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2605.13843 2026-05-14 astro-ph.GA astro-ph.CO

The Galaxy Luminosity Functions in ASTRID: Predictions for LSST

Fatemeh Hafezianzadeh, Tianqing Zhang, Paul Rogozenski, Patrick Lachance, Yihao Zhou, Tiziana Di Matteo, Rupert A. C. Croft, Simeon Bird, Rachel Mandelbaum

AI总结 本文利用ASTRID宇宙学流体动力学模拟,为Vera C. Rubin天文台的Legacy Survey of Space and Time(LSST)项目生成了验证过的星系光度函数和光度预测。研究结合恒星群体合成模型与物理驱动的尘埃消光模型,准确再现了不同红移和波段下的观测星系统计特性,并据此构建了包含约3.78亿个星系的LSST模拟光度目录。研究还提供了LSST各波段的光度函数预测,推导了最佳拟合的Schechter参数,并计算了从第一年到第十年不同观测深度的星系数目分布。

Comments 17 pages, 13 figures

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We present validated and forward-modelled galaxy luminosity functions and photometric predictions for the Vera C. Rubin Observatory Legacy Survey of Space and Time using the ASTRID cosmological hydrodynamical simulation. Galaxy magnitudes are computed by combining stellar population synthesis modeling with a physically motivated dust attenuation prescription in which the optical depth scales with metal surface density. The dust model is calibrated at z = 0 using SDSS luminosity functions and tested at intermediate redshifts (z = 0.5, 1.0, and 1.5) in rest-frame B, V , R, and I bands. We find that the attenuated luminosity functions reproduce observed galaxy statistics across multiple wavelengths and redshifts. Using this calibrated framework, we construct LSST-ready mock photometric catalogs over 0 <= z <= 2 in steps of Delta z = 0.1, containing ~378 million galaxies. We provide predicted apparent-magnitude luminosity functions in the LSST ugrizy bands, derive best-fit Schechter parameters as a compact analytic representation, and compute differential and cumulative galaxy number counts as a function of survey depth from Year 1 to Year 10.

2605.13842 2026-05-14 astro-ph.GA astro-ph.IM

From DES to KiDS: Domain adaptation for cross-survey detection of low-surface-brightness galaxies

Hareesh Thuruthipilly, Krzysztof Lisiecki, Junais, Katarzyna Małek, Agnieszka Pollo, William J. Pearson, Antonio Vanzanella, Saptarshi Pal, Miguel Figueira, Pratik Dabhade, Anna Durkalec, Aidan P. Cotter, Unnikrishnan Sureshkumar, Nandini Hazra, Patryk Matera, Subhrata Dey, Michal Vrábel, Anirban Dutta, Henry Willems, Nicola Principi Cavaterra, Natalia Dobrowolska, Wojciech Knop

AI总结 该研究旨在解决跨巡天观测中低表面亮度星系(LSBG)的检测问题,利用域适应技术将基于暗能量巡天(DES)训练的深度学习模型应用于千里度巡天(KiDS)数据,实现了对KiDS DR5数据中LSBGs和超弥散星系(UDGs)的自动识别。研究共发现了20,180个LSBG和434个UDG,并揭示了它们的结构参数、颜色分布及与环境相关的演化特征,为未来大型巡天如LSST和Euclid提供了可扩展的LSBG目录构建方法。

Comments Accepted to Astronomy & Astrophysics

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Low-surface-brightness galaxies (LSBGs) are vital for understanding galaxy formation, but their diffuse nature makes them challenging to detect. Upcoming large-scale surveys are expected to uncover large numbers of LSBGs, requiring robust automated methods to identify them across heterogeneous datasets. As a precursor to the Legacy Survey of Space and Time (LSST) and Euclid, we explore domain adaptation techniques for cross-survey LSBG identification. Using models trained on the Dark Energy Survey (DES), we search for LSBGs in the Kilo-Degree Survey Data Release 5 (KiDS DR5). We used an ensemble consisting of one convolutional neural network (CNN) and two transformer models trained on DES cutouts and applied to KiDS DR5 imaging data. Structural parameters were estimated with galfitm, and photometric redshifts and stellar population properties were estimated through spectral energy distribution fitting with CIGALE. We identify 20,180 LSBGs and 434 ultra-diffuse galaxies (UDGs) in KiDS DR5. Their structural parameters are similar to known LSBGs from DES and the Hyper Suprime-Cam SSP Survey (HSC-SSP). The KiDS-LSBGs follow a continuous size-luminosity relation connecting classical dwarf galaxies and UDGs, and their colours are bimodal ($\sim73\%$ blue, $\sim27\%$ red). Cross-matching with spectroscopic and cluster catalogues provides redshifts for 4,913 systems, enabling a systematic characterisation of the star-forming main sequence of LSBGs. Strong environmental trends are evident, with cluster LSBGs and UDGs exhibiting redder colours and reduced star formation compared to non-cluster systems. We demonstrate that domain adaptation enables robust cross-survey LSBG identification with deep learning models, providing a scalable pathway for constructing homogeneous LSBG catalogues for the LSST and Euclid era.

2605.13837 2026-05-14 cond-mat.quant-gas cond-mat.str-el quant-ph

Nagaoka supermetal in the particle-doped triangular Hubbard model

Rui Cao, Xiangyue Zhang, Hui Tan, Jian-Shu Xu, Yuan-Yao He, Jianmin Yuan, Yongqiang Li

AI总结 本文研究了掺杂粒子的三角晶格Hubbard模型,揭示了一种由强关联和几何阻挫共同驱动的新型量子金属态——Nagaoka超金属态。该态表现出电阻率随温度的亚线性依赖以及电荷压缩率和零频谱权重的奇异行为,其本质源于重构能带中高阶范霍夫奇点所导致的态密度幂律发散。该研究为理解几何阻挫系统中的非费米液体态提供了新视角,并可在当前超冷原子实验中实现。

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While the interplay of correlations and geometric frustration in doped Mott insulators provides a fertile ground for exotic quantum phases, the nature of the metallic state emerging upon particle doping remains poorly understood. In this work, we investigate the triangular-lattice Hubbard model with particle doping and provide compelling evidence for an intrinsic, interaction-driven quantum state, which we term the Nagaoka supermetal. This state is characterized by a sublinear temperature dependence in the DC resistivity, along with singular behaviors in the charge compressibility and zero-frequency spectral weight. To understand the origin of these singular properties, we derive an effective low-energy model and demonstrate that a higher-order Van Hove singularity emerges from the reconstructed dispersion. This singularity gives rise to a power-law divergence in the density of states, capturing the anomalous properties observed in the supermetallic regime. Our findings offer a new perspective on non-Fermi liquid states in geometrically frustrated systems and are directly accessible in current ultracold atom experiments.

2605.13832 2026-05-14 quant-ph

Combining moment matrices, symmetric extension, and Lovász theta: $Φ_{\text{E8}}$ is entangled

Jȩdrzej Stempin, Gerard Anglès Munné, Santiago Llorens, Felix Huber

AI总结 本文解决了Yu等人在《自然通讯》上提出的一个关于纠缠理论的开放问题,证明了14量子比特态$Φ_{\text{E8}}$是纠缠的。研究结合对称扩展和矩矩阵方法,构造了一个显式的纠缠见证算子,给出了一个半定规划的有理不可行性证明。该方法统一并扩展了涉及泡利反对易图Lovász theta数的多种早期方法,具有良好的可扩展性和应用灵活性。

Comments 14 pages, 1 figure, comments welcome!

