title
string | abstract
string | url
string | arxiv_id
string | date
string | category
string |
|---|---|---|---|---|---|
11D Supergravity and Hidden Symmetries
|
We review the structure of maximal $D=11$ and $D=10$ supergravities. Upon dimensional reduction, these theories give rise to the unique maximal supergravities in all lower spacetime dimensions $D<10$. In $D$ dimensions, maximal supergravity exhibits the exceptional global symmetry group E$_{11-D}$, part of which is realized as hidden symmetries and only manifest after proper dualization of the fields. We also briefly review the reformulation of $D=11$ supergravity as an exceptional field theory which renders the appearance of hidden symmetries manifest.
|
https://arxiv.org/abs/2303.12682v2
|
2303.12682
|
2023-03-22
|
natural-language-processing
|
(1+1)-d U(1) Quantum link models from effective Hamiltonians of dipolar molecules
|
We study the promising idea of using dipolar molecular systems as analog
quantum simulators for quantum link models, which are discrete versions of
lattice gauge theories. In a quantum link model the link variables have a
finite number of degrees of freedom and discrete values. We construct the
effective Hamiltonian of a system of dipolar molecules with electric
dipole-dipole interactions, where we use the tunable parameters of the system
to match it to the target Hamiltonian describing a U(1) quantum link model in
1+1 dimensions.
|
http://arxiv.org/abs/2001.10002v1
|
2001.10002
|
2020-01-27
|
natural-language-processing
|
(1+1) Genetic Programming With Functionally Complete Instruction Sets Can Evolve Boolean Conjunctions and Disjunctions with Arbitrarily Small Error
|
Recently it has been proven that simple GP systems can efficiently evolve a conjunction of $n$ variables if they are equipped with the minimal required components. In this paper, we make a considerable step forward by analysing the behaviour and performance of a GP system for evolving a Boolean conjunction or disjunction of $n$ variables using a complete function set that allows the expression of any Boolean function of up to $n$ variables. First we rigorously prove that a GP system using the complete truth table to evaluate the program quality, and equipped with both the AND and OR operators and positive literals, evolves the exact target function in $O(\ell n \log^2 n)$ iterations in expectation, where $\ell \geq n$ is a limit on the size of any accepted tree. Additionally, we show that when a polynomial sample of possible inputs is used to evaluate the solution quality, conjunctions or disjunctions with any polynomially small generalisation error can be evolved with probability $1 - O(\log^2(n)/n)$. The latter result also holds if GP uses AND, OR and positive and negated literals, thus has the power to express any Boolean function of $n$ distinct variables. To prove our results we introduce a super-multiplicative drift theorem that gives significantly stronger runtime bounds when the expected progress is only slightly super-linear in the distance from the optimum.
|
https://arxiv.org/abs/2303.07455v1
|
2303.07455
|
2023-03-13
|
natural-language-processing
|
11K Hands: Gender recognition and biometric identification using a large dataset of hand images
|
The human hand possesses distinctive features which can reveal gender
information. In addition, the hand is considered one of the primary biometric
traits used to identify a person. In this work, we propose a large dataset of
human hand images (dorsal and palmar sides) with detailed ground-truth
information for gender recognition and biometric identification. Using this
dataset, a convolutional neural network (CNN) can be trained effectively for
the gender recognition task. Based on this, we design a two-stream CNN to
tackle the gender recognition problem. This trained model is then used as a
feature extractor to feed a set of support vector machine classifiers for the
biometric identification task. We show that the dorsal side of hand images,
captured by a regular digital camera, convey effective distinctive features
similar to, if not better, those available in the palmar hand images. To
facilitate access to the proposed dataset and replication of our experiments,
the dataset, trained CNN models, and Matlab source code are available at
(https://goo.gl/rQJndd).
|
http://arxiv.org/abs/1711.04322v9
|
1711.04322
|
2017-11-12
|
natural-language-processing
|
(1,1) L-space knots
|
We characterize the (1, 1) knots in the three-sphere and lens spaces that
admit non-trivial L-space surgeries. As a corollary, 1-bridge braids in these
manifolds admit non- trivial L-space surgeries. We also recover a
characterization of the Berge manifold amongst 1-bridge braid exteriors.
|
http://arxiv.org/abs/1610.04810v2
|
1610.04810
|
2018-01-14
|
natural-language-processing
|
11-{\mu}s Time-resolved, Continuous Dual-Comb Spectroscopy with Spectrally Filtered Mode-locked Frequency Combs
|
Broadband dual-comb spectroscopy (DCS) based on portable mode-locked fiber
frequency combs is a powerful tool for in situ, calibration free, multi-species
spectroscopy. While the acquisition of a single spectrum with mode-locked DCS
typically takes microseconds to milliseconds, the applications of these
spectrometers have generally been limited to systems and processes with time
changes on the order of seconds or minutes due to the need to average many
spectra to reach a high signal-to-noise ratio (SNR). Here, we demonstrate
high-speed, continuous, fiber mode-locked laser DCS with down to 11 $\mu$s time
resolution. We achieve this by filtering the comb spectra using portable
Fabry-Perot cavities to generate filtered combs with 1 GHz tooth spacing. The 1
GHz spacing increases the DCS acquisition speed and SNR for a given optical
bandwidth while retaining a sufficient spacing to resolve absorption features
over a wide range of conditions. We measure spectra of methane inside a rapid
compression machine throughout the 16 ms compression cycle with 133 cm$^{-1}$
bandwidth (4000 comb teeth) and 1.4 ms time resolution by spectrally filtering
one of the combs. By filtering both combs, we measured a single-shot, 25
cm$^{-1}$ (750 comb teeth) spectrum of CO around 6330 cm$^{-1}$ in 11 $\mu$s.
The technique enables simultaneously high-speed and high-resolution DCS
measurements, and can be applied anywhere within the octave-spanning spectrum
of robust and portable fiber mode-locked frequency combs.
|
http://arxiv.org/abs/2005.13050v1
|
2005.13050
|
2020-05-26
|
natural-language-processing
|
(1+1) Newton-Hooke Group for the Simple and Damped Harmonic Oscillator
|
It is demonstrated that, in the framework of the orbit method, a simple and
damped harmonic oscillators are indistinguishable at the level of an abstract
Lie algebra. This opens a possibility for treating the dissipative systems
within the orbit method. In depth analysis of the coadjoint orbits of the
$(1+1)$ dimensional Newton-Hooke group are presented. Further, it is argued
that the physical interpretation is carried by a specific realisation of the
Lie algebra of smooth functions on a phase space rather than by an abstract Lie
algebra.
|
http://arxiv.org/abs/1703.09583v2
|
1703.09583
|
2017-05-16
|
natural-language-processing
|
11 New Transiting Brown Dwarfs and Very Low Mass Stars from TESS
|
We present the discovery of 11 new transiting brown dwarfs and low-mass M-dwarfs from NASA's TESS mission: TOI-2844, TOI-3122, TOI-3577, TOI-3755, TOI-4462, TOI-4635, TOI-4737, TOI-4759, TOI-5240, TOI-5467, and TOI-5882. They consist of 5 brown dwarf companions and 6 very low mass stellar companions ranging in mass from $25 M_{\rm J}$ to $128 M_{\rm J}$. We used a combination of photometric time-series, spectroscopic, and high resolution imaging follow-up as a part of the TESS Follow-up Observing Program (TFOP) in order to characterize each system. With over 50 transiting brown dwarfs confirmed, we now have a large enough sample to directly test different formation and evolutionary scenarios. We provide a renewed perspective on the transiting brown dwarf desert and its role in differentiating between planetary and stellar formation mechanisms. Our analysis of the eccentricity distribution for the transiting brown dwarf sample does not support previous claims of a transition between planetary and stellar formation at $\sim42$ $M_{\rm J}$. We also contribute a first look into the metallicity distribution of transiting companions in the range $7 - 150$ $M_{\rm J}$, showing that this too does not support a $\sim42$ $M_{\rm J}$ transition. Finally, we also detect a significant lithium absorption feature in one of the brown dwarf hosts (TOI-5882) but determine that the host star is likely old based on rotation, kinematic, and photometric measurements. We therefore claim that TOI-5882 may be a candidate for planetary engulfment.
|
https://arxiv.org/abs/2501.09795v1
|
2501.09795
|
2025-01-16
|
natural-language-processing
|
1:1 orbital resonance of circumbinary planets
|
The recent detection of the third planet in Kepler-47 has shown that binary
stars can host several planets in circumbinary orbits. To understand the
evolution of such systems we have performed two-dimensional hydrodynamic
simulations of the circumbinary disc with two embedded planets for several
Kepler systems. In two cases, Kepler-47 and -413, the planets are captured in a
1:1 mean-motion resonance at the planet parking position near the inner edge of
the disc. The orbits are fully aligned, have mean eccentricities of about 0.25
to 0.30, and the planets are entangled in a horseshoe type of motion.
Subsequent n-body simulations without the disc show that the configurations are
stable. Our results point to the existence of a new class of stable resonant
orbits around binary stars. It remains to be seen if such orbits exist in
reality.
|
http://arxiv.org/abs/1908.10395v1
|
1908.10395
|
2019-08-27
|
natural-language-processing
|
11 Summaries of Papers on Explainable Reinforcement Learning With Some Commentary
|
Model interpretability was a bullet point in Concrete Problems in AI Safety (2016). Since then, interpretability has come to comprise entire research directions in technical safety agendas (2020). It is safe to say that interpretability is now a very popular area of research. In fact, the topic is sufficiently mainstream that there are books on the topic and corporate services promising to provide it.
Interpretability for reinforcement learning, however, has received much less attention than for supervised learning. So what's the state of research on this topic? What does progress in interpretable RL look like, and are we making progress?
What is this post? This post summarizes 11 recent papers on explaining reinforcement learning agents (in ICLR and related conferences), then provides commentary on the research. The summaries - and not the commentary - are the main point of this post. Though people like paper summaries, this is the kind of interpretive labor that isn't traditionally awarded space in research venues. We primarily select papers appearing between 2018 and 2020, in order to bridge the gap between foundational papers published in 2010-2017 and the more recent and diverse directions of research in the field.
|
https://openreview.net/forum?id=esxSIHrH2n
| null |
2022-01-17
|
natural-language-processing
|
11 T Dipole for the Dispersion Suppressor Collimators
|
Chapter 11 in High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary
Design Report. The Large Hadron Collider (LHC) is one of the largest scientific
instruments ever built. Since opening up a new energy frontier for exploration
in 2010, it has gathered a global user community of about 7,000 scientists
working in fundamental particle physics and the physics of hadronic matter at
extreme temperature and density. To sustain and extend its discovery potential,
the LHC will need a major upgrade in the 2020s. This will increase its
luminosity (rate of collisions) by a factor of five beyond the original design
value and the integrated luminosity (total collisions created) by a factor ten.
The LHC is already a highly complex and exquisitely optimised machine so this
upgrade must be carefully conceived and will require about ten years to
implement. The new configuration, known as High Luminosity LHC (HL-LHC), will
rely on a number of key innovations that push accelerator technology beyond its
present limits. Among these are cutting-edge 11-12 tesla superconducting
magnets, compact superconducting cavities for beam rotation with ultra-precise
phase control, new technology and physical processes for beam collimation and
300 metre-long high-power superconducting links with negligible energy
dissipation. The present document describes the technologies and components
that will be used to realise the project and is intended to serve as the basis
for the detailed engineering design of HL-LHC.
|
http://arxiv.org/abs/1705.09497v1
|
1705.09497
|
2017-05-26
|
natural-language-processing
|
11 TeraFLOPs per second photonic convolutional accelerator for deep learning optical neural networks
|
Convolutional neural networks (CNNs), inspired by biological visual cortex systems, are a powerful category of artificial neural networks that can extract the hierarchical features of raw data to greatly reduce the network parametric complexity and enhance the predicting accuracy. They are of significant interest for machine learning tasks such as computer vision, speech recognition, playing board games and medical diagnosis. Optical neural networks offer the promise of dramatically accelerating computing speed to overcome the inherent bandwidth bottleneck of electronics. Here, we demonstrate a universal optical vector convolutional accelerator operating beyond 10 TeraFLOPS (floating point operations per second), generating convolutions of images of 250,000 pixels with 8 bit resolution for 10 kernels simultaneously, enough for facial image recognition. We then use the same hardware to sequentially form a deep optical CNN with ten output neurons, achieving successful recognition of full 10 digits with 900 pixel handwritten digit images with 88% accuracy. Our results are based on simultaneously interleaving temporal, wavelength and spatial dimensions enabled by an integrated microcomb source. This approach is scalable and trainable to much more complex networks for demanding applications such as unmanned vehicle and real-time video recognition.
|
https://arxiv.org/abs/2011.07393v1
|
2011.07393
|
2020-11-14
|
natural-language-processing
|
11th Low-Level RF Workshop (LLRF2023)
|
This volume contains contributions presented at the 11th Low-Level RF Workshop which was held in Gyeongju, South Korea on October 22-27, 2023. This workshop continued the series of successful international workshops held in Newport News, USA (2001), Geneva, Switzerland (2005), Knoxville, USA (2007), Tsukuba, Japan (2009), Hamburg, Germany (2011), Tahoe City, USA (2013), Shanghai, China (2015), Barcelona, Spain (2017), Chicago, USA (2019), and Brugg-Windisch, Switzerland (2023).
|
https://arxiv.org/abs/2310.03199v4
|
2310.03199
|
2023-10-04
|
natural-language-processing
|
11 x 11 Domineering is Solved: The first player wins
|
We have developed a program called MUDoS (Maastricht University Domineering
Solver) that solves Domineering positions in a very efficient way. This enables
the solution of known positions so far (up to the 10 x 10 board) much quicker
(measured in number of investigated nodes).
More importantly, it enables the solution of the 11 x 11 Domineering board, a
board up till now far out of reach of previous Domineering solvers. The
solution needed the investigation of 259,689,994,008 nodes, using almost half a
year of computation time on a single simple desktop computer. The results show
that under optimal play the first player wins the 11 x 11 Domineering game,
irrespective if Vertical or Horizontal starts the game.
