set-aware calibration enabled by a fidelity-aware feature modulation (FAFM) mechanism. Benchmarking against representative approaches spanning classical conformer generation (RDKit), semiempirical quantum methods (xTB), data-driven geometry refinement pipelines (Auto3D), and machine-learning interatomic potentials (UMA) on external drug-like molecules demonstrates that GeoOpt-Net achieves sub-milli-\AA{} all-atom RMSD with near-zero B3LYP/TZVP single-point energy deviations, indicating DFT-ready geometries that closely reproduce both structural and energetic references. Beyond geometric metrics, GeoOpt-Net generates initial guesses intrinsically compatible with DFT convergence criteria, yielding nonzero ``All-YES'' convergence rates (65.0\% under loose and 33.4\% under default thresholds), and substantially reducing re-optimization steps and wall-clock time. GeoOpt-Net further exhibits smooth and predictable energy scaling with molecular complexity while preserving key electronic observables such as dipole moments. Collectively, these results establish GeoOpt-Net as a scalable, physically consistent geometry refinement framework that enables efficient acceleration of DFT-based quantum-chemical workflows. oai:arXiv.org:2601.22723v1 physics.chem-ph cs.AI physics.atm-clus Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Chengchun Liu, Wendi Cai, Boxuan Zhao, Fanyang Mo https://arxiv.org/abs/2601.22727 arXiv:2601.22727v1 Announce Type: new Abstract: Future high-energy physics experiments using SiPMs as photosensitive elements may require operation at low temperatures (down to 80 K) to measure single photons with high time resolution in a highly radioactive environment. This calls for a complete characterization of these sensors over a wide temperature range to find the best compromise between detector performance and cooling requirements. This paper presents the design of a transimpedance amplifier featuring high gain ($\sim 7500$ $\mathrm{V/A}$), very high speed ($ < 500$ $\mathrm{ps}$ rise time) and low input noise ($\lesssim 0.2$ $\mathrm{pA/\sqrt{Hz}}$), able to faithfully reproduce all the features of SiPM signals with very low noise and time jitter. These features make the amplifier suitable for precise measurements of the time-of-arrival of single-photon signals, as well as gain and recovery time. This article provides a detailed and thorough analysis of the circuit. The network was simulated and measured in two configurations that differ in their open-loop gain and dominant pole frequencies. After selecting the best configuration for our purposes, the amplifier was characterized in detail at ambient temperature and at 80 K. Finally, we evaluated the amplifier using a SiPM operated at low over-voltage. While SiPMs are typically characterized at high over-voltage to enhance gain and minimize timing jitter, testing at low over-voltage allowed us to assess the amplifier's performance under more challenging and realistic conditions for single-photon timing. oai:arXiv.org:2601.22727v1 physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Paolo Carniti (INFN Milano-Bicocca, University of Milano-Bicocca), Claudio Gotti (INFN Milano-Bicocca, University of Milano-Bicocca), Gianluigi Pessina (INFN Milano-Bicocca, University of Milano-Bicocca), Davide Trotta (INFN Milano-Bicocca, University of Milano-Bicocca) https://arxiv.org/abs/2601.22743 arXiv:2601.22743v1 Announce Type: new Abstract: Mechanical models of brain tissue are a beneficial tool to simulate neurosurgical interventions, disease progression, or brain development. However, the accuracy and predictive capacity of such a model relies on a precise experimental characterization of the tissue's mechanical behavior. Such a characterization is yet limited by inconsistent or contradictory experimental responses reported in the literature, particularly when measurements are performed in different time or length scales. Although brain tissue has been extensively investigated in previous studies, the combination of experimental findings from different scales has received limited attention. In this study, we combine ex vivo mechanical responses of porcine brain tissue obtained at different time scales in a mechanical model. We investigated the mechanical behavior of three different brain regions in the quasi-static domain with multi-modal large strain rheometer measurements and at high frequencies with magnetic resonance elastography (MRE). A comparative analysis of the mechanical parameters obtained from both experimental techniques demonstrated consistent regional variations in the viscoelastic behavior across the two domains. However, the mechanical behavior changes from a higher elasticity in the quasi-static and low frequency domain to a dominating viscosity at high frequencies. Based on the quasi-static and the high frequency behavior, we calibrated a fractional Kelvin-Voigt model and consequently unified the two responses in a single mechanical model to obtain a comprehensive characterization of the tissue's mechanical behavior. oai:arXiv.org:2601.22743v1 physics.med-ph cond-mat.mtrl-sci physics.bio-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ Laura Ruhland, Nina Reiter, Silvia Budday, Kai Willner https://arxiv.org/abs/2601.22750 arXiv:2601.22750v1 Announce Type: new Abstract: Doubly charged molecular cations often carry signatures of electronic correlation and electron-nuclear entanglement present in the parent cation. Here, we produce ethylene dications using a combination of an extreme ultraviolet pump and near-infrared probe pulses, observing a peak in the dication yield at a pump-probe delay of approximately 15 fs. Ab-initio calculations, which explicitly take into account coupled electron-nuclear dynamics induced by the pump and the multiphoton nature of the probe-induced ionization step, reproduced the observed delay in the yield. It originates from resonant enhancement of the multiphoton ionization of the electronically excited ethylene cation as the carbon-carbon double bond expands. However, this effect is tempered by rapid nonadiabatic relaxation of the excited ionic states. Our results suggest a general mechanism whereby ultrafast nonadiabatic relaxation of a molecular ion can compete with its strong-field ionization rate, confining the dication yield to a narrow temporal window of a few femtoseconds. oai:arXiv.org:2601.22750v1 physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ 10.1021/acs.jpclett.5c03271 J. Phys. Chem. Lett. 2026, 17, 797-803 Carlos Marante, Lina Frans\'en, Alexie Boyer, Vincent Loriot, Franck L\'epine, Luca Argenti, Morgane Vacher, Saikat Nandi https://arxiv.org/abs/2601.22768 arXiv:2601.22768v1 Announce Type: new Abstract: This study aims to investigate the effects of electroactive morphing on a 70cm chord A320 wing by means of near trailing edge slight deformation and vibration. Wing morphing is performed by Macro Fiber Composites (MFC) mini-piezoelectric actuators distributed along the span of the ''Reduced Scale'' (RS) A320 prototype of the H2020 No 723402 European research project SMS, ''Smart Morphing and Sensing for aeronautical configurations'', (https://cordis.europa.eu/project/id/723402 and www.smartwing.org/SMS/EU). The configuration studied corresponds to a low-subsonic regime (Mach number 0.063) with a 10 degree incidence and a Reynolds number of 1 Million. The numerical simulations are carried out with the Navier-Stokes Multi-Block (NSMB) solver, which takes into account the deformation of the rear part of the wing implemented experimentally with the piezoelectric actuators. A detailed physical analysis of the morphing effects on the wake dynamics and on the aerodynamic performance is conducted with a constant amplitude of 0.7cm over a wide range of actuation frequencies [10-600]Hz. Optimal vibration ranges of [180-192]Hz and [205-215]Hz were found to respectively provide a 1% drag reduction and a 2% lift-to-drag ratio increase compared to the non-morphing (static) configuration. The natural frequencies associated with the shear layer Kelvin-Helmholtz (KH) vortices and the Von-Karman (VK) vortex shedding were found to play a central role in the modification of the wake dynamics by morphing as well as in the increase of the aerodynamic performance. Actuating at (or close to) the upper shear layer (USL) natural frequency (~185Hz) provides an order of 1% drag reduction and 1% lift-to-drag ratio increase, while actuating at (or close to) the lower shear layer (LSL) natural frequency (~208Hz) provides an order of 8% lift increase and 2% lift-to-drag increase. Furthermore, the linear variation of the actuation frequency over time, called wobulation, was shown to have significant effects. This approach demonstrated, through an appropriate mapping, the ability to quickly and efficiently detect optimal constant actuation frequency ranges providing aerodynamic performance increase and simultaneously reducing the amplitude of the main instability modes. oai:arXiv.org:2601.22768v1 physics.class-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Journal of Fluids and Structures, 2023, 123, pp.104016 C. Rouaix (IMFT, UOIT = Ontario Tech University), C. Jim\'enez-Navarro (IMFT), M. Carvalho (UO, PRISME), C. Raibaudo (UO, PRISME), J. Abou-Khalil (IMFT, LAPLACE), A. Marouf (IMFT), Y. Hoarau (ICube), G. Harran (IMFT), J. C. R. Hunt (UOIT = Ontario Tech University), H. Hangan (UOIT = Ontario Tech University), J. F. Rouchon (LAPLACE), M. Braza (IMFT) https://arxiv.org/abs/2601.22793 arXiv:2601.22793v1 Announce Type: new Abstract: We introduce a fast Eikonal Phase Retrieval (EPR) formulation that accelerates eikonal phase retrieval by more than two orders of magnitude while retaining controlled accuracy. The method is derived from a second-order asymptotic expansion in the propagation distance $L$ and complemented by the leading Wentzel--Kramers--Brillouin (WKB) wave-optics correction, yielding an efficient iterative correction scheme preconditioned by FFT-diagonal, energy-dependent inverse operators (Paganin-type filters). To ensure robustness across practical experimental regimes, we combine two complementary solvers: (i) a local $O(L^2)$ closure that is accurate when eikonal shifts remain sub-pixel, and (ii) a non-local formulation for multi-pixel shifts, in which intensity is propagated through an explicit eikonal ray mapping using a mass-conserving bilinear redisribution on the detector grid, and detector residuals are transferred back to the object grid by the corresponding adjoint (transpose), implemented as bilinear interpolation, before applying an approximate FFT-diagonal preconditioner to accelerate convergence. The same framework supports polychromatic data through a compact spectral discretisation, allowing energy-dependent transport and inversion while keeping the iteration GPU/FFT efficient. Overall, this unified approach enables accurate and computationally efficient phase retrieval across propagation conditions relevant to high-throughput PPC-$\mu$CT experiments. oai:arXiv.org:2601.22793v1 physics.optics physics.med-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Alessandro Mirone, Theresa Urban, Joseph Brunet, Claire L. Walsh, Peter D. Lee, Paul Tafforeau https://arxiv.org/abs/2601.22794 arXiv:2601.22794v1 Announce Type: new Abstract: Laser wakefield acceleration can generate a femtosecond-scale broadband X-ray betatron radiation pulse from electrons accelerated by an intense laser pulse in a plasma. The micrometer-scale of the source makes wakefield betatron radiation well-suited for advanced imaging techniques, including diffraction and phase-contrast imaging. Recent progress in laser technology can expand these capabilities into the attosecond regime, where the practical applications would significantly benefit from the increased energy contained within the pulse. Here we use numerical simulations combined with batch Bayesian optimization to enhance the radiation produced by an attosecond betatron source. The method enables an efficient exploration of a multi-parameter space and identifies a regime in which a plasma density spike triggers the generation of a high-charge electron beam. This results in an improvement of more than one order of magnitude in the on-axis time-averaged power within the central time containing half of the radiated energy, compared to the reference case without the density spike. oai:arXiv.org:2601.22794v1 physics.plasm-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Dominika Maslarova, Albert Hansson, Mufei Luo, Vojt\v{e}ch Horn\'y, Julien Ferri, Istvan Pusztai, T\"unde F\"ul\"op https://arxiv.org/abs/2601.22958 arXiv:2601.22958v1 Announce Type: new Abstract: Integrated on-chip photonics increasingly relies on wave propagation that remains stable in the presence of fabrication imperfections, tight bends, and dense routing. Valley photonic crystals (VPCs) offer an attractive path: by opening a gap at the Dirac points of a hexagonal lattice, one can engineer guided modes confined to domain walls that thread around corners with reduced backreflection. We develop a design framework that co-optimizes the photonic bulk band gap and valley Chern number using a modified particle-swarm optimization (PSO), while evaluating the photonic band structure via plane-wave expansion and the topological characteristics using a gauge-invariant lattice discretization to compute the Berry-curvature. The optimized structures exhibit a clean valley-Hall gap with edge bands traversing the gap and high interface transmission in full-wave simulations. These results consolidate topology-aware geometry optimization for robust on-chip guiding. oai:arXiv.org:2601.22958v1 physics.optics Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Devansh Satra, Abhishek Kumar, Anshuman Kumar https://arxiv.org/abs/2601.22960 arXiv:2601.22960v1 Announce Type: new Abstract: The n2EDM experiment at the Paul Scherrer Institute aims to conduct a high-sensitivity search for the electric dipole moment of the neutron. Magnetic stability and control are achieved through a combination of passive shielding, provided by a magnetically shielded room (MSR), and a surrounding active field compensation system by an Active Magnetic Shield (AMS). The AMS is a feedback-controlled system of eight coils spanned on an irregular grid, designed to provide magnetic stability to the enclosed volume by actively suppressing external magnetic disturbances. It can compensate static and variable magnetic fields up to $\pm 50$ $\mu$T (homogeneous components) and $\pm 5$ $\mu$T/m (first-order gradients), suppressing them to a few $\mu$T in the sub-Hertz frequency range. We present a full finite element simulation of magnetic fields generated by the AMS in the presence of the MSR. This simulation is of sufficient accuracy to approach our measurements. We demonstrate how the simulation can be used with an example, obtaining an optimal number and placement of feedback sensors using genetic algorithms. oai:arXiv.org:2601.22960v1 physics.ins-det nucl-ex Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ N. J. Ayres, G. Ban, G. Bison, K. Bodek, V. Bondar, T. Bouillaud, G. L. Caratsch, E. Chanel, W. Chen, C. Crawford, V. Czamler, C. B. Doorenbos, S. Emmeneger, S. K. Ermakov, M. Ferry, M. Fertl, A. Fratangelo, D. Galbinski, W. C. Griffith, Z. D. Grujic, K. Kirch, V. Kletzl, J. Krempel, B. Lauss, T. Lefort, A. Lejuez, K. Michielsen, J. Micko, P. Mullan, O. Naviliat-Cuncic, F. M. Piegsa, G. Pignol, C. Pistillo, I. Rien\"acker, D. Ries, S. Roccia, D. Rozp\k{e}dzik, L. Sanchez-Real Zielniewicz, N. von Schickh, P. Schmidt-Wellenburg, E. P. Segarra, L. Segner, N. Severijns, K. Svirina, J. Thorne, J. Vankeirsbilck, N. Yazdandoost, J. Zejma, N. Ziehl, G. Zsigmond https://arxiv.org/abs/2601.22979 arXiv:2601.22979v1 Announce Type: new Abstract: Wichmann-Kroll corrections are calculated in both hydrogen-like electronic ions and muonic systems ($Z = \{36$--$92\}$) using two independent methods. The Gaussian finite basis set approach, enhanced with dual basis construction, analytical large-distance corrections, and $B$-spline representations, provides computational efficiency. The Green function method, based on semi-analytical construction from Dirac solutions with Fermi nuclear charge distributions, offers higher systematic accuracy and freedom from basis-dependent artifacts. Results are consistent with the literature values, providing reliable reference data for precision spectroscopy of exotic atoms. oai:arXiv.org:2601.22979v1 physics.atom-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Zoia A. Mandrykina, Zewen Sun, Natalia S. Oreshkina https://arxiv.org/abs/2601.22981 arXiv:2601.22981v1 Announce Type: new Abstract: We directly observe and spatially map an optical analog of the Magnus effect, where intrinsic spin-orbit-like coupling of light generates a spin-dependent transverse displacement of the atom-light interaction profile for a $^{40}$Ca$^+$ ion. Probed on a quadrupole transition using a tightly focused beam, we observe displacements of the maximum in the profile of the effective interaction by several 100 nm originating from intrinsic longitudinal electric field components beyond the paraxial approximation. The tight focus of the beam induces additional transverse polarization gradients, which we characterize through a phase-sensitive measurement and spatial maps for different beam configurations. The results establish the physical basis of polarization-gradient interactions relevant to optical tweezer-based quantum control. oai:arXiv.org:2601.22981v1 physics.atom-ph quant-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Philip Leindecker, Louis P. H. Gallagher, Edgar Brucke, Dominique Zehnder, Luka Milanovic, Matteo Marinelli, Rene Gerritsma, Robert J. C. Spreeuw, Jonathan Home, Cornelius Hempel https://arxiv.org/abs/2601.22998 arXiv:2601.22998v1 Announce Type: new Abstract: Absorption profiles of vector light upon interaction with atomic vapor carries distinct signatures of external magnetic field vector. However, this signature becomes ambiguous for anti parallel magnetic field vectors of equal magnitude, which makes their absorption profiles visually indistinguishable. To resolve this ambiguity, we present theoretical analysis of the interaction of vector light with optically polarized atoms immersed in reference and test magnetic fields. Furthermore, we demonstrate the complete characterization of the arbitrarily oriented (transverse) test magnetic field via Fourier analysis of the absorption profile. This analysis reveals a one to one correspondence between the magnetic field properties and the profiles contrast and rotational angle. Our findings open an avenue to design an optical vector atomic magnetometer based on structured light fields. oai:arXiv.org:2601.22998v1 physics.atom-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ S. Ramakrishna, S. Fritzsche https://arxiv.org/abs/2601.23003 arXiv:2601.23003v1 Announce Type: new Abstract: We present a theoretical framework for electromagnetic scattering by particles with a permittivity that is periodically varying in time, based on a perturbative approach. Within this framework, we derive explicit expressions for the scattering matrix of the dynamic system in a first-order Born approximation, relating it directly to the corresponding static problem. We show that inelastic scattering amplitudes are governed by overlap integrals between static modes at the input and output frequencies. Using this insight, we analyze scattering from a time-modulated, isotropic, dielectric sphere and a high-permittivity dielectric cylinder, and demonstrate how modal orthogonality can suppress inelastic channels, while appropriate tuning of geometric parameters can significantly enhance them. In particular, we show that cylindrical resonators support strong inelastic scattering when resonance-to-resonance optical transitions, induced by the temporal variation, involve a high-Q supercavity mode. Comparison with full time-Floquet calculations confirms that the first-order Born approximation remains quantitatively accurate for modest modulation amplitudes and provides clear physical intuition for frequency conversion and resonance-mediated scattering processes in time-modulated photonic resonators. oai:arXiv.org:2601.23003v1 physics.optics Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Dionysios Galanis, Evangelos Almpanis, Nikolaos Papanikolaou, Nikolaos Stefanou https://arxiv.org/abs/2601.23025 arXiv:2601.23025v1 Announce Type: new Abstract: We study the behaviour of a thin fluid filament (a rivulet) flowing in an