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We solve an open problem in entanglement theory posed by Yu et al., {\it Nature Communications 12, 1012 (2021)}. The problem is to show, via an entanglement witness, that the $14$-qubit state $Φ_{\text{E8}}$ is entangled. Inspired by a method from quantum codes, we combine symmetric extension with moment matrices to prove that $Φ_{\text{E8}}$ is entangled. The proof has the form of a rational infeasibility certificate for a semidefinite program, yielding an explicit entanglement witness. Our approach unifies and extends several earlier methods that involve the Lovász theta number of the Pauli anti-commutativity graph, promising scalability and flexibility in further applications.

2605.13828 2026-05-14 physics.optics

Integrated ytterbium gain for visible-near-infrared photonics

Tianyi Zeng, Erik W. Masselink, Tsung-Han Wu, Nathan Brooks, Peter Chang, Grisha Spektor, Zachary L. Newman, Danxian Liu, Scott B. Papp, David R. Carlson, Scott A. Diddams, Kiyoul Yang

AI总结 该研究提出了一种基于氧化铝光子平台的集成镱增益器件,在近红外波段实现了单模激光和光学放大功能。该平台表现出超过0.5瓦的输出功率、70%以上的光-光转换效率以及接近量子极限的3.3分贝噪声系数,并成功将飞秒脉冲放大至14千瓦峰值功率,实现了从780纳米到476纳米的可见光超连续谱生成。该成果为构建可扩展的可见-近红外光子系统奠定了基础,适用于相干激光阵列、锁模激光器、光学钟和微波振荡器等应用。

Comments 9 pages, 4 figures, supplementary information included. T. Zeng and E. W. Masselink contributed equally to this work

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Rare-earth gain media form the foundation of modern optical communications, emerging quantum hardware, and ultrafast optics. While chip-scale integration can enable fiber-like, and potentially beyond-fiber, functionality with unprecedented scalability, development in the visible and near-infrared remains in its early stages. Here, we demonstrate ytterbium-based optical gain integrated into an aluminum oxide photonic platform, achieving both single-mode lasing and optical amplification in the near-infrared regime. This platform delivers optical amplification with output powers exceeding 0.5 W, an optical-to-optical conversion efficiency above 70%, and a noise figure of 3.3 dB, approaching the quantum limit for phase-insensitive amplification. Furthermore, we achieve femtosecond pulse amplification to a record peak power of 14 kW, enabling supercontinuum generation with visible dispersive waves extending from 780 to 476 nm in conjunction with nonlinear photonic devices. This platform is compatible with heterogeneous integration into standard photonic circuits, laying the foundation for scalable visible-near-infrared photonic systems, including coherent laser arrays, mode-locked lasers, optical clocks, and microwave oscillators.

2605.13826 2026-05-14 cs.LG cond-mat.mtrl-sci physics.chem-ph

Reducing cross-sample prediction churn in scientific machine learning

Gordan Prastalo, Kevin Maik Jablonka

AI总结 科学机器学习通常只报告模型的预测性能,但未说明相同预测在不同训练数据采样下是否保持一致。本文提出“跨样本预测波动”这一概念,指在相同测试样本上,不同训练数据子集训练出的模型预测结果可能不一致。研究发现,传统参数侧方法无法有效减少该波动,而数据侧方法如 $K$-bootstrap 袋外采样和提出的 twin-bootstrap 方法,能在不损失准确率的前提下显著降低预测波动,为科学机器学习评估提供了更全面的指标。

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Scientific machine learning reports predictive performance. It does not report whether the same prediction would survive a different draw of training data. Across $9$ chemistry benchmarks, two classifiers trained on independent bootstraps of the same training set agree on aggregate accuracy to within $1.3\text{--}4.2$ percentage points but disagree on the class label of $8.0\text{--}21.8\%$ of test molecules. We call this gap \emph{cross-sample prediction churn}. The standard parameter-side techniques (deep ensembles, MC dropout, stochastic weight averaging) do not reduce this gap; two data-side methods do. The first is $K$-bootstrap bagging, which cuts the rate $40\text{--}54\%$ on every dataset at no accuracy cost ($K{\times}$-ERM compute). The second is \emph{twin-bootstrap}, our proposal: two networks trained jointly on independent bootstraps with a sym-KL consistency loss between their predictions, which at matched $2{\times}$-ERM compute reduces churn a further median $45\%$ beyond bagging-$K{=}2$. Cross-sample prediction churn deserves a column alongside predictive performance in scientific-ML benchmark reports, because without it the parameter-side and data-side methods are indistinguishable on the metric they actually differ on.

2605.13819 2026-05-14 hep-ex

Search for charginos and neutralinos with $B-L$ $R$-parity violating decays in $\sqrt{s}=13$ TeV and $13.6$ TeV $pp$ collisions with the ATLAS detector

ATLAS Collaboration

AI总结 本研究利用ATLAS探测器在13 TeV和13.6 TeV质子对撞数据中搜索通过违反R宇称耦合衰变的共轭子和中性子,重点关注其通过希格斯玻色子衰变的信号。分析基于包含三个或更多b标签喷注和一个或两个电子或μ子的事件,数据集总积分亮度为140 fb⁻¹和56 fb⁻¹。实验结果与标准模型预测一致,并对超出标准模型的过程设定了95%置信水平的模型无关截面限制,同时对具有额外B-L规范对称性的最小超对称标准模型中的共轭子和中性子生产设定了质量排除限制。

Comments Comments: 47 pages in total, author list starting page 30, 9 figures, 6 tables, submitted to Phys. Rev. D. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HMBS-2024-09/

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A search is performed for the electroweak pair production of charginos and associated production of a chargino and neutralino, each of which decays through an $R$-parity-violating coupling into a lepton and a $W$, $Z$, or Higgs boson. This search targets the Higgs boson decay channel of the charginos and neutralinos, using events with three or more $b$-tagged jets and one or two electrons or muons. The analyzed data corresponds to an integrated luminosity of 140 fb$^{-1}$ and 56 fb$^{-1}$ of proton-proton collision data produced by the Large Hadron Collider at center-of-mass energies of $\sqrt{s}=13$ TeV and $\sqrt{s}=13.6$ TeV respectively, collected by the ATLAS experiment between 2015 and 2023. The data are found to be consistent with predictions from the Standard Model. The results are interpreted as limits at 95% confidence level on model-independent cross sections for processes beyond the Standard Model. Limits are also set on the production of charginos and neutralinos for a Minimal Supersymmetric Standard Model with an additional $B-L$ gauge symmetry that is spontaneously broken. Charginos and neutralinos with masses between 150 GeV and 1100 GeV are excluded at 95% confidence level for a scenario in which they decay via Higgs bosons, assuming equal decay branching fractions to each lepton flavor. Additional limits are derived for flavor-specific decay scenarios.