In addition, several other boards hitherto unsolved were solved. Using the
convention that Vertical starts, the 8 x 15, 11 x 9, 12 x 8, 12 x 15, 14 x 8,
and 17 x 6 boards are all won by Vertical, whereas the 6 x 17, 8 x 12, 9 x 11,
and 11 x 10 boards are all won by Horizontal.
|
http://arxiv.org/abs/1602.05404v1
|
1602.05404
|
2016-02-17
|
natural-language-processing
|
120 Domain-Specific Languages for Security
|
Security engineering, from security requirements engineering to the implementation of cryptographic protocols, is often supported by domain-specific languages (DSLs). Unfortunately, a lack of knowledge about these DSLs, such as which security aspects are addressed and when, hinders their effective use and further research. This systematic literature review examines 120 security-oriented DSLs based on six research questions concerning security aspects and goals, language-specific characteristics, integration into the software development lifecycle (SDLC), and effectiveness of the DSLs. We observe a high degree of fragmentation, which leads to opportunities for integration. We also need to improve the usability and evaluation of security DSLs.
|
https://arxiv.org/abs/2408.06219v2
|
2408.06219
|
2024-08-12
|
natural-language-processing
|
120-fs single-pulse generation from stretched-pulse fiber Kerr resonators
|
Fiber Kerr resonators are simple driven resonators with desirable wavelength and repetition rate flexibility for generating ultrashort pulses for applications including telecommunications, biomedicine, and materials processing. However, fiber Kerr resonators to date often generate longer pulses and require more complicated techniques for generating single pulses than would be desirable for applications. Here we address these limits by demonstrating robust single-pulse performance with 120-fs pulse durations in fiber Kerr resonators based on stretched-pulse solitons. Through matching numerical and experimental studies, stretched-pulse soliton performance is found to strongly depend on the total cavity length, and the optimum length is found to depend on the drive, Raman scattering, and the total pulse stretching. By designing the cavity for this optimum with the described setup, stable stretched-pulse solitons with 120-fs duration are experimentally observed. In addition, soliton trapping is demonstrated with a pulsed drive source despite large intracavity breathing and single-pulse performance is observed. Robust with high performance single-pulse generation is a critical step toward useful femtosecond pulse generation.
|
https://arxiv.org/abs/2112.03323v2
|
2112.03323
|
2021-12-06
|
natural-language-processing
|
120 GOPS Photonic Tensor Core in Thin-film Lithium Niobate for Inference and in-situ Training
|
Photonics offers a transformative approach to artificial intelligence (AI) and neuromorphic computing by enabling low-latency, high-speed, and energy-efficient computations. However, conventional photonic tensor cores face significant challenges in constructing large-scale photonic neuromorphic networks. Here, we propose a fully integrated photonic tensor core, consisting of only two thin-film lithium niobate (TFLN) modulators, a III-V laser, and a charge-integration photoreceiver. Despite its simple architecture, it is capable of implementing an entire layer of a neural network with a computational speed of 120 GOPS, while also allowing flexible adjustment of the number of inputs (fan-in) and outputs (fan-out). Our tensor core supports rapid in-situ training with a weight update speed of 60 GHz. Furthermore, it successfully classifies (supervised learning) and clusters (unsupervised learning) 112 * 112-pixel images through in-situ training. To enable in-situ training for clustering AI tasks, we offer a solution for performing multiplications between two negative numbers.
|
https://arxiv.org/abs/2311.16896v3
|
2311.16896
|
2023-11-28
|
natural-language-processing
|
120 km single-photon Brillouin optical time domain reflectometry
|
We present a novel distributed Brillouin optical time domain reflectometer (BOTDR) using standard telecommunication fibers based on single-photon avalanche diodes (SPADs) in gated mode, hd-BOTDR, with a range of 120 km and 10 m spatial resolution. We experimentally demonstrate the ability to perform a distributed temperature measurement, by detecting a hot spot at 100 km. Instead of using a frequency scan like conventional BOTDR, we use a frequency discriminator based on the slope of a fiber Bragg grating (FBG) to convert the count rate of the SPAD into a frequency shift. A procedure to take into account the FBG drift during the acquisition and perform sensitive and reliable distributed measurements is described. We also present the possibility to differentiate strain and temperature.
|
https://arxiv.org/abs/2302.07065v1
|
2302.07065
|
2023-02-14
|
natural-language-processing
|
120 Tbit/s Transmission over Single Mode Fibre using Continuous 91 nm Hybrid Raman-EDFA Amplification
|
Hybrid distributed Raman-EDFA amplifiers, with a continuous 91 nm gain
bandwidth, are used to enable a record single mode fibre transmission capacity
of 120.0 Tbit/s using 312x35 GBd DP-256QAM over 9x70 km spans.
|
http://arxiv.org/abs/1804.01845v1
|
1804.01845
|
2018-03-16
|
natural-language-processing
|
121,123Sb NQR as a microscopic probe in Te doped correlated semimetal FeSb2 : emergence of electronic Griffith phase, magnetism and metallic behavior %
|
$^{121,123}Sb$ nuclear quadrupole resonance (NQR) was applied to
$Fe(Sb_{1-x}Te_x)_2$ in the low doping regime (\emph{x = 0, 0.01} and
\emph{0.05}) as a microscopic zero field probe to study the evolution of
\emph{3d} magnetism and the emergence of metallic behavior. Whereas the NQR
spectra itself reflects the degree of local disorder via the width of the
individual NQR lines, the spin lattice relaxation rate (SLRR) $1/T_1(T)$ probes
the fluctuations at the $Sb$ - site. The fluctuations originate either from
conduction electrons or from magnetic moments. In contrast to the semi metal
$FeSb_2$ with a clear signature of the charge and spin gap formation in
$1/T_1(T)T ( \sim exp/ (\Delta k_BT) ) $, the 1\% $Te$ doped system exhibits
almost metallic conductivity and a almost filled gap. A weak divergence of the
SLRR coefficient $1/T_1(T)T \sim T^{-n} \sim T^{-0.2}$ points towards the
presence of electronic correlations towards low temperatures wheras the
\textit{5\%} $Te$ doped sample exhibits a much larger divergence in the SLRR
coefficient showing $1/T_1(T)T \sim T^{-0.72} $. According to the specific heat
divergence a power law with $n\ =\ 2\ m\ =\ 0.56$ is expected for the SLRR.
Furthermore $Te$-doped $FeSb_2$ as a disordered paramagnetic metal might be a
platform for the electronic Griffith phase scenario. NQR evidences a
substantial asymmetric broadening of the $^{121,123}Sb$ NQR spectrum for the
\emph{5\%} sample. This has purely electronic origin in agreement with the
electronic Griffith phase and stems probably from an enhanced $Sb$-$Te$ bond
polarization and electronic density shift towards the $Te$ atom inside
$Sb$-$Te$ dumbbell.
|
http://arxiv.org/abs/1710.09571v1
|
1710.09571
|
2017-10-26
|
natural-language-processing
|
1213Li at SemEval-2021 Task 6: Detection of Propaganda with Multi-modal Attention and Pre-trained Models
|
This paper presents the solution proposed by the 1213Li team for subtask 3 in SemEval-2021 Task 6: identifying the multiple persuasion techniques used in the multi-modal content of the meme. We explored various approaches in feature extraction and the detection of persuasion labels. Our final model employs pre-trained models including RoBERTa and ResNet-50 as a feature extractor for texts and images, respectively, and adopts a label embedding layer with multi-modal attention mechanism to measure the similarity of labels with the multi-modal information and fuse features for label prediction. Our proposed method outperforms the provided baseline method and achieves 3rd out of 16 participants with 0.54860/0.22830 for Micro/Macro F1 scores.
|
https://aclanthology.org/2021.semeval-1.142
| null |
2021-08-01
|
natural-language-processing
|
1-2-1: Renaissance of Single-Network Paradigm for Virtual Try-On
|
Virtual Try-On (VTON) has become a crucial tool in ecommerce, enabling the realistic simulation of garments on individuals while preserving their original appearance and pose. Early VTON methods relied on single generative networks, but challenges remain in preserving fine-grained garment details due to limitations in feature extraction and fusion. To address these issues, recent approaches have adopted a dual-network paradigm, incorporating a complementary "ReferenceNet" to enhance garment feature extraction and fusion. While effective, this dual-network approach introduces significant computational overhead, limiting its scalability for high-resolution and long-duration image/video VTON applications. In this paper, we challenge the dual-network paradigm by proposing a novel single-network VTON method that overcomes the limitations of existing techniques. Our method, namely MNVTON, introduces a Modality-specific Normalization strategy that separately processes text, image and video inputs, enabling them to share the same attention layers in a VTON network. Extensive experimental results demonstrate the effectiveness of our approach, showing that it consistently achieves higher-quality, more detailed results for both image and video VTON tasks. Our results suggest that the single-network paradigm can rival the performance of dualnetwork approaches, offering a more efficient alternative for high-quality, scalable VTON applications.
|
https://arxiv.org/abs/2501.05369v1
|
2501.05369
|
2025-01-09
|
natural-language-processing
|
123-321 Models of Classical Novae
|
High-resolution spectroscopy has revealed large concentrations of CNO and
sometimes other intermediate-mass elements in the shells ejected during nova
outbursts, suggesting that the solar composition material transferred from the
secondary mixes with the outermost layers of the underlying white dwarf during
the thermonuclear runaway. Multidimensional simulations have shown that
Kelvin-Helmholtz instabilities provide self-enrichment of the accreted envelope
with material from the outermost layers of the white dwarf, at levels that
agree with observations. However, the Eulerian and time-explicit nature of most
multidimensional codes used to date and the overwhelming computational load
have limited their applicability, and no multidimensional simulation has been
conducted for a full nova cycle. This paper explores a new methodology that
combines 1-D and 3-D simulations. The early stages of the explosion (i.e.,
mass-accretion and initiation of the runaway) have been computed with the 1-D
hydrodynamic code SHIVA. When convection extends throughout the entire
envelope, the structures for each model were mapped into 3-D Cartesian grids
and were subsequently followed with the multidimensional code FLASH. Two key
physical quantities were extracted from the 3-D simulations and subsequently
implemented into SHIVA, which was used to complete the simulation through the
late expansion and ejection stages: the time-dependent amount of mass
dredged-up from the outer white dwarf layers, and the time-dependent convective
velocity profile throughout the envelope. More massive envelopes than those
reported from previous models with pre-enrichment have been found. This results
in more violent outbursts, characterized by higher peak temperatures and
greater ejected masses, with metallicity enhancements in agreement with
observations.
|
http://arxiv.org/abs/1912.08443v1
|
1912.08443
|
2019-12-18
|
natural-language-processing
|
1-2-3-Go! Policy Synthesis for Parameterized Markov Decision Processes via Decision-Tree Learning and Generalization
|
Despite the advances in probabilistic model checking, the scalability of the verification methods remains limited. In particular, the state space often becomes extremely large when instantiating parameterized Markov decision processes (MDPs) even with moderate values. Synthesizing policies for such \emph{huge} MDPs is beyond the reach of available tools. We propose a learning-based approach to obtain a reasonable policy for such huge MDPs. The idea is to generalize optimal policies obtained by model-checking small instances to larger ones using decision-tree learning. Consequently, our method bypasses the need for explicit state-space exploration of large models, providing a practical solution to the state-space explosion problem. We demonstrate the efficacy of our approach by performing extensive experimentation on the relevant models from the quantitative verification benchmark set. The experimental results indicate that our policies perform well, even when the size of the model is orders of magnitude beyond the reach of state-of-the-art analysis tools.
|
https://arxiv.org/abs/2410.18293v2
|
2410.18293
|
2024-10-23
|
natural-language-processing
|
1-2-3 Reproducibility for Quantum Software Experiments
|
Various fields of science face a reproducibility crisis. For quantum software engineering as an emerging field, it is therefore imminent to focus on proper reproducibility engineering from the start. Yet the provision of reproduction packages is almost universally lacking. Actionable advice on how to build such packages is rare, particularly unfortunate in a field with many contributions from researchers with backgrounds outside computer science. In this article, we argue how to rectify this deficiency by proposing a 1-2-3~approach to reproducibility engineering for quantum software experiments: Using a meta-generation mechanism, we generate DOI-safe, long-term functioning and dependency-free reproduction packages. They are designed to satisfy the requirements of professional and learned societies solely on the basis of project-specific research artefacts (source code, measurement and configuration data), and require little temporal investment by researchers. Our scheme ascertains long-term traceability even when the quantum processor itself is no longer accessible. By drastically lowering the technical bar, we foster the proliferation of reproduction packages in quantum software experiments and ease the inclusion of non-CS researchers entering the field.
|
https://arxiv.org/abs/2201.12031v1
|
2201.12031
|
2022-01-28
|
natural-language-processing
|
1.23-Tb/s per Wavelength Single-Waveguide On-Chip Optical Interconnect Enabled by Mode-division Multiplexing
|
We experimentally demonstrate a record net capacity per wavelength of 1.23~Tb/s over a single silicon-on-insulator (SOI) multimode waveguide for optical interconnects employing on-chip mode-division multiplexing and 11$\times$11 multiple-in-multiple-out (MIMO) digital signal processing.
|
https://arxiv.org/abs/2010.10348v2
|
2010.10348
|
2020-10-17
|
natural-language-processing
|
125 Gbps Pre-Compensated Nonlinear Frequency-Division Multiplexed Transmission
|
Record-high data rate of 125 Gb/s and SE over 2 bits/s/Hz in burst-mode
single-polarization NFDM transmissions were achieved over 976 km of SSMF with
EDFA-only amplification by transmitting and processing 222 32 QAM-modulated
nonlinear subcarriers simultaneously
|
http://arxiv.org/abs/1710.00776v1
|
1710.00776
|
2017-08-25
|
natural-language-processing
|
125 GeV Higgs boson mass and muon g-2 in 5D MSSM
|
In the MSSM, the tension between the observed Higgs boson mass and the
experimental result of the muon $g-2$ measurement requires a large mass
splitting between stops and smuons/charginos/neutralinos. We consider a
5-dimensional (5D) framework of the MSSM with the Randall-Sundrum warped
background metric, and show that such a mass hierarchy is naturally achieved in
terms of geometry. In our setup, the supersymmetry is broken at the ultraviolet
(UV) brane, while all the MSSM multiplets reside in the 5D bulk. An appropriate
choice of the bulk mass parameters for the MSSM matter multiplets can naturally
realize the sparticle mass hierarchy desired to resolve the tension. Gravitino
is localized at the UV brane and hence becomes very heavy, while the gauginos
spreading over the bulk acquire their masses suppressed by the 5th dimensional
volume. As a result, the LSP neutralino is a candidate for the dark matter as
usual in the MSSM. In addition to reproducing the SM-like Higgs boson mass of
around 125 GeV and the measured value of the muon $g-2$, we consider a variety
of phenomenological constraints, and present the benchmark particle mass
spectra which can be explored at the LHC Run-2 in the near future.
|
http://arxiv.org/abs/1606.05329v3
|
1606.05329
|
2016-10-27
|
natural-language-processing
|
125 GeV Higgs decay with lepton flavor violation in the $\mu\nu$SSM
|
Recently, the CMS and ATLAS Collaborations have reported direct searches for
the 125 GeV Higgs decay with lepton flavor violation, $h\rightarrow \mu \tau$.