air-filled Hele-Shaw cell. Transverse and longitudinal deformations can propagate on this rivulet, although both are linearly attenuated in the parameter range we use. On this seemingly simple system, we impose an external acoustic forcing, homogeneous in space and harmonic in time. When the forcing amplitude exceeds a given threshold, the rivulet responds nonlinearly, adopting a peculiar pattern. We investigate the dance of the rivulet both experimentally using spatiotemporal measurements, and theoretically using a model based on depth-averaged Navier-Stokes equations. The instability is due to a three-wave resonant interaction between waves along the rivulet, the resonance condition fixing the pattern wavelength. Although the forcing is additive, the amplification of transverse and longitudinal waves is effectively parametric, being mediated by the linear response of the system to the homogeneous forcing. Our model successfully explains the mode selection and phase-locking between the waves, it notably allows us to predict the frequency dependence of the instability threshold. The dominant spatiotemporal features of the generated pattern are understood through a multiple-scale analysis. oai:arXiv.org:2601.23025v1 physics.flu-dyn nlin.PS Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ 10.1017/jfm.2025.11104 Journal of Fluid Mechanics , Volume 1028 , 10 February 2026 , A13 Gr\'egoire Le Lay, Adrian Daerr https://arxiv.org/abs/2601.23061 arXiv:2601.23061v1 Announce Type: new Abstract: An active research line within the broader field of network science is the one concerning link prediction. Close in scope to network reconstruction, link prediction targets specific connections with the aim of uncovering the missing ones, as well as predicting those most likely to emerge in the future, from the available information. In this paper, we consider two families of methods, i.e. those rooted in statistical physics and those based upon machine learning: the members of the first family identify missing links as the most probable non-observed ones, the probability coefficients being determined by solving maximum-entropy benchmarks over the accessible network structure; the members of the second family, instead, associate the presence of single edges to explanatory node-specific variables. Running likelihood-based models such as the Configuration Model, or one of its many fitness-based variants, in parallel with the Gradient Boosting Decision Tree algorithm reveals that the former's accuracy is comparable to (and sometimes slightly higher than) the latter's. Such a result confirms that white-box algorithms are viable competitors to the currently available black-box ones, being computationally faster and more interpretable than the latter. oai:arXiv.org:2601.23061v1 physics.soc-ph physics.app-ph physics.data-an Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Francesca Santucci, Giulio Cimini, Tiziano Squartini https://arxiv.org/abs/2601.23067 arXiv:2601.23067v1 Announce Type: new Abstract: Structured light fields, featuring unique topological properties and high tunability, have opened new frontiers in light-matter interactions with magnetic systems. However, the ultrafast and reconfigurable optical encoding of various types of topological magnetic textures remains a significant challenge. Here, we systematically investigate the encoding mechanism of structured light in magnets via the higher-order Poincar\'e sphere. By uncovering the precise relationship between the winding number of structured light and the topological charge of magnetic textures, we establish a fundamental topological connection between light and magnetism. This framework enables ultrafast, all-optical encoding of diverse topological spin textures in magnetic media, including skyrmions, antiskyrmions and skyrmion bags. Our work advances the fundamental understanding and all-optical control of topological magnetism, offering a promising route for designing skyrmion-based devices. oai:arXiv.org:2601.23067v1 physics.optics Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Zhang Qifan, Yu Wangke, Nie Zhongquan, Shen Yijie, Lin Shirong https://arxiv.org/abs/2601.23071 arXiv:2601.23071v1 Announce Type: new Abstract: ThermoLIB is Python/Cython library designed to be used as a post-processing tool for constructing free energy surfaces from the output of molecular simulations, transforming them between different collective variables (CVs) and extracting thermodynamic and kinetic information. ThermoLIB is available for download on GitHUB and comes with extended documentation as well as many tutorials. The implementation is based on the theory of maximum likelihood estimators and includes error bars on and full covariance matrix between all points on the free energy surface using the Fisher information matrix. The free energy surfaces can be transformed a posteriori to other collective variables, projected towards lower dimensional CV-spaces and even deprojected towards higher dimensional CV-spaces if additional information from the simulation is provided in the form of a conditional probability. Finally, one can extract usefull thermodynamic and kinetic properties such as the reaction free energy and kinetic rate constant. Error bars on the free energy surfaces are propagated throughout al these operations. We briefly illustrate the capabilities of ThermoLIB by means of some tutorials and case studies. oai:arXiv.org:2601.23071v1 physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-sa/4.0/ Massimo Bocus, Louis Vanduyfhuys https://arxiv.org/abs/2601.23077 arXiv:2601.23077v1 Announce Type: new Abstract: Traditional compartmental models, including SIR, SEIR, and SIRS frameworks, remain the analytical standard for epidemic forecasting. However, real-world data validation consistently reveals significant predictive failures, such as peak underestimations of up to 50%. This research identifies a persistent fundamental methodological error: the calibration of prevalence-based (stock) models using raw daily incidence (flow) data without proper transformation. We propose an integrated protocol utilizing an exponentially weighted convolution to reconstruct active cases from reported incidence: $I(t) \approx \frac{1}{p} \int_{0}^{t} NDC(\tau) e^{-\gamma(t-\tau)} d\tau$. This transformation accounts for the recovery rate $\gamma$ and the ascertainment rate $p$. We demonstrate that increasing structural complexity, such as adding latency (SEIR) or waning immunity (SIRS), fails to resolve the incidence-prevalence gap. Simulation results show that without the proposed universal pre-processor, these advanced models inherit the systematic biases of misaligned data types, leading to significant errors in estimating latent periods and the "heavy tail" of endemicity. The proposed convolution transformation must serve as a universal prerequisite for any compartmental framework, bridging the gap between clinical reporting and mechanistic modeling. oai:arXiv.org:2601.23077v1 physics.soc-ph physics.bio-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Jose de Jesus Bernal-Alvarado, David Delepine https://arxiv.org/abs/2601.23097 arXiv:2601.23097v1 Announce Type: new Abstract: The vortex-induced vibration of multiple spring-mounted bodies free to move in the orthogonal direction of the flow is investigated. In a first step, we derive a Linear Arbitrary Lagrangian Eulerian (L-ALE) method to solve the fluid-structure linear problem as well as a forced problem where a harmonic motion of the bodies is imposed. We then propose a low computational-cost impedance-based criterion to predict the instability thresholds. A global stability analysis of the fluid-structure system is then performed for a tandem of cylinders and the instability thresholds obtained are found to be in perfect agreement with the predictions of the impedance-based criterion. An extensive parametric study is then performed for a tandem of cylinders and the effects of mass, damping and spacing between the bodies are investigated. Finally we also apply the impedance-based method to a three-body system to show its validity to a higher number of bodies. oai:arXiv.org:2601.23097v1 physics.flu-dyn Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Th\'eo Mouyen, Javier Sierra, David Fabre, Flavio Giannetti https://arxiv.org/abs/2601.23106 arXiv:2601.23106v1 Announce Type: new Abstract: The next-generation of cryogenic neutrinoless double-beta decay experiments require increasingly fast readout in order to improve background discrimination. These experiments, operated as cryogenic calorimeters at $\sim$10 mK, are usually read out by high-impedance neutron transmutation doped (NTD) thermistors, which provide good energy resolution, but are limited by $\sim$1 ms response times. Superconducting detectors, such as transition-edge sensors (TESs) with a time resolution of $\sim$100 $\mu$s, offer superior timing performance over NTD semiconductor bolometers. To make this technology viable for an application to a thousand or more channels, multiplexed readout is necessary in order to minimize the thermal load and radioactive contamination induced by the readout. Frequency-domain multiplexing readout (fMux) for TESs, previously developed at Berkeley Lab and McGill University, is currently in use for mm-wave telescopes with detector sampling rates in the order of 100 Hz. We demonstrate a new readout system, based on the McGill/Berkeley digital fMux readout, to satisfy the higher bandwidth and noise requirements of the next generation of TES-instrumented cryogenic calorimeters. The new readout samples detectors at 156 kHz, three orders of magnitude faster than its cosmology-oriented predecessor. Each multiplexing readout module comprises ten superconducting resonators in the MHz range and a superconducting quantum interference device (SQUID), interfaced to high-bandwidth field programmable gate array (FPGA)-based electronics for digital signal processing and low-latency feedback. oai:arXiv.org:2601.23106v1 physics.ins-det astro-ph.IM nucl-ex Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ M. Adami\v{c} (McGill,LBNL), M. Beretta (UCB,INFN), J. Camilleri (LBNL,Virginia Tech), C. Capelli (LBNL,Zurich U.), M. A. Dobbs (McGill), T. Elleflot (LBNL), B. K. Fujikawa (LBNL), Yu. G. Kolomensky (LBNL,UCB), D. Mayer (MIT), J. Montgomery (McGill), V. Novosad (ANL), A. M. Sindhwad (UCB), V. Singh (UCB), G. Smecher (t0.technology), A. Suzuki (LBNL), B. Welliver (UCB) https://arxiv.org/abs/2601.23117 arXiv:2601.23117v1 Announce Type: new Abstract: Gas pressure sensors based on nanomechanical membranes have recently demonstrated an ultra-wide ten-decade measurement range, a gas-type-independent response, and a self-calibrating operation with uncertainties of approximately $1\,\%$. The readout relied on tabletop free-space laser interferometers. Here we present a centimeter-sized, portable implementation in which a square Si$_3$N$_4$ membrane is read out via a fiber-based laser interferometer. We perform pressure measurements between $5\times10^{-5}$ and $10^{-1}$~mbar in a confined $0.7$~L volume cooled to $78$~K. Because no suitable commercial pressure sensor exists for direct cryogenic comparison, we benchmark our device against room-temperature commercial gauges connected to the cold volume through a pipe of limited conductance. The measured relationship between the two sensors is compared with models accounting for temperature- and pumping-induced pressure gradients within the measurement chamber. These models agree with the measurements to within $<10\,\%$ for helium and $<13\,\%$ for nitrogen. The achieved readout sensitivity of $S_x = 8\times10^{-14}\,\mathrm{m}/\sqrt{\mathrm{Hz}}$ theoretically enables resolving the thermal displacement noise spectrum of a trampoline membrane at atmospheric pressure, with a peak response of $48\,S_x$ $\left(25\,S_x\right)$ at $295\,\mathrm{K}$ $\left(78\,\mathrm{K}\right)$. Our results suggest that the previously achieved pressure measurement range of ten decades with trampoline membranes is compatible with fiber-based optical readout. This paves the way for widely applicable pressure sensors in the centimeter size range in cryogenic environments. oai:arXiv.org:2601.23117v1 physics.app-ph physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Christoph Reinhardt, Lea Lara Stankewitz, Daniel Hartwig, Sandy Croatto, Hossein Masalehdan, Nils S\"ultmann, Axel Lindner, Roman Schnabel https://arxiv.org/abs/2601.23137 arXiv:2601.23137v1 Announce Type: new Abstract: Pairs of entangled photons are crucial for photonic quantum technologies. The demand for integrability and multi-functionality suggests 'flat' platforms - ultrathin layers and metasurfaces - as sources of photon pairs. With the success in demonstrating spontaneous parametric down-conversion (SPDC) from such sources, an alternative process to generate photon pairs, spontaneous four-wave mixing (SFWM), also starts to attract interest. In materials with nonzero second-order nonlinear susceptibility $\chi^{(2)}$, SFWM can generate photon pairs both directly, through the third-order nonlinear susceptibility $\chi^{(3)}$, and in a cascaded way, through second harmonic generation (SHG) followed by SPDC. Usually, the cascaded process is more efficient. Here, we show that in a thin layer, direct SFWM dominates, because the wavevector mismatch for SFWM is much smaller than for SHG or SPDC. To demonstrate it, we implement the photon pair generation via SFWM in a second-order nonlinear material - a thin layer of lithium niobate (LN). The existence of both second- and third-order nonlinear processes offers broader opportunities for quantum state engineering. oai:arXiv.org:2601.23137v1 physics.optics quant-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Changjin Son, Maria Chekhova https://arxiv.org/abs/2601.23140 arXiv:2601.23140v1 Announce Type: new Abstract: The electron density at the separatrix ($n_{e,\mathrm{sep}}$) plays a central role in balancing energy confinement, detachment achievement, and ELM suppression in tokamaks, thereby influencing core-edge integration. To study what determines this key parameter, a database of H-mode separatrix density measurements from Alcator C-Mod, ASDEX Upgrade, and JET tokamaks has been assembled using a consistent analysis method across all devices. This dataset is used to derive a regression scaling expression based solely on engineering parameters, and the results are compared to predictions from the two-point model. The agreement found is remarkable: both the regression and model provide similar parameter dependencies and tokamak-specific multiplicative constants. Building on this agreement, a fully predictive formula that combines the regression dependencies and the two-point model multiplicative constant is proposed. This formula is able to estimate $n_{e,\mathrm{sep}}$ across the three machines within a factor of 1.5, and provides projections to next-step devices (ITER, SPARC, DTT, JT-60SA and COMPASS-U) that are in agreement with available SOLPS simulations. oai:arXiv.org:2601.23140v1 physics.plasm-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ D. Silvagni, O. Grover, A. Stagni, J. W. Hughes, M. A. Miller, B. Lomanowski, L. Balbinot, G. Ciraolo, W. Dekeyser, M. Dunne, L. Frassinetti, C. Giroud, T. Happel, I. Jepu, A. Kallenbach, A. Kirjasuo, A. Kuang, T. Luda, D. Moulton, O. Pan, C. Perez von Thun, T. Puetterich, G. Rubino, S. A. Silburn, H. J. Sun, D. Umezaki, H. Zohm, the ASDEX Upgrade team, JET contributors, the EUROfusion tokamak exploitation team https://arxiv.org/abs/2601.23178 arXiv:2601.23178v1 Announce Type: new Abstract: Thermal state reconstruction -- reversing convection to recover the thermal structure of the mantle at an earlier geologic time -- is an important tool to understand the evolution of mantle convection and its relation to seismic tomographic images and observations at the surface. Thermal state reconstructions are computationally expensive. Here we transformed the basic computational element, numerical solvers, into neural operators, a class of machine learning models for learning mappings between function spaces. Focusing on a specific architecture, Fourier Neural Operators, we demonstrate that they can represent not only a surrogate model like the Stokes system of equations using a purely physics informed approach, but also discover operators without explicit mathematical formulations or even ill-posedness from data, including the direct mapping between two convecting thermal states separated by a long time interval much larger than the Courant Fredrich Lewy condition and its reversal. These neural operators significantly accelerate forward and inverse convection modeling by transforming forward physical processes into surrogate models with lower complexity while utilizing auto-differentiation to calculate gradients. With this framework, we demonstrate the strength and weaknesses of four methods for thermal state reconstructions: Reverse buoyancy, reverse convection operator, an inversion with only the terminal thermal state, and a joint inversion with the terminal thermal state and surface velocity evolution. The reverse convection operator is shown to perform poorly in the presence of observational noise, but the joint inversion overcomes this limitation. The joint technique could probably become a solution to large-scale thermal state inversion problems using seismic tomography and plate tectonic reconstructions. oai:arXiv.org:2601.23178v1 physics.geo-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Chenxi Kong, Michael Gurnis, Zachary E. Ross https://arxiv.org/abs/2601.23190 arXiv:2601.23190v1 Announce Type: new Abstract: This study explores a physics-data driven hybrid approach for sea-ice column physics models, in which a machine learning (ML) component acts as a state-dependent parameterization of forecast errors. We examine how perturbations in snow thermodynamics and sea-ice radiative properties affect forecast errors, and train dedicated neural networks (NNs) for each model configuration. The performance of the hybrid models is evaluated for long lead-time forecasts and compared against a benchmark system based on climatological forecast-error estimates. The NN-based hybrids prove to be stable, robust to initial condition and atmospheric forcing errors, and consistently outperform their climatology-based counterpart. To derive guiding principles for efficiently handling possible physical model updates, we perform transfer learning experiments to test whether pretrained NNs optimized for one model configuration can be successfully adapted to another. Results indicate that direct evaluation of pretrained networks on the target task provides useful insights into their adaptability, recommending transfer learning whenever performance exceeds a trivial baseline. Finally, a feature-importance analysis shows that atmospheric forcing inputs have negligible influence on NN predictive skill, while ice-layer enthalpies play a key role in achieving satisfactory performance. oai:arXiv.org:2601.23190v1 physics.ao-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ Giovanni De Cillis, Alberto Carrassi, Julien Brajard, Laurent Bertino, Matteo Broccoli, Dorotea Iovino, Tobias Sebastian Finn, Marc Bocquet https://arxiv.org/abs/2601.23191 arXiv:2601.23191v1 Announce Type: new Abstract: Perovskite solar cells (PSCs) have emerged as strong contenders for the next generation of photovoltaic (PV) technologies due to their exceptional light absorption properties, tunability, and affordability in manufacturing. Here, we presented an ingenious hexagonal nanowire (HNW)-based PSC that achieves broadband absorption, minimizes reflectance, and offers robust polarization insensitivity by improving light-matter interaction and increasing charge-collection efficiency. The rotational symmetry of the HNW configuration yielded polarization-independent absorbance under both TE and TM illumination across the visible and near-infrared spectra. The optimization of the geometrical parameters of CH3NH3PbI3-based HNW structure, including diameter, period, and fill ratio, offered a wide rangeof variations that influenced both optical properties and device performance. To further intensify photon confinement, a dielectric SiO2 sphere is partially embedded in the ITO layer, improving long-wavelength absorbance and increasing electron-hole pair generation near the active region. We analyzed the finite-difference time-domain (FDTD) method to examine the optical properties of our proposed structure. This study demonstrates that our proposed structure has achieved a higher generation rate, enhanced absorbance, and a higher optical short-circuit current density (Jsc) of 29.53 mA/cm2. Electrical performance is assessed by solving the coupled drift-diffusion and Poisson equations for the dynamics of carrier transport. The optimized HNW structure achieved a notable power conversion efficiency of 24.2%, highlighting a strong connection between optical confinement and effective carrier transport. These attributes render the proposed HNW PSC a viable option for high-performance PV systems and scalable thin-film solar technologies. oai:arXiv.org:2601.23191v1 physics.optics physics.app-ph physics.comp-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ Kawshik Nath, Bibekananda Nath, Ahmed Zubair https://arxiv.org/abs/2601.23194 arXiv:2601.23194v1 Announce Type: new Abstract: This study describes both experimentally and theoretically an important hitherto undiscovered feature of the scattering of micron_sized spherical objects when illuminated with highly focused circularly polarized light. This is a regime of high experimental relevance which has not been described in full detail. The experiments are complemented with the analytical formulas explaining the field scattered directed toward the backward hemispace. In particular, it is proven that this field shows a very regular oscillatory dependency with the optical size. This phenomenon is typically hidden in the total scattered field, as the field is scattered much less toward the backward hemisphere than toward the forward one. These regular oscillations are measured experimentally. It is proven that, by analyzing them, it is possible to determine the index of refraction of isolated micron_sized particles, opening new paths for applications in sensing and metrology. oai:arXiv.org:2601.23194v1 physics.optics Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ 10.1002/lpor.202300665 Laser & Photonics Reviews 18 (2), 2300665 (2024) Mart\'in Molezuelas-Ferreras, \'Alvaro Nodar, Mar\'ia Barra-Burillo, Jorge Olmos-Trigo, Jon Lasa-Alonso, Iker G\'omez-Viloria, Elena Posada, J. J. Miguel Varga, Rub\'en Esteban, Javier Aizpurua, Luis E. Hueso, Cefe Lopez, Gabriel Molina-Terriza https://arxiv.org/abs/2601.23202 arXiv:2601.23202v1 Announce Type: new Abstract: Nonradiating optical anapoles are special configurations of charge_current distributions that do not radiate. It was theoretically predicted that, for microspheres, electric and magnetic dipolar coefficients can simultaneously vanish by engineering the incident light, leading to the excitation of nonradiating hybrid optical anapoles. In this work, the experimental detection of hybrid optical anapoles in dielectric microspheres (TiO2) is reported using dual detection optical spectroscopy, developed to enable sequential measurement of forward and backward scattering under tightly_focused Gaussian beam (TFGB) illumination. The results show that the excitation of TiO2 microspheres (diameter, d approx. 