2605.13809 2026-05-14 hep-th

"Metric-affine-like" generalization of YM (mal-YM): detailed classical consideration

Władysław Wachowski

AI总结 本文研究了一种类似于度量仿射结构的杨-米尔斯理论(mal-YM)的推广形式。该理论中,联络不再与纤维上的厄米形式兼容,从而引入了额外的非阿贝尔标量场和张量场,形成了类似施特克尔贝格理论的结构。通过自发对称性破缺,这些新场可以获得质量,且在质量趋于无穷时恢复标准杨-米尔斯理论。文章对这一理论进行了详细的经典层面上的分析,包括几何动机、场变换、对称性破缺、作用量、运动方程等内容。

Comments 23 pages

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We consider the ``metric-affine-like'' generalization of the Yang-Mills theory (mal-YM) which we first proposed earlier. In this model, the connection is no longer assumed to be compatible with the Hermitian form in the fibers. As a consequence, along with the usual YM potential $\boldsymbol{A}_a$ and the field strength tensor $\boldsymbol{F}_{ab}$, it contains non-trivially interacting fields $\boldsymbol{B}_a$, $\boldsymbol{h}$, and $\boldsymbol{G}_{ab}$, $\boldsymbol{N}_a$, forming a non-Abelian generalization of Stückelberg theory. Due to the spontaneous symmetry breaking $GL(n,\mathbb{C}) \to U(n)$, these new fields can be made massive and the limit $M\to\infty$ restores the standard YM theory. We perform a detailed analysis of this theory on the classical level. We discuss in detail geometric motivation for the model, field transformations, gauge symmetry and its spontaneous breaking, action, equations of motion, Noether identities, gauge fixing, and other issues.

2605.13807 2026-05-14 cond-mat.str-el cond-mat.dis-nn cs.LG physics.comp-ph quant-ph

Parallel Scan Recurrent Neural Quantum States for Scalable Variational Monte Carlo

Ejaaz Merali, Mohamed Hibat-Allah, Mohammad Kohandel, Richard T. Scalettar, Ehsan Khatami

AI总结 本文提出了一种基于并行扫描结构的递归神经量子态(PSR-NQS),旨在解决传统递归神经网络在量子多体系统模拟中可扩展性差的问题。通过结合自回归递归波函数与可并行化的递归方法,该方法能够在一维和二维空间中高效地进行变分蒙特卡洛训练,并在较大规模的二维自旋晶格上取得了与量子蒙特卡洛数据一致的高精度结果。研究证明了递归架构在资源消耗较低的情况下,仍具备实现可扩展量子态模拟的实用性和潜力。

Comments 13 pages, 2 figures, 6 tables

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Neural-network quantum states have emerged as a powerful variational framework for quantum many-body systems, with recent progress often driven by massively parallel architectures such as transformers. Recurrent neural network quantum states, however, are frequently regarded as intrinsically sequential and therefore less scalable. Here we revisit this view by showing that modern recurrent architectures can support fast, accurate, and computationally accessible neural quantum state simulations. Using autoregressive recurrent wave functions together with recent advances in parallelizable recurrence, we develop variational ansätze, called parallel scan recurrent neural quantum states (PSR-NQS), which can be trained efficiently within variational Monte Carlo in one and two spatial dimensions. We demonstrate accurate benchmark results and show that, with iterative retraining, our approach reaches two-dimensional spin lattices as large as $52\times52$ while remaining in agreement with available quantum Monte Carlo data. Our results establish recurrent architectures as a practical and promising route toward scalable neural quantum state simulations with modest computational resources.

2605.13805 2026-05-14 cond-mat.mtrl-sci

Chiral molecule-induced contributions to ferromagnetic resonance

Jurgen Lindner, Pedro Contreras-Gallardo, Abhishek Singh, Ruslan Salikhov, Anna Semisalova, Olav Hellwig, Rodolfo Gallardo, Anna Lewandowska-Andralojc, Kilian Lenz, Aleksandra Lindner

AI总结 本研究探讨了手性分子界面对手性驱动自旋选择性的动态磁响应的影响,特别关注其对具有垂直磁各向异性的薄层Co/Ni多层膜的磁化动力学的作用。通过宽带铁磁共振谱实验,发现手性分子修饰并未显著改变共振场和线宽。基于实验结果,研究提出了一个宏观自旋模型,区分了由手性引起的平衡态自由能变化与非平衡态自旋转移矩效应,为在铁磁共振实验中分离这两种效应提供了理论依据。

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Despite extensive research on chirality-driven spin selectivity, most studies have focused on static magnetic properties, while the influence of chirality on the dynamic magnetic response remains largely unexplored. Here, we investigate how chiral molecular interfaces affect magnetization dynamics in thin Co/Ni multilayers with perpendicular magnetic anisotropy using broadband ferromagnetic resonance spectroscopy. A comparison between bare (reference) films and molecule-functionalized (hybrid) samples reveals no measurable changes in either the resonance field or the linewidth that could be attributed to the presence of the chiral environment. Motivated by our findings we develop a macrospin description that distinguishes equilibrium modifications of the magnetic free-energy landscape (MIPAC-type effects) from non-equilibrium, CISS-induced spin torques. Our analysis shows that equilibrium modifications primarily shift the resonance condition via changes to the free energy landscape and thereby the effective field, whereas damping-like non-equilibrium torques provide a distinct channel for varying the effective damping rate. This approach establishes clear criteria for disentangling chiral-interface-induced energy modifications from torque-driven dynamical effects in ferromagnetic resonance experiments.

2605.13802 2026-05-14 math-ph math.MP math.PR

Irregular SLE(4) martingales and isomonodromic deformations

Harini Desiraju, Aleksandra Korzhenkova, Eveliina Peltola

AI总结 本文研究了黎曼球面上非福克斯型单值性保持变形,考虑了包含不规则奇点的变形参数,包括奇点位置和Birkhoff不变量。通过推导这些变形参数的Loewner演化,构造了在存在双重极点情形下SLE(4)过程的鞅可观测量,并利用共形场论中中心电荷为1的 confluent BPZ 方程唯一地刻画了这些可观测量。

Comments 36 pages, 1 figure

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We consider non-Fuchsian monodromy preserving deformations on a Riemann sphere. The associated isomonodromic deformation parameters on this surface comprise the positions of the singularities, together with the Birkhoff (spectral) invariants owing to the presence of irregular singularities. Our first main result is the derivation of the Loewner evolution of these isomonodromic deformation parameters. Using this result, we construct martingale observables for Schramm-Loewner evolution (SLE(4)) processes in the presence of double poles. Geometrically, the expressions contain the pre-Schwarzian and Schwarzian of the Loewner evolution, arising from conformal covariance of the observable. Furthermore, we characterize these SLE(4) observables uniquely in terms of confluent BPZ equations of a CFT with central charge c=1.