In this work, we analyze the signal of the lepton flavour violating (LFV) Higgs
decay $h\rightarrow \mu \tau$ in the $\mu$ from $\nu$ Supersymmetric Standard
Model ($\mu\nu$SSM) with slepton flavor mixing. Simultaneously, we consider the
constraints from the LFV decay $\tau \rightarrow \mu \gamma$, the muon
anomalous magnetic dipole moment and the lightest Higgs mass around 125 GeV.
|
http://arxiv.org/abs/1511.08979v2
|
1511.08979
|
2017-01-11
|
natural-language-processing
|
125Te spin-lattice relaxation in a candidate to Weyl semimetals WTe2
|
The tungsten ditelluride WTe2 was suggested to belong to the Weyl semimetal
family. We studied 125Te spin-lattice relaxation and NMR spectra in a WTe2
single crystal within a large range from 28 K up to room temperature.
Measurements were carried out on a Bruker Avance 500 NMR pulse spectrometer for
two orientations of the crystalline c axis, parallel and perpendicular to
magnetic field. Relaxation proved to be single-exponential. The relaxation time
varied depending on the sample position in magnetic field and frequency offset.
The relaxation rate increased about linearly with temperature below 70 K
however the dependence became nearly quadratic at higher temperatures. The
relaxation rate within the total temperature range was fitted using a
theoretical model developed in [41] for Weyl semimetals and assuming the
decrease of the chemical potential with increasing temperature. The results
obtained for 125Te spin-lattice relaxation evidence in favor of the topological
nontriviality of the WTe2 semimetal. The 125Te NMR spectra agreed with the
occurrence of nonequivalent tellurium sites and varied insignificantly with
temperature.
|
http://arxiv.org/abs/2007.12510v2
|
2007.12510
|
2020-07-29
|
natural-language-processing
|
$12\;660$ spotted stars toward the OGLE Galactic bulge fields
|
We present the discovery and statistical analysis of $12\;660$ spotted
variable stars toward and inside the Galactic bulge from over two-decade-long
Optical Gravitational Lensing Experiment (OGLE) data. We devise a new method of
dereddening of individual stars toward the Galactic bulge where strong and
highly nonuniform extinction is present. In effect, $11\;812$ stars were
classified as giants and $848$ as dwarfs. Well defined correlations between the
luminosity, variability amplitude and rotation period were found for the
giants. Rapidly rotating dwarfs with periods $P \leq 2$ d show I-band
amplitudes lower than 0.2 mag which is substantially less than the amplitudes
of up to 0.8 mag observed in giants and slowly rotating dwarfs. We also notice
that amplitudes of stars brighter than $I_0 \approx 16$ mag do not exceed
0.3-0.4 mag. We divide the stars into three groups characterized by correlation
between light and color variations. The positive correlation is characteristic
for stars that are cooler when fainter, which results from the variable
coverage of the stellar surface with spots similar to the sunspots. The
variability of stars that are cooler when brighter (negative correlation) can
be characterized by chemical spots with overabundance of heavy elements inside
and variable line-blanketing effect, which is observed in chemically peculiar
stars. The null correlation may results from very high level of the magnetic
activity with rapidly variable magnetic fields. This division is readily
visible on the color-magnitude diagram (CMD), which suggests that it may depend
on the radius of the stars. We detect 79 flaring objects and discuss briefly
their properties. Among others, we find that relative brightening during flares
is correlated with brightness amplitude.
|
http://arxiv.org/abs/1903.05651v2
|
1903.05651
|
2019-06-19
|
natural-language-processing
|
12.6 dB squeezed light at 1550 nm from a bow-tie cavity for long-term high duty cycle operation
|
Squeezed states are an interesting class of quantum states that have numerous applications. This work presents the design, characterisation, and operation of a bow-tie optical parametric amplifier (OPA) for squeezed vacuum generation. We report the high duty cycle operation and long-term stability of the system that makes it suitable for post-selection based continuous-variable quantum information protocols, cluster-state quantum computing, quantum metrology, and potentially gravitational wave detectors. Over a 50 hour continuous operation, the measured squeezing levels were greater than 10 dB with a duty cycle of 96.6%. Alternatively, in a different mode of operation, the squeezer can also operate 10 dB below the quantum noise limit over a 12 hour period with no relocks, with an average squeezing of 11.9 dB. We also measured a maximum squeezing level of 12.6 dB at 1550 nm. This represents one of the best reported squeezing results at 1550 nm to date for a bow-tie cavity. We discuss the design aspects of the experiment that contribute to the overall stability, reliability, and longevity of the OPA, along with the automated locking schemes and different modes of operation.
|
https://arxiv.org/abs/2211.06632v1
|
2211.06632
|
2022-11-12
|
natural-language-processing
|
128383 (2004 JW52) is an Ordinary Jupiter Trojan Asteroid
|
The Jupiter Trojan asteroid 128383 (2004 JW52) was recently reported to have optical colors that are incongruous with its dynamical class. New and archival observations show that this is not the case. This is a reminder that we must always rule out the possibility that the Point Spread Function (PSF) of a minor planet is blended with that of a background sidereal source in survey images before its colors in the associated survey catalog can be considered reliable.
|
https://arxiv.org/abs/2201.01785v1
|
2201.01785
|
2022-01-05
|
natural-language-processing
|
1.28 and 5.12 Gbps multi-channel twinax cable receiver ASICs for the ATLAS Inner Tracker Pixel Detector Upgrade
|
We present two prototypes of a gigabit transceiver ASIC, GBCR1 and GBCR2,
both designed in a 65-nm CMOS technology for the ATLAS Inner Tracker Pixel
Detector readout upgrade.
The first prototype, GBCR1, has four upstream receiver channels and one
downstream transmitter channel with pre-emphasis. Each upstream channel
receives the data at 5.12 Gbps through a 5 meter AWG34 Twinax cable from an
ASIC driver located on the pixel module and restores the signal from the high
frequency loss due to the low mass cable. The signal is retimed by a recovered
clock before it is sent to the optical transmitter VTRx+. The downstream driver
is designed to transmit the 2.56 Gbps signal from lpGBT to the electronics on
the pixel module over the same cable. The peak-peak jitter (throughout the
paper jitter is always peak-peak unless specified) of the restored signal is
35.4 ps at the output of GBCR1, and 138 ps for the downstream channel at the
cable ends. GBCR1 consumes 318 mW and is tested.
The second prototype, GBCR2, has seven upstream channels and two downstream
channels. Each upstream channel works at 1.28 Gbps to recover the data directly
from the RD53B ASIC through a 1 meter custom FLEX cable followed by a 6 meter
AWG34 Twinax cable. The equalized signal of each upstream channel is retimed by
an input 1.28 GHz phase programmable clock. Compared with the signal at the
FLEX input, the additional jitter of the equalized signal is about 80 ps when
the retiming logic is o . When the retiming logic is on, the jitter is 50 ps at
GBCR2 output, assuming the 1.28 GHz retiming clock is from lpGBT. The
downstream is designed to transmit the 160 Mbps signal from lpGBT through the
same cable connection to RD53B and the jitter is about 157 ps at the cable
ends. GBCR2 consumes about 150 mW when the retiming logic is on. This design
was submitted in November 2019.
|
http://arxiv.org/abs/2008.09738v1
|
2008.09738
|
2020-08-22
|
natural-language-processing
|
128 Identical Quantum Sources Integrated on a Single Silica Chip
|
Quantum technology is playing an increasingly important role due to the
intrinsic parallel processing capabilities endorsed by quantum superposition,
exceeding upper limits of classical performances in diverse fields. Integrated
photonic chip offers an elegant way to construct large-scale quantum systems in
a physically scalable fashion, however, nonuniformity of quantum sources
prevents all the elements from being connected coherently for exponentially
increasing Hilbert space. Here, we experimentally demonstrate 128 identical
quantum sources integrated on a single silica chip. By actively controlling the
light-matter interaction in femtosecond laser direct writing, we are able to
unify the properties of waveguides comprehensively and therefore the
spontaneous four-wave mixing process for quantum sources. We verify the
indistinguishability of the on-chip sources by a series of heralded two-source
Hong-Ou-Mandel interference, with all the dip visibilities above 90%. In
addition, the brightness of the sources is found easily reaching MHz and being
applicable to both discrete-variable and continuous-variable platform, showing
either clear anti-bunching feature or large squeezing parameter under different
pumping regimes. The demonstrated scalability and uniformity of quantum
sources, together with integrated photonic network and detection, will enable
large-scale all-on-chip quantum processors for real-life applications.
|
http://arxiv.org/abs/2005.12918v1
|
2005.12918
|
2020-05-26
|
natural-language-processing
|
129I and 247Cm in Meteorites Constrain the Last Astrophysical Source of Solar r-process Elements
|
The composition of the early Solar System can be inferred from meteorites. Many elements heavier than iron were formed by the rapid neutron-capture process (r process), but the astrophysical sources where this occurred remain poorly understood. We demonstrate that the near-identical half-lives ($\simeq$ 15.6 Myr) of the radioactive r-process nuclei 129I and 247Cm preserve their ratio, irrespective of the time between production and incorporation into the Solar System. We constrain the last r-process source by comparing the measured meteoritic 129I / 247Cm = 438 $\pm$ 184 to nucleosynthesis calculations based on neutron star merger and magneto-rotational supernova simulations. Moderately neutron-rich conditions, often found in merger disk ejecta simulations, are most consistent with the meteoritic value. Uncertain nuclear physics data limit our confidence in this conclusion.
|
https://arxiv.org/abs/2006.04833v2
|
2006.04833
|
2020-06-08
|
natural-language-processing
|
(1, 2) and weak (1, 3) homotopies on knot projections
|
In this paper, we obtain the necessary and sufficient condition that two knot
projections are related by a finite sequence of the first and second flat
Reidemeister moves (Theorem 1). We also consider an equivalence relation that
is called weak (1, 3) homotopy. This equivalence relation occurs by the first
flat Reidemeister move and one of the third flat Reidemeister moves. We
introduce a map sending weak (1, 3) homotopy classes to knot isotopy classes
(Sec. 3). Using the map, we determine which knot projections are trivialized
under weak (1, 3) homotopy (Corollary 3).
|
http://arxiv.org/abs/2004.06312v1
|
2004.06312
|
2020-04-14
|
natural-language-processing
|
1/2 Approximate MMS Allocation for Separable Piecewise Linear Concave Valuations
|
We study fair distribution of a collection of m indivisible goods among a group of n agents, using the widely recognized fairness principles of Maximin Share (MMS) and Any Price Share (APS). These principles have undergone thorough investigation within the context of additive valuations. We explore these notions for valuations that extend beyond additivity. First, we study approximate MMS under the separable (piecewise-linear) concave (SPLC) valuations, an important class generalizing additive, where the best known factor was 1/3-MMS. We show that 1/2-MMS allocation exists and can be computed in polynomial time, significantly improving the state-of-the-art. We note that SPLC valuations introduce an elevated level of intricacy in contrast to additive. For instance, the MMS value of an agent can be as high as her value for the entire set of items. Further, the equilibrium computation problem, which is polynomial-time for additive valuations, becomes intractable for SPLC. We use a relax-and-round paradigm that goes through competitive equilibrium and LP relaxation. Our result extends to give (symmetric) 1/2-APS, a stronger guarantee than MMS. APS is a stronger notion that generalizes MMS by allowing agents with arbitrary entitlements. We study the approximation of APS under submodular valuation functions. We design and analyze a simple greedy algorithm using concave extensions of submodular functions. We prove that the algorithm gives a 1/3-APS allocation which matches the current best-known factor. Concave extensions are hard to compute in polynomial time and are, therefore, generally not used in approximation algorithms. Our approach shows a way to utilize it within analysis (while bypassing its computation), and might be of independent interest.
|
https://arxiv.org/abs/2312.08504v1
|
2312.08504
|
2023-12-13
|
natural-language-processing
|
12-bit Delta-Sigma ADC operating at a temperature of up to 250C in Standard 0.18 $μ$m SOI CMOS
|
Some applications require electronic systems to operate at extremely high temperature. Extending the operating temperature range of automotive-grade CMOS processes -- through the use of dedicated design techniques -- can provide an important cost-effective advantage. We present a second-order discrete-time delta-sigma analog-to-digital converter operating at a temperature of up to 250 $^\circ$C, well beyond the 175 $^\circ$C qualification temperature of the automotive-grade CMOS process used for its fabrication (XFAB XT018). The analog-to-digital converter incorporates design techniques that are effective in mitigating the adverse effects of the high temperature, such as increased leakage currents and electromigration. We use configurations of dummy transistors for leakage compensation, clock-boosting methods to limit pass-gate cross-talk, and we optimized the circuit architecture to ensure stability and accuracy at high temperature. Comprehensive measurements demonstrate that the analog-to-digital converter achieves a signal-to-noise ratio exceeding 93 dB at 250 $^\circ$C, with an effective number of bits of 12, and a power consumption of only 44~mW. The die area of the converter is only 0.065~mm$^2$ and the area overhead of the high-temperature mitigation circuits is only 13.7%. The Schreier Figure of Merit is 140~dB at the maximum temperature of 250 $^\circ$C, proving the potential of the circuit for reliable operation in challenging applications such as gas and oil extraction and aeronautics.
|
https://arxiv.org/abs/2501.00482v1
|
2501.00482
|
2024-12-31
|
natural-language-processing
|
12B(n,gamma)13B reaction as alternative path to astrophysical synthesis of 13C isotope
|
The total cross sections of the neutron radiative capture on 12B at
astrophysical energies to the ground state of 13B have been calculated in the
energy range of 10E-8 to 10 MeV within the framework of a modified potential
cluster model with the classification of orbital states according to Young
diagrams. Reaction rates in the temperature range of 0.01 to 10 T9 and their
analytical parameterization were obtained. The calculated rates of
12B(n,gamma)13B excess the previous results by approximately to one order.