1 um) under TFGB illumination leads to the appearance of scattering minima in both the forward and backward directions within specific wavelength ranges. These scattering minima are found to be due to vanishing electric and magnetic dipolar coefficients associated with hybrid optical anapoles. The ability to confine electromagnetic fields associated with hybrid optical anapoles can give rise to several novel optical phenomena and applications. oai:arXiv.org:2601.23202v1 physics.optics Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ 10.1002/adom.202501315 Advanced Optical Materials 13 (27), e01315 (2025) Uttam Manna, Iker G\'omez-Viloria, Robert Sevik, Isaac Tribaldo, Mahua Biswas, Gabriel Molina-Terriza, Jorge Olmos-Trigo https://arxiv.org/abs/2601.23214 arXiv:2601.23214v1 Announce Type: new Abstract: The theoretical description of optical forces and torques on micron_sized particles is a crucial area of research and has formed the foundation for advancements in optical trapping and manipulation technologies. In this study, we derive analytical expressions for optical forces and torques on micron_sized spherical particles illuminated by focused Laguerre_Gaussian (LG) beams, employing the well_defined helicity multipolar decomposition of electromagnetic fields and Mie theory. We developed a multifunctional program, Multipolar Optical Forces Toolbox, based on this theoretical framework. The program, available on GitHub, was used to generate optical trapping stability maps. These maps predict trap stability across a wide range of system parameters and serve as a practical tool for designing advanced optical trapping experiments. Our analysis reveals the important role of helicity p and orbital angular momentum l on the dynamics of particles trapped off_axis in LG beams and demonstrates the unique nature of the tangential torque. Our findings also highlight notable differences in longitudinal optical forces resulting from pure helicity modifications in Gaussian beams. Furthermore, we showcase the ability of LG beams to isolate Mie resonances, offering a novel approach to locate the spectral positions of the resonances of high multipolar modes. These insights deepen the understanding of helicity in LG optical traps and pave the way for the development of more advanced optical manipulation techniques. oai:arXiv.org:2601.23214v1 physics.optics Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ 10.1063/5.0255437 APL Photonics 10, 051101 (2025) Iker G\'omez-Viloria, Enrique Ayll\'on Garc\'ia, Jorge Olmos-Trigo, Quimey Pears Stefano, Jon Lasa-Alonso, Mart\'in Molezuelas-Ferreras, Gabriel Molina-Terriza https://arxiv.org/abs/2601.23270 arXiv:2601.23270v1 Announce Type: new Abstract: While configuration interaction singles (CIS) provides a computationally efficient description of excited states, it systematically overestimates excitation energies and performs poorly for strongly correlated systems, partially due to the lack of orbital relaxation and the strong ground-state bias of Hartree-Fock orbitals. To address these limitations, we present a unified variational framework that extends CIS by incorporating orbital optimization (state-specific and state-averaged), linear-response orbital relaxation via double-CIS schemes, and spin-symmetry breaking and restoration. In spin-projected state-averaged formulations, standard multistate parametrizations are no longer valid because the projection operator breaks the unitary invariance of orbital rotations and induces nonorthogonal couplings among states. By formulating a rigorous state-averaged objective in the projected subspace, we derive analytic gradients and Hessians and enable robust optimization using a trust-region augmented Hessian algorithm. Benchmark calculations show that spin projection alone significantly exacerbates the CIS overestimation in weakly correlated systems, whereas combining spin projection with state averaging or double-CI corrections substantially reduces errors, particularly for Rydberg excitations. We further demonstrate that state averaging and spin projection provide complementary and essential benefits in strongly correlated regimes, as illustrated by the bond dissociation of hydrogen fluoride. oai:arXiv.org:2601.23270v1 physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by/4.0/ Takashi Tsuchimochi, Benjamin Mokhtar https://arxiv.org/abs/2601.23271 arXiv:2601.23271v1 Announce Type: new Abstract: Laser-driven capacitor-coil targets provide a compact platform for generating strong magnetic fields and are widely used in magnetized high-energy-density plasma experiments. In addition to magnetic-field generation, these targets also produce plasma in the coil region, which can influence the subject physical processes, interact with secondary targets or external plasmas in their applications. However, direct, time-resolved measurements of the plasma density surrounding the coil remain limited. Here, we report interferometric measurements of the plasma density evolution in laser-driven capacitor-coil targets irradiated by the University of Osaka LFEX laser. Two-dimensional electron density maps reveal two distinct plasma sources loading the coil region: plasma generated in the coil itself and plasma produced by laser ablation of the target plates. These results provide quantitative information on plasma loading and evolution in capacitor-coil targets and are directly relevant to the design and modeling of magnetized high-energy-density plasma experiments. oai:arXiv.org:2601.23271v1 physics.plasm-ph Mon, 02 Feb 2026 00:00:00 -0500 new http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Yang Zhang, Ryo Omura, Rinya Akematsu, King Fai Farley Law, Brandon K. Russell, Geoffrey Pomraning, Kian Orr, Kai Kimura, Muhammad Fauzan Syahbana, Yuga Karaki, Hiroki Matsubara, Ryuya Yamada, Jinyuan Dun, Ryunosuke Takizawa, Yasunobu Arikawa, Tatiana Pikuz, Yuji Fukuda, Lan Gao, Hantao Ji, Shinsuke Fujioka https://arxiv.org/abs/2601.23275 arXiv:2601.23275v1 Announce Type: new Abstract: Recently, it has been demonstrated theoretically that the interaction of two PsH atoms, each being a stable bound state of a hydrogen atom and a positronium atom, is attractive, leading to the formation of a molecular complex denoted as (PsH)2. However, the physical nature of this interaction has remained elusive. In the present study, we show that the stabilizing mechanism is entirely encoded in the quantum correlations between the two positrons and, to a lesser extent, in the electron-positron correlations. Notably, the interaction cannot be recovered at the mean-field (Hartree-Fock) level, nor by computational models that include only electron-electron correlation effects. Accordingly, the bond formed between PsH units, termed here a two-positron gluonic bond to emphasize its fundamentally distinct character from the two-positron covalent bonds present in pure antimatter molecules, emerges only when matter and antimatter particles form a common bound state. When classified within the framework of known bonding mechanisms, this gluonic bond falls into the category of stabilizing dispersion interactions, giving rise to a van der Waals complex. However, its remarkably large bond dissociation energy, compared with those of strongly bonded van der Waals complexes of similar size, reveals an anomalously strong interaction. For this reason, we propose that (PsH)2 is most appropriately described as a "super" van der Waals complex stabilized by a "super" van der Waals bond. oai:arXiv.org:2601.23275v1 physics.chem-ph physics.atm-clus Mon, 02 Feb 2026 00:00:00 -0500 new http://creativecommons.org/licenses/by-nc-nd/4.0/ Mohammad Goli, Dario Bressanini, Shant Shahbazian https://arxiv.org/abs/2601.20998 arXiv:2601.20998v1 Announce Type: cross Abstract: The stellar initial mass function (sIMF) is often treated as a stochastic probability distribution, yet such an interpretation implies Poisson noise that is inconsistent with growing observational evidence. In particular, the observed relation between the mass of the most massive star formed in an embedded cluster and the cluster's total stellar mass supports a deterministic sampling process, known as optimal sampling. However, the physical origin of optimal sampling has not been formally established in the literature. In this work, we show that the stellar mass distribution implied by optimal sampling emerges from applying the Maximum Entropy principle to the fragmentation of star-forming clumps, whose structure is set by density-dependent cooling in the optically thin regime. Here, the maximum entropy leads to unbiased distributions. By applying calculus of variations to minimize the entropy functional obtained assuming fragmentation, we recover the power-law form of the sIMF, and we show that any distribution deviating from the sIMF violates the Maximum Entropy principle. This work provides a first-principles foundation for the deterministic nature of star formation. Thus, the sIMF is the distribution resulting from a maximally unbiased system. oai:arXiv.org:2601.20998v1 astro-ph.GA astro-ph.SR physics.class-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Eda Gjergo, Zhiyu Zhang, Pavel Kroupa https://arxiv.org/abs/2601.21151 arXiv:2601.21151v1 Announce Type: cross Abstract: Recent machine-learning approaches to weather forecasting often employ a monolithic architecture, where distinct physical mechanisms (advection, transport), diffusion-like mixing, thermodynamic processes, and forcing are represented implicitly within a single large network. This representation is particularly problematic for advection, where long-range transport must be treated with expensive global interaction mechanisms or through deep, stacked convolutional layers. To mitigate this, we present PARADIS, a physics-inspired global weather prediction model that imposes inductive biases on network behavior through a functional decomposition into advection, diffusion, and reaction blocks acting on latent variables. We implement advection through a Neural Semi-Lagrangian operator that performs trajectory-based transport via differentiable interpolation on the sphere, enabling end-to-end learning of both the latent modes to be transported and their characteristic trajectories. Diffusion-like processes are modeled through depthwise-separable spatial mixing, while local source terms and vertical interactions are modeled via pointwise channel interactions, enabling operator-level physical structure. PARADIS provides state-of-the-art forecast skill at a fraction of the training cost. On ERA5-based benchmarks, the 1 degree PARADIS model, with a total training cost of less than a GPU month, meets or exceeds the performance of 0.25 degree traditional and machine-learning baselines, including the ECMWF HRES forecast and DeepMind's GraphCast. oai:arXiv.org:2601.21151v1 cs.LG physics.ao-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Carlos A. Pereira, St\'ephane Gaudreault, Valentin Dallerit, Christopher Subich, Shoyon Panday, Siqi Wei, Sasa Zhang, Siddharth Rout, Eldad Haber, Raymond J. Spiteri, David Millard, Emilia Diaconescu https://arxiv.org/abs/2601.22215 arXiv:2601.22215v1 Announce Type: cross Abstract: Determinations of the Hubble constant based on the local distance ladder remain in significant tension with early-Universe inferences from the cosmic microwave background. While this tension is often discussed in terms of new physics or unmodeled systematics, the role of the assumed priors on the model parameters has received comparatively little attention. Recently, Desmond et al. (2025) pointed out that the commonly adopted flat prior on distance moduli upweights smaller distances and systematically favors high inferred values of the Hubble constant. Motivated by this observation, we perform a comprehensive Bayesian recalibration of the distance ladder, applying physically motivated priors uniformly to all distances, including the Milky Way Cepheids, which are incorporated directly into the joint fit. Together with a conservative treatment of the Gaia EDR3 residual parallax offset, the Hubble constant shifts from $H_0 = 73.0 \pm 1.0 \, \mathrm{km/s/Mpc}$ to $H_0 = 70.6 \pm 1.0 \, \mathrm{km/s/Mpc}$, reducing the Hubble tension from $5 \, \sigma$ to $2 \, \sigma$. Our results show that the assumed priors -- often treated as innocuous defaults -- may play a central role in the Hubble tension. Because all local distance ladders rely on the calibration of distances, similar prior-driven effects are expected to arise across distance-ladder methods. oai:arXiv.org:2601.22215v1 astro-ph.CO astro-ph.GA physics.data-an Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Marcus H\"og{\aa}s, Edvard M\"ortsell https://arxiv.org/abs/2601.22283 arXiv:2601.22283v1 Announce Type: cross Abstract: We propose a protocol to measure impulses beyond the standard quantum limit. The protocol reduces noise in all three spatial dimensions and consists of squeezing a mechanical system's state via a series of jumps in the frequency of the harmonic potential. We quantify how decoherence in a realistic system of an optically levitated, dielectric nanoparticle limits the ultimate sensitivity. We predict that $\sim$10 dB of squeezing is achievable with current technology, enabling quantum-enhanced detection of weak impulses. oai:arXiv.org:2601.22283v1 quant-ph hep-ex physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Giacomo Marocco, David C. Moore, Daniel Carney https://arxiv.org/abs/2601.22298 arXiv:2601.22298v1 Announce Type: cross Abstract: Conditional generative models map input variables to complex, high-dimensional distributions, enabling realistic sample generation in a diverse set of domains. A critical challenge with these models is the absence of calibrated uncertainty, which undermines trust in individual outputs for high-stakes applications. To address this issue, we propose a systematic conformal prediction approach tailored to conditional generative models, leveraging density estimation on model-generated samples. We introduce a novel method called CP4Gen, which utilizes clustering-based density estimation to construct prediction sets that are less sensitive to outliers, more interpretable, and of lower structural complexity than existing methods. Extensive experiments on synthetic datasets and real-world applications, including climate emulation tasks, demonstrate that CP4Gen consistently achieves superior performance in terms of prediction set volume and structural simplicity. Our approach offers practitioners a powerful tool for uncertainty estimation associated with conditional generative models, particularly in scenarios demanding rigorous and interpretable prediction sets. oai:arXiv.org:2601.22298v1 cs.LG cs.AI physics.ao-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Qidong Yang, Qianyu Julie Zhu, Jonathan Giezendanner, Youssef Marzouk, Stephen Bates, Sherrie Wang https://arxiv.org/abs/2601.22316 arXiv:2601.22316v1 Announce Type: cross Abstract: Numerical analytical heat transfer models play a critical role in geothermal design and feasibility studies. Classical solutions, such as those proposed by Gringarten et al. 1975, rely on simplified assumptions and systematically overestimate thermal performance, which can lead to unrealistic engineering decisions. This study presents a generalized analytical model for enhanced geothermal systems that explicitly captures thermal interactions between fractures while preserving analytical tractability. The formulation is based on Green\'s functions and reproduces realistic thermal behavior under conditions representative of fractured geothermal reservoirs. The resulting solution is computationally efficient and sufficiently simple to be implemented directly in standard spreadsheets, without requiring Laplace space transformations or numerical inversion algorithms. The model is validated against numerical simulations performed using CMG STARS and Volsung software, showing close agreement in temperature evolution, including the effects of interacting fractures. Compared with classical analytical approaches, the proposed model corrects optimistic bias and provides more reliable predictions of production temperature and energy recovery. These results have direct implications for geothermal feasibility studies, well design, and power forecasting, effectively bridging the gap between legacy analytical models and numerical or commercial engineering tools. Building on the analytical framework originally introduced by Gringarten et al. 1975, the proposed formulation generalizes classical heat transfer solutions to account for fracture interaction while retaining analytical simplicity and practical applicability. oai:arXiv.org:2601.22316v1 math.AP physics.geo-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Nelson Barros-Galvis or Christine Ehlig-Economides or Cristi Darley Guevara https://arxiv.org/abs/2601.22321 arXiv:2601.22321v1 Announce Type: cross Abstract: We examine the statistics of Alfvenic deflections in both sub-Alfvenic and super-Alfvenic solar wind with particular focus on a common parameter that underlies the definition of switchbacks: the magnetic deflection angle. Our findings are in general agreement with earlier studies that suggest magnetic deflection angles > 90 degrees are very unlikely to occur in sub-Alfvenic regimes. We find that their upper limit exhibits an identifiable trend with the Alfven Mach number Ma, suggesting that gradual steepening of Alfvenic deflections with increasing Ma is a plausible mechanism controlling deflection angles in the young solar wind. Further analysis