2605.13799 2026-05-14 astro-ph.HE

Tidal disruption of a low-mass star in an active galactic nucleus as the origin of the PS16dtm outburst

Marzena Śniegowska, Bożena Czerny, Michal Zajaček, Valentina Rosa, Vladimír Karas, Taj Jankovič, Tanja Petrushevska, Dragana Ilić, Benny Trakhtenbrot, Petr Kurfürst

AI总结 论文研究了PS16dtm这一发生在窄线 Seyfert 1 类星系中心的天体爆发事件,推测其起源于一个正在吸积物质的活动星系核中低质量恒星的潮汐破坏。通过光谱和时序分析,研究认为该事件可能涉及一颗约0.3倍太阳质量的主序星或低质量巨星的部分潮汐破坏,并提出恒星可能处于与吸积盘反向旋转的轨道上。研究还指出观测角度较大,实际破坏过程未被直接观测到,未来需要更多X射线波段的观测以验证该模型并进一步理解该系统回归正常活动星系核状态的过程。

Comments 17 pages, 10 figures, submitted to A&A. Comments welcome

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The event PS16dtm, which occured in the center of the Narrow Line Seyfert 1 (NLS1) galaxy SDSS J015804.75-005221.8 (z = 0.080440), is one of the few candidates for a tidal disruption event in an already-acretting active galactic nucleus (AGN). We aim to shed light on the character of the tidal disruption event in this source since it exhibits unusual peculiarities, such as the double-peak optical/UV light curve and a low blackbody temperature with a lack of X-ray emission. We perform spectral analysis of the source before and during the event. We model the time evolution of the luminosity profile using a numerical code that describes the viscous evolution of the flow. From the combined spectral and timing studies, we interpret the event as the disruption of a $\sim 0.3 M_{\odot}$ main-sequence star, or gradual partial disruption of the low-mass giant star. The star is likely on a circular orbit, embedded in the accretion disc. The discussion of the evolution of the star rather suggests that the orbit is counter-rotating. We observe the system at a sufficiently large viewing angle that the actual disruption process is not directly observed. The disrupted star and inner disc are shielded from the observer by a gaseous envelope. Further observations of the system returning to the previous NLS1 state, particularly in the X-ray band, are needed to confirm the proposed scenario and to put constraints on the return to a regular NLS1 state.

2605.13797 2026-05-14 gr-qc astro-ph.CO hep-ph hep-th

Thin Accretion Disks around Rotating Charged Black Holes in an Effective Higher-Curvature Spacetime

Mohammad Hassani, Kourosh Nozari, Sara Saghafi

AI总结 本文研究了在一种有效高曲率时空背景下的旋转带电黑洞周围薄吸积盘的结构与辐射特性。该时空是对 Kerr-Newman 几何的一种经验性修正,通过引入类似高斯-博内特的参数 $α$ 来改变度规函数 $Δ$。研究发现,增大 $α$ 会使吸积盘的最内稳定圆轨道向内移动,并增强其辐射通量和温度,而电荷的存在则因静电效应抑制这些量。结果表明,这种高曲率修正会导致与 Kerr 黑洞显著不同的可观测效应,显示吸积盘可作为探测强引力区域物理性质的有效工具。

Comments 31 pages,10 figures, 1 table. Accepted for Publication in Journal of High Energy Astrophysics

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We investigate the structure and emission properties of a thin accretion disk around a rotating charged black hole described by an effective higher-curvature-inspired spacetime, constructed as a phenomenological deformation of the Kerr Newman geometry. In this framework, the deformation is introduced through a modification of the metric function $Δ$ by an effective Gauss-Bonnet-like parameter $α$, such that the spacetime reduces to the standard Kerr Newman solution in the limit $α\to 0$. Adopting a kinematical approach, we use test-particle motion to derive the specific energy, specific angular momentum, and angular velocity of circular orbits, and analyze the effects of the parameters $α$ and charge $Q$ on the innermost stable circular orbit (ISCO), radiative efficiency, radiation flux, temperature, and differential luminosity of the disk. We find that increasing $α$ shifts the ISCO inward and enhances the disk's radiation flux and temperature, while the presence of charge suppresses these quantities due to electrostatic effects. Our results demonstrate that effective higher curvature deformations of rotating black hole spacetimes can lead to observable deviations from the Kerr case, highlighting accretion disks as sensitive probes of strong-gravity effects without relying on a specific underlying gravitational theory.

2605.13796 2026-05-14 quant-ph cs.CR

Backdoor Threats in Variational Quantum Circuits: Taxonomy, Attacks, and Defenses

Lei Jiang, Fan Chen

AI总结 本文系统调研了变分量子电路中的后门攻击问题,分析了其在数据污染、编译器层面和量子原生机制等方面的攻击方式,并总结了现有检测与防御方法的局限性。研究明确了相关术语与威胁模型,揭示了后门攻击在量子计算环境中的独特挑战,为构建鲁棒的量子-经典混合系统防御机制提供了方向。

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英文摘要

Variational quantum algorithms (VQAs) are a central paradigm for noisy intermediate-scale (NISQ) quantum computing, yet their reliance on predesigned and pretrained variational quantum circuits (VQCs) introduces critical security vulnerabilities, particularly backdoor attacks. These attacks embed hidden malicious behaviors that remain dormant under normal conditions but are activated by specific triggers, leading to adversarial outcomes such as incorrect predictions or manipulated objective values. This paper presents a survey of backdoor attacks in VQCs, covering data-poisoning, compiler-level, and quantum-native mechanisms. We formalize key terminology and threat models, and review existing attack strategies along with their empirical characteristics. We also analyze current detection and defense approaches, highlighting their limitations, especially against quantum-specific threats. By synthesizing recent advances, this survey outlines the evolving security landscape of VQCs and identifies key challenges and future directions for developing robust, quantum-aware defenses in hybrid quantum-classical systems.

2605.13791 2026-05-14 hep-th hep-lat hep-ph

Universal Confining Strings: From Compact QED to the Hadron Spectrum

M. C. Diamantini, F. Quevedo, C. A. Trugenberger, L. Zapata

AI总结 本文研究了通过限制弦或磁通管描述夸克禁闭的问题,提出紧致QED在磁单极子凝聚相中可通过一个具有质量的二形式场描述,从而在强耦合下形成一个红外固定的弦理论。该弦具有有限厚度,包含超越Nambu-Goto弦的共振模,能更好地拟合实验数据,并成功重现了改进的Arvis势及重夸克质量比,支持了Polyakov关于禁闭规范理论红外普适性的猜想。

Comments 25 pages, 5 figures

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英文摘要

We investigate the description of quark confinement in terms of confining strings or flux tubes. We show that compact QED with a topological $θ$-term, in the dyon condensation phase, is described by a massive two-form field $B_{μν}$ that gives rise to a string theory with an IR Brazovskii-Lifshitz fixed point at strong coupling. This corresponds to a quantum consistent "free string" in (3+1) dimensions, representing the dual of asymptotic freedom in the UV. Contrary to critical strings, which correspond to trivial Gaussian fixed points, this string is stabilized by a finite thickness, determined by the mass of the $B_{μν}$ field, instead of living in a higher-dimensional space. It correspondingly contains a massive world-sheet resonance, in addition to the Nambu-Goto phonons, that improves fitting with data. We compute the confining potential and show that it reproduces a generalized Arvis potential $V(L) = aL \sqrt{1 - c/L^2}$ with running parameters $a(L), c(L)$. We compute the mass difference ratios for the heaviest quarkonium and find 2.5 percent agreement with experiment already at the infrared fixed point. We also compute the intercept of Regge trajectories and find that the thickness of Brazovskii-Lifshitz strings tends to increase it from the Nambu-Goto value $α_0 = 1/12$. Overall, our findings strongly support Polyakov's longstanding conjecture on universality of confining gauge theories in the IR.