Cross sections and reaction rates of 12C(n,gamma)13C are calculated and
compared to the n10B, n11B, n12B, and p12C reaction rates. It is proposed that
obtained rates of the 12B(n,gamma)13B reaction should be taken into account in
novel scenarios of stable isotope 13C synthesis without of 12C hydrogen
burning.
|
http://arxiv.org/abs/2004.13525v1
|
2004.13525
|
2020-04-26
|
natural-language-processing
|
$1/2$ BPS Structure Constants and Random Matrices
|
We study three point functions of half BPS operators in $\mathcal{N}=4$ super Yang-Mills theory focusing on correltors of two of the operators with dimension of order $\Delta\sim N^2$ and a light single trace operator. These describe vacuum expectation values of type IIB supergravity modes in LLM backgrounds that do not necessarily preserve the same symmetries as the background solution. We propose a class of complex matrix models that fully capture the combinatorics of the problem, and describe their solution in the large $N$ limit. In simple regimes when the dual description is in terms of widely separated condensates of giant gravitons we find that the models are solvable in the large $N$ and can be approximated by unitary Jacobi ensembles; we describe how these distributions are reproduced in the dual bubbling geometry picture for large droplets. In the case of two eigenvalue droplets the model is exactly solvable at finite $N$. As a result we compute all half-BPS structure constants of heavy-heavy-light type, and reproduce the formulas found via holographic renormalization in the large $N$ limit. We also comment on structure constants of three heavy operators.
|
https://arxiv.org/abs/2305.06390v1
|
2305.06390
|
2023-05-10
|
natural-language-processing
|
1/2-BPS vortex strings in $\mathcal{N}=2$ supersymmetric ${\rm U}(1)^N$ gauge theories
|
Strings in $\mathcal{N}=2$ supersymmetric ${\rm U}(1)^N$ gauge theories with
$N$ hypermultiplets are studied in the generic setting of an arbitrary
Fayet-Iliopoulos triplet of parameters for each gauge group and an invertible
charge matrix. Although the string tension is generically of a square-root
form, it turns out that all existing BPS (Bogomol'nyi-Prasad-Sommerfield)
solutions have a tension which is linear in the magnetic fluxes, which in turn
are linearly related to the winding numbers. The main result is a series of
theorems establishing three different kinds of solutions of the so-called
constraint equations, which can be pictured as orthogonal directions to the
magnetic flux in ${\rm SU}(2)_R$ space. We further prove for all cases, that a
seemingly vanishing Bogomol'nyi bound cannot have solutions. Finally, we write
down the most general vortex equations in both master form and Taubes-like
form.
|
http://arxiv.org/abs/2008.13440v1
|
2008.13440
|
2020-08-31
|
natural-language-processing
|
1/2 BPS Wilson loops in non-conformal N = 2 gauge theories and localization: a three-loop analysis
|
We study the 1/2 BPS circular Wilson loop in four-dimensional SU(N), $N = 2$ SYM theories with massless hypermultiplets and non-vanishing $\beta$-function. Using super-symmetric localization on $S_4$ , we map the path-integral associated with this observable onto an interacting matrix model. Despite the breaking of conformal symmetry at the quantum level, we show that, within a specific regime, the matrix model predictions remain consistent with the perturbative results in flat space up to order $g^6$ . At this order, our analysis reveals that the reorganization of Feynman diagrams based on the matrix model interaction potential, widely tested in (super)conformal models, also applies to these non-conformal set-ups and is realized by interference mechanisms.
|
https://arxiv.org/abs/2410.14847v1
|
2410.14847
|
2024-10-18
|
natural-language-processing
|
12C+12C Reaction Rates and the Evolution of a Massive Star
|
Carbon fusion is important to understand the late stages in the evolution of a massive star. Astronomically interesting energy ranges for the 12C+12C reactions have been, however, poorly constrained by experiments. Theoretical studies on stellar evolution have relied on reaction rates that are extrapolated from those measured in higher energies. In this work, we update the carbon fusion reaction rates by fitting the astrophysical S-factor data obtained from direct measurements based on the Fowler, Caughlan, & Zimmerman (1975) formula. We examine the evolution of a 20 M_sun star with the updated 12C+12C reaction rates performing simulations with the MESA (Modules for Experiments for Stellar Astrophysics) code. Between 0.5 and 1 GK, the updated reaction rates are 0.35 to 0.5 times less than the rates suggested by Caughlan and Fowler (1988). The updated rates result in the increase of core temperature by about 7% and of the neutrino cooling by about a factor of three. Moreover, the carbon-burning lifetime is reduced by a factor of 2.7. The updated carbon fusion reaction rates lead to some changes in the details of the stellar evolution model, their impact seems relatively minor compared to other uncertain physical factors like convection, overshooting, rotation, and mass-loss history. The astrophysical S-factor measurements in lower energies have large errors below the Coulomb barrier. More precise measurements in lower energies for the carbon burning would be useful to improve our study and to understand the evolution of a massive star.
|
https://arxiv.org/abs/2406.13458v1
|
2406.13458
|
2024-06-19
|
natural-language-processing
|
$^{12}$C+$^{12}$C scattering as the reference system for reaction cross section
|
In our previous paper, we tested the chiral (Kyushu) folding model for $^{12}$C+$^{12}$C scattering, since the profile function in the Glauber mode is constructed for the system. We found that the folding model is reliable for reaction cross sections $\sigma_{\rm R}$ in $30 \lsim E_{\rm lab} \lsim 100 $~MeV and $250 \lsim E_{\rm lab} \lsim 400 $~MeV. Accurate data are available for $^{12}$C scattering on $^{9}$Be, $^{12}$C, $^{27}$Al targets in $30 \lsim E_{\rm lab} \lsim 400 $~MeV. We determine matter radius $r_{m}({\rm exp})$ of $^{12}$C from the accurate $\sigma_{\rm R}({\rm exp})$, using the Kyushu $g$-matrix folding model. Our result is $r_{\rm m}^{12}({\rm exp}) =2.352 \pm 0.013$~fm for $^{12}$C. The model is applied for the accurate data on $^{12}$C+$^{27}$Al scattering, and yields $r_{\rm m}({\rm exp}) =2.936 \pm 0.012$~fm for $^{27}$Al. Our conclusion is that $r_{\rm m}({\rm exp}) =2.352 \pm 0.013$~fm agrees with $r_{\rm m}({\rm exp}) =2.35 \pm 0.02$~fm determined from interaction cross sections by Tanihata {\it et. al.}.
|
https://arxiv.org/abs/2306.15178v1
|
2306.15178
|
2023-06-27
|
natural-language-processing
|
12C/13C isotopic ratios in red-giant stars of the open cluster NGC 6791
|
Carbon isotope ratios, along with carbon and nitrogen abundances, are derived
in a sample of 11 red-giant members of one of the most metal-rich clusters in
the Milky Way, NGC 6791. The selected red-giants have a mean metallicity and
standard deviation of [Fe/H]=+0.39+-0.06 (Cunha et al. 2015). We used high
resolution H-band spectra obtained by the SDSS-IV Apache Point Observatory
Galactic Evolution Experiment (APOGEE). The advantage of using high-resolution
spectra in the H-band is that lines of CO are well represented and their line
profiles are sensitive to the variation of 12C/13C. Values of the 12C/13C ratio
were obtained from a spectrum synthesis analysis. The derived 12C/13C ratios
varied between 6.3 and 10.6 in NGC 6791, in agreement with the final isotopic
ratios from thermohaline-induced mixing models. The ratios derived here are
combined with those obtained for more metal poor red-giants from the literature
to examine the correlation between 12C/13C, mass, metallicity and evolutionary
status.
|
http://arxiv.org/abs/1711.08183v2
|
1711.08183
|
2017-11-28
|
natural-language-processing
|
$^{12}$C/$^{13}$C of Kepler giant stars: the missing piece of the mixing puzzle
|
Despite a rich observational background, few spectroscopic studies have dealt with the measurement of the carbon isotopic ratio in giant stars. However, it is a key element in understanding the mixing mechanisms that occur in the interiors of giant stars. We present the CNO and $^{12}$C/$^{13}$C abundances derived for 71 giant field stars. Then, using this new catalogue and complementary data from the Kepler and Gaia satellites, we study the efficiency of mixing occurring in the giant branch as a function of the stellar properties. We have determined the abundances of CNO and more specifically 12C/13C using the FIES Spectrograph on the Nordic Optical Telescope, for 71 giant field stars. In addition, asteroseismology is available for all stars, providing their mass, age as well as the evolutionary states. Finally, astrometry from Gaia data is also available for the majority of the sample. We compare these new determinations with stellar evolution models taking into account the effects of transport processes. To exploit the complete potential of our extensive catalogue and considering both the Galactic evolution and the impact of stellar evolution, we built mock catalogues using the Besancon Galaxy model in which stellar evolution models taking into account the effects of thermohaline instability are included. We confirm that 12C/13C at the surface of core He-burning stars is lower than that of first ascent RGB stars. 12C/13C measured at the surface of the core He-burning stars increases with [Fe/H] and mass while it decreases with age. These trends are all very well explained by the thermohaline mixing that occurs in red giants. We have shown that our models can explain the behaviour of 12C/13C versus N/O, although the observations seem to show a lower N/O than the models. We also note that more constraints on the thick disc core He-burning stars are needed to understand this difference.
|
https://arxiv.org/abs/2312.08197v1
|
2312.08197
|
2023-12-13
|
natural-language-processing
|
12C/13C ratio and CNO abundances in the classical very old metal-poor dwarf HD 140283
|
The isotope abundances provide powerful diagnostics of the chemical enrichment in our Galaxy. The star HD 140283 is one of the best-studied very metal-poor dwarf stars. It is very old, and the chemical abundance in this star is a good witness of the chemical composition of the matter in the early Galaxy. The aim of this work is to measure the precise abundances of carbon, nitrogen, oxygen, and mainly the 12C/13C isotopic ratio in this very old metal-poor star in order to have a good reference for the computations of the chemical evolution of the Galaxy. We used very high spectral resolution data, with extremely high signal-to-noise ratios obtained with the spectrographs ESPaDOnS at the CFHT, ESPRESSO at the VLT, and HARPS at the ESO 3.6m telescope. For the first time, we were able to measure the 12C/13C ratio in a very old metal-poor dwarf that was born at the very beginning of the Galaxy: 27 < 12C/13C < 45. We also obtained a precise determination of the abundance of the CNO elements in this star. These abundances suggest that the effect of super-asymptotic giant branch stars or fast-rotating massive stars was significant in the early Galaxy.
|
https://arxiv.org/abs/2108.04072v1
|
2108.04072
|
2021-08-09
|
natural-language-processing
|
$^{12}$C and $α$-clusters, $0^+$ spectrum, and Hoyle-state candidates in $^{24}$Mg
|
Background: A recent inelastic alpha-scattering experiment [Phys. Rev. Lett. 129, 102701 (2022)] found $0^+$ resonances in $^{24}$Mg on and above the $^{12}$C+$^{12}$C break-up threshold. It has been conjectured that the states have a $^{12}$C+$^{12}$C cluster structure, and play a similar role in accelerating $^{12}$C+$^{12}$C fusion to the manner in which the Hoyle state accelerates production of $^{12}$C in massive stars. Purpose: We wish to build up a quantitative theoretical basis for the considerations of the Hoyle-state paradigm, by calculating the distribution of the $0^+$ states in the shell, as well as in the relevant cluster models. Methods: We determine the spectrum of excited $0^+$ states in $^{24}$Mg nucleus using multiconfigurational dynamical symmetry calculations leading to a unified description of the quartet (or shell), $^{12}$C+$^{12}$C and $^{20}$Ne+$^{4}$He cluster configurations. Results: The density of $0^+$ states in the quartet spectrum is comparable to that found in experiment; however, the density of cluster states is considerably less. Conclusions: The recently observed alpha-scattering resonances do not seem to be simple $^{12}$C+$^{12}$C cluster states, but are more plausibly interpreted as fragmented cluster states due to coupling to quartet excitations, as background states.