reveals that large velocity fluctuations tend to be important in the largest sub-Alfvenic magnetic deflections with increasing contributions from the parallel component very close to Ma = 1, while virtually no magnetic deflections in the super-Alfvenic regime exhibit such large velocity perturbations. We also determine the local ratio of radial Poynting flux SR to kinetic energy flux KR and find that large sub-Alfvenic deflection angles tend to be dominated by SR, while super-Alfvenic deflections are eventually dominated by the KR associated with the radial solar wind flow. Our results show that within the vicinity of the Alfven surface (where Ma = 1), there is a critical region of parameter space within which velocity deflections approach the Alfven velocity and KR/SR is close to unity. We refer to this region (where | log10(Ma)| < 0.2) as the conversion layer. The conversion layer may play a significant role in the evolution of magnetic defections by providing the medium for converting magnetic energy to particle energy and likely driving the formation of magnetic switchbacks in super-Alfvenic solar wind. oai:arXiv.org:2601.22321v1 astro-ph.SR physics.space-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Dominic Payne, Mojtaba Akhavan-Tafti, Joshua Goodwill, Samuel Badman, Riddhi Bandyopadhyay, Subash Adhikari, William Matthaeus, Gary Zank, Chen Shi, Michael Stevens, Roberto Livi, Yeimy Rivera, Kristoff Paulson https://arxiv.org/abs/2601.22333 arXiv:2601.22333v1 Announce Type: cross Abstract: In this paper we have revisited the energy-momentum squared gravity theory, by taking into account the second derivative of the matter Lagrangian with respect to the metric, encapsulating relations originated from thermodynamical grounds. After obtaining the scalar tensor representation of the energy-momentum squared gravity with the new corrections, we have analyzed the physical implications by relying on the linear stability theory. The results show that the current cosmological system is compatible with the expansion of the Universe for some specific matter Lagrangians, explaining the emergence of matter domination era, approaching the late time accelerated expansion era close to the de-Sitter phenomenology. oai:arXiv.org:2601.22333v1 gr-qc hep-th physics.comp-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Mihai Marciu https://arxiv.org/abs/2601.22396 arXiv:2601.22396v1 Announce Type: cross Abstract: Despite the growing utility of Large Language Models (LLMs) for simulating human behavior, the extent to which these synthetic personas accurately reflect world and moral value systems across different cultural conditionings remains uncertain. This paper investigates the alignment of synthetic, culturally-grounded personas with established frameworks, specifically the World Values Survey (WVS), the Inglehart-Welzel Cultural Map, and Moral Foundations Theory. We conceptualize and produce LLM-generated personas based on a set of interpretable WVS-derived variables, and we examine the generated personas through three complementary lenses: positioning on the Inglehart-Welzel map, which unveils their interpretation reflecting stable differences across cultural conditionings; demographic-level consistency with the World Values Survey, where response distributions broadly track human group patterns; and moral profiles derived from a Moral Foundations questionnaire, which we analyze through a culture-to-morality mapping to characterize how moral responses vary across different cultural configurations. Our approach of culturally-grounded persona generation and analysis enables evaluation of cross-cultural structure and moral variation. oai:arXiv.org:2601.22396v1 cs.CL cs.AI cs.CY cs.HC physics.soc-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Candida M. Greco, Lucio La Cava, Andrea Tagarelli https://arxiv.org/abs/2601.22417 arXiv:2601.22417v1 Announce Type: cross Abstract: The low-energy nuclear isomeric state of \textsuperscript{229m}Th provides a unique bridge between nuclear and atomic physics, enabling applications such as nuclear clocks and precision metrology. However, efficient and controllable production of \textsuperscript{229m}Th remains a major experimental challenge. We propose an efficient scheme to produce the $^{229\mathrm{m}}$Th in storage rings (SRs) and electron beam ion traps (EBITs), using a cascade decay pathway. Highly charged ions are excited to higher nuclear states via nuclear excitation by inelastic electron scattering (NEIES) and nuclear excitation by electron capture (NEEC), followed by radiative or internal conversion cascades that populate the isomer. Our calculations demonstrate that, under typical SRs and EBITs conditions, optimized indirect excitation pathways significantly enhance \textsuperscript{229m}Th production rate. In particular, NEIES can provide an enhancement of up to four orders of magnitude through cascade de-excitation at high energies, while NEEC can contribute an additional enhancement of up to several tens of times. Such a significant increase in the \textsuperscript{229m}Th yield rate would facilitate its application in various nuclear photonics fields, especially in the development of atomic nuclear clocks. oai:arXiv.org:2601.22417v1 nucl-th physics.atom-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Yumiao Wang, Yi Yang, Yixin Li, Ding Yue, Kai Zhao, Youjing Wang, Changbo Fu, Yugang Ma https://arxiv.org/abs/2601.22460 arXiv:2601.22460v1 Announce Type: cross Abstract: Understanding water-metal interactions is central to disciplines spanning catalysis, electrochemistry, and atmospheric science. Monolayer ice phases are well established on hydrophilic surfaces, where strong water-substrate interactions stabilize ordered hydrogen-bond networks. In contrast, their formation on hydrophobic metals has been deemed ther-modynamically unfavourable, with water typically assembling into amorphous films, three-dimensional crystallites, or interlocked bilayer ice. Here, we demonstrate the synthesis of a monolayer ice phase on the hydrophobic Au(111) surface using a low-energy-electron-assisted growth method. Combined experimental characterizations including low-energy electron diffraction, angle-resolved photoemission spectroscopy, and X-ray photoelectron spectroscopy, complemented by first-principles calculations, prove that the monolayer ice phase composes of intact water molecules. This approach provides a generalizable strategy for stabilizing ordered two-dimensional ice on inert substrates and offers new insight into the interplay between water and low-energy electrons at hydrophobic interfaces. oai:arXiv.org:2601.22460v1 cond-mat.mtrl-sci physics.chem-ph physics.comp-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ 10.1021/jacs.5c17012 J. Am. Chem. Soc. (2026) Qiaoxiao Zhao, Meiling Xu, Dong Li, Zhicheng Gao, Yudian Zhou, Wenbo Liu, Jingyan Chen, Peng Cheng, Sheng Meng, Kehui Wu, Yanchao Wang, Lan Chen, Baojie Feng https://arxiv.org/abs/2601.22559 arXiv:2601.22559v1 Announce Type: cross Abstract: This work shows that the recently discovered operator contraction identity for solving the discreet Path Integral of the harmonic oscillator can be applied equally to fermions in any dimension. This then yields an exactly solvable model for studying the sign problem where the Path Integral Monte Carlo energy at any time step for any number of fermions is known analytically, or can be computed numerically. It is found that repulsive/attractive pairwise interaction shifts the sign problem to larger/smaller imaginary time, but does not make it more severe than the non-interacting case. More surprisingly, for closed-shell number of fermions, the sign problem goes away at large imaginary time. Fourth-order and newly found variable-bead algorithms are used to compute ground state energies of quantum dots with up to 110 electrons and compared to results obtained by modern neural networks. oai:arXiv.org:2601.22559v1 cond-mat.str-el physics.comp-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Siu A. Chin https://arxiv.org/abs/2601.22640 arXiv:2601.22640v1 Announce Type: cross Abstract: Conventionally, dispersion forces mediated by quantum vacuum fluctuations are known to exhibit universal distance scalings, with retardation typically leading to a faster decay of the interaction. Here, we show that this expectation fails for intrinsically discrete systems. Using the microscopic scattering approach, we study the Casimir-Polder interaction between two atomic arrays, and uncover an unconventional distance scaling in which the force crosses over from a faster decay at short separations to a slower decay in the retarded regime. This behavior originates from the discrete lattice structure and can be consistently understood within the scattering picture. Extending our analysis to Rydberg atomic arrays, we predict an even stronger deviation from conventional scaling and propose an experimentally feasible scheme for direct measurement. Our results provide a new platform for exploring dispersion forces beyond the continuum limit. oai:arXiv.org:2601.22640v1 quant-ph physics.atom-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Qihang Ye, Qihang Ye, Bing Miao, Lei Ying https://arxiv.org/abs/2601.22798 arXiv:2601.22798v1 Announce Type: cross Abstract: We develop a quantum theory for the scattering of squeezed coherent light by a dissipative dielectric slab. Using the Green-function quantization approach, we derive the transformation of the field quadratures and show how dispersion, absorption, and multiple reflections distort the incident squeezing. We find that the slab can selectively attenuate or amplify quadrature noise depending on the slab parameters and provide expressions for the output power spectra. oai:arXiv.org:2601.22798v1 quant-ph physics.optics Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ G. Pooseh https://arxiv.org/abs/2601.22807 arXiv:2601.22807v1 Announce Type: cross Abstract: This article presents the observations of the extreme ground-level enhancement (GLE #77) of Solar Cycle 25 that occurred on 11 November 2025, using ground-based NaI(Tl) gamma-ray detectors deployed at Arctic and Antarctic stations, together with neutron monitor data and particle measurements from the GOES-18 satellite. The event was associated with an intense X-class solar flare and a strong solar energetic proton event. This paper reports the first ground-based detection of a GLE using gamma-ray detectors operating simultaneously in both polar regions, which are concurrent with increases in neutron monitor counts. Thus highlights the capability of polar gamma-ray detectors to complement traditional neutron monitor observations during extreme solar proton events. A detailed analysis revealed distinct prompt and delayed responses during the event evolution. Interestingly, the signature of the prompt peak of GLE#77 (at 10:38 UT) was observed up to high-rigidity neutron monitors (low latitudes). However, the delayed peak (at 13:08 UT) was not seen at the stations with rigidity > 6 GV. The timing of the prompt and delayed peaks coincided with the proton flux peaks observed by the GOES-18 satellite at energies > 150 MeV and 12-99 MeV, respectively. It is observed that the GLE amplitude has a strong dependence on geomagnetic cutoff rigidity and has a weak solar zenith angle dependence. oai:arXiv.org:2601.22807v1 astro-ph.SR astro-ph.HE physics.space-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Pranali Thakur, Geeta Vichare, Selvaraj Chelliah https://arxiv.org/abs/2601.22824 arXiv:2601.22824v1 Announce Type: cross Abstract: Methyl cyanide, CH$_3$CN, is present in diverse regions in space, in particular in the warm parts of star-forming regions where it is a common molecule. Rotational transitions of $^{13}$CH$_3$CN and CH$_3$$^{13}$CN in their $v_8 = 1$ lowest excited vibrational states ($E_{\rm vib} \approx 520$ K) are quite prominent in Sagittarius B2(N). In order to be able to search for transitions of the next higher vibrational state $v_8 = 2$, we recorded spectra of samples enriched in $^{13}$CH$_3$CN and CH$_3$$^{13}$CN up to $v_8 = 2$ in the 35 to 1091~GHz region and reinvestigated existing spectra of CH$_3$CN in its natural isotopic composition between 1085 and 1200 GHz. Perturbations caused by near-degeneracies in $K = 4$ of $v_8 = 2^0$ and $K = 2$ of $v_8 = 2^{-2}$ yielded accurate information on the energy spacing of 22.93 and 21.79 cm$^{-1}$ between the $l$-components of $^{13}$CH$_3$CN and CH$_3$$^{13}$CN, respectively. Fermi-type interaction between $K = 13$ and 14 of $v_8 = 1^{-1}$ and $v_8 = 2^{+2}$ probe the energy differences between the two states of both isotopomers. In addition, a $\Delta K \pm2$, $\Delta l \mp1$ interaction between the ground vibrational state of $^{13}$CH$_3$CN and $v_8 = 1^{+1}$ provides information on their energy spacing. Furthermore, we obtained improved or extended ground state rotational transition frequencies of $^{13}$CH$_3$$^{13}$CN and extensive data for $^{13}$CH$_3$C$^{15}$N and CH$_3$$^{13}$C$^{15}$N. Finally, we report the results of our search for transitions of $^{13}$CH$_3$CN and CH$_3$$^{13}$CN in their $v_8 = 2$ states toward Sagittarius B2(N). oai:arXiv.org:2601.22824v1 astro-ph.GA astro-ph.IM astro-ph.SR physics.ao-ph physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ 10.1021/acsearthspace-chem.5c00353 Holger S. P. M\"uller, Arnaud Belloche, Frank Lewen, Stephan Schlemmer https://arxiv.org/abs/2601.22872 arXiv:2601.22872v1 Announce Type: cross Abstract: Small polycyclic aromatic hydrocarbons and somewhat larger cyano derivatives were detected in the cold dark cloud TMC-1 recently. Their formation from smaller hydrocarbons is not well understood, in part because abundances of many species are not known. Methylallene, CH$_3$CHCCH$_2$, may be one of the building blocks, but its rotational spectrum was characterized only to a very limited extent. We recorded rotational transitions in the 36$-$501 GHz region to extend the existing line list of methylallene and thus enable searches for the molecule in space. Quantum-chemical calculations were carried out to evaluate initial spectroscopic parameters. We obtained transition frequencies with $J \le 61$ and $K_a \le 21$ and resolved the internal rotation splitting of the CH$_3$ group at least partially. As a result, a full set of distortion parameters up to sixth order along with two octic ones were determined, as well as parameters describing the internal rotation of the methyl group. The spectroscopic parameters are accurate enough to identify methylallene up to 720 GHz, sufficient for searches even in the warm interstellar medium. oai:arXiv.org:2601.22872v1 astro-ph.GA astro-ph.IM astro-ph.SR physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ 10.1080/00268976.2026.2625421 Holger S. P. M\"uller, Frank Lewen, Jean-Claude Guillemin, Stephan Schlemmer https://arxiv.org/abs/2601.22874 arXiv:2601.22874v1 Announce Type: cross Abstract: Drawing inspiration from swarm intelligence, we show that short-range attractive interactions between thermally driven Brownian quasiparticles enable energy-efficient optimization. As quasiparticles can be generated directly within a material, the swarm size can be adjusted with minimal energy overhead. Using an optimization task defined by a spatially varying temperature landscape, we quantitatively show that interacting swarms reliably identify global optima and significantly outperform non-interacting searchers within a well-defined regime of interaction strength and swarm size. This improvement arises from emergent cooperative behavior, where local interactions guide the swarm toward high-quality solutions without central coordination. To link our physical model to experimental realizations, we coarse-grain the quasiparticle dynamics onto a sensor lattice and generate trajectories emulating particle-tracking measurements. We further show that the interacting swarm adapts robustly to landscapes that evolve over time. These findings establish interacting Brownian quasiparticles as a physical platform for scalable and energy-efficient unconventional computing. oai:arXiv.org:2601.22874v1 cond-mat.stat-mech cond-mat.dis-nn nlin.AO physics.comp-ph physics.data-an Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Alessandro Pignedoli, Atreya Majumdar, Karin Everschor-Sitte https://arxiv.org/abs/2601.22967 arXiv:2601.22967v1 Announce Type: cross Abstract: Microbes constantly interact with their environment by depleting and transforming food sources. Theoretical studies have mainly focused on Lotka-Volterra models, which do not account for food source dynamics. In contrast, consumer-resource models, which consider food source dynamics, are less explored. In particular, it is still unclear what physical mechanisms control oscillatory dynamics at a single population level, a phenomenon which can only be captured by a consumer-resource model. Here, we present a minimalistic consumer-resource model of a single microbial population with growth and death dynamics, consuming a continuously replenishing substrate. Our model reveals that decaying oscillations can occur around steady state if and only if the timescale of microbial adaptation to food supply changes exceeds the death timescale. This interplay of timescales allows us to rationalize the emergence of oscillatory dynamics when adding various biophysical ingredients to the model. We find that microbial necromass recycling or complementary use of multiple food sources reduces the parameter range for oscillations and increases the decay rate of oscillations. Requiring multiple simultaneous food sources has the opposite effect. Essentially, facilitating growth reduces the likelihood of oscillations around a fixed point. We further demonstrate that such damped oscillatory behavior is correlated with persistent oscillatory behavior in a noisy environment. We hope our work will motivate further investigations of consumer-resource models to improve descriptions of environments where food source distributions vary in space and time. oai:arXiv.org:2601.22967v1 q-bio.PE cond-mat.soft physics.bio-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by-nc-nd/4.0/ Benedetta Ciarmoli, Sophie Marbach https://arxiv.org/abs/2601.22973 arXiv:2601.22973v1 Announce Type: cross Abstract: Optical absorption and reabsorption of light emitted from active regions in nitride laser diodes (LDs) have been shown to reduce the light extraction efficiency of these devices. It was proven that the presence of Si and Mg may considerably increase the optical absorption. This effect is much stronger in the high-energy (short-wavelength) range of the spectrum. The absorption increase is directly related to the ionization of the Si donor and Mg acceptor levels, which are controlled by the electron and hole quasi-Fermi levels. It is shown that the absorption may be increased because of the higher ionization of Mg caused by the compensation in the p-type region and the high ionization of Si in the n-type region. It was explained theoretically why optical efficiency is increased by removal of doping in waveguides. It was also shown that good material quality leads to a low absorption level, especially in the Mg-doped p-type part of the device. oai:arXiv.org:2601.22973v1 cond-mat.mtrl-sci physics.optics Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Konrad Sakowski, Cyprian Sobczak, Pawel Strak, Izabella Grzegory, Robert Czernecki, Jacek Piechota, Agata Kaminska, Stanislaw Krukowski https://arxiv.org/abs/2601.23002 arXiv:2601.23002v1 Announce Type: cross Abstract: Recent advances in X-ray free-electron laser diagnostics have enabled direct probing of the electronic structure under extreme pressures and temperatures, such as those encountered in stellar interiors and inertial confinement fusion experiments, challenging theoretical models for interpreting experimental data. Kohn-Sham density functional theory (KSDFT) has been successfully applied to analyze experimental X-ray scattering measurements, but its high computational cost renders routine application impractical. Orbital-free DFT (OFDFT) is a substantially more efficient alternative, with computational cost scaling linearly with system size and a weak temperature dependence, yet it often lacks the accuracy required for electronic structure description. Overcoming this limitation, we present a non-empirical Kohn-Sham-assisted orbital-free density functional framework for calculations at extreme conditions, which enables efficient OFDFT simulations with KSDFT-level accuracy for electron densities, electron-ion