2605.13781 2026-05-14 astro-ph.EP

Global evolution of electric fields during planet encircling dust storms on Mars

Ina Taxis, Leonardos Gkouvelis, Richard A. Urata, Melinda A. Kahre, Amanda S. Brecht

AI总结 本文研究火星全球性沙尘暴期间电场的生成与演变过程,利用NASA阿姆斯火星全球气候模型中的双模尘埃粒径分布,并结合摩擦带电和静电诊断方案,模拟了沙尘暴期间电场能量密度及放电特性。研究发现,电场的生成受尘埃负载、湍流碰撞活动和电导率依赖的电荷弛豫等因素共同影响,且日间电导率变化显著抑制了电场的积累,多数事件处于弱辉光或汤森放电阶段。该成果为识别全球性沙尘暴期间静电放电高发区域提供了定量框架,对未来的探测器和载人任务的仪器设计、电源保护及任务规划具有重要意义。

Comments Accepted for publication in Astronomy & Astrophysics

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英文摘要

Planet-encircling dust storms fundamentally reshape Martian weather and the near-surface electrostatic environment. We investigate the generation and evolution of electric fields during global dust storms using bimodal dust size distributions from the NASA Ames Mars Global Climate Model, coupled with a triboelectric charging and electrostatic diagnostic scheme that links collisional charging to the local dynamical state of the atmosphere. Focusing on the dust-lifting and buildup phase and its subsequent evolution, we quantify the electric-field energy density and discharge characteristics, including onset thresholds, event frequency, and spatial clustering. The simulations reveal broad storm-active belts of enhanced electrification, with the most frequent threshold exceedances occurring in southern low-to-mid latitudes and secondary activity in northern low-to-mid latitudes. Modeled near-surface electric fields reach $10^{2}$--$10^{3}\ \mathrm{V\,m^{-1}}$ comparable to values inferred for smaller-scale dust phenomena. The results indicate that electric-field generation is controlled by the interplay between dust loading, turbulence-driven collisional activity, and conductivity-dependent charge relaxation, with diurnal conductivity variations strongly suppressing daytime electric-field buildup and most events remaining in the weak glow or Townsend discharge regime. While the model captures the large-scale distribution of electrically favorable conditions, the predicted spatial extent of activity likely represents an upper bound, as small-scale turbulent structures are not fully resolved. These results provide a quantitative framework to identify regions where electrostatic discharges are most likely during GDSs and to inform instrument design, power-system protection, and operations planning for future robotic and human missions.

2605.13774 2026-05-14 math.OC math.DS math.OA quant-ph

Affiliated operators for classical and quantum control

Dimitrios Giannakis, Gage Hoefer

AI总结 本文提出了一种基于冯·诺依曼代数理论的框架,用于研究无限维希尔伯特空间上双线性控制系统的可控性问题。该框架假设漂移项和控制项都隶属于同一希尔伯特空间上的有限型冯·诺依曼代数,并在控制项满足基本范数约束的条件下,证明了时间最优控制的存在性。此外,即使在算子可能无界的情况下,文中也展示了如何定义系统的动力学李代数并用于判断近似可控性,并将该方法应用于经典动力系统,通过Koopman算子形式拓展了其适用范围。

Comments 30 pages, no figures

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英文摘要

Using techniques from the theory of von Neumann algebras, we propose a framework for addressing questions of controllability of bilinear systems on infinite dimensional Hilbert spaces. In the setup, we assume only that the drift and control terms arising in a bilinear control system are affiliated with a von Neumann algebra of finite type acting on the same Hilbert space. When the control terms satisfy basic norm bound conditions, we prove existence of time-optimal controls. In the more general setting where all operators may be unbounded, we show how the dynamical Lie algebra for the system is still well-defined and may be used to check approximate controllability of the system in question. We discuss how this approach can be applied to classical dynamical systems through the Koopman operator formalism, and investigate potential candidates for the von Neumann algebra which may guide the choice of controls. We illustrate how an affiliation relation naturally arises in both classical and quantum control systems with a few examples.

2605.13763 2026-05-14 cond-mat.mes-hall cond-mat.mtrl-sci

Magnetization-dependent and stacking-tunable Edelstein effect in two-dimensional magnet 2H-VTe2

Weiyi Pan, Jaroslav Fabian

AI总结 本研究通过第一性原理计算和对称性分析,揭示了二维铁磁半导体2H-VTe2中内禀的埃德斯坦效应,并发现其行为强烈依赖于磁化方向。研究还表明,通过改变双层2H-VTe2的堆叠方式,可以可逆调控额外的自旋积累分量,为实现高效自旋轨道转矩器件提供了新的材料平台。

Comments 16 pages, 11 figures

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The Edelstein effect in magnetic systems enables magnetization switching via the coupling between current-induced spin accumulation and intrinsic magnetic order, and is therefore highly promising for next-generation spintronic devices. Realizing and manipulating the Edelstein effect in two-dimensional (2D) magnetic systems is particularly desirable for achieving high-efficiency and multifunctional spintronic applications. In this work, based on first-principles calculations and symmetry analysis, we demonstrate that the Edelstein effect can intrinsically arise in the 2D in-plane ferromagnetic semiconductor 2H-VTe2, with its behavior strongly dependent on the magnetization orientation. For monolayer 2H-VTe2 with D3h crystal symmetry, under an applied current along the +x direction, only the time-reversal-even z component and the time-reversal-odd y(x) component of the spin accumulation are allowed when the magnetization is aligned along +x (+y). For ferromagnetic bilayer 2H-VTe2 in AB or BA stacking, where the crystal symmetry is reduced to C3v, additional spin components emerge with the presence of in-plane magnetization. Specifically, for magnetization along +x (+y), besides dSz_even and dSy_odd (dSz_even and dSx_odd), extra components such as dSy_even and dSz_odd (dSy_even) become allowed. Notably, these additional components can be reversibly switched by changing the stacking configuration from AB to BA via interlayer sliding. Our results not only deepen the understanding of current-induced spin accumulation in 2D magnetic systems from both symmetry and first-principles perspectives, but also identify 2H-MX2 materials as a promising platform for realizing intrinsic and tunable Edelstein effects in high-efficiency spin-orbit torque devices.

2605.13760 2026-05-14 physics.ins-det hep-ex

Application of exhaustive simulation flow for advanced performance prediction of monolithic active pixel sensors

E. Sacchetti, M. Babeluk, T. Bergauer, M. Friedl, C. Irmler, B. Pilsl, R. Russo, C. Schwanda, L. Gaioni, V. Re, E. Riceputi, G. Traversi, S. Giroletti, L. Ratti, G. F. Benfratello, S. Bettarini, F. Bosi, G. Casarosa, L. Corona, F. Forti, A. Gabrielli, M. Massa, L. Massaccesi, M. Minuti, A. Moggi, S. Mondal, G. Rizzo, M. Rovini, A. Taffara, M. Barbero, P. Barrillon, R. Boudagga, P. Breugnon, D. Fougeron, P. Pangaud, J. Serrano, V. Vobbilisetti, D. Xu, D. Auguste, J. Bonis, Y. Peinaud, M. Winter, J. Baudot, G. Bertolone, A. Dorokhov, G. Dujany, L. Federici, C. Finck, A. Himmi, C. Hu-Guo, A. Kumar, M. Maushart, F. Morel, H. Pham, I. Ripp-Baudot, R. Sefri, P. Stavroulakis, I. Valin, F. Bernlochner, C. Bespin, J. Dingfelder, T. Kishishita, H. Kruger, L. Schall, M. Vogt, M. Karagounis, Y. Buch, A. Frey, B. Schwenker, M. Schwickardi, K. Hara, D. Jeans, K. R. Nakamura, Y. Okazaki, T. Higuchi, Y. Onuki, S. Wang, C. Lacasta, C. Marinas, J. Mazorra de Cos, L. Molina-Bueno, A. Bevan, M. Bona, D. Howgill, W. Song, J. Gong, X. Gao, A. Fernandez Prieto, A. Gallas Torreira