|
https://arxiv.org/abs/2312.08318v1
|
2312.08318
|
2023-12-13
|
natural-language-processing
|
$^{12}$C(e,e'pN) Measurements of Short Range Correlations in the Tensor-to-Scalar Interaction Transition Region
|
High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the $^{12}$C$(e,e'p)$ and $^{12}$C$(e,e'pN)$ reactions (where $N$ is either $n$ or $p$), at high-$Q^2$ and $x_B>1.1$. The data span a missing-momentum range of 300--1000 MeV/c and are predominantly sensitive to the transition region of the strong nuclear interaction from a Tensor to Scalar interaction. The data are well reproduced by theoretical calculations using the Generalized Contact Formalism with both chiral and phenomenological nucleon-nucleon ($NN$) interaction models. This agreement suggests that the measured high missing-momentum protons up to $1000$ MeV/c predominantly belong to short-ranged correlated (SRC) pairs. The measured $^{12}$C$(e,e'pN)$ / $^{12}$C$(e,e'p)$ and $^{12}$C$(e,e'pp)$ / $^{12}$C$(e,e'pn)$ cross-section ratios are consistent with a decrease in the fraction of proton-neutron SRC pairs and increase in the fraction of proton-proton SRC pairs with increasing missing momentum. This confirms the transition from an isospin-dependent tensor $NN$ interaction at $\sim 400$ MeV/c to an isospin-independent scalar interaction at high-momentum around $\sim 800$ MeV/c as predicted by theoretical calculation.
|
https://arxiv.org/abs/2004.07304v2
|
2004.07304
|
2020-04-15
|
natural-language-processing
|
12CO (3-2) High-Resolution Survey (COHRS) of the Galactic Plane: Complete Data Release
|
We present the full data release of 12CO (3-2) High-Resolution Survey (COHRS), which has mapped the inner Galactic plane over the range of 9.5$^{\circ}$ $\le$ l $\le$ 62.3$^{\circ}$ and $|b| \le 0.5^{\circ}$. The COHRS has been carried out using the Heterodyne Array Receiver Program (HARP) on the 15 m James Clerk Maxwell Telescope (JCMT) in Hawaii. The released data are smoothed to have a spatial resolution of 16.6 arcsec and a velocity resolution of 0.635 km/s, achieving a mean root-mean-square of $\sim 0.6$ K on $T_\mathrm{A}^*$. The COHRS data are useful for investigating detailed three-dimensional structures of individual molecular clouds and large-scale structures such as spiral arms in the Galactic plane. Furthermore, data from other available public surveys of different CO isotopologues and transitions with similar angular resolutions to this survey, such as FUGIN, SEDIGISM, and CHIMPS/CHIMPS2, allow studying the physical properties of molecular clouds and comparing their states with each other. In this paper, we report further observations on R2 and improved data reduction since the original COHRS release. We discuss the characteristics of the COHRS data and present integrated-emission images and a position-velocity (PV) map of the region covered. The PV map shows a good match with the spiral-arm traces from the existing CO and HI surveys. We also obtain and compare integrated one-dimensional distributions of 12CO (1-0) and (3-2) and those of star-forming populations to each other.
|
https://arxiv.org/abs/2210.05570v1
|
2210.05570
|
2022-10-11
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natural-language-processing
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12CO and 13CO J=3-2 observations toward N11 in the Large Magellanic Cloud
|
After 30 Doradus, N11 is the second largest and brightest nebula in the LMC.
This large nebula has several OB associations with bright nebulae at its
surroundings. N11 was previously mapped at the lowest rotational transitions of
$^{12}$CO (J=1--0 and 2--1), and in some particular regions pointings of the
$^{13}$CO J=1--0 and 2--1 lines were also performed. Using ASTE we mapped the
whole extension of the N11 nebula in the $^{12}$CO J=3--2 line, and three
sub-regions in the $^{13}$CO J=3--2 line. The regions mapped in the $^{13}$CO
J=3--2 were selected based on that they may be exposed to the radiation at
different ways: a region lying over the nebula related to the OB association
LH10 (N11B), another one that it is associated with the southern part of the
nebula related to the OB association LH13 (N11D), and finally a farther area at
the southwest without any embedded OB association (N11I). We found that the
morphology of the molecular clouds lying in each region shows some signatures
that could be explained by the expansion of the nebulae and the action of the
radiation. Fragmentation generated in a molecular shell due to the expansion of
the N11 nebula is suggested. The integrated line ratios $^{12}$CO/$^{13}$CO
show evidences of selective photodissociation of the $^{13}$CO, and probably
other mechanisms such as chemical fractionation. The CO contribution to the
continuum at 870 $\mu$m was directly derived. The distribution of the
integrated line ratios $^{12}$CO J=3--2/2--1 show hints of stellar feedback in
N11B and N11D. The ratio between the virial and LTE mass (M$_{\rm vir}$/M$_{\rm
LTE}$) is higher than unity in all analyzed molecular clumps, which suggests
that the clumps are not gravitationally bounded and may be supported by
external pressure. A non-LTE analysis suggests that we are mapping gas with
densities about a few 10$^{3}$ cm$^{-3}$.
|
http://arxiv.org/abs/1905.08829v1
|
1905.08829
|
2019-05-21
|
natural-language-processing
|
12CO and 13CO observation of the low-metallicity dwarf galaxy DDO 154
|
The conversion factor from carbon monoxide (CO) intensity to molecular gas mass is a source of large uncertainty in understanding gas and its relation to star formation in galaxies. In particular, the conversion factor in low metallicity environments have remained elusive, as currently only two galaxies have been detected in any CO isotopes in environments with 12+log (O/H) < 8.0. Here we report 12CO(J=1-0) and 13CO(J=1-0) observations towards a star forming region in DDO 154, a low metallicity dwarf irregular galaxy at 12+log (O/H) = 7.67. This is a re-observation of a previous non-detection at higher angular and velocity resolution. No significant emission was detected. By estimating the molecular gas mass from associated star formation, we find that DDO 154 has a conversion factor of more than 10^3 times the Milky Way. Alternatively, if we estimate molecular mass using dust continuum emission, the conversion factor is at least 2 orders of magnitude larger than the Milky Way. These estimates signify a large amount of CO-dark molecular gas in this galaxy.
|
https://arxiv.org/abs/2311.11495v1
|
2311.11495
|
2023-11-20
|
natural-language-processing
|
12CO emission from EP Aqr: Another example of an axi-symmetric AGB wind?
|
The CO(1-0) and (2-1) emission of the circumstellar envelope of the AGB star
EP Aqr has been observed using the IRAM PdBI and the IRAM 30-m telescope. The
line profiles reveal the presence of two distinct components centered on the
star velocity, a broad component extending up to ~10 km/s and a narrow
component indicating an expansion velocity of ~2 km/s. An early analysis of
these data was performed under the assumption of isotropic winds. The present
study revisits this interpretation by assuming instead a bipolar outflow nearly
aligned with the line of sight. A satisfactory description of the observed flux
densities is obtained with a radial expansion velocity increasing from ~2 km/s
at the equator to ~10 km/s near the poles. The angular aperture of the bipolar
outflow is ~45 deg with respect to the star axis, which makes an angle of ~13
deg with the line of sight. A detailed study of the CO(1-0) to CO(2-1) flux
ratio reveals a significant dependence of the temperature on the star latitude,
smaller and steeper at the poles than at the equator at large distances from
the star. Under the hypothesis of radial expansion and of rotation invariance
about the star axis, the effective density has been evaluated in space as a
function of star coordinates. Evidence is found for an enhancement of the
effective density in the northern hemisphere of the star at angular distances
in excess of ~3" and covering the whole longitudinal range. The peak velocity
of the narrow component is observed to vary slightly with position on the sky,
a variation consistent with the model and understood as the effect of the
inclination of the star axis with respect to the line of sight. While the
phenomenological model presented here reproduces well the general features of
the observations, significant differences are also revealed, which would
require a better spatial resolution to be properly described.
|
http://arxiv.org/abs/1508.05208v2
|
1508.05208
|
2015-08-24
|
natural-language-processing
|
$^{12}$CO emission from the Red Rectangle
|
Observations of an unprecedented quality made by ALMA on the Red Rectangle of
CO(3-2) and CO(6-5) emissions are analysed jointly with the aim of obtaining as
simple as possible a description of the gas morphology and kinematics. Evidence
is found for polar conical outflows and for a broad equatorial torus in
rotation and expansion. Simple models of both are proposed. Comparing CO(6-5)
and CO(3-2) emissions provides evidence for a strong temperature enhancement
over the polar outflows. Continuum emission (dust) is seen to be enhanced in
the equatorial region. Observed asymmetries are briefly discussed.
|
http://arxiv.org/abs/1503.00858v2
|
1503.00858
|
2015-04-13
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natural-language-processing
|
1-2 Conjectures for Graphs with Low Degeneracy Properties
|
In a recent work, Keusch proved the so-called 1-2-3 Conjecture, raised by Karo\'nski, {\L}uczak, and Thomason in 2004: for every connected graph different from $K_2$, we can assign labels~$1,2,3$ to the edges so that no two adjacent vertices are incident to the same sum of labels. Despite this significant result, several problems close to the 1-2-3 Conjecture in spirit remain widely open. In this work, we focus on the so-called 1-2 Conjecture, raised by Przyby{\l}o and Wo\'zniak in 2010, which is a counterpart of the 1-2-3 Conjecture where labels~$1,2$ only can be assigned, and both vertices and edges are labelled. We consider both the 1-2 Conjecture in its original form, where adjacent vertices must be distinguished w.r.t.~their sums of incident labels, and variants for products and multisets. We prove some of these conjectures for graphs with bounded maximum degree (at most~$6$) and bounded maximum average degree (at most~$3$), going beyond earlier results of the same sort.
|
https://arxiv.org/abs/2504.21452v2
|
2504.21452
|
2025-04-30
|
natural-language-processing
|
$1/2$-conjectures on the domination game and claw-free graphs
|
Let $\gamma_g(G)$ be the game domination number of a graph $G$. Rall
conjectured that if $G$ is a traceable graph, then $\gamma_g(G) \le \left\lceil
\frac{1}{2}n(G)\right\rceil$. Our main result verifies the conjecture over the
class of line graphs. Moreover, in this paper we put forward the conjecture
that if $\delta(G) \geq 2$, then $\gamma_g(G) \leq \left\lceil \frac{1}{2}n(G)
\right\rceil$. We show that both conjectures hold true for claw-free cubic
graphs. We further prove the upper bound $\gamma_g(G) \le \left\lceil
\frac{11}{20} \, n(G) \right\rceil$ over the class of claw-free graphs of
minimum degree at least $2$. Computer experiments supporting the new conjecture
and sharpness examples are also presented.
|
http://arxiv.org/abs/2010.14273v1
|
2010.14273
|
2020-10-27
|
natural-language-processing
|
12C within the Semimicroscopic Algebraic Cluster Model
|
The Semimicroscopic Algebraic Cluster Model (SACM) is applied to 12C as a
system of three alpha- clusters. The microscopic model space, which observes
the Pauli-Exclusion-Principle (PEP), is constructed. It is shown that the 12C
nucleus can effectively be treated as a two-cluster system 8Be+alpha. The
experimental spectrum is well reproduced. The geometrical mapping is discussed
and it is shown that the ground state must correspond to a triangular
structure, which is in agreement with other microscopic calculations. The
non-zero B(E2; 0_2+ --> 2_1+) transition requires a mixing of SU(3) irreducible
representations (irreps) whose consequences are discussed. The Hoyle state
turns out to contain large shell excitations. The results are compared to
another phenomenological model, which assumes a triangular structure and, using
simple symmetry arguments, can reproduce the states observed at low energy.
This model does not observe the PEP and one objective of our contribution is to
verify the extend of importance of the PEP.
|
http://arxiv.org/abs/1710.09428v1
|
1710.09428
|
2017-10-25
|
natural-language-processing
|
12-dimensional Lie Algebra of Entangled Spin Fields
|
In this paper was proved (i) the equivalence of Dirac equation for mass $\mathsf{m}$ with two entangled Proca fields of mass $\mathsf{2m}$ and (ii) is proposed an equation and (iii) an 12-dimensional Lie algebra for the entangled spin fields.
|
https://arxiv.org/abs/2404.04359v1
|
2404.04359
|
2024-04-05
|
natural-language-processing
|
1+2 dimensional radially symmetric wave maps revisit
|
The author gives an alternative and simple proof of the global existence of smooth solutions to the Cauchy problem for wave maps from the 1+2-dimensional Minkowski space to an arbitrary compact smooth Riemannian manifold without boundary, for arbitrary smooth, radially symmetric data. the author can also treat non-compact manifold under some additional assumptions which generalize the existing ones.
|
https://arxiv.org/abs/2302.09954v1
|
2302.09954
|
2023-02-20
|
natural-language-processing
|
[1,2]-Domination in Generalized Petersen Graphs
|
A vertex subset $S$ of a graph $G=(V,E)$ is a $[1,2]$-dominating set if each
vertex of $V\backslash S$ is adjacent to either one or two vertices in $S$. The
minimum cardinality of a $[1,2]$-dominating set of $G$, denoted by
$\gamma_{[1,2]}(G)$, is called the $[1,2]$-domination number of $G$. In this
paper the $[1,2]$-domination and the $[1,2]$-total domination numbers of the
generalized Petersen graphs $P(n,2)$ are determined.
|
http://arxiv.org/abs/1906.11966v1
|
1906.11966
|
2019-06-27
|
natural-language-processing
|
12 GeV CEBAF - The Physics and Experiments
|
In this talk the role of spin and polarization is discussed in experimental
search for new excited baryon states and in the study of the internal
quark-gluon structure of the proton and neutron. Also the perspective of spin
physics at the 12 GeV CEBAF electron accelerator is discussed and what we hope
to learn about fundamental properties of hadrons such as their
multi-dimensional structure through the momentum and spatial imaging, and about
the forces on the quarks in the proton and how quark confinement may be
realized through the spatial distribution of such forces.
|
http://arxiv.org/abs/1702.07072v2
|
1702.07072
|
2017-02-24
|
natural-language-processing
|
12-in-1: Multi-Task Vision and Language Representation Learning
|
Much of vision-and-language research focuses on a small but diverse set of independent tasks and supporting datasets often studied in isolation; however, the visually-grounded language understanding skills required for success at these tasks overlap significantly. In this work, we investigate these relationships between vision-and-language tasks by developing a large-scale, multi-task training regime. Our approach culminates in a single model on 12 datasets from four broad categories of task including visual question answering, caption-based image retrieval, grounding referring expressions, and multi-modal verification. Compared to independently trained single-task models, this represents a reduction from approximately 3 billion parameters to 270 million while simultaneously improving performance by 2.05 points on average across tasks. We use our multi-task framework to perform in-depth analysis of the effect of joint training diverse tasks. Further, we show that finetuning task-specific models from our single multi-task model can lead to further improvements, achieving performance at or above the state-of-the-art.