structure factors, and equations of state across a broad range of conditions. Benchmark comparisons with quantum Monte Carlo data for dense hydrogen and validation against Rayleigh weight measurements of hot dense beryllium demonstrate the reliability of the framework and speedups of up to several hundred times compared with KSDFT. We further show that even at temperatures on the order of 100 eV, quantum non-locality remains essential for correctly describing the electronic structure of dense hydrogen. oai:arXiv.org:2601.23002v1 cond-mat.mtrl-sci physics.plasm-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Cheng Ma, Qiang Xu, Zhenhao Zhang, Ke Wang, Ying Sun, Wenhui Mi, Zhandos A. Moldabekov, Tobias Dornheim, Jan Vorberger, Sebastian Schwalbe, Xuecheng Shao https://arxiv.org/abs/2601.23028 arXiv:2601.23028v1 Announce Type: cross Abstract: We demonstrate high-fidelity, tunable, and ultrafine-resolution on-chip frequency beamsplitters using a quantum frequency processor based on an integrated pulse shaper with six spectral channels. Near-ideal Hadamard gate performance is achieved, with fidelity F > 0.9995 and modified success probability P > 0.9621 maintained across frequency spacings from 2-5 GHz and down to as few as four spectral pulse shaper channels. The system's support of frequency spacings as narrow as 2 GHz significantly surpasses prior bulk demonstrations and enables arbitrary splitting ratios via spectral phase or modulation index control. These results establish a scalable and resource-efficient platform for integrated frequency-bin quantum photonics, opening new directions in quantum information processing, including densely parallel single-qubit operations and multidimensional gate implementations. oai:arXiv.org:2601.23028v1 quant-ph physics.optics Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Chen-You Su, Kaiyi Wu, Lucas M. Cohen, Saleha Fatema, Navin B. Lingaraju, Hsuan-Hao Lu, Andrew M. Weiner, Joseph M. Lukens, Jason D. McKinney https://arxiv.org/abs/2601.23044 arXiv:2601.23044v1 Announce Type: cross Abstract: Although photons are robust, room-temperature carriers well suited to quantum machine learning, the absence of photon-photon interactions hinder the realization of memory functionalities that are critical for capturing long-range context. Recently, measurement-based implementations of photonic quantum memristors (PQMRs) have enabled tunable non-Markovian responses. However, their memory remains confined to local elements, in contrast to biological or artificial networks where memory is shared across the system. Here, we propose a scalable PQMR network that enables measurement-based memory sharing. Each memristive node updates its internal state using the history of its own and neighbouring quantum states, thereby realizing distributed memory. By modelling each node as a photonic quantum memtransistor, we demonstrate pronounced enhancements in both classical and quantum hysteresis at the device level, as well as enhanced network-level quantum hysteresis. Implemented as a quantum reservoir, the architecture achieves improved Fashion-MNIST classification accuracy and confidence via increased data separability. Our approach paves the way toward high-capacity quantum machine learning using memristive devices compatible with linear-optical quantum computing. oai:arXiv.org:2601.23044v1 quant-ph physics.optics Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Chaehyeon Lim, Hyungchul Park, Beomjoon Chae, Jeonghun Kwak, Soo-Yeon Lee, Namkyoo Park, Sunkyu Yu https://arxiv.org/abs/2601.23047 arXiv:2601.23047v1 Announce Type: cross Abstract: The discovery of the non-zero value of $\theta_{13}$ has opened an exciting opportunity to probe the Earth's matter effects in three-flavor oscillations of atmospheric neutrinos. These matter effects depend on both neutrino energy and the electron density distributions encountered during their propagation through Earth. In this contribution, we present preliminary sensitivities from the DeepCore detector, a densely instrumented sub-array of the IceCube neutrino observatory at the South Pole, demonstrating its ability to observe these matter effects in atmospheric neutrino oscillations. Using simulated data equivalent to 9.3 years of observations at IceCube DeepCore, we show the sensitivity of the DeepCore to reject the vacuum oscillation hypothesis and align with the Preliminary Reference Earth Model. Additionally, we present the expected improvement in sensitivity for rejecting the vacuum oscillations using the upcoming IceCube Upgrade, a low-energy extension of the IceCube detector. oai:arXiv.org:2601.23047v1 hep-ph hep-ex physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ 10.1007/978-981-96-4986-0_76 Springer Proc.Phys. 322 (2026) 463-466 Anuj Kumar Upadhyay (For the IceCube Collaboration) https://arxiv.org/abs/2601.23056 arXiv:2601.23056v1 Announce Type: cross Abstract: La-Fe-Si-based alloys are among the most application-ready magnetocaloric materials for room-temperature magnetic refrigeration. Powder metallurgy methods have been previously demonstrated to successfully produce structures with sub-mm features for magnetic refrigerators in a scalable method. In this work, we explore the rotating magnetocaloric effect (RMCE) present in a 0.27 mm thin plate of sintered and hydrogenated La(Fe,Mn,Si)$_{13}$. The high aspect ratio ($\sim$50) of the thin plate leads to an anisotropic magnetocaloric effect (MCE), dependent on the relative orientation of the external magnetic field, and an RMCE when the external field is rotated. We find a maximum rotating adiabatic temperature change ($\Delta T_{ad}^{rot}$) of 1.17 K with the rotation of a 1 T magnetic field and 1.12 K when rotating a 0.6 T magnetic field, a reduction of only 4% for a 40% reduction in applied field strength. Magnetostatic computations revealed a considerable rotating isothermal entropy change ($\Delta S_{iso}^{rot}$), comparable to the conventional MCE of Gd for similar fields, reaching 3.97 J K$^{-1}$ kg$^{-1}$ for 1 T and 3.68 J K$^{-1}$ kg$^{-1}$ for 0.6 T (7% reduction), highlighting La-Fe-Mn-Si alloys as high potential candidates for a magnetic refrigerator based on the RMCE utilizing relatively low external magnetic field amplitudes, such as 0.6 T. oai:arXiv.org:2601.23056v1 cond-mat.mtrl-sci physics.app-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Rafael Almeida, Tom\'as Ventura, Ricardo Moura Costa Pinto, Jo\~ao Oliveira Silva, Konrad Loewe, Rodrigo Kiefe, Jo\~ao Sequeira Amaral, Jo\~ao Pedro Ara\'ujo, Jo\~ao Horta Belo https://arxiv.org/abs/2601.23057 arXiv:2601.23057v1 Announce Type: cross Abstract: The IceCube detector, using its densely instrumented center, called DeepCore, can detect multi-GeV atmospheric neutrinos. The oscillation pattern of neutrinos is altered due to interactions with ambient electrons as they pass through Earth. The changes in these patterns are influenced by the amount of matter and its specific arrangement. As neutrinos propagate, they retain information about the densities they encounter. Our study demonstrates that IceCube DeepCore can utilize the Earth's matter effects to distinguish between a homogeneous matter density profile and a layered structure density profile of Earth. In this contribution, we present that IceCube DeepCore data equivalent to 9.3 years of observation can reject the homogeneous matter density profile with a confidence level of 1.4$\sigma$. oai:arXiv.org:2601.23057v1 hep-ph hep-ex physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ 10.1007/978-981-96-4986-0_73 Springer Proc.Phys. 322 (2026) 447-450 J Krishnamoorthi (For the IceCube Collaboration) https://arxiv.org/abs/2601.23079 arXiv:2601.23079v1 Announce Type: cross Abstract: Earth's mass and internal structure have been primarily studied through gravitational and seismic methods. Neutrinos, however, offer an independent way to explore Earth's interior via matter effects in neutrino oscillations that depend on the electron distribution inside Earth, and hence its matter density. Our study uses atmospheric neutrinos at DeepCore, a densely instrumented sub-detector of the IceCube Neutrino Observatory, to estimate Earth's mass and layer densities. We also assess how the upcoming IceCube Upgrade, with denser instrumentation, could improve these measurements. oai:arXiv.org:2601.23079v1 hep-ph hep-ex physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ 10.1007/978-981-96-4986-0_68 Springer Proc.Phys. 322 (2026) 417-421 Sharmistha Chattopadhyay (For the IceCube Collaboration) https://arxiv.org/abs/2601.23093 arXiv:2601.23093v1 Announce Type: cross Abstract: The IceCube neutrino observatory consists of an array of Digital Optical Modules (DOMs) instrumenting one cubic-kilometer of deep glacial ice at the South Pole. DeepCore, a densely-spaced sub-array of DOMs at the bottom central region of IceCube, enables the detection of atmospheric neutrinos with an energy threshold in the GeV range. The high statistics data of DeepCore provides a unique opportunity to perform neutrino oscillation studies as well as explore various sub-leading Beyond the Standard Model (BSM) physics signatures. We consider a well-motivated minimal extension of the Standard Model by an additional anomaly-free, gauged lepton-number symmetry, such as $L_e - L_\mu$ or $L_e - L_\tau$. These symmetries give rise to flavor-dependent long-range interaction mediated through a very light neutral gauge boson. In this contribution, we present the sensitivity of the IceCube DeepCore detector to search for this flavor-dependent long-range interaction potential with a runtime of 9.3 years. oai:arXiv.org:2601.23093v1 hep-ph hep-ex physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ 10.1007/978-981-96-4986-0_71 Springer Proc.Phys. 322 (2026) 435-439 Gopal Garg (For the IceCube Collaboration) https://arxiv.org/abs/2601.23123 arXiv:2601.23123v1 Announce Type: cross Abstract: Magnon-photon hybrid systems consisting of a three-dimensional electromagnetic resonator and a bulk magnetic insulator constitute the standard experimental platform in cavity magnonics. Here, we demonstrate a modular loop-gap resonator design optimized to couple with thin films of magnetic insulators. We achieve the strong-coupling regime using this loop-gap resonator coupled to a 75~nm-thick epitaxial film of yttrium iron garnet at room temperature. We further show how to perform field-differential spectroscopy of the hybrid magnon-photon system, which eliminates the unwanted signal from other loop-gap modes uncoupled to the magnetic film. In addition to the uniform ferromagnetic resonance mode, the loop-gap resonator enables an hybridization with the standing spin-wave modes forming across the thickness of the film. Our approach unlocks the use of epitaxial films and multilayers of magnetic insulators to tune the magnon band structure in cavity magnonics experiments. oai:arXiv.org:2601.23123v1 cond-mat.mes-hall physics.app-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://creativecommons.org/licenses/by/4.0/ Francesca Zanichelli, Davit Petrosyan, Hanchen Wang, Patrick Helbingk, Richard Schlitz, Pietro Gambardella, William Legrand https://arxiv.org/abs/2601.23205 arXiv:2601.23205v1 Announce Type: cross Abstract: There are two well documented models of gamma ray bursts (GRBs), the "Standard' model and the "Cannonball" model. They have often been reviewed [1] and sometimes compared [2]. Here, to avoid understandable biases, I show below the results of an experiment: letting an AI compare the data and the two models. All of what follows (but two references, two footnotes and the next sentence) is the result of asking Perplexity.ai to perform this confrontational task. It should be easy for an impartial reader to reach very clear conclusions. oai:arXiv.org:2601.23205v1 astro-ph.HE physics.soc-ph Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ A. De R\'ujula https://arxiv.org/abs/2601.23263 arXiv:2601.23263v1 Announce Type: cross Abstract: We study theoretically how high-gain effects affect the measurement outcome of visible signal spectra in undetected photon measurement schemes. We consider two interferometric configurations: firstly, the SU(1,1) interferometer where the idler incurs loss and additional dispersion in between two identical, lossless, squeezers; secondly, the induced coherence interferometer where the idler incurs loss and additional dispersion in between two identical, lossless, squeezers and where the second squeezer is seeded by the idler and a vacuum ancilla mode. Furthermore, we consider a distributed loss configuration where the idler incurs loss as it propagates in the nonlinear medium. Motivated by experimental evidence and due to the fact that broadband sources are ideal for these measurement schemes, we use the dispersive data of a third-order dispersion engineered integrated waveguide parametric down conversion (PDC) source presented in New Journal of Physics 26, 123025 (2024) to model the PDC spectra in the three configurations. For each configuration we consider the case of idler-only (i) absorption, (ii) additional dispersion, and (iii) the combined effects. We obtain results which outline the strength and weaknesses of the different configurations at different operation points. oai:arXiv.org:2601.23263v1 quant-ph physics.optics Mon, 02 Feb 2026 00:00:00 -0500 cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Martin Houde, Franz Roeder, Christine Silberhorn, Benjamin Brecht, Nicol\'as Quesada https://arxiv.org/abs/2402.14626 arXiv:2402.14626v2 Announce Type: replace Abstract: We develop a dissipation-based framework for earthquake rupture on homogeneous faults that explicitly separates the onset of unstable slip from the conditions required for self-sustained rupture propagation. This distinction explains the coexistence of self-arresting earthquakes and run-away ruptures (subshear and supershear events) observed in numerical simulations and empirical studies. We identify two distinct characteristic fault sizes: a nucleation radius controlling the instability of slip, and in general a larger propagation radius controlling whether an unstable rupture can be energetically sustained. Ruptures initiated above the nucleation scale but below the propagation scale spontaneously arrest. We further derive the Gutenberg-Richter law for self-arresting earthquakes by linking rupture physics to the fractal geometry of faulting. Finally, we interpret run-away ruptures as extreme events generated by an amplifying mechanism, consistent with the dragon-king concept. These results provide a unified physical basis for earthquake initiation, arrest, and seismicity statistics. oai:arXiv.org:2402.14626v2 physics.geo-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Didier Sornette, Xueting Wei, Xiaofei Chen https://arxiv.org/abs/2407.19601 arXiv:2407.19601v2 Announce Type: replace Abstract: We show that Purcell effect can lead to a substantial enhancement in the maximum cooling power for solid-state laser cooling. We numerically demonstrate such enhancement in a patterned slot-waveguide structure using ytterbium-doped silica as the active material. The enhancement arises primarily from the increase of saturation power density and the escape efficiency, and can persist in spite of the presence of parasitic absorption in the structure surrounding the active material. Our results point to a new opportunity in photonic structure design for optical refrigeration. oai:arXiv.org:2407.19601v2 physics.optics physics.app-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ 10.1103/8hmg-w9tx Mohammed Benzaouia, Shanhui Fan https://arxiv.org/abs/2410.07744 arXiv:2410.07744v3 Announce Type: replace Abstract: Quantum adiabatic optimization has long been expected to outperform classical methods in solving NP-type problems. While this has been proven in certain experiments, its main applications still reside in academic problems where the size of the system to be solved would not represent an obstacle to any modern desktop computer. Here we develop a systematic procedure to find the global optima of the modularity function to discover community structure in complex networks solely relying on pure annealers rather than hybrid solutions. We bypass the one-hot encoding constraints by hierarchically and recursively encoding binary instances of the problem that can be solved without the need to guess the exact penalties for the Lagrange multipliers. We study the variability, and robustness of the annealing process as a function of network size, directness of connections, topology, and the resolution of the communities. We show how our approach produces meaningful and at least equally optimal solutions to state-of-the-art community detection algorithms while maintaining tractable computing times. Lastly, due to its recursive nature, the annealing process returns intermediate subdivisions thus offering interpretable rather than black-box solutions. These \textit{dendrograms} can be used to unveil normal and pathological hidden hierarchies in brain networks hence opening the door to clinical workflows. Overall, this represents a first step towards an applicable practice-oriented usage of pure quantum annealing potentially bridging two segregated communities in modern science and engineering; that of network science and quantum computing. oai:arXiv.org:2410.07744v3 physics.soc-ph cs.SI math.CO Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Joan Falc\'o-Roget, Kacper Jurek, Barbara Wojtarowicz, Karol Capa{\l}a, Katarzyna Rycerz https://arxiv.org/abs/2501.13521 arXiv:2501.13521v2 Announce Type: replace Abstract: We identify troubling cases of so-called `permanent underdetermination' in both dark energy and inflationary cosmology. We bring to bear (a) a taxonomy of possible responses to underdetermination, and (b) an understanding of both dark energy and inflationary cosmology from an effective field theory point of view. We argue that, under certain conditions, there are viable responses which can arguably alleviate at least some of the concerns about underdetermination in the dark energy and inflationary sectors. However, the epistemic threat of permanent underdetermination remains a significant challenge. oai:arXiv.org:2501.13521v2 physics.hist-ph gr-qc Mon, 02 Feb 2026 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ William J. Wolf, James Read https://arxiv.org/abs/2503.09415 arXiv:2503.09415v2 Announce Type: replace Abstract: SPARKX is an open-source Python package developed to analyze simulation data from heavy-ion collision experiments. By offering a comprehensive suite of tools, SPARKX simplifies data analysis workflows, supports multiple formats such as OSCAR2013, and integrates seamlessly with SMASH and JETSCAPE/X-SCAPE. This paper describes SPARKX's architecture, features, and applications and demonstrates its effectiveness through detailed examples and performance benchmarks. SPARKX enhances productivity and precision in relativistic kinematics studies. oai:arXiv.org:2503.09415v2 physics.data-an hep-ph nucl-th Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ 10.1140/epjc/s10052-025-15258-8 Eur. Phys. J. C 86 (2026) 1, 27 Nils Sass, Hendrik Roch, Niklas G\"otz, Renata Krupczak, Carl B. Rosenkvist https://arxiv.org/abs/2506.21720 arXiv:2506.21720v2 Announce Type: replace Abstract: Simulating showers of particles in highly-granular calorimeters is a key frontier in the application of machine learning to particle physics. Achieving high accuracy and speed with generative machine learning models can enable them to augment traditional simulations and alleviate a major computing constraint. Recent developments have shown how diffusion based generative shower simulation approaches that do not rely on a fixed structure, but instead generate geometry-independent point clouds, are very efficient. We present a transformer-based extension to previous architectures which were developed for simulating electromagnetic showers in the highly granular electromagnetic calorimeter of the International Large Detector, ILD. The attention mechanism now allows us to generate complex hadronic showers with more pronounced substructure across both the electromagnetic and hadronic calorimeters. This is the first time that machine learning methods are used to holistically generate showers across the electromagnetic and hadronic calorimeter in highly granular imaging calorimeter systems. oai:arXiv.org:2506.21720v2 physics.ins-det cs.LG hep-ex hep-ph physics.data-an Mon, 02 Feb 2026 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ 10.1088/1748-0221/21/01/P01042 