AI总结 本文提出了一种用于单片有源像素传感器(MAPS)先进性能预测的全面仿真流程,覆盖了从敏感区域信号生成到像素数字逻辑输出的全过程,特别关注时间到达(ToA)和时间超过阈值(ToT)测量的精度。该方法结合了蒙特卡罗仿真(Allpix Squared)与高精度电路仿真(SPICE),并引入了像素阱的布局集成,以精确描述漏电流和穿通电流等关键特性,同时考虑了辐照效应对电荷传播和前端响应的影响。该方法已应用于Belle II顶点探测器升级所开发的MAPS,并通过与TJ-Monopix2实验数据的对比验证了其有效性。

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Monolithic active pixel sensor (MAPS) developments have pushed the detection performance in various directions, especially relative to timing where nanosecond-level precision is now considered. This evolution calls for a simultaneous upgrade of the simulation tools. We have developed a simulation flow that covers steps from the signal creation in the sensitive volume to the output of the pixel digital logic that performs the time-of-arrival and time-over-threshold (ToA/ToT) measurements. This approach adds several new features to the traditional use the of the TCAD - Allpix Squared duo, among which : the integration of the pixel wells from the layout in order to precisely describe the pixel key characteristics such as leakage and punch-through currents and the coupling of Monte Carlo simulations (Allpix Squared) with high precision electrical simulations (SPICE). The first (Allpix Squared) for the precise description of the current induced at the collection electrode and the second (SPICE) to guarantee high precision simulation of the front-end electronics using realistic signal events. Irradiation is also modeled, both from the charge propagation side (charge trapping) and from the front-end response side (high input signal discharge). We have applied this methodology to the MAPS developed in the context of the Belle II vertex detector upgrade. In this contribution, we detail the key features of the exhaustive simulation flow, present the outcome of the comparison with the TJ-Monopix2 measurements and discuss the interest of the methodology for the development of modern MAPS.

2605.13758 2026-05-14 quant-ph math.OC

Phase Matching for a Generalized Grover's Algorithm

Chris Cardullo, Min Kang

AI总结 本文研究了一种广义的Grover算法,旨在为每次迭代步骤寻找最优的相位变化,以最大化目标态的观测概率,并考虑相位匹配的条件。研究发现,当目标概率接近1时,传统Grover算法和相位匹配策略不再最优,此时最优相位变化偏离π且不再满足相位匹配。文章提出了一个优化框架,用于根据当前振幅向量和集合规模确定最优相位变化,并通过数值和解析方法进行分析,最后以一个5量子比特系统为例,展示了在最后一次迭代中,最优相位变化不同于传统算法且不满足相位匹配,但仍能提升目标态的概率。

Comments 8 pages, 3 figures

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We study the fully generalized Grover's algorithm to find the optimal phase changes for each step of the iteration to maximize gain in probability of observation of the target, and when phase matching is required. We find that classical Grover's algorithm and phase matching remains to be optimal till the target probability gets close 1. However, as the probability of observation approaches 1, the optimal phase changes differ from $π$ and no longer observe phase matching. We provide the optimization statement to find the optimal phase changes given the current amplitude vector and the size of the set. To analyze this formula, we approach it from a numerical and analytical perspective, with the analytical perspective focusing on special cases that simplify the optimization and allow for general statements about its behavior. Finally, we provide an example of a 5 qubit system and show that for the final iteration the optimal phase changes differ from traditional Grover's algorithm and do not observe phase matching, but lead to an increase in the probability of the target.

2605.13750 2026-05-14 physics.soc-ph cs.GT q-bio.PE

The Co-evolution of Costly Signaling and Cooperation in Social Dilemmas

Mahdi Abolhasani, Saman Moghimi-Araghi, Mohammad Salahshour

AI总结 该研究探讨了在社会困境中,昂贵合作行为与昂贵信号机制如何共同演化的问题。通过构建一个信号与行为相互影响的模型,研究发现信号的演化更多取决于其引发的合作反应,而非单纯的信号成本。研究显示,在不同博弈场景和群体结构下,信号机制能够促进合作的维持,尤其在空间结构中合作更易增强,而在囚徒困境中则需引入动态关联因素来解释其演化机制。

Comments 25 pages, 9 figures

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Costly cooperation and costly signaling are both difficult to reconcile with simple fitness maximization, yet both are common in biological and social systems. We study a model in which agents emit costly signals and condition their actions on the signals they observe. Across the Prisoner's Dilemma (PD), Snowdrift (SD), and Stag Hunt (SH) games, we ask when this coevolutionary process can sustain cooperation and how it changes across well-mixed populations, spatial lattices, and fluctuating strategic environments. The simulations show that signals are selected less by their raw production costs than by the cooperative responses they currently elicit. In well-mixed populations, the mechanism sustains partial cooperation in PD and SD and drives near-complete cooperation in SH. On lattices, cooperation is strengthened further by local assortment. A reduced mean-field analysis explains why average population feedback is already sufficient in SD and SH, but not in the PD. To account for the PD dynamics, the reduced theory must include transient correlations associated with rare signals, inheritance, or spatial clustering. Our results therefore delineate a class of settings in which costly signals persist because they transiently organize cooperative responses and thereby reshape the effective strategic environment.

2605.13747 2026-05-14 quant-ph

Optimal Quantum Illumination with Nonlocal Non-Gaussian Operations

Luis D. Zambrano Palma, Yusef Maleki, M. Suhail Zubairy

AI总结 本文研究了利用非局域非高斯操作优化量子照明的问题,提出了一种新的非局域非高斯操作协议,能够在实际条件(如光子损耗)下生成性能优于传统两模式压缩态的探针态。通过使用50:50分束器和光子数差检测,该方法显著提升了目标探测的信噪比,展示了其在资源效率和实验可行性方面的优势。

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Enhancing quantum illumination with highly entangled probes remains an active area of research. In this context, non-Gaussian operations provide an effective route for engineering probe states that can surpass the standard two-mode squeezed state (TMSS). In this work, we investigate a specific nonlocal non-Gaussian operation protocol and show that the engineered state using this protocol outperforms previously considered local non-Gaussian scenarios, engineered based on photon catalysis, addition, and subtraction under realistic conditions, including photon loss. Furthermore, by employing a $50{:}50$ beam splitter with photon-number difference detection, we demonstrate a significant enhancement in the signal-to-noise ratio (SNR) for target detection relative to the TMSS. Thus, our protocol exhibits improved performance, highlighting a resource-efficient and experimentally feasible probe for enhanced quantum illumination.