|
https://arxiv.org/abs/1912.02315v2
|
1912.02315
|
2019-12-05
|
natural-language-processing
|
12 Labours tools for developing Functional Tissue Units
|
A brief introduction of the technical approach to model FTUs as an aggregate of cells, whose state transition dynamics are mathematically represented as port-hamiltonians or Differential Algebraic equations is presented. A python library and browser based tool to enable modellers to compose the FTU graph, specify the cellular equations and the interconnection between the cells at the level of physical quantities they exchange consistent with the technical approach is discussed.
|
https://arxiv.org/abs/2406.10301v1
|
2406.10301
|
2024-06-13
|
natural-language-processing
|
12 loops and triple wrapping in ABJM theory from integrability
|
Adapting a method recently proposed by C. Marboe and D. Volin for ${\cal
N}$=4 super-Yang-Mills, we develop an algorithm for a systematic weak coupling
expansion of the spectrum of anomalous dimensions in the $sl(2)$-like sector of
planar $\mathcal{N}$=6 super-Chern-Simons. The method relies on the Quantum
Spectral Curve formulation of the problem and the expansion is written in terms
of the interpolating function $h(\lambda)$, with coefficients expressible as
combinations of Euler-Zagier sums with alternating signs. We present explicit
results up to 12 loops (six nontrivial orders) for various twist L=1 and L=2
operators, corresponding to triple and double wrapping terms, respectively,
which are beyond the reach of the Asymptotic Bethe Ansatz as well as
L\"uscher's corrections. The algorithm works for generic values of L and S and
in principle can be used to compute arbitrary orders of the weak coupling
expansion. For the simplest operator with L=1 and spin S=1, the Pad\'e
extrapolation of the 12-loop result nicely agrees with the available
Thermodynamic Bethe Ansatz data in a relatively wide range of values of the
coupling. A Mathematica notebook with a selection of results is attached.
|
http://arxiv.org/abs/1506.09089v2
|
1506.09089
|
2015-11-16
|
natural-language-processing
|
12 mJ per Class On-Device Online Few-Shot Class-Incremental Learning
|
Few-Shot Class-Incremental Learning (FSCIL) enables machine learning systems to expand their inference capabilities to new classes using only a few labeled examples, without forgetting the previously learned classes. Classical backpropagation-based learning and its variants are often unsuitable for battery-powered, memory-constrained systems at the extreme edge. In this work, we introduce Online Few-Shot Class-Incremental Learning (O-FSCIL), based on a lightweight model consisting of a pretrained and metalearned feature extractor and an expandable explicit memory storing the class prototypes. The architecture is pretrained with a novel feature orthogonality regularization and metalearned with a multi-margin loss. For learning a new class, our approach extends the explicit memory with novel class prototypes, while the remaining architecture is kept frozen. This allows learning previously unseen classes based on only a few examples with one single pass (hence online). O-FSCIL obtains an average accuracy of 68.62% on the FSCIL CIFAR100 benchmark, achieving state-of-the-art results. Tailored for ultra-low-power platforms, we implement O-FSCIL on the 60 mW GAP9 microcontroller, demonstrating online learning capabilities within just 12 mJ per new class.
|
https://arxiv.org/abs/2403.07851v1
|
2403.07851
|
2024-03-12
|
natural-language-processing
|
12-photon entanglement and scalable scattershot boson sampling with optimal entangled-photon pairs from parametric down-conversion
|
Entangled photon sources with simultaneously near-unity heralding efficiency
and indistinguishability are the fundamental elements for scalable photonic
quantum technologies. We design and realize a degenerate entangled-photon
source from an ultrafast pulsed laser pumped spontaneous parametric
down-conversion (SPDC), which show simultaneously ~97% heralding efficiency and
~96% indistinguishability between independent single photons. Such a
high-efficiency and frequency-uncorrelated SPDC source allows generation of the
first 12-photon genuine entanglement with a state fidelity of 0.572(24). We
further demonstrate a blueprint of scalable scattershot boson sampling using 12
SPDC sources and a 12*12-modes interferometer for three-, four-, and five-boson
sampling, which yields count rates more than four orders of magnitudes higher
than all previous SPDC experiments. Our work immediately enables
high-efficiency implementations of multiplexing, scattershot boson sampling,
and heralded creation of remotely entangled photons, opening up a promising
pathway to scalable photonic quantum technologies.
|
http://arxiv.org/abs/1810.04823v1
|
1810.04823
|
2018-10-11
|
natural-language-processing
|
12 rational curves on Enriques surfaces
|
Given d in IN, we prove that any polarized Enriques surface (over any field of characteristic different from 2 or with a smooth K3 cover) of degree greater than 12d^2 contains at most 12 rational curves of degree at most d. For d>2 we construct examples of Enriques surfaces of high degree that contain exactly 12 rational degree d curves.
|
https://arxiv.org/abs/2005.12939v2
|
2005.12939
|
2020-05-26
|
natural-language-processing
|
[1, 2]-sets and [1, 2]-total Sets in Trees with Algorithms
|
A set $S \subseteq V$ of the graph $G = (V, E)$ is called a $[1, 2]$-set of
$G$ if any vertex which is not in $S$ has at least one but no more than two
neighbors in $S$. A set $S \subseteq V$ is called a $[1, 2]$-total set of $G$
if any vertex of $G$, no matter in $S$ or not, is adjacent to at least one but
not more than two vertices in $S$. In this paper we introduce a linear
algorithm for finding the cardinality of the smallest $[1, 2]$-sets and $[1,
2]$-total sets of a tree and extend it to a more generalized version for $[i,
j]$-sets, a generalization of $[1, 2]$-sets. This answers one of the open
problems proposed in [5]. Then since not all trees have $[1, 2]$-total sets, we
devise a recursive method for generating all the trees that do have such sets.
This method also constructs every $[1, 2]$-total set of each tree that it
generates.
|
http://arxiv.org/abs/1706.05248v1
|
1706.05248
|
2017-06-16
|
natural-language-processing
|
12-spin-qubit arrays fabricated on a 300 mm semiconductor manufacturing line
|
Intels efforts to build a practical quantum computer are focused on developing a scalable spin-qubit platform leveraging industrial high-volume semiconductor manufacturing expertise and 300 mm fabrication infrastructure. Here, we provide an overview of the design, fabrication, and demonstration of a new customized quantum test chip, which contains 12-quantum-dot spin-qubit linear arrays, code named Tunnel Falls. These devices are fabricated using immersion and extreme ultraviolet lithography (EUV), along with other standard high-volume manufacturing (HVM) processes, as well as production-level process control. We present key device features and fabrication details, as well as qubit characterization results confirming device functionality. These results corroborate our fabrication methods and are a crucial step towards scaling of extensible 2D qubit array schemes.
|
https://arxiv.org/abs/2410.16583v2
|
2410.16583
|
2024-10-22
|
natural-language-processing
|
$(1-2u^2)$-constacyclic codes over $\mathbb{F}_p+u\mathbb{F}_p+u^2\mathbb{F}_p$
|
Let $\mathbb{F}_p$ be a finite field and $u$ be an indeterminate. This
article studies $(1-2u^2)$-constacyclic codes over the ring
$\mathbb{F}_p+u\mathbb{F}_p+u^2\mathbb{F}_p$, where $u^3=u$. We describe
generator polynomials of this kind of codes and investigate the structural
properties of these codes by a decomposition theorem.
|
http://arxiv.org/abs/1506.07273v1
|
1506.07273
|
2015-06-24
|
natural-language-processing
|
$(1-2u^3)$-constacyclic codes and quadratic residue codes over $\mathbb{F}_{p}[u]/\langle u^4-u\rangle$
|
Let
$\mathcal{R}=\mathbb{F}_{p}+u\mathbb{F}_{p}+u^2\mathbb{F}_{p}+u^3\mathbb{F}_{p}$
with $u^4=u$ be a finite non-chain ring, where $p$ is a prime congruent to $1$
modulo $3$. In this paper we study $(1-2u^3)$-constacyclic codes over the ring
$\mathcal{R}$, their equivalence to cyclic codes and find their Gray images. To
illustrate this, examples of $(1-2u^3)$-constacyclic codes of lengths $2^m$ for
$p=7$ and of lengths $3^m$ for $p=19$ are given. We also discuss quadratic
residue codes over the ring $\mathcal{R}$ and their extensions. A Gray map from
$\mathcal{R}$ to $\mathbb{F}_{p}^4$ is defined which preserves self duality and
gives self-dual and formally self-dual codes over $\mathbb{F}_{p}$ from
extended quadratic residue codes.
|
http://arxiv.org/abs/1508.06045v2
|
1508.06045
|
2016-03-10
|
natural-language-processing
|
$(1+2u)$-constacyclic codes over $\mathbb{Z}_4+u\mathbb{Z}_4$
|
Let $R=\mathbb{Z}_4+u\mathbb{Z}_4,$ where $\mathbb{Z}_4$ denotes the ring of
integers modulo $4$ and $u^2=0$. In the present paper, we introduce a new Gray
map from $R^n$ to $\mathbb{Z}_{4}^{2n}.$ We study $(1+2u)$-constacyclic codes
over $R$ of odd lengths with the help of cyclic codes over $R$. It is proved
that the Gray image of $(1+2u)$-constacyclic codes of length $n$ over $R$ are
cyclic codes of length $2n$ over $\mathbb{Z}_4$. Further, a number of linear
codes over $\mathbb{Z}_4$ as the images of $(1+2u)$-constacyclic codes over $R$
are obtained.
|
http://arxiv.org/abs/1504.03445v1
|
1504.03445
|
2015-04-14
|
natural-language-processing
|
$(1-2u^k)$-constacyclic codes over $\mathbb{F}_p+u\mathbb{F}_p+u^2\mathbb{F}_+u^{3}\mathbb{F}_{p}+\dots+u^{k}\mathbb{F}_{p}$
|
Let $\mathbb{F}_p$ be a finite field and $u$ be an indeterminate. This
article studies $(1-2u^k)$-constacyclic codes over the ring
$\mathcal{R}=\mathbb{F}_p+u\mathbb{F}_p+u^2\mathbb{F}_p+u^{3}\mathbb{F}_{p}+\cdots+u^{k}\mathbb{F}_{p}$
where $u^{k+1}=u$. We illustrate the generator polynomials and investigate the
structural properties of these codes via decomposition theorem.
|
http://arxiv.org/abs/1512.02332v2
|
1512.02332
|
2019-04-17
|
natural-language-processing
|
12 Years of Data, Results and Experiences in the European Researchers' Night Project
|
Since twelve years the researchers of the Roman area organize the European
Researchers' Night, a project funded by European Commission to discover science
and meet researchers through an Europe-wide public event dedicated to fun
learning. Since the first edition in 2006, when the National Laboratory of
INFN's in Frascati hosted 4000 visitors the project is always grown up to
50,000 attendees and more than 50 scientific partners. In the last edition, The
Frascati Scienza association, which was born to coordinate the event, operated
in over 30 Italian cities from south to north of the peninsula. In addition,
the Made in Science project - European Research Week 2016/17 - has been the one
of the largest project funded by the European Commission and it's often
referred to as a model for organization and communication to the general
public. The 12 yeas data collected and results obtained, as well as some of the
most important experiences in public communication of science will be shown.
|
http://arxiv.org/abs/1902.03893v2
|
1902.03893
|
2019-02-12
|
natural-language-processing
|
12 Years of Self-tracking for Promoting Physical Activity from a User Diversity Perspective: Taking Stock and Thinking Ahead
|
Despite the indisputable personal and societal benefits of regular physical activity, a large portion of the population does not follow the recommended guidelines, harming their health and wellness. The World Health Organization has called upon governments, practitioners, and researchers to accelerate action to address the global prevalence of physical inactivity. To this end, an emerging wave of research in ubiquitous computing has been exploring the potential of interactive self-tracking technology in encouraging positive health behavior change. Numerous findings indicate the benefits of personalization and inclusive design regarding increasing the motivational appeal and overall effectiveness of behavior change systems, with the ultimate goal of empowering and facilitating people to achieve their goals. However, most interventions still adopt a "one-size-fits-all" approach to their design, assuming equal effectiveness for all system features in spite of individual and collective user differences. To this end, we analyze a corpus of 12 years of research in self-tracking technology for health behavior change, focusing on physical activity, to identify those design elements that have proven most effective in inciting desirable behavior across diverse population segments. We then provide actionable recommendations for designing and evaluating behavior change self-tracking technology based on age, gender, occupation, fitness, and health condition. Finally, we engage in a critical commentary on the diversity of the domain and discuss ethical concerns surrounding tailored interventions and directions for moving forward.
|
https://arxiv.org/abs/2206.01421v1
|
2206.01421
|
2022-06-03
|
natural-language-processing
|
1/2 Z Topological Invariants and the Half Quantized Hall Effect
|
The half-quantized Hall phase represents a unique metallic or semi-metallic state of matter characterized by a fractional quantum Hall conductance, precisely half of an integer $\nu$ multiple of $e^{2}/h$. Here we demonstrate the existence of a novel $\frac{1}{2}\mathbb{Z}$ topological invariant that sets the half-quantized Hall phase apart from two-dimensional ordinary metallic ferromagnets. The $\frac{1}{2}\mathbb{Z}$ classification is determined by the line integral of the intrinsic anomalous Hall conductance, which is safeguarded by two distinct categories of local unitary and anti-unitary symmetries in proximity to the Fermi surface of electron states. We further validate the $\frac{1}{2}\mathbb{Z}$ topological order in the context of the quantized Hall phase by examining semi-magnetic topological insulator $\mathrm{Bi}_{2}\mathrm{Te}_{3}$ and $\mathrm{Bi}_{2}\mathrm{Se}_{3}$ film for $\nu=1$ and topological crystalline insulator SnTe films for $\nu=2$ or $4$. Our findings pave the way for future exploration and understanding of topological metals and their unique properties.