Journal of Instrumentation, Volume 21, January 2026, P01042 Thorsten Buss, Frank Gaede, Gregor Kasieczka, Anatolii Korol, Katja Kr\"uger, Peter McKeown, Martina Mozzanica https://arxiv.org/abs/2507.13195 arXiv:2507.13195v2 Announce Type: replace Abstract: We study the evolution of the kinetic energy (or gradient norm) of an incident linearly polarized monochromatic wave propagating in correlated random media. We explore the optical flux transverse to the mean Poynting flux at the paraxial-nonparaxial (vectorial) transition along with vortex counting. Here, by paraxial-nonparaxial transition we mean a gradual loss of validity of the paraxial approximation such that it is necessary to solve Maxwell-consistently employing the dyadic Green's function. The vortex number appears to increase approximately with a cubic root of the propagation distance for sufficiently small correlation length. Furthermore, a kink appears in nucleation rate at the position of maximum scintillation upon increasing correlation length. A driven steady state is reached due to the filtering of evanescent waves upon propagation. Finally, we present the spectrum of the incompressible kinetic energy and how it evolves from the paraxial case to that of a (nonparaxial) random field. oai:arXiv.org:2507.13195v2 physics.optics Mon, 02 Feb 2026 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ 10.1103/5rww-88k5 Phys. Rev. Research 8, 013113 (2026) Yuchen Ke, Nandini Bhattacharya, Fabian Maucher https://arxiv.org/abs/2508.12117 arXiv:2508.12117v2 Announce Type: replace Abstract: Seismicity catalogs are larger than ever due to an explosion of techniques for enhanced earthquake detection and an abundance of high-quality datasets. Bayesian inference is an appealing framework for locating earthquakes due to its ability to propagate and quantify uncertainty into the inversion results, but traditional methods do not scale well to high-dimensional parameter spaces, making them unsuitable for double-difference relocation where the number of parameters can reach the millions. Here we introduce SPIDER, a scalable Bayesian inference framework for double-difference hypocenter relocation. SPIDER uses a physics-informed neural network Eikonal solver together with a highly efficient sampler called Stochastic Gradient Langevin Dynamics to generate posterior samples jointly for entire seismicity catalogs. We show that traditional double-difference relocation formulations neglect residual correlation between observations with common events, which biases uncertainty estimates. Our formulation is designed to whiten this residual correlation, and is readily parallelized over multiple GPUs for enhanced computational efficiency. We demonstrate the capabilities of SPIDER on a rigorous synthetic seismicity catalog and three real data catalogs from California and Japan. We introduce several ways to analyze high-dimensional posterior distributions to aid in scientific interpretation and evaluation. oai:arXiv.org:2508.12117v2 physics.geo-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Zachary E. Ross, John D. Wilding, Kamyar Azizzadenesheli, Aitaro Kato https://arxiv.org/abs/2508.12827 arXiv:2508.12827v2 Announce Type: replace Abstract: Background In vivo mechanical behaviour of the abdominal wall has been poorly characterised and important details are missing regarding the occurrence and post-operative recurrence rate of hernias which can be as high as 30 %. This study aimed to assess the correlation between abdominal wall displacement and intra-abdominal pressure, as well as abdominal compliance. Methods Eighteen healthy participants performed audio-guided passive (breathing) and active (coughing, Valsalva maneuver) exercises. Axial dynamic changes of abdominal muscles and visceral area were measured using MRI, and intra-abdominal pressure with ingested pressure sensor. Findings Correlations between abdominal wall displacement and intra-abdominal pressure were specific to participant, exercise, and varying between rectus abdominis and lateral muscles. Strong correlations were found between rectus abdominis displacement and intra-abdominal pressure during breathing (r = 0.92 $\pm$ 0.06), as well as lateral muscles displacement with intra-abdominal pressure during coughing and Valsalva maneuver (r = --0.98 $\pm$ 0.03 and -- 0.94 $\pm$ 0.05 respectively). The abdominal pseudo-compliance varied greatly among participants during muscular contraction, the coefficient of variation reaching up to 70 %. Interpretation The combination of intra-abdominal pressure and dynamic MRI measurements enables the identification of participant-specific behaviour pattern. Intra-abdominal pressure and abdominal wall dynamic undergo consistent and predictable interactions. However, this relationship is subject-specific and may not be extrapolated to other individuals. Therefore, both intra-abdominal pressure and abdominal wall motion must be measured in the same participant in order to accurately characterise the abdominal wall behaviour. These results are of great importance for mesh design, surgical decision-making, and personalised healthcare. oai:arXiv.org:2508.12827v2 physics.med-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Clinical Biomechanics, 2024, 121, pp.106396 Victoria Joppin (LBA UMR T24, CRMBM), Arthur Jourdan (LBA UMR T24), David Bendahan (CRMBM), Andr\'ea Soucasse (LBA UMR T24), Maxime Guye (CRMBM, TIMONE), Catherine Masson (LBA UMR T24), Thierry B\`ege (LBA UMR T24) https://arxiv.org/abs/2508.16533 arXiv:2508.16533v2 Announce Type: replace Abstract: High laser intensities enable the production of electron-positron pairs from bright gamma rays passing through strong fields. Potentially the most promising approach for all-optical experiments in the near term uses dense but higher divergence electron beams from laser wakefield acceleration to produce gamma rays through inverse Compton scattering. Achieving many-photon collisions between these gamma rays and the high intensity laser pulse in practice is extremely difficult, however, due to significant shot-to-shot jitter in laser pointing and timing. We model these practical difficulties using simulated Monte-Carlo experiments. By using a more efficient algorithm for sampling infrequent pair production with particle splitting, we enable the exploration of a multi-dimensional parameter space. Using Gaussian Process Regression we then efficiently find optimal conditions for maximising pair production by changing the laser spot size, the energy in the colliding beam, and the stand-off distance between the laser wakefield accelerator and the focus of the colliding laser pulse. We find that the optimal stand-off distance increases with the degree of laser jitter and that the best conditions for producing electron-positron pairs are not the same as the best conditions for maximising the energy in the gamma rays. With \unit[100]{J} of laser energy, we estimate rates of pair production of around 1 pair per 100 electrons are achievable even with jitter of 10s of microns and 10s of femtoseconds. oai:arXiv.org:2508.16533v2 physics.plasm-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Christopher Arran, Stuart Morris, Christopher P. Ridgers https://arxiv.org/abs/2509.06458 arXiv:2509.06458v2 Announce Type: replace Abstract: A gas-phase sample consisting of lithium iodide, $\mathrm{LiI}$, molecules and their dimer $\mathrm{(LiI)}_2$, are Coulomb exploded by an intense 25 femtosecond laser pulse. In the case of $\mathrm{LiI}$, we focus on the double ionization that creates a pair of $\mathrm{Li}^+$ and $\mathrm{I}^+$ recoil ions. From the kinetic energy distribution of the $\mathrm{Li}^+$ ions, extracted using coincidence filtering, we determine the distribution of internuclear distances $P(R)$ via the ground state potential curve of $\mathrm{LiI}^{2+}$ obtained from an ab initio calculation that accounts for non-Coulombic effects. We find that the center of $P(R)$ is close to the expected internuclear separation based on the three vibrational states of $\mathrm{LiI}$ populated, whereas the width of $P(R)$ exceeds the theoretical value by $\sim$ 52 %. We discuss if fragmentation via excited $\mathrm{LiI}^{2+}$ potential curves affects the determination of $P(R)$. In the case of the dimer, $\mathrm{(LiI)}_2$, we observe kinetic energies and relative emission directions of $\mathrm{Li}^+$, $\mathrm{I}^+$, and $\mathrm{I}^{2+}$ recoil ions consistent with Coulomb explosion of the parallelogram-shaped dimer after removing up to six electrons by the laser pulse. oai:arXiv.org:2509.06458v2 physics.atom-ph physics.atm-clus Mon, 02 Feb 2026 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Henrik H. Kristensen, Emil Hansen, Jeppe K. Christensen, Simon H. Albrechtsen, Frank Jensen, Henrik Stapelfeldt https://arxiv.org/abs/2509.07621 arXiv:2509.07621v2 Announce Type: replace Abstract: Magnetic reconnection is an explosive process that accelerates particles to high energies in Earth's magnetosphere, offering a unique natural laboratory to study this phenomenon. This study investigates how well data-driven fully kinetic simulations can reproduce the ion and electron energy distributions observed during a reconnection event by the Magnetospheric Multiscale (MMS) mission.We performed fully kinetic 2D simulations initialized with plasma parameters derived from the MMS event and compared the resulting ion and electron energy distributions with observations. Key numerical and physical parameters were systematically varied to assess their influence on the resulting particle spectra. The simulations capture the overall shape and evolution of nonthermal energy distributions for both species, but generally underestimate the very high-energy tail of the electron spectrum. Variations in numerical parameters have negligible effects on the resulting spectra, while the initial upstream temperatures instead play a more pronounced role in reproducing the observed distributions.We present a novel analysis of data-driven fully kinetic simulations of MR, showing that key aspects of particle acceleration can be captured, while also highlighting the limitations of 2D simulations and the need for more realistic (e.g., 3D) setups to reproduce the observed particle energization accurately. oai:arXiv.org:2509.07621v2 physics.space-ph astro-ph.EP physics.plasm-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ 10.1051/0004-6361/202558575 Nadja Reisinger, Fabio Bacchini https://arxiv.org/abs/2509.21348 arXiv:2509.21348v4 Announce Type: replace Abstract: Understanding the asymptotic behaviour of numerical dynamo models is critical for extrapolating results to the physical conditions that characterise terrestrial planetary cores. Here we investigate the behaviour of convection-driven dynamos reaching a MAC (magnetic-Archimedes-Coriolis) balance on the convective length scale and compare the results with non-magnetic convection cases. In particular, the dependence of physical quantities on the Ekman number, $Ek$, is studied in detail. The scaling of velocity dependent quantities is observed to be independent of the force balance and in agreement with quasi-geostrophic theory. The primary difference between dynamo and non-magnetic cases is that the fluctuating temperature is order unity in the former such that the buoyancy force scales with the Coriolis force. The MAC state yields a scaling for the flow speeds that is identical to the so-called CIA (Coriolis-inertia-Archimedes) scaling. There is an $O(Ek^{1/3})$ length scale present within the velocity field irrespective of the leading order force balance. This length scale is consistent with the asymptotic scaling of the terms of the governing equations and is not an indication that viscosity plays a dominant role. The peak of the kinetic energy spectrum and the ohmic dissipation length scale both exhibit an Ekman number dependence of approximately $Ek^{1/6}$, which is consistent with a scaling of $Rm^{-1/2}$, where $Rm$ is the magnetic Reynolds number. For the dynamos, advection remains comparable to, and scales similarly with, both inertia and viscosity, implying that nonlinear convective Rossby waves play an important role in the dynamics even in a MAC regime. oai:arXiv.org:2509.21348v4 physics.geo-ph astro-ph.EP astro-ph.SR Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Justin A. Nicoski, Andy Esseln, Chris Davies, Michael A. Calkins https://arxiv.org/abs/2509.21378 arXiv:2509.21378v2 Announce Type: replace Abstract: In this paper we address the issue of stability for the near-inertial Pollard waves, as a model for the halocline in the region of the Arctic Ocean centered around the North Pole, derived in Puntini (2025a). Adopting the short-wavelength instability approach, the stability of such flows reduces to study the stability of a system of ODEs along fluid trajectories, leading to the result that, when the steepness of the near-inertial Pollard waves exceeds a specific threshold, those waves are linearly unstable. The explicit dispersion relation of the model allows to easily compute such threshold, knowing the physical properties of the water column. oai:arXiv.org:2509.21378v2 physics.geo-ph math.AP physics.ao-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Christian Puntini https://arxiv.org/abs/2510.09491 arXiv:2510.09491v3 Announce Type: replace Abstract: This article presents a detailed investigation of solid-fluid phase coexistence in a bilayer dusty plasma crystal subjected to varying confinement ring bias voltages in a DC glow discharge argon plasma. Melamine formaldehyde particles were employed to form a stable, hexagonally ordered bilayer crystal within a confinement ring electrically isolated from the grounded cathode. By systematically adjusting the confinement ring bias, a distinct phase coexistence emerged characterized by a fluid-like melted core surrounded by a solid crystalline periphery. Crucially, analysis of the phonon spectra revealed frequency shifts that deviate significantly from the predictions of classical monolayer Mode-Coupling Instability (MCI) theory. Stability analysis further demonstrated that dynamic interlayer particle pairing and the associated increase in non-reciprocal interaction strength are strongly correlated with the onset of structural destabilization. These findings highlight previously underappreciated mechanisms driving the melting transition in bilayer dusty plasmas, offering a more comprehensive understanding of phase behavior in complex plasma systems. The results underscore the importance of interlayer coupling and confinement effects in tuning structural transitions. oai:arXiv.org:2510.09491v3 physics.plasm-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Siddhartha Mangamuri (Department of Physics, Indian Institute of Science Education and Research, Homi Bhabha Road, Pune, India), L\'ena\"ic Cou\"edel (Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, Saskatchewan, Canada), Surabhi Jaiswal (Department of Physics, Indian Institute of Science Education and Research, Homi Bhabha Road, Pune, India) https://arxiv.org/abs/2510.21054 arXiv:2510.21054v4 Announce Type: replace Abstract: Predictive dosimetry is central to enabling personalized radiopharmaceutical therapy (RPT), particularly in prostate specific membrane antigen (PSMA) targeted theranostics. In this work, we develop a three layer computational framework that integrates physiologically based pharmacokinetic (PBPK) modeling with machine learning (ML) to predict both physical (AUC, absorbed dose) and biological (BED, EQD2) dosimetric endpoints in tumors and major organs. In the first layer, we generated 640 virtual patients using PBPK simulations of F-18, Ga-68, and Cu-64 labeled PSMA PET tracers paired with Lu-177 PSMA therapy, producing 15360 tumor and organ time activity curves (TACs) under realistic biological variability and PET-like noise. In the second layer, TACs were transformed into quantitative kinetic features and mapped to physical and biological dose metrics. In the third layer, ML models (Random Forest, Extra Trees, Ridge, Gradient Boosting, and XGBoost) were trained to predict RPT doses from PET derived features, with performance evaluated using mean absolute percentage error (MAPE) and R2. Cu-64 PSMA-617 based PET yielded the most robust predictions, achieving tumor dose MAPE as low as 8 percent and 10 to 20 percent for normal organs, while F-18 DCFPyL showed volume dependent performance and Ga-68 PSMA-11 exhibited higher variability. SHAP analysis revealed that peak uptake, clearance, and early kinetic features dominated predictive performance across organs and endpoints. This PBPK ML framework enables scalable, physiology informed predictive dosimetry and provides a foundation for trial design and patient specific treatment planning in PSMA targeted RPT. These results demonstrate that pre therapy PET can serve as a reliable surrogate for post therapy dosimetry, enabling scalable personalization of PSMA targeted RPT. oai:arXiv.org:2510.21054v4 physics.med-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Hamid Abdollahi (Department of Radiology, University of British Columbia, Vancouver, Canada, Department of Basic and Translation Research, BC Cancer Research institute, Vancouver, Canada), James Fowler (Department of Basic and Translation Research, BC Cancer Research institute, Vancouver, Canada, Department of Physics & Astronomy, University of British Columbia, Vancouver, Canada), Carlos Uribe (Department of Basic and Translation Research, BC Cancer Research institute, Vancouver, Canada, Department of Molecular Imaging and Therapy, BC Cancer, Vancouver, Canada), Arman Rahmim (Department of Radiology, University of British Columbia, Vancouver, Canada, Department of Basic and Translation Research, BC Cancer Research institute, Vancouver, Canada, Department of Physics & Astronomy, University of British Columbia, Vancouver, Canada) https://arxiv.org/abs/2510.25288 arXiv:2510.25288v2 Announce Type: replace Abstract: We investigate the capacity of a flat partially reactive patch of arbitrary shape to trap independent particles that undergo steady-state diffusion in the three-dimensional space. We focus on the total flux of particles onto the patch that determines its reactive capacitance. To disentangle the respective roles of the reactivity and the shape of the patch, we employ a spectral expansion of the reactive capacitance over a suitable Steklov eigenvalue problem. We derive several bounds on the reactive capacitance to reveal its monotonicity with respect to the reactivity and the shape. Two probabilistic interpretations are presented as well. An efficient numerical tool is developed for solving the associated Steklov spectral problem for patches of arbitrary shape. We propose and validate, both theoretically and numerically, a simple, fully explicit approximation for the reactive capacitance that depends only on the surface area and the electrostatic capacitance of the patch. This approximation opens promising ways to access various characteristics of diffusion-controlled reactions in general domains with multiple small well-separated patches. Direct applications of these results in statistical physics and physical chemistry are discussed. oai:arXiv.org:2510.25288v2 physics.chem-ph math-ph math.MP math.SP Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Denis S. Grebenkov, Raphael Maurette https://arxiv.org/abs/2511.03439 arXiv:2511.03439v2 Announce Type: replace Abstract: We present the first open access version of the QMeCha (Quantum MeCha) code, a quantum Monte Carlo (QMC) package developed to study many-body interactions between different types of quantum particles, with a modular and easy-to-expand structure. The present code has been built to solve the Hamiltonian of a system that can include nuclei and fermions of different mass and charge, e.g. electrons and positrons, embedded in an environment of classical charges and quantum Drude oscillators. To approximate the ground state of this many-particle operator, the code features different wavefunctions. For the fermionic particles, beyond the traditional Slater determinant, QMeCha also includes Geminal functions such as the Pfaffian, and presents different types of explicit correlation terms in the Jastrow factors. The classical point charges and quantum Drude oscillators, described through different variational ans\"atze, are used to model a molecular environment capable of explicitly describing dispersion, polarization, and electrostatic effects experienced by the nuclear and fermionic subsystem. To integrate these