2605.13738 2026-05-14 astro-ph.IM astro-ph.CO gr-qc hep-ex

Inpainting over the cracks: challenges of applying pre-merger searches for massive black hole binaries to realistic LISA datasets

Gareth Cabourn Davies, Ian Harry

AI总结 本文研究了在实际LISA数据集中应用预合并搜索方法检测大质量黑洞双星系统的挑战。作者比较了两种方法:一种是零延迟滤波方法,另一种是首次采用的“补全”(inpainting)技术。实验表明,即使在数据存在长达三天的缺失情况下,补全方法仍能有效识别出预合并信号,并展示了在信号重叠情况下通过去除已确认信号来识别较弱信号的策略。

Comments 13 pages, 10 figures, 4 tables

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A key science target of the Large Interferometer Space Antenna (LISA) is to carry out multi-messenger observations of massive black hole binaries, observing the merger simultaneously in gravitational waves and with electromagnetic observatories. Identifying that a merger is happening and providing an updating estimate of the sky location in the hours, days and weeks before the merger is critical to enable electromagnetic observations of the merger event. In this work we demonstrate and compare two methods for premerger identification of massive black hole binaries; a zero-latency filter approach and, for the first time, an approach using an ``inpainting'' technique. We apply these methods to the LISA Data Challenge dataset 2a--Sangria-HM--and demonstrate the successful recovery of the 14 signals in the dataset that we expected to be identifiable at least half a day before merger. We show that the inpainting method can identify premerger signals even when gaps are present in the data, demonstrating the recovery of a signal even when 3 day-long data gaps are added to the 14 days preceding merger. Finally, we explore the challenge of overlapping signals, using a region of overlapping signals in the Sangria-HM dataset, all of which merge within a 10-day window, and show how removing signals that have been confidently identified from the data allows us to identify quieter signals in the same period.

2605.13732 2026-05-14 gr-qc

Cosmological perturbations in the theory of gravity with non-minimal derivative coupling. I. Modes of perturbations

R. I. Kamalitdinov, S. V. Sushkov

AI总结 本文研究了具有非极值导数耦合的引力理论中,各向同性且均匀宇宙模型的扰动行为,该模型采用空间平坦的弗里德曼-勒梅特-罗伯逊-沃克度规。理论的拉格朗日量包含耦合项 $ηG^{μν}\nabla_μϕ\nabla_νϕ$,属于广义霍尔登斯基因拉格朗日量的特例,其场方程为二阶形式。研究发现,非极值导数耦合在早期宇宙中显著影响演化过程,导致无需精细调参的准德西特膨胀阶段,而在晚期则退化为标准宇宙演化。作者推导了描述标量、矢量和张量扰动模式的完整方程,并通过解析和数值方法分析了其演化行为,表明所有扰动模式在膨胀阶段均被放大,这一特性与弗里德曼宇宙模型有本质区别。

Comments 14 pages, 6 figures

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We consider perturbations in the isotropic and homogeneous cosmological model with the spatially flat Friedmann-Lemaitre-Robertson-Walker metric in the framework of the theory of gravity with non-minimal derivative coupling. The Lagrangian of the theory contains the coupling term $ηG^{μν}\nabla_μϕ\nabla_νϕ$ and represents the particular example of a general Horndeski Lagrangian, which results in second-order field equations. It is known that the non-minimal derivative coupling crucially changes scenarios of the Universe evolution on early times. In particular, the $η$-term is dominating on early times and leads to a primary quasi-de Sitter (inflationary) stage which needs no fine-tuned potential. On late times the influence of non-minimal derivative coupling on the Universe evolution completely disappears, and this naturally leads to the transition to the standard cosmological evolution (post-inflationary stage). We have derived a complete set of equations which describe an evolution of scalar, vector and tensor modes of perturbations. All modes are analyzed analytically in two asymptotic cases, and then we construct exact numerical solutions which describe an entire evolution of the modes. We show that all modes, including vector ones, are amplified in the quasi-de Sitter (inflationary) stage, and such the behavior is cardinally distinct from that in Friedmann cosmology.

2605.13728 2026-05-14 astro-ph.SR

Detector for fast wave trains in the solar radio emission

V. A. Dmitriev, E. G. Kupriyanova, A. V. Mikhalchuk

AI总结 本文旨在开发一种自动检测太阳射电数据中快速波列的方法,以提升对日冕中能量释放过程的诊断能力。研究采用分类神经网络和机器学习技术,利用2011年HiRAS射电谱仪在20 MHz至2.5 GHz频段获取的动态射电谱数据,结合50个全局日冕极紫外波事件作为标记,成功识别出50个具有类似快速波列时间特征的候选事件,其中13个与全局波相关,显著拓展了此类事件的观测样本。

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Quasi-periodic fast propagating (QFP) wave trains observed in the solar corona after some energetic events (solar flares, coronal mass ejections, jets) open possibilities for diagnostics of spatial and temporal scales of the impulsive energy release processes, that are absent in the standard model of a solar flare. Besides, the dynamics of the wave trains and their characteristic spatial and temporal signatures allow to localize the initial energy release volume magenta and to perform fine diagnostics of the transverse structures of plasma inhomogeneities in the solar corona. However, the small number of such events registered significantly limits their promising diagnostic potential. The aim of this paper is to perform an automatic search for fast wave trains in radio data. We apply classifying neural network/machine learning methods. Dynamic radio spectra obtained by HiRAS radio spectrographs within the 20 MHz -- 2.5 GHz frequency band during 2011 were used. We consider 50 global coronal EUV waves as marker events for more a targeted search in HiRAS data. Our automatic detector revealed 50 independent QFP-candidates events with the temporal signatures similar to that of the fast wave trains, with 13 candidates connected with the global waves.

2605.13722 2026-05-14 cond-mat.mes-hall

Shubnikov-de Haas Characterization of Superconductor-Semiconductor Heterostructures

A. M. Zimmerman, Saeed Fallahi, Sergei Gronin, Tyler Lindemann, Patrick Sohr, Ray Kallaher, Alejandro Alcaraz Ramirez, Georg W. Winkler, Samuel M. L. Teicher, William Cole, Sebastian Heedt, Eoin O'Farrell, Gijs de Lange, Roman Lutchyn, Michael J. Manfra, John Watson

AI总结 本文提出了一种利用舒布尼科夫-德哈斯(SdH)振荡测量方法,对超导体-半导体异质结构中的基本材料参数进行表征的新方法。通过分析异质结构中金属态与二维电子气(2DEG)耦合系统的磁阻数据,能够提取量子阱载流子密度、自旋轨道耦合强度以及输运和量子散射时间等关键参数。该方法无需复杂制备或毫开尔文测量,即可快速获取近邻诱导超导能隙的信息,为优化混合材料体系提供了重要工具。

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英文摘要

Hybrid superconductor-semiconductor nanostructures are a central component for research spanning condensed matter physics and quantum information processing. Continued progress relies critically on the ability to characterize, control, and optimize several intrinsic material properties including spin-orbit coupling, band offsets, and disorder in a device-relevant stack that necessarily couples the electronic states of a superconducting metal film and a semiconductor. Here we report a new method to extract fundamental material parameters utilizing simple Shubnikov-de Haas (SdH) oscillation measurements in heterostructures in which metallic electronic states are coupled to a two-dimensional electron gas (2DEG) residing in an InAs quantum well beneath an aluminum thin film. Proper analysis of the full magnetoresistance data facilitates extraction of the quantum well carrier density, spin-orbit coupling strength, and both transport and quantum scattering times. Most importantly, the extracted scattering times in the 2DEG are impacted by the metal-semiconductor coupling strength allowing us to quickly gain information on proximity-induced superconducting gap without any fabrication or mK measurements. The wealth of information that is accessed with these simple measurements positions this methodology as an important tool for hybrid materials optimization.