|
https://arxiv.org/abs/2409.15655v1
|
2409.15655
|
2024-09-24
|
natural-language-processing
|
1/2$^-$ $α$ cluster resonances of $^{13}$C studied by the analytic continuation in the coupling constant
|
The 1/2$^-$ resonant states in $^{13}{\rm C}$ are investigated to search for the Hoyle-analog state. In order to treat the resonance states located around the 3$\alpha+n$ threshold, the analytic continuation in the coupling constant (ACCC) has been combined with the real-time evolution method (REM). The properties of the 1/2$^-$ resonance states such as the radii and monopole transition probabilities are calculated. We show the 1/2$^-_3$ and 1/2$^-_4$ states are well-developed $\alpha$ cluster states, and the 1/2$^-_4$ state is a candidate of the Hoyle-analog state.
|
https://arxiv.org/abs/2404.09712v1
|
2404.09712
|
2024-04-15
|
natural-language-processing
|
(130) Elektra Delta -- on the stability of the new third moonlet
|
The aim of this work is to verify the stability of the proposed orbital solutions for the third moonlet (Delta) taking into account a realistic gravitational potential for the central body of the quadruple system (Alpha). We also aim to estimate the location and size of a stability region inside the orbit of Gamma. First, we created a set of test particles with intervals of semi-major axis, eccentricities, and inclinations that covers the region interior to the orbit of Gamma, including the proposed orbit of Delta and a wide region around it. We considered three different models for the gravitational potential of Alpha: irregular polyhedron, ellipsoidal body and oblate body. For a second scenario, Delta was considered a massive spherical body and Alpha an irregular polyhedron. Beta and Gamma were assumed as spherical massive bodies in both scenarios. The simulations showed that a large region of space is almost fully stable only when Alpha was modeled as simply as an oblate body. For the scenario with Delta as a massive body, the results did not change from those as massless particles. Beta and Gamma do not play any relevant role in the dynamics of particles interior to the orbit of Gamma. Delta's predicted orbital elements are fully unstable and far from the nearest stable region. The primary instability source is Alpha's elongated shape. Therefore, in the determination of the orbital elements of Delta, it must be taken into account the gravitational potential of Alpha assuming, at least, an ellipsoidal shape.
|
https://arxiv.org/abs/2304.14967v1
|
2304.14967
|
2023-04-28
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natural-language-processing
|
130GeV gamma-ray line through axion conversion
|
We apply the axion-photon conversion mechanism to the 130 GeV $\gamma$-ray
line observed by the Fermi satellite. Near the Galactic center, some
astrophysical sources and/or particle dark matter can produce energetic axions
(or axionlike particles), and the axions convert to $\gamma$ rays in Galactic
magnetic fields along their flight to the Earth. Since continuum $\gamma$-ray
and antiproton productions are sufficiently suppressed in axion production, the
scenario fits the 130 GeV $\gamma$-ray line without conflicting with cosmic ray
measurements. We derive the axion production cross section and the decay rate
of dark matter to fit the $\gamma$-ray excess as functions of axion parameters.
In the scenario, the $\gamma$-ray spatial distributions depend on both the dark
matter profile and the magnetic field configuration, which will be tested by
future $\gamma$-ray observations, e.g., H.E.S.S. II, CTA, and GAMMA-400. As an
illustrative example, we study realistic supersymmetric axion models, and show
the favored parameters that nicely fit the $\gamma$-ray excess.
|
http://arxiv.org/abs/1310.3474v3
|
1310.3474
|
2015-04-27
|
natural-language-processing
|
130 mA/mm $β$-Ga$_2$O$_3$ MESFET with Low-Temperature MOVPE-Regrown Ohmic Contacts
|
We report on the demonstration of metalorganic vapor phase epitaxy-regrown (MOVPE) ohmic contacts in an all MOVPE-grown $\beta$-Ga$_2$O$_3$ metal-semiconductor field effect transistor (MESFET). The low-temperature (600$^{\circ}$C) heavy (n$^{+}$) Si-doped regrown layers exhibit extremely high conductivity with sheet resistance of 73 $\Omega$/$\square$ and record low metal/n$^{+}$-Ga$_2$O$_3$ contact resistance of 80 m$\Omega$.mm and specific contact resistivity of 8.3$\times$10$^{-7}$ $\Omega$.cm$^{2}$ were achieved. The fabricated MESFETs exhibit a maximum drain-to-source current of 130 mA/mm, a high I$_{ON}$/I$_{OFF}$ of $>$10$^{10}$ with a high power FOM of 25 MW/cm$^{2}$ were achieved without any field plates. Nanoparticle-assisted Raman thermometry, thermal modeling, and infrared thermography were performed to assess the device self-heating under the high current and power conditions. This demonstration shows the promise of MOVPE technique for the realization of high-performance lateral $\beta$-Ga$_2$O$_3$ devices and also highlights the need for device-level thermal management.
|
https://arxiv.org/abs/2103.04275v2
|
2103.04275
|
2021-03-07
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natural-language-processing
|
130 years of spectroheliograms at Paris-Meudon observatories (1892-2022)
|
Broad-band observations of the solar photosphere began in Meudon in 1875 under the auspices of Jules Janssen. For his part, Henri Deslandres initiated imaging spectroscopy in 1892 at Paris observatory. He invented, concurrently with George Hale in Kenwood (USA) but quite independently, the spectroheliograph designed for monochromatic imagery of the solar atmosphere. Deslandres developed two kinds of spectrographs: the ''spectroh{\'e}liographe des formes'', i.e. the narrow bandpass instrument to reveal chromospheric structures (such as filaments, prominences, plages and active regions); and the ''spectroh{\'e}liographe des vitesses'', i.e. the section spectroheliograph to record line profiles of cross sections of the Sun with a 20''-30'' spatial step. This second apparatus was intended to measure the velocities (more exactly the Dopplershifts) of dynamic features. Deslandres moved to Meudon in 1898 with his instruments and tested various combinations, in order to improve the spectral and spatial resolutions, leading to the final large quadruple spectroheliograph in 1908. CaII K systematic observations started at this date and were followed in 1909 by H$\alpha$. The service was organized by Lucien d'Azambuja and continues today. Optical and mechanical parts were revisited in 1989 and the digital technology was introduced in 2002. Full line profiles are registered for all pixels of the Sun since 2018, so that the instrument produces now data-cubes. The collection is one of the longest available (more than 100 000 observations). It contains sporadic images from 1893 to 1907 (during the development phase) and systematic observations along 10 solar cycles since 1908, in H$\alpha$ and CaII K lines. This paper summarizes 130 years of observations, instrumental research and technical advances.
|
https://arxiv.org/abs/2301.11105v1
|
2301.11105
|
2023-01-26
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natural-language-processing
|
$(1^3+1)(2^3+1)\cdots(n^3+1)$ is not a cube
|
For a positive integer $n,$ define $$C_n=\prod_{k=1}^n(k^3+1).$$ In this
paper we prove that there are no cubes in the integer sequence
$C_n,~n=1,2,\cdots.$
|
http://arxiv.org/abs/1612.08158v1
|
1612.08158
|
2016-12-24
|
natural-language-processing
|
13.16 Tbit/s Free-space Optical Transmission over 10.45 km for Geostationary Satellite Feeder-links
|
We report a 13.16 Tbit/s 54-channel DWDM free-space optical data transmission field trial emulating the worst-case scenario for optical GEO satellite uplinks through the atmosphere, and show the system performance under turbulent conditions.
|
https://arxiv.org/abs/2006.05349v1
|
2006.05349
|
2020-06-08
|
natural-language-processing
|
131 and 304 Å Emission Variability Increases Hours Prior to Solar Flare Onset
|
Thermal changes in coronal loops are well-studied, both in quiescent active regions and in flaring scenarios. However, relatively little attention has been paid to loop emission in the hours before the onset of a solar flare; here, we present the findings of a study of over 50 off-limb flares of GOES class C5.0 and above. We investigated the integrated emission variability for Solar Dynamics Observatory Atmospheric Imaging Assembly channels 131, 171, 193, and 304 \r{A}ngstroms for 6 hours before each flare, and compared these quantities to the same time range and channels above active regions without proximal flaring. We find significantly increased emission variability in the 2-3 hours before flare onset, particularly for the 131 and 304 channels. This finding suggests a potential new flare prediction methodology. The emission trends between the channels are not consistently well-correlated, suggesting a somewhat chaotic thermal environment within the coronal portion of the loops that disturbs the commonly-observed heating and cooling cycles of quiescent active region loops. We present our approach, the resulting statistics, and discuss the implications for heating sources in these pre-flaring active regions.
|
https://arxiv.org/abs/2411.12704v1
|
2411.12704
|
2024-11-19
|
natural-language-processing
|
1320 nm Light Source From Deuterium Treated Silicon
|
We report an efficient room temperature photon source at 1320 nm telecommunication wavelength from nanostructured silicon surface. The activation of this light source was realized by treating the surface of Si wafer by vapor of heavy water (D2O) containing a mixture of hydrofluoric and nitric acids. Treatment without deuterium generates an intense light emission band at the band-edge of Si, while the deuterium treatment alone creates a strong emission band at 1320 nm in the near infrared. It was found that the deuterium is actively involved in the formation of a nanostructured Si surface as evidenced from relative strength of the Si-O vibrational modes and presence of N-D bondings. The origin of this photon source was discussed in terms of oxygen related defect states and dislocations. The Si surface treated by Deuterium containing mixture exhibits a strong rectifying electrical activity as it is demonstrated by Schottky diodes fabricated on these wafers. Being compatible with mature silicon circuitry, the source may find applications in photonics and optoelectronics.
|
https://arxiv.org/abs/2105.04653v1
|
2105.04653
|
2021-05-10
|
natural-language-processing
|
1321+045: a Compact Steep Spectrum radio source in a cool-core galaxy cluster
|
Cluster-central gigahertz peak and compact steep spectrum (CSS) sources offer an opportunity to study the earliest phases of AGN feedback, but few have yet been examined in detail. We present results from radio and X-ray observations of 1321+045, a CSS source in a 4.4 keV cluster at z=0.263. The cluster has a strongly cooling core, and disturbances from a minor cluster merger may have triggered a period of jet activity which formed the 16 kpc radio lobes 2.0 [+0.3,-0.2] Myr ago. However, new VLBA imaging shows a ~20 pc jet on a different projected axis, which is probably only a few hundred years old. We consider possible histories for the system, with either one or two periods of jet activity. While this single system is informative, a broader study of the youngest cluster-central radio sources is desirable.
|
https://arxiv.org/abs/2110.08358v1
|
2110.08358
|
2021-10-15
|
natural-language-processing
|
1324- and 2143-avoiding Kazhdan-Lusztig immanants and k-positivity
|
Immanants are functions on square matrices generalizing the determinant and permanent. Kazhdan-Lusztig immanants, which are indexed by permutations, involve $q=1$ specializations of Type A Kazhdan-Lusztig polynomials, and were defined in (Rhoades-Skandera, 2006). Using results of (Haiman, 1993) and (Stembridge, 1991), Rhoades and Skandera showed that Kazhdan-Lusztig immanants are nonnegative on matrices whose minors are nonnegative. We investigate which Kazhdan-Lusztig immanants are positive on $k$-positive matrices (matrices whose minors of size $k \times k$ and smaller are positive). We show that the Kazhdan-Lusztig immanant indexed by $v$ is positive on $k$-positive matrices when $v$ avoids 1324 and 2143 and for all non-inversions $i<j$ of $v$, either $j-i \leq k$ or $v_j-v_i\leq k$. Our main tool is Lewis Carroll's identity.
|
https://arxiv.org/abs/2002.07851v2
|
2002.07851
|
2020-02-18
|
natural-language-processing
|
1324-avoiding permutations revisited
|
We give an improved algorithm for counting the number of $1324$-avoiding
permutations, resulting in $14$ further terms of the generating function, which
is now known for all patterns of length $\le 50$. We re-analyse the generating
function and find additional evidence for our earlier conclusion that unlike
other classical length-$4$ pattern-avoiding permutations, the generating
function does not have a simple power-law singularity, but rather, the number
of $1324$-avoiding permutations of length $n$ behaves as \[ B\cdot \mu^n \cdot
\mu_1^{\sqrt{n}} \cdot n^g. \] We estimate $\mu=11.600 \pm 0.003$, $\mu_1 =
0.0400 \pm 0.0005$, $g = -1.1 \pm 0.1$ while the estimate of $B$ depends
sensitively on the precise value of $\mu$, $\mu_1$ and $g$. This reanalysis
provides substantially more compelling arguments for the presence of the
stretched exponential term $\mu_1^{\sqrt{n}}$.
|
http://arxiv.org/abs/1709.01248v2
|
1709.01248
|
2017-11-18
|
natural-language-processing
|
$^{133}$Cs and $^{75}$As NMR investigation of the normal metallic state of the quasi-one-dimensional Cs$_2$Cr$_3$As$_3$
|
We report $^{133}$Cs NMR and $^{75}$As Nuclear Quadrupole Resonance (NQR)
measurements on the normal metallic state above $T_c$ of a
quasi-one-dimensional superconductor Cs$_2$Cr$_3$As$_3$ ($T_c < 1.6$~K). From
the $^{133}$Cs NMR Knight shift $^{133}K$ measured at the Cs1 site, we show
that the uniform spin susceptibility $\chi_{spin}$ increases from 295~K to
$\sim$ 60~K, followed by a mild suppression; $\chi_{spin}$ then levels off
below $\sim$10~K. In contrast, a vanishingly small magnitude of $^{133}K$
indicates that Cs2 sites contribute very little to electrical conduction and
the exchange interactions between 3d electrons at Cr sites. Low frequency Cr
spin dynamics, reflected on $^{75}$As $1/T_1T$ (the nuclear spin-lattice
relaxation rate $1/T_1$ divided by temperature $T$), shows an analogous trend
as $\chi_{spin}$. Comparison with the results of $1/T_1T$ near $T_c$ with
Rb$_2$Cr$_3$As$_3$ ($T_c=6.1$~K) and Rb$_2$Cr$_3$As$_3$ ($T_c=4.8$~K)
establishes a systematic trend that substitution of K$^{+}$ ions with larger
alkali ions progressively suppresses Cr spin fluctuations together with $T_c$.
|
http://arxiv.org/abs/1605.04347v1
|
1605.04347
|
2016-05-13
|
natural-language-processing
|
133Cs-NMR study on aligned powder of competing spin chain compound Cs2Cu2Mo3O12
|
S = 1/2 competing spin chain compound Cs2Cu2Mo3O12 has two dominant exchange
interactions of the nearest neighbouring ferromagnetic J1= 93 K and the second
nearest neighbouring antiferromagnetic J2= +33 K, and is expected to show the
nematic Tomonaga-Luttinger liquid (TLL) state under high magnetic field region.