wavefunctions, efficient variational Monte Carlo and diffusion Monte Carlo protocols have been developed, together with a robust wavefunction optimization procedure that features correlated sampling. oai:arXiv.org:2511.03439v2 physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by-nc-nd/4.0/ Matteo Barborini, Jorge Charry, Matej Ditte, Andronikos Leventis, Georgios Kafanas, Alexandre Tkatchenko https://arxiv.org/abs/2511.07638 arXiv:2511.07638v3 Announce Type: replace Abstract: Tandem catalysis involves two or more catalysts arranged in proximity within a single reaction vessel, with the aim of synergistically aligning the catalysts' reaction pathways to maximize overall system performance. This study presents a proof of concept showing the integration of continuum transport modeling with design optimization in a simplified two-dimensional flow reactor setup for electrochemical CO$_2$ reduction. Ag catalysts provide the CO$_2$ $\rightarrow$ CO reaction capability, and Cu catalysts provide the CO $\rightarrow$ high-value products reaction capability. Given a set of input parameters, the optimization algorithm uses adjoint methods to modify the Ag/Cu surface patterning in order to maximize the current density toward high-value products, such as ethylene. The optimized designs yield significant performance enhancement especially at more negative applied voltages (i.e., stronger surface reactions) and for larger numbers of patterning sections. For an applied voltage of $-1.7$ V vs. SHE, the $12$-section optimized design increases the current density towards ethylene by up to $65$% compared to the unoptimized $2$-section design. For the optimized cases, observed differences in the production and consumption of CO (the key intermediate species) and minimized zones of low CO reactant surface concentration on Cu sections explain the improved reactor performance. oai:arXiv.org:2511.07638v3 physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Jack Guo (Computational Engineering Division, Lawrence Livermore National Laboratory, Livermore, CA, USA), Thomas Roy (Computational Engineering Division, Lawrence Livermore National Laboratory, Livermore, CA, USA), Nitish Govindarajan (Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, USA), Joel B. Varley (Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, USA), Jonathan Raisin (SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, CA, USA, TotalEnergies Research & Technology USA LLC, Houston, TX, USA), Jinyoung Lee (SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, CA, USA, SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, CA, USA, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology), Ji-Wook Jang (School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Graduate School of Carbon Neutrality, Ulsan National Institute of Science and Technology), Dong Un Lee (SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, CA, USA, SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, CA, USA), Thomas F. Jaramillo (SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering, Stanford University, Stanford, CA, USA, SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, CA, USA), Tiras Y. Lin (Computational Engineering Division, Lawrence Livermore National Laboratory, Livermore, CA, USA) https://arxiv.org/abs/2511.13266 arXiv:2511.13266v3 Announce Type: replace Abstract: We show that the antisymmetric Mueller generator provides a universal algebraic kernel for geometric phase in classical polarization optics and in quantum two-level systems. For any ideal retarder, the antisymmetric 3x3 block of its Mueller matrix (the antisymmetric generator of the adjoint SU(2) action on the Stokes vector) encodes the angular-velocity vector that drives the tangential motion on the Poincar\'e sphere and fully determines the Pancharatnam-Berry phase, while the symmetric block is geometrically neutral. The same antisymmetric generator governs the evolution of pure qubit states on the Bloch sphere. This unified viewpoint yields operational criteria to identify and control geometric-phase contributions from measured Mueller matrices and from qubit process tomography. oai:arXiv.org:2511.13266v3 physics.gen-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Jos\'e J. Gil https://arxiv.org/abs/2512.01855 arXiv:2512.01855v2 Announce Type: replace Abstract: The High Granularity Timing Detector (HGTD) will be installed in the ATLAS experiment as part of the Phase-II upgrade for the High Luminosity-Large Hadron Collider (HL-LHC). It will mitigate pile-up effects in the forward region, and measure per bunch luminosity. The design of HGTD is based on Low Gain Avalanche Detector (LGAD) sensors. This paper presents the results of beam-test campaigns conducted at CERN and DESY in 2023 and 2024 on single LGADs from HGTD pre-production test structures, before and after neutron irradiation up to fluences of $2.5 \times 10^{15}~\mathrm{n_{eq}/cm^2}$. The tested LGADs can meet HGTD requirements in terms of charge collection, time resolution, and hit efficiency, even under HL-LHC end-of-life conditions, supporting their deployment in the final detector. oai:arXiv.org:2512.01855v2 physics.ins-det hep-ex Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ A. Aboulhorma, M. Ait Tamlihat, H. M. Alfanda, O. Atanova, N. Atanov, I. Azzouzi, J. Barreiro Guimar\~aes da Costa, T. Beau, D. Benchekroun, F. Bendebba, G. Bergamin, Y. Bimgdi, A. Blot, A. Boikov, J. Bonis, D. Boumediene, C. Brito, A. S. Brogna, A. M. Burger, L. Cadamuro, Y. Cai, N. Cartalade, R. Casanova Mohr, R. Cherkaoui El Moursli, Y. Che, X. Chen, E. Y. S. Chow, L. D. Corpe, C. G. Crozatier, L. D'Eramo, S. Dahbi, D. Dannheim, G. Daubard, Y. Davydov, J. Debevc, Y. Degerli, E. Delagnes, F. Deliot, M. Dhellot, P. Dinaucourt, G. Di Gregorio, P. J. Dos Santos De Assis, C. Duan, O. Duarte, F. Dulucq, J. Ehrecke, Y. El Ghazali, A. El Moussaouy, A. Falou, L. Fan, Y. Fan, Z. Fan, K. Farman, F. Fassi, Y. Feng, M. Ferreira, F. Filthaut, F. Fischer, P. Fust\'e, J. Fu, J. Garc\'ia Rodriquez, G. Gaspar De Andrade, V. Gautam, Z. Ge, R. Gon\c{c}alo, M. Gouighri, S. Grinstein, K. Gritsay, F. Guilloux, S. Guindon, A. Haddad, S. E. D. Hammoud, L. Han, A. M. Henriques Correia, M. Hidaoui, B. Hiti, J. Hofner, S. Hou, P. J. Hsu, X. Huang, Y. Huang, K. Hu, C. Insa, J. Jeglot, X. Jia, G. Kramberger, M. Kuriyama, B. Y. Ky, D. Lacour, A. Lafarge, B. Lakssir, A. Lantheaume, D. Laporte, C. de La Taille, M. A. L. Leite, A. Leopold, H. Li, L. Li, M. Li, S. Li, S. Li, Y. Li, Z. Li, S. Liang, Z. Liang, B. Liu, K. Liu, K. Liu, Y. L. Liu, Y. W. Liu, F. L. Lucio Alves, M. Lu, Y. J. Lu, F. Lyu, D. Macina, R. Madar, N. Makovec, S. Malyukov, I. Mandi\'c, T. Manoussos, S. Manzoni, G. Martin-Chassard, F. Martins, L. Masetti, R. Mazini, E. Mazzeo, K. Ma, X. Ma, R. Menegasso, J-P. Meyer, Y. Miao, A. Migayron, M. Mihovilovic, M. Milovanovic, M. Missio, V. Moskalenko, N. Mouadili, A. Moussa, I. Nikolic-Audit, C. C. Ohm, H. Okawa, S. Okkerman, M. Ouchrif, C. P\'en\'elaud, A. Parreira, B. Pascual Dias, R. E. de Paula, J. Pinol Bel, P. -O. Puhl, C. Puigdengoles Olive, M. Puklavec, J. Qin, M. Qi, H. Ren, H. Riani, S. Ridouani, V. Rogozin, L. Royer, F. Rudnyckyj, E. F. Saad, G. T. Saito, A. Salem, H. Santos, S. Scarfi, Ph. Schwemling, N. Seguin-Moreau, L. Serin, R. P. Serrano Fernandez, A. Shaikovskii, Q. Sha, L. Shan, R. Shen, X. Shi, P. Skomina, H. Smitmanns, H. L. Snoek, A. P. Soulier, A. Stein, H. Stenzel, J. Strandberg, W. Sun, X. Sun, Y. Sun, Y. Tan, K. Tariq, Y. Tayalati, S. Terzo, A. Torrento Coello, S. Trincaz-Duvoid, U. M. Vande Voorde, I. Velkovska, R. P. Vieira, L. A. Vieira Lopes, A. Visibile, A. Wang, C. Wang, S. M. Wang, T. Wang, T. Wang, W. Wang, Y. Wang, Y. Wang, J. Wan, Q. Weitzel, J. Wu, M. Wu, W. Wu, Y. Wu, L. Xia, D. Xu, H. Xu, L. Xu, Z. Yan, H. Yang, H. Yang, X. Yang, X. Yang, J. Ye, I. Youbi, J. Yuan, I. Zahir, H. Zeng, D. Zhang, J. Zhang, L. Zhang, Z. Zhang, M. Zhao, Z. Zhao, X. Zheng, Z. Zhou, Y. Zhu, X. Zhuang https://arxiv.org/abs/2512.12404 arXiv:2512.12404v2 Announce Type: replace Abstract: The rising demand for higher education has led universities to offer courses in multiple formats, including Intensive Instruction Courses (IICs), to meet the needs of a diverse student body. While active teaching methods improve physics understanding in standard courses, little research has examined their effectiveness in IICs. This research explored the most efficient methodologies for promoting meaningful learning in intensive physics courses. To this end, an integrated pedagogical proposal was designed based on the opinions gathered from a focus group of teachers with previous experience teaching these courses, as well as on existing literature, highlighting methodologies, types of assessment, and characteristics of ICCs. To evaluate its efficiency, a quasi-experiment was conducted in which students were divided into two groups: an experimental group (EG), which followed the teaching proposal, and a control group (CG), which received non-innovated lessons. Results were measured using the BEMA electromagnetism concepts inventory before and after the intervention. Statistical analysis revealed that Hake's Gain was greater in the EG, both in general terms and in each thematic unit of the course. The intervention in the EG showed that the use of active methodologies was more efficient than those used in the CG in the context of IICs. The results obtained suggest the need to continue investigating other factors involved in the teaching-learning process of IICs. oai:arXiv.org:2512.12404v2 physics.ed-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Marcela Vallejo, Ema Huerta, Joselen M. Pena, Jose Leiva, Ethan Rodriguez https://arxiv.org/abs/2512.17243 arXiv:2512.17243v2 Announce Type: replace Abstract: The global aid system functions as a complex and evolving ecosystem; yet widespread understanding of its structure remains largely limited to aggregate volume flows. Here we map the network topology of global aid using a dataset of unprecedented scale: over 10 million transaction records connecting 2,456 publishing organisations across 230 countries between 1967 and 2025. We apply bipartite projection and dimensionality reduction to reveal the geometry of the system and unveil hidden patterns. This exposes distinct functional clusters that are otherwise sparsely connected. We find that while governments and multilateral agencies provide the primary resources, a small set of knowledge brokers provide the critical connectivity. Universities and research foundations specifically act as essential bridges between disparate islands of implementers and funders. We identify a core solar system of 25 central actors who drive this connectivity including unanticipated brokers like J-PAL and the Hewlett Foundation. These findings demonstrate that influence in the aid ecosystem flows through structural connectivity as much as financial volume. Our results provide a new framework for donors to identify strategic partners that accelerate coordination and evidence diffusion across the global network. oai:arXiv.org:2512.17243v2 physics.soc-ph econ.GN q-fin.EC Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Paul X. McCarthy, Xian Gong, Marian-Andrei Rizoiu, Paolo Boldi https://arxiv.org/abs/2601.11650 arXiv:2601.11650v2 Announce Type: replace Abstract: Modern process simulators enable detailed process design, simulation, and optimization; however, constructing and interpreting simulations is time-consuming and requires expert knowledge. This limits early exploration by inexperienced users. To address this, a large language model (LLM) agent is integrated with AVEVA Process Simulation (APS) via Model Context Protocol (MCP), allowing natural language interaction with rigorous process simulations. An MCP server toolset enables the LLM to communicate programmatically with APS using Python, allowing it to execute complex simulation tasks from plain-language instructions. Two water-methanol separation case studies assess the framework across different task complexities and interaction modes. The first shows the agent autonomously analyzing flowsheets, finding improvement opportunities, and iteratively optimizing, extracting data, and presenting results clearly. The framework benefits both educational purposes, by translating technical concepts and demonstrating workflows, and experienced practitioners by automating data extraction, speeding routine tasks, and supporting brainstorming. The second case study assesses autonomous flowsheet synthesis through both a step-by-step dialogue and a single prompt, demonstrating its potential for novices and experts alike. The step-by-step mode gives reliable, guided construction suitable for educational contexts; the single-prompt mode constructs fast baseline flowsheets for later refinement. While current limitations such as oversimplification, calculation errors, and technical hiccups mean expert oversight is still needed, the framework's capabilities in analysis, optimization, and guided construction suggest LLM-based agents can become valuable collaborators. oai:arXiv.org:2601.11650v2 physics.chem-ph cs.AI Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Jingkang Liang, Niklas Groll, G\"urkan Sin https://arxiv.org/abs/2601.18047 arXiv:2601.18047v2 Announce Type: replace Abstract: We present a method for implementing an optical neural network using only linear optical resources, namely field displacement and interferometry applied to coherent states of light. The nonlinearity required for learning in a neural network is realized via an encoding of the input into phase shifts allowing for far more straightforward experimental implementation compared to previous proposals for, and demonstrations of, $\textit{in situ}$ inference. Beyond $\textit{in situ}$ inference, the method enables $\textit{in situ}$ training by utilizing established techniques like parameter shift rules or physical backpropagation to extract gradients directly from measurements of the linear optical circuit. We also investigate the effect of photon losses and find the model to be very resilient to these. oai:arXiv.org:2601.18047v2 physics.optics cs.ET cs.LG Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Amanuel Anteneh, Kyungeun Kim, J. M. Schwarz, Israel Klich, Olivier Pfister https://arxiv.org/abs/2601.18797 arXiv:2601.18797v2 Announce Type: replace Abstract: Partially coherent light offers salutary capabilities in optical information processing that cannot be matched by coherent light. To date, this `coherence advantage' has been confirmed in proof-of-principle optical communications protocols using bulk optics. Taking full advantage of such opportunities necessitates processing multimode partially coherent light in integrated photonics platforms that alone provide the requisite stability for cascaded operations on a large scale. Here we demonstrate on-chip manipulation of four-mode partially coherent light described by a $4\times4$ Hermitian coherence matrix. Starting with generic maximally incoherent light, we utilize an on-chip hexagonal mesh of Mach-Zehnder interferometers to perform all the unitary and non-unitary tasks that are critical for realizing structured coherence: controlling the coherence rank (the number of non-zero eigenvalues of the coherence matrix); tuning the field entropy; molding the structure of the coherence matrix via $4\times4$ unitary transformations constructed out of sequences of $2\times2$ unitaries acting on pairs of modes; and tomographic reconstruction of the coherence matrix by measuring the modal Stokes parameters associated with Kronecker-Pauli matrices. These results confirm the scalability of utilizing $2\times2$ on-chip building blocks for the synthesis and reconstruction of high-dimensional coherence matrices, and provide a decisive step towards large-scale on-chip manipulation of massively moded partially coherent light for applications in optical information processing. oai:arXiv.org:2601.18797v2 physics.optics Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by/4.0/ Amin Hashemi, Abbas Shiri, Bahaa E. A. Saleh, Andrea Blanco-Redondo, Ayman F. Abouraddy https://arxiv.org/abs/2601.19444 arXiv:2601.19444v2 Announce Type: replace Abstract: High-precision spectroscopy of simple atomic systems can be used to advance the theory of atomic energy levels but can also serve as a sensitive probe of nuclear charge radii. For this last purpose, we report an improved measurement of the $2\,^3{S}_1 \to 2\,^1{S}_0$ transition frequency in $^4$He with 48 Hz uncertainty (0.25 ppt), using a Bose-Einstein condensed sample confined in a magic-wavelength optical dipole trap. A systematic Doppler shift from condensate motion is suppressed by time-resolved ion detection, and the transition frequency is calibrated via a White Rabbit link to a remote active hydrogen maser clock. Combined with previous $^3$He measurements and improved theory, we obtain the most precise determination to date of the charge-radius difference between the helion and alpha particle ($r_{h}^2 -r_{\alpha}^2$) of $1.0676(10)\text{fm}^2$. This is consistent with other recent determinations and confirms that the current discrepancy between QED theory and experimentally observed ionization energies of excited states in helium is not apparent in the isotope shift. oai:arXiv.org:2601.19444v2 physics.atom-ph Mon, 02 Feb 2026 00:00:00 -0500 replace http://creativecommons.org/licenses/by-nc-nd/4.0/ K. Steinebach, J. C. J. Koelemeij, H. L. Bethlem, K. S. E. Eikema https://arxiv.org/abs/2601.21704 arXiv:2601.21704v2 Announce Type: replace Abstract: This paper examines the connection between photonic band-gap formation in two types of two-dimensional photonic crystals and the emergence of reverse electromagnetic energy flows generated by linearly polarized plane waves incident on a photonic-crystal slab. We show that these reverse energy flows, observed in both transmitted and reflected fields, originate from vortex structures in the Poynting vector. The resulting energy-flow patterns exhibit striking analogies to vortex formation in fluid motion past obstacles. The geometry and dynamics of the Poynting-vector vortices determine whether the incident electromagnetic energy is impeded, leading to the formation of photonic band gaps, or instead guided through the structure, enabling transmission. oai:arXiv.org:2601.21704v2 physics.optics Mon, 02 Feb 2026 00:00:00 -0500 replace http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Andrey Pryamikov https://arxiv.org/abs/2404.16050 arXiv:2404.16050v4 Announce Type: replace-cross Abstract: The simulation hypothesis has recently excited renewed interest in the physics and philosophy communities. However, the hypothesis specifically concerns {\textit{computers}} that simulate physical universes. So to formally investigate the hypothesis, we need to understand it in terms of computer science (CS) theory. In addition we need a formal way to couple CS theory with physics. Here I couple those fields by using the physical Church-Turing thesis. This allow me to exploit Kleene's second recursion, to prove that not only is it possible for {us} to be a simulation being run on a computer, but that we might be in a simulation being run a computer \emph{by us}. In such a ``self-simulation'', there would be two identical instances of us, both equally ``real''. I then use Rice's theorem to derive impossibility results concerning simulation and self-simulation; derive implications for (self-)simulation if we are being simulated in a program using fully homomorphic encryption; and briefly investigate the graphical structure of universes simulating other universes which contain computers running their own simulations. I end by describing some of the possible avenues for future research. While motivated in terms of the simulation hypothesis, the results in this paper are direct consequences of the Church-Turing thesis. So they apply far more broadly than the simulation hypothesis. oai:arXiv.org:2404.16050v4 cs.LO physics.hist-ph Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by-nc-nd/4.0/ David H. Wolpert https://arxiv.org/abs/2406.09195 arXiv:2406.09195v5 Announce Type: replace-cross Abstract: Thousands of experiments are analyzed and papers are published each year involving the statistical analysis of grouped data. While this area of statistics is often perceived -- somewhat naively -- as saturated, several misconceptions still affect everyday practice, and new frontiers have so far remained unexplored. Researchers must be aware of the limitations affecting their analyses and what are