2605.13721 2026-05-14 cond-mat.dis-nn

Do Hopfield Networks Dream of Stored Patterns? A Statistical-Mechanical Theory of Dreaming in Multidirectional Associative Memories

Adriano Barra, Fabrizio Durante, Andrea Ladiana, Michela Marra Solazzo

AI总结 本文提出了一种多向联想记忆模型——梦觉 $L$-方向联想记忆(DLAM),该模型结合了离线“梦境”机制和监督异联想耦合,统一在单一能量函数框架下,属于基于能量的模型(EBMs)。通过统计力学方法,研究揭示了梦境机制如何通过抑制经验协方差矩阵的高特征值干扰模式,提升模式检索性能,并与层间耦合协同作用,实现传统方法无法达到的检索区域。该模型在分离混合输入模式方面表现出色,能够从单一混合信号中逐层恢复出各模式,并在数据与计算的权衡上展现出新特性,为神经信息处理提供了更丰富的理论基础。

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英文摘要

We introduce the Dreaming $L$-directional Associative Memory (DLAM), a multi-layer Hebbian architecture in which off-line dreaming and supervised heteroassociative coupling coexist within a single energy function, placing our approach within the framework of energy-based models (EBMs). The replica-symmetric free energy, derived via the Guerra interpolation scheme, yields self-consistency equations governing the order parameters across the control-parameter space. The effective local field decomposes into signal, intra-layer dreaming noise, and inter-layer noise. Dreaming improves retrieval by differentially attenuating high-eigenvalue interference modes of the empirical correlation matrix, suppressing inter-pattern crosstalk while preserving the signal. Dreaming and inter-layer coupling prove synergistic, opening retrieval regions unreachable by either mechanism alone, as confirmed by Monte Carlo simulations for $L=3$. Their interplay is most pronounced on pattern disentanglement: given a mixture state as input, the network splits the constituent patterns one-per-layer, recovering each modality-specific pattern from a common cue that simultaneously blends noisy evidence from all sensory channels. Phase diagrams are planar projections of the hyperspace $(α,β,ρ,t)$-where $α$ is the storage load, $β$ the fast-noise inverse temperature, $ρ$ the dataset entropy, and $t$ the sleeping time. In the $(ρ,t)$-plane, the diagrams reveal a data-computation trade-off: off-line consolidation substitutes for additional training data, extending to heteroassociative architectures a phenomenon previously established for autoassociative networks. Enriching the standard Hopfield model with heteroassociativity and dreaming gives rise to EBMs capable of complex tasks beyond classical pattern recognition, contributing to a modern theory of neural information processing.

2605.13719 2026-05-14 astro-ph.HE

The Very Late Time Afterglow of GW170817 Favors a Wobbling Jet

Hao Wang, Ore Gottlieb, Aman Katira, Muskan Yadav, Lei Lei, Yi-Zhong Fan, Da-Ming Wei

AI总结 GW170817 是唯一一次通过多信使观测确认的双中子星并合事件,其余辉被持续监测近十年,为研究喷流特性提供了独特机会。研究发现其非常晚期余辉的衰减较浅,难以用传统准直喷流模型解释。本文提出该余辉由一个摆动喷流驱动,该喷流在天空中拖拽出一个环形结构,从而在喷流拐点后形成逐渐变长的发光弧,导致更缓慢的衰减。通过贝叶斯分析,研究证实环形喷流比准直喷流更符合观测数据,且表明喷流摆动角度约为27度,暗示中子星盘可能存在显著倾斜。

Comments 8 pages, 2 figures, 1 table. Comments are welcome

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英文摘要

GW170817 remains the only binary neutron star merger detected through multimessenger emission. Its afterglow has been monitored for nearly a decade, offering an unprecedented opportunity to probe the properties of the outflow. The shallow decay of the very late-time afterglow challenges the prediction of a collimated structured jet. Motivated by recent general-relativistic magnetohydrodynamic simulations, we propose that the GW170817 afterglow is powered by a wobbling jet that drags a ring on the sky. This structure predicts a post-break decay rate shallower than that of a collimated jet, as observers will see a progressively longer emitting arc after the break. A misaligned ring-shaped jet can therefore self-consistently explain the multimessenger data without invoking any extra component. Through a Bayesian analysis of the multimessenger data, we find a ring-shaped jet is favored over a collimated jet at a significance level of 4.8$σ$. Our results imply a wobbling angle of $\sim 27^\circ$. Such a large angle points to a significant disk tilt, potentially arising from disk-infalling gas interaction or asymmetric angular momentum ejection. Similar shallow decays have also been found in other GRB afterglows, raising the possibility that wobbling jets are common among GRBs.

2605.13714 2026-05-14 gr-qc astro-ph.HE

Quantum Field Theory of Black Hole Perturbations with Backreaction VI. Apparent Horizons, Quasi-Local Mass and Effective Classical Metrics

Jonas Neuser, Thomas Thiemann

AI总结 本文研究了黑洞扰动的量子场论,考虑了回作用效应,发展了一种适用于任意阶的规范不变方法。通过分析视界(作为事件视界的观测者依赖推广)的形状及其面积变化,揭示了蒸发黑洞的物理特性,并展示了如何从约化相空间变量重构四维度规。进一步地,通过量子态的期望值,得到了修正的经典度规,并可用于绘制量子修正的彭罗斯图,为后续的量子化过程和视界面积演化提供了理论基础。

Comments 30 pages

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英文摘要

In a recent series of papers we developed a first-principle and gauge invariant approach to black hole perturbation theory valid to any order. We included back reaction effects to tackle the situation of evaporating black holes and obtained an explicit expression for the dynamics of the reduced phase space to second order. The physics of evaporating black holes is in particular encoded by apparent horizons, an observer dependent generalisation of the event horizon. We determine the shape of the apparent horizon to second order in the perturbations. The area of the apparent horizon is an interesting observable which is expected to decrease in the quantum theory due to Hawking evaporation. We show how the full four dimensional metric can be reconstructed in terms of the reduced phase space variables. In the quantum theory, taking expectation values of this metric, we obtain an effective classical metric, whose causal structure can then be visualised in a quantum corrected Penrose diagram. We conclude with an outlook into the quantisation procedure in the reduced phase space formalism and the implications on the area of the apparent horizon.

2605.13712 2026-05-14 cond-mat.mes-hall

Enhanced Near-Field Thermal Radiation Driven by Multiple Corner and Edge Modes in Subwavelength Square Nanowires

Jose Ordonez-Miranda, Minggang Luo, Michele Diego, Roman Anufriev, Victor Guillemot, Masahiro Nomura, Sebastian Volz

AI总结 本研究揭示了亚波长方形单晶硅碳纳米线之间的近场热辐射主要由多个角和边共振模式主导,而非平面表面的单一表面声子极化子通道。通过波动电动力学模拟发现,这些共振位于SiC的Reststrahlen带内,随着纳米线变薄发生红移,并使热导率提升四倍。当纳米线间距接近其厚度时,热传导增强达到最大值,表明方形单元结构为几何调控近场热传输提供了理想的平台,对纳米尺度热管理与能量转换具有重要意义。

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英文摘要

We demonstrate that the near-field thermal radiation between subwavelength SiC nanowires with square cross sections is dominated by multiple corner and edge resonances rather than the single surface-phonon-polariton channel of planar surfaces. Fluctuational electrodynamics simulations reveal that these resonances lie within the SiC Reststrahlen band, redshift for thinner nanowires, and yield a four-fold enhancement of thermal conductance. This maximum enhancement occurs when the separation gap nearly matches the nanowire thickness, balancing dimensional confinement and interwire coupling. These findings establish square nanowires as a versatile platform for geometrycontrolled near-field heat transfer in nanoscale heat management and energy conversion.