The recent theoretical study by Sato et al. has shown that in the nematic TLL
state, the spin fluctuations are expected to be highly anisotropic, that is,
its transverse component is suppressed. Our previous NMR study on the present
system showed that the dominant contribution to nuclear spin relaxation comes
from the longitudinal component. In order to conclude that the transverse
component of spin fluctuations is suppressed, the knowledge of hyperfine
coupling is indispensable. This article is solely devoted to investigate the
hyperfine coupling of 133Cs-NMR site to prove that the anisotropic part of
hyperfine coupling, which connects the nuclear spin relaxation with the
transverse spin fluctuations is considerably large to be A_an=+770 Oe/mu_B.
|
http://arxiv.org/abs/1712.06219v1
|
1712.06219
|
2017-12-18
|
natural-language-processing
|
133In: A Rosetta Stone for decays of r-process nuclei
|
The $\beta$ decays from both the ground state and a long-lived isomer of $^{133}$In were studied at the ISOLDE Decay Station (IDS). With a hybrid detection system sensitive to $\beta$, $\gamma$, and neutron spectroscopy, the comparative partial half-lives (logft) have been measured for all their dominant $\beta$-decay channels for the first time, including a low-energy Gamow-Teller transition and several First-Forbidden (FF) transitions. Uniquely for such a heavy neutron-rich nucleus, their $\beta$ decays selectively populate only a few isolated neutron unbound states in $^{133}$Sn. Precise energy and branching-ratio measurements of those resonances allow us to benchmark $\beta$-decay theories at an unprecedented level in this region of the nuclear chart. The results show good agreement with the newly developed large-scale shell model (LSSM) calculations. The experimental findings establish an archetype for the $\beta$ decay of neutron-rich nuclei southeast of $^{132}$Sn and will serve as a guide for future theoretical development aiming to describe accurately the key $\beta$ decays in the rapid-neutron capture (r-) process.
|
https://arxiv.org/abs/2306.01842v1
|
2306.01842
|
2023-06-02
|
natural-language-processing
|
134 Billion Intersecting Brane Models
|
The landscape of string vacua is very large, but generally expected to be finite in size. Enumerating the number and properties of the vacua is an important task for both the landscape and the swampland, in part to gain a deeper understanding of what is possible and "generic". We obtain an exact counting of distinct intersecting brane vacua of type IIA string theory on the $\mathbb{T}^6/\mathbb{Z}_2\times\mathbb{Z}_2$ orientifold. Care is taken to only count gauge-inequivalent brane configurations. Leveraging the recursive nature by which branes may be added together one-by-one, we use dynamic programming to efficiently count the number of solutions of the tadpole, K-theory and supersymmetry consistency conditions. The distributions of 4D gauge group rank and complex structure moduli for the entire ensemble of intersecting brane vacua are presented. The methods we developed here may be useful in obtaining sharp upper and lower bounds on other corners of the landscape.
|
https://arxiv.org/abs/2206.03506v2
|
2206.03506
|
2022-06-07
|
natural-language-processing
|
13.56MHz Rectifying Diodes Based on Metal Halide Perovskite
|
The increasing use of portable and wireless technologies has led to a growing focus on radio-frequency identification (RFID) tags. Among the various devices in RFID tags, rectifying diodes are the most demanding in terms of high-frequency performance, and these diodes are dominated by organic materials. However, their intrinsic low carrier mobility largely limits the rectifying ability of organic diodes. As an alternative, metal halide perovskites (MHPs) possess high carrier mobility, making them potential candidates for higher-frequency applications. Whereas their ion-migration issue may deteriorate their high-frequency performance. In this study, we report rectifying diodes based on MHPs that can rectify an incoming sinusoidal signal at 13.56 MHz. The diodes exhibit a high rectification ratio of 1.9 x 103 at 1 V and can rectify signals at even higher frequencies. We designed a triangular wave detection method to measure the intensity of ion-migration at different frequencies. Interestingly, the ion-migration did not occur at such a high frequency. The high-frequency stagnant ions and excellent carrier mobility make MHPs unexpectedly suitable for high-frequency applications, providing a promising solution to ion-migration issues and paving the way for perovskites in high-frequency areas.
|
https://arxiv.org/abs/2307.00458v1
|
2307.00458
|
2023-07-02
|
natural-language-processing
|
$^{137,138,139}$La($n$, $\gamma$) cross sections constrained with statistical decay properties of $^{138,139,140}$La nuclei
|
The nuclear level densities and $\gamma$-ray strength functions of
$^{138,139,140}$La were measured using the $^{139}$La($^{3}$He, $\alpha$),
$^{139}$La($^{3}$He, $^{3}$He$^\prime$) and $^{139}$La(d, p) reactions. The
particle-$\gamma$ coincidences were recorded with the silicon particle
telescope (SiRi) and NaI(Tl) (CACTUS) arrays. In the context of these
experimental results, the low-energy enhancement in the A$\sim$140 region is
discussed. The $^{137,138,139}$La($n, \gamma)$ cross sections were calculated
at $s$- and $p$-process temperatures using the experimentally measured nuclear
level densities and $\gamma$-ray strength functions. Good agreement is found
between $^{139}$La($n, \gamma)$ calculated cross sections and previous
measurements.
|
http://arxiv.org/abs/1701.03712v1
|
1701.03712
|
2017-01-13
|
natural-language-processing
|
138175 (2000 EE104) and the Source of Interplanetary Field Enhancements
|
We present the first optical observations taken to characterize the
near-Earth object 138175 (2000 EE104). This body is associated with
Interplanetary Field Enhancements (IFEs), thought to be caused by interactions
between the solar wind magnetic field and solid material trailing in the orbit
of the parent body. Based on optical photometry, the radius (in meters) and
mass (in kilograms) of an equal-area sphere are found to be r_n =
250(0.1/p_R)**0.5 and M_n = 1e11(0.1/p_R)**1.5, respectively, where p_R is the
red geometric albedo and density 1500 kg/m3 is assumed. The measured colors are
intermediate between those of C-type (primitive) and S-type (metamorphosed)
asteroids but, with correction for the likely effects of phase-reddening, are
more consistent with a C-type classification than with S-type. No evidence for
co-moving companions larger than about 40(0.1/p_R) meter in radius is found,
and no dust particle trail is detected, setting a limit to the trail optical
depth 2e-9. Consideration of the size distribution produced by impact
pulverization makes it difficult to generate the mass of nanodust (minimum 1e5
kg to 1e6 kg) required to account for IFEs, unless the size distribution is
unusually steep. Furthermore, impact pulverization timescales for source
objects of the required size are much longer than the dynamical timescale.
While the new optical data do not definitively refute the hypothesis that
boulder pulverization is the source of IFEs, neither do they provide any
support for it.
|
http://arxiv.org/abs/2007.07192v1
|
2007.07192
|
2020-07-14
|
natural-language-processing
|
$^{138}{\rm Ba}(d,α)$ study of states in $^{136}{\rm Cs}$: Implications for new physics searches with xenon detectors
|
We used the $^{138}$Ba$(d,\alpha)$ reaction to carry out an in-depth study of states in $^{136}$Cs, up to around 2.5~MeV. In this work, we place emphasis on hitherto unobserved states below the first $1^+$ level, which are important in the context of solar neutrino and fermionic dark matter (FDM) detection in large-scale xenon experiments. We identify for the first time candidate metastable states in $^{136}$Cs, which would allow a real-time detection of solar neutrino and FDM events in xenon detectors, with high background suppression. Our results are also compared with shell-model calculations performed with three Hamiltonians that were previously used to evaluate the nuclear matrix element (NME) for $^{136}$Xe neutrinoless double beta decay. We find that one of these Hamiltonians, which also systematically underestimates the NME compared to the others, dramatically fails to describe the observed low-energy $^{136}$Cs spectrum, while the other two show reasonably good agreement.
|
https://arxiv.org/abs/2301.11371v3
|
2301.11371
|
2023-01-26
|
natural-language-processing
|
139 GHz UV phase-locked Raman laser system for thermometry and sideband cooling of $^9$Be$^+$ ions in a Penning trap
|
We demonstrate phase locking of two ultraviolet laser sources by modulating a fundamental infrared laser with 4th-order sidebands using an electro-optic modulator and phase locking of one sideband to a second fundamental infrared laser. Subsequent sum frequency generation and second harmonic generation successfully translates the frequency offset to the ultraviolet domain. The phase lock at 139 GHz is confirmed through stimulated Raman transitions for thermometry of $^9$Be$^+$ ions confined in a cryogenic Penning trap. This technique might be used for sideband cooling of single $^9$Be$^+$ ions as well as sympathetic cooling schemes and quantum logic based measurements in Penning traps in the future.
|
https://arxiv.org/abs/2106.13532v2
|
2106.13532
|
2021-06-25
|
natural-language-processing
|
$^{139}$La NMR investigation of the interplay between the lattice, charge, and spin dynamics in charge ordered high $T_c$ cuprate La$_{1.875}$Ba$_{0.125}$CuO$_{4}$
|
We investigate the interplay between the lattice, charge, and spin dynamics in charge ordered high $T_c$ cuprate La$_{1.875}$Ba$_{0.125}$CuO$_{4}$ ($T_{c} =4$~K) based on the inverse Laplace transform (ILT) analysis of the $^{139}$La nuclear spin-lattice relaxation rate $1/T_1$ (dubbed ILTT$_{1}$ analysis here after). A major thrust of the ILTT$_{1}$ analysis is that one can deduce the probability density function $P(1/T_1)$ of distributed $1/T_1$. We demonstrate that $1/T_{1}^{lm}$, defined as the log-mean (i.e. the center of gravity on a logarithmic scale) of $P(1/T_1)$, can be well approximated by $1/T_{1}^{str}$ deduced from the phenomenological stretched fit, however, $P(1/T_1)$ can provide much richer insight into how the lattice, charge, and spin fluctuations and their distribution develop near and below the long range charge order at $T_{charge} \sim 54$~K. Upon entering the charge ordered state, a divergent increase of $1/T_{1}^{lm}$ toward the spin ordering at $T_{spin}^{\mu SR} \simeq 35$~K is accompanied by an asymmetric broadening of $P(1/T_1)$. Even deep inside the charge ordered state, $1/T_{1}$ at a gradually diminishing fraction of $^{139}$La sites continues to slow down as temperature is lowered, as expected for canonical superconducting CuO$_2$ planes without enhanced spin fluctuations. The fraction of such canonical $^{139}$La sites almost disappears by $\simeq 40$~K. In contrast, nearly a half of the $^{139}$La sites in La$_{1.885}$Sr$_{0.115}$CuO$_{4}$ ($T_{charge} \simeq 80$~K) still exhibits the canonical behavior without enhanced spin fluctuations even near its $T_{c} = 31$~K. These contrasting behaviors explain why superconductivity in La$_{1.875}$Ba$_{0.125}$CuO$_{4}$ is more strongly suppressed than in La$_{1.885}$Sr$_{0.115}$CuO$_{4}$ despite the lower onset temperature of the charge order.
|
https://arxiv.org/abs/2203.04265v1
|
2203.04265
|
2022-03-08
|
natural-language-processing
|
$^{139}$La-NMR study of spin-dynamics coupled with hole mobility in $T$*-type La$_{0.86}$Eu$_{0.86}$Sr$_{0.28}$CuO$_{4-δ}$
|
In $T$*-type cuprate oxides with five oxygen coordination, little is known about the relationship between the spin correlations and dope carriers. We performed $^{139}$La-nuclear magnetic resonance (NMR) and electrical resistivity measurements on an as-sintered (AS) and oxidation annealed (OA) polycrystalline $T$*-type La$_{0.86}$Eu$_{0.86}$S$_{0.28}$CuO$_4$ (LESCO) to investigate its magnetic and superconducting (SC) properties. Upon cooling, the NMR spectrum of AS LESCO broadened below 3 K, at which the nuclear spin-lattice relaxation rate $1/T_1$ against the temperature exhibited a maximum, thereby indicating the appearance of static magnetism. The temperature dependence of $1/T_1$ between 3 K and 20 K was similar to that of the resistivity displaying the semiconducting behavior. Furthermore, the energy scale of the transport gap and spin-dynamics estimated was found to be comparable. These results suggest a close connection between the mobility of the doped carriers and low-energy spin-dynamics, as reported for lightly doped $T$-type La$_{2-x}$Sr$_x$CuO$_4$. In the OA SC sample, we confirmed the absence of a magnetic order and the Korringa relation above 10 K. Therefore, in the $T$*-type LESCO with $x$ = 0.28, the magnetic state coupled with holes drastically turns to the weakly correlated metallic state by oxidation annealing.
|
https://arxiv.org/abs/2110.12333v1
|
2110.12333
|
2021-10-24
|
natural-language-processing
|
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