the new possibilities in their hands. Motivated by this need, the article introduces a unifying approach to the analysis of grouped data, which allows us to study the class of divisible statistics -- that includes Pearson's $\chi^2$, the likelihood ratio as special cases -- with a fresh perspective. The contributions collected in this manuscript span from modeling and estimation to distribution-free goodness-of-fit tests. Perhaps the most surprising result presented here is that, in a sparse regime, all tests proposed in the literature are dominated by members of the class of weighted linear statistics. oai:arXiv.org:2406.09195v5 stat.ME math.ST physics.data-an stat.CO stat.TH Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ Sara Algeri, Estate V. Khmaladze https://arxiv.org/abs/2409.17121 arXiv:2409.17121v2 Announce Type: replace-cross Abstract: The ultraslow dynamics of glass-formers has been explained by two views considered as mutually exclusive: one invokes locally hindered mobility, the other rests on the complexity of the configuration space. Here we demonstrate that the evolution responds strongly to the details of the dynamics by changing the speed of time-flow: it has time-reparametrization softness. This finding reconciles both views: while local constraints reparametrize the flow of time, the global landscape determines relationships between different correlations at the same times. We show that modern algorithms developed to accelerate the relaxation to equilibrium act by changing the time reparametrization. Their success thus relies on their ability to exploit reparametrization softness. We conjecture that these results extend beyond the realm of glasses to the optimization of more general constraint satisfaction problems and to broader classes of algorithms. oai:arXiv.org:2409.17121v2 cond-mat.dis-nn cond-mat.soft cond-mat.stat-mech physics.comp-ph Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ 10.1073/pnas.2520818123 Proc. Natl. Acad. Sci USA 123, e2520818123 (2026) Federico Ghimenti, Ludovic Berthier, Jorge Kurchan, Fr\'ed\'eric van Wijland https://arxiv.org/abs/2506.11576 arXiv:2506.11576v5 Announce Type: replace-cross Abstract: Szegedy's quantization of a reversible Markov chain provides a quantum walk whose spectral gap is quadratically larger than that of the classical walk. Quantum computers are therefore expected to provide a speedup of Metropolis-Hastings (MH) simulations. Existing generic methods to implement the quantum walk require coherently computing the transition probabilities of the underlying Markov kernel. However, reversible computing methods require a number of qubits that scales with the complexity of the computation. This overhead is undesirable in near-term fault-tolerant quantum computing, where few logical qubits are available. In this work, we present a Szegedy quantum walk construction which follows the classical proposal-acceptance logic, and does not require further reversible computing methods. We also compare this construction with an alternative to Szegedy's approach which also provides a quadratic gap amplification. Since each step of the quantum walks uses a constant number of proposal and acceptance steps, we expect the end-to-end quadratic speedup to hold for MH Markov Chain Monte-Carlo simulations. oai:arXiv.org:2506.11576v5 quant-ph cond-mat.stat-mech physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ Baptiste Claudon, Pablo Rodenas-Ruiz, Jean-Philip Piquemal, Pierre Monmarch\'e https://arxiv.org/abs/2506.15587 arXiv:2506.15587v2 Announce Type: replace-cross Abstract: We investigate the emergence of cohesive flocking in open, boundless space using a multi-agent reinforcement learning framework. Agents integrate positional and orientational information from their closest topological neighbours and learn to balance alignment and attractive interactions by optimizing a local cost function that penalizes both excessive separation and close-range crowding. The resulting Vicsek-like dynamics is robust to algorithmic implementation details and yields cohesive collective motion with high polar order. The optimal policy is dominated by strong aligning interactions when agents are sufficiently close to their neighbours, and a flexible combination of alignment and attraction at larger separations. We further characterize the internal structure and dynamics of the resulting groups using liquid-state metrics and neighbour exchange rates, finding qualitative agreement with empirical observations in starling flocks. These results suggest that flocking may emerge in groups of moving agents as an adaptive response to the biological imperatives of staying together while avoiding collisions. oai:arXiv.org:2506.15587v2 cond-mat.soft cs.MA physics.bio-ph Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ Martino Brambati, Antonio Celani, Marco Gherardi, Francesco Ginelli https://arxiv.org/abs/2506.22681 arXiv:2506.22681v5 Announce Type: replace-cross Abstract: This work introduces a Hamiltonian approach to regularization and linearization of central-force particle dynamics through a new canonical extension of the so-called "projective decomposition". The regularization scheme is formulated within the framework of classic analytical Hamiltonian dynamics as a redundant-dimensional canonical/symplectic coordinate transformation, combined with an evolution parameter transformation, on extended phase space. By considering a generalized version of the standard projective decomposition, we obtain a family of such canonical transformations which differ at the momentum level. From this family of transformations, a preferred coordinate set is chosen that possesses a simple and intuitive connection to the particle's local reference frame. Using this transformation, closed-form solutions are readily obtained for inverse-square and inverse-cubic radial forces, or any superposition thereof. Governing equations are numerically validated for the classic two-body problem incorporating the J2 gravitational perturbation. oai:arXiv.org:2506.22681v5 math.DS astro-ph.EP math-ph math.MP physics.class-ph Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ Joseph T. A. Peterson, Manoranjan Majji, John L. Junkins https://arxiv.org/abs/2507.04596 arXiv:2507.04596v2 Announce Type: replace-cross Abstract: This work shows that the interiors of perturbed zero-helicity vortices display simply connected topology with a crescent-shaped boundary. Flux surfaces in fluid and magnetic vortices were explored analytically, while particle trajectories in the context of plasma confinement were examined numerically, demonstrating the existence of both toroidal and simply connected topologies. This new topology appears for perturbations in a broad class, with amplitudes and spatial variance allowed to be arbitrarily small. This work proves the closedness of field lines under odd-parity perturbations of zero-helicity vortices. oai:arXiv.org:2507.04596v2 math-ph math.MP physics.flu-dyn physics.plasm-ph Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ Taosif Ahsan, Samuel A. Cohen, Alan H. Glasser https://arxiv.org/abs/2507.08085 arXiv:2507.08085v3 Announce Type: replace-cross Abstract: Conformal prediction is a distribution-free and model-agnostic uncertainty-quantification method that provides finite-sample prediction intervals with guaranteed coverage. In this work, for the first time, we apply conformal-prediction to generate uncertainty bands for physical observables in nuclear physics, such as the total cross section and nucleon-nucleon phase shifts. We demonstrate the method's flexibility by considering three scenarios: (i) a pointwise model, where expansion coefficients in chiral effective field theory are treated as random variables; (ii) a Gaussian-process model for the coefficients; and (iii) phase shifts at various energies and partial waves calculated using local interactions from chiral effective field theory. In each case, conformal-prediction intervals are constructed and validated empirically. Our results show that conformal prediction provides reliable and adaptive uncertainty bands even in the presence of non-Gaussian behavior, such as skewness and heavy tails. These findings highlight conformal prediction as a robust and practical framework for quantifying theoretical uncertainties. oai:arXiv.org:2507.08085v3 nucl-th physics.data-an Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ 10.1103/2n82-2jvv Phys. Rev. C 113, 014004 (2026) Habib Yousefi Dezdarani, Ryan Curry, Alexandros Gezerlis https://arxiv.org/abs/2508.09256 arXiv:2508.09256v2 Announce Type: replace-cross Abstract: The family of multi-plane phase retrieval sensors, such as the curvature and nonlinear curvature wavefront sensors (WFS), contain tip/tilt information embedded in their signals. We have built a nonlinear curvature WFS to study different wavefront reconstruction methods and test the ability to extract tip/tilt information. Using reliable and fast centroiding algorithms, combined with knowledge of the measured $z$-distance to each measurement plane, we demonstrate that image jitter may be sensed and compensated for using a fast steering mirror and the WFS in closed loop. This approach obviates the need for peripheral components such as quad-cells or access to a separate scientific imaging channel. Our laboratory experiments validate tip/tilt estimation and correction using nlCWFS data, achieving tip/tilt accuracy of +/-0.1, lambda/D for an unaberrated beam and better than ~+/-0.5, lambda/D in the presence of aberrations, consistent with prior numerical simulations. We further demonstrate a closed-loop tip/tilt control implementation and show a qualitative improvement in the stability and overall quality of multi-plane phase retrieval reconstructions. oai:arXiv.org:2508.09256v2 astro-ph.IM physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by-nc-nd/4.0/ Caleb G. Abbott, Justin R. Crepp, Brian Sands https://arxiv.org/abs/2508.10694 arXiv:2508.10694v5 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:2508.10694v5 cond-mat.soft math.AP math.DS physics.bio-ph Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ Molly Brennan, Edwina F. Yeo, Philip Pearce, Mohit P. Dalwadi https://arxiv.org/abs/2509.04746 arXiv:2509.04746v2 Announce Type: replace-cross Abstract: The Efimov effect, a remarkable realization of discrete scale invariance, emerges in the three-body problem with short-range interactions and is understood as a renormalization group (RG) limit cycle within Short-Range Effective Field Theory (SREFT). While the analytic form of the three-body renormalization relation has been established for a sharp cutoff regulator, its universality for other regulators remains underexplored. In this work, we derive the universal functional form of the three-body renormalization relation for general separable regulators through a detailed analysis of the Skorniakov-Ter-Martirosian and Faddeev equations. We find that the relation follows from a real M\"{o}bius transformation characterized by three parameters. This universality is verified numerically for various regulators. Although the functional form remains the same, the parameters characterizing the limit cycle exhibit regulator dependence. These findings broaden the class of RG limit cycles in SREFT and offer a more complete understanding of three-body renormalization. oai:arXiv.org:2509.04746v2 cond-mat.quant-gas nucl-th physics.atom-ph Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ 10.1103/s4fj-fdxj Phys. Rev. A 113, 013314 (2026) Langxuan Chen, Feng Wu, Xincheng Lin, Sebastian K\"onig, Ubirajara van Kolck, Pengfei Zhang https://arxiv.org/abs/2509.18426 arXiv:2509.18426v2 Announce Type: replace-cross Abstract: This paper addresses the modeling of parasitics of the match standard in the symmetric-reciprocal-match (SRM) calibration method of vector network analyzers (VNAs). In the general SRM procedure, the match standard is assumed to be fully known. Here, we demonstrate that the match can be modeled with an arbitrary frequency-dependent model using a non-linear global optimization procedure. To highlight the validity of the suggested approach, numerical tests were conducted, demonstrating the ability to recover the match standard parasitic model down to software numerical precision. Additionally, we performed microstrip line measurements to compare the SRM calibration with match modeling to the multiline thru-reflect-line (TRL) calibration one, showing that automatic model extraction can achieve accuracy similar to using a match standard defined through multiline TRL calibration. oai:arXiv.org:2509.18426v2 eess.SP physics.ins-det Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by-sa/4.0/ Ziad Hatab, Michael Ernst Gadringer, Arash Arsanjani, Wolfgang Boesch https://arxiv.org/abs/2510.16358 arXiv:2510.16358v3 Announce Type: replace-cross Abstract: The use of quantum light to probe exciton properties in semiconductor and molecular nanostructures typically occurs in the low-intensity regime. A substantial enhancement of exciton-photon coupling can be achieved with photonic cavities, where excitons hybridize with cavity modes to form polariton states. To provide a theoretical framework for interpreting emerging experimental efforts in this direction, we develop a scattering theory describing the interaction of frequency-entangled photon pairs with cavity polariton and bipolariton states under various coupling regimes. Employing the Tavis-Cummings model in combination with our scattering approach, we present a quantitative analysis of how the interaction of the entangled photon pair with the polariton/bipolariton modifies its joint spectral amplitude (JSA). Specifically, we examine the effects of the cavity-mode steady-state population, exciton-cavity coupling strength, and different forms of the input photon JSA. Our results show that the entanglement entropy of the scattered photons is highly sensitive to the interplay between the input JSA and the spectral line shapes of the polariton resonances, emphasizing the cavity filtering effects. We suggest that biphoton scattering quantum light spectroscopy best serves as a sensitive probe of polariton and bipolariton states in the photon-vacuum cavity state. Our approach is not only robust to various regimes of cavity-exciton coupling, but also amenable to extensions beyond the Tavis-Cummings model, enabling the representation of a broad class of molecular systems and solid state quantum materials. oai:arXiv.org:2510.16358v3 quant-ph physics.optics Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Andrei Piryatinski, Nishaant Jacobus, Sameer Dambal, Eric R. Bittner, Yu Zhang, Ajay Ram Srimath Kandada https://arxiv.org/abs/2510.23729 arXiv:2510.23729v2 Announce Type: replace-cross Abstract: We present hydrodynamic simulations with the moving-mesh code AREPO of Tidal Disruption Encores (TDEEs) in nuclear star clusters (NSCs). TDEEs arise when a stellar-mass black hole (sBH) disrupts a star within the NSC, producing debris that is unbound from the sBH but remains gravitationally bound to the central massive black hole (MBH), leading to a delayed secondary flare. We find that the morphology and thermodynamics of the fallback material depend sensitively on the disruption geometry, MBH mass, and sBH-MBH separation. We identify two distinct morphological outcomes: ring encores, where debris circularize into a torus, and direct encores, where streams plunge toward the MBH, with encore luminosities peaking at times corresponding to the freefall timescale and one orbital period, respectively. Across all simulated cases, we find these events exhibit luminosities of $10^{40}-10^{42}$ erg/s with lightcurves characteristic of their morphology. Our work greatly improves the predictions of TDEE lightcurves and empowers observations to probe into NSC dynamics and sBH population while providing possible explanations for anomalous TDE-like flares. oai:arXiv.org:2510.23729v2 astro-ph.HE physics.comp-ph Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ Ian P. A. Johnson, Taeho Ryu, Rosalba Perna https://arxiv.org/abs/2512.19870 arXiv:2512.19870v2 Announce Type: replace-cross Abstract: Electronic excited states are central to a vast array of physical and chemical phenomena, yet accurate and efficient methods for preparing them on quantum devices remain challenging and comparatively underexplored. We introduce a general dissipative algorithm for selectively preparing ab initio electronic excited states. The key idea is to recast excited-state preparation as an effective ground-state problem by suitably modifying the underlying Lindblad dynamics so that the target excited state becomes the unique steady state of a designed quantum channel. We develop three complementary strategies, tailored to different types of prior information about the excited state, such as symmetry and approximate energy. We demonstrate the effectiveness and versatility of these schemes through numerical simulations of atomic and molecular spectra, including valence excitations in prototypical planar conjugated molecules and transition-metal complexes. Taken together, these results provide a new pathway for advancing quantum simulation methods for realistic strongly correlated electronic systems. oai:arXiv.org:2512.19870v2 quant-ph physics.chem-ph Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by/4.0/ Hao-En Li, Lin Lin https://arxiv.org/abs/2601.12941 arXiv:2601.12941v2 Announce Type: replace-cross Abstract: Background: Digital Image Correlation (DIC) is a widely used full-field measurement technique, but both open-source and commercial packages often have limitations such as operating-system restrictions, lack of support for deployment on computing clusters, and poor scalability to gigapixel-scale images common in Scanning Electron Microscopy DIC (SEM-DIC). Objective: Pyvale is an open-source software package designed for sensor simulation, uncertainty quantification, placement optimization, and calibration/validation. A key component of this is the development of a dedicated 2D DIC module intended for standalone use and integration within broader workflows. Methods: Pyvale provides a user-friendly Python interface with performant compiled routines underneath. At its core is a multithreaded, reliability-guided DIC algorithm. Its open-source MIT license enables wide deployment, including on computing clusters and in automated pipelines. Results: Benchmarking with the publicly available 2D DIC challenge 2.0 dataset shows that Pyvale achieves metrological performance comparable to existing commercial and open-source DIC codes. It can correlate gigapixel-scale image pairs in under 5 minutes on high-specification desktop workstations, with memory peaking at approximately 50 GB. Conclusions: Pyvale's strong metrological foundation, coupled with its scalability for SEM-DIC, positions it as a platform for sustained, community-driven development. Its design and licensing provide a foundation for future improvements in open-source DIC and integration into experimental design and validation workflows. oai:arXiv.org:2601.12941v2 eess.IV cond-mat.mtrl-sci physics.data-an Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://creativecommons.org/licenses/by-nc-sa/4.0/ Joel Hirst, Lorna Sibson, Adel Tayeb, Ben Poole, Megan Sampson, Wiera Bielajewa, Michael Atkinson, Alex Marsh, Rory Spencer, Rob Hamill, Cory Hamelin, Allan Harte, Lloyd Fletcher https://arxiv.org/abs/2601.16941 arXiv:2601.16941v2 Announce Type: replace-cross Abstract: We theoretically compare the quantum Fisher information (QFI) for three configurations of absorption spectroscopy with undetected idler photons: an SU(1,1) interferometer with inter-source idler loss, an induced-coherence (IC) setup in which the idler partially seeds a second squeezer together with a vacuum ancilla, and a distributed-loss (DL) scheme with in-medium attenuation. We calculate the QFI as a function of parametric gain for both full and signal-only detection access. For losses below 99% and low to moderate gain, the SU(1,1) configuration provides the largest QFI. At high gain and intermediate loss, the IC scheme performs best, while under extreme attenuation (transmission $<$ 1%) the DL model becomes optimal. These results delineate the measurement regimes in which each architecture is optimal in terms of information theory. oai:arXiv.org:2601.16941v2 quant-ph physics.optics Mon, 02 Feb 2026 00:00:00 -0500 replace-cross http://arxiv.org/licenses/nonexclusive-distrib/1.0/ Martin Houde, Franz Roeder, Christine Silberhorn, Benjamin Brecht, Nicol\'as Quesada