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2602.04150 2026-05-21 q-bio.PE cond-mat.dis-nn nlin.AO

A brief review of evolutionary game dynamics in the reinforcement learning paradigm

强化学习范式下进化博弈动力学的简要回顾

Guozhong Zheng, Xin Ou, Shengfeng Deng, Jiqiang Zhang, Li Chen

AI总结 本文探讨了在强化学习范式下,进化博弈动力学在解释合作、公平、信任和资源协调等现代文明核心问题中的最新进展,以及该范式相较于传统模仿学习范式的优势。

Comments 27 pages, 7 figures, invited review

Journal ref Communications in Theoretical Physics 78, 067601 (2026)

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AI中文摘要

合作、公平、信任和资源协调是现代文明的基石,然而它们的出现仍无法充分解释理论预测与行为实验之间的持续差异。部分原因可能在于先前理论模型中常用的模仿学习范式,该范式假设个体仅根据预设的固定规则复制成功邻居。本文回顾了近期在进化博弈动力学中采用强化学习(RL)作为替代范式的新进展。在RL中,个体通过试错学习,并根据环境反馈内省性地完善其策略。我们首先介绍了进化博弈理论中的关键概念和两种学习范式,然后综合了将RL应用于阐明合作、信任、公平、最优资源协调和生态动态方面的进展。总体而言,这些研究表明,RL提供了一个有前景的统一框架,用于理解人类和自然系统中观察到的多样化社会和生态现象。

英文摘要

Cooperation, fairness, trust, and resource coordination are cornerstones of modern civilization, yet their emergence remains inadequately explained by the persistent discrepancies between theoretical predictions and behavioral experiments. Part of this gap may arise from the imitation learning paradigm commonly used in prior theoretical models, which assumes individuals merely copy successful neighbors according to predetermined, fixed rules. This review examines recent advances in evolutionary game dynamics that employ reinforcement learning (RL) as an alternative paradigm. In RL, individuals learn through trial and error and introspectively refine their strategies based on environmental feedback. We begin by introducing key concepts in evolutionary game theory and the two learning paradigms, then synthesize progress in applying RL to elucidate cooperation, trust, fairness, optimal resource coordination, and ecological dynamics. Collectively, these studies indicate that RL offers a promising unified framework for understanding the diverse social and ecological phenomena observed in human and natural systems.

2602.04092 2026-05-21 stat.AP econ.EM stat.ME

Time-to-Event Estimation with Unreliably Reported Events in Medicare Health Plan Payment

Medicare健康计划支付中不可靠事件报告的时间到事件估计

Oana M. Enache, Sherri Rose

AI总结 本文提出了一种时间到事件估计器,用于评估医疗保险中的新诊断编码和可能的虚报,并介绍了一个开源软件包,以提高与医疗保险报销行为相关的可重复方法开发。

Comments 44 pages, 10 figures

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AI中文摘要

OBJECTIVE: 为了提出有助于评估医疗保险中新诊断编码和可能虚报的时间到事件估计器,并介绍一个开源软件包,以促进与医疗保险报销行为相关的更可重复的方法开发。 STUDY SETTING AND DESIGN: 对基于保险公司或提供者编码的模拟虚报进行观察性分析,这些编码可能受到医疗保险经办机构风险调整的激励。 DATA SOURCES AND ANALYTIC SAMPLE: 两年期间分别模拟了医疗保险经办机构人口和传统医疗保险人口的新健康状况编码数据,其中编码模式与每个计划中已知的做法一致。 PRINCIPAL FINDINGS: 我们提出了几种新的时间到事件估计器,用于估计医疗保险经办机构中的新编码强度和可能的虚报,包括考虑不可靠的报告。我们利用国家卫生研究院的All of Us研究在模拟数据中展示了估计器的性能,并开发了一个开源的R包来模拟纵向的现实标记虚报数据,这些数据之前对研究人员不可用。在模拟中,我们的新型估计器恢复了不同监控期内的虚报差异。低估对我们的新型估计器影响有限,而现有的估计器对低估更敏感。 CONCLUSIONS: 我们提出的估计器可以帮助研究人员和政策制定者跟踪新的编码行为(例如,可能受到风险调整公式更新的激励)并以更大规模进行跟踪,同时考虑多个现实数据因素。此外,我们提供的R包可用于改进编码强度和虚报方法的开发、可及性和可重复性评估。

英文摘要

OBJECTIVE: To propose time-to-event estimators that help evaluate incident diagnostic coding and possible upcoding in Medicare as well as introduce an open-source software package that enables more reproducible methods development relevant to Medicare billing behavior. STUDY SETTING AND DESIGN: Observational analysis of simulated upcoding based on coding by insurers or providers that may be incentivized by Medicare Advantage risk adjustment. DATA SOURCES AND ANALYTIC SAMPLE: Two years of separately simulated incident health condition coding data for a Medicare Advantage population and a Traditional Medicare population where coding patterns are aligned with known practices in each program. PRINCIPAL FINDINGS: We propose several novel time-to-event estimators of incident coding intensity and possible upcoding in Medicare Advantage, including accounting for unreliable reporting. We demonstrate estimator performance in simulated data leveraging the National Institutes of Health's All of Us study and also develop an open source R package to simulate longitudinal realistic labeled upcoding data, which were not previously available for researchers. In simulations, our novel estimators recovered differences in upcoding within and across monitoring periods. Undercoding had a limited effect on our novel estimators while an existing estimator was more sensitive to undercoding. CONCLUSIONS: Our proposed estimators can help researchers and policymakers track new coding behaviors (e.g., as may be incentivized by risk adjustment formula updates) earlier and at scale while accounting for several real-world data considerations. Further, the R package we provide can be used to improve the development, accessibility, and reproducible evaluation of coding intensity and upcoding methodology.

2602.03540 2026-05-21 gr-qc

Finite time pseudo-rip singularity in cosmology

宇宙学中的有限时间伪撕裂奇点

Mariusz P. Dąbrowski, Teodor Borislavov Vasilev

AI总结 本文研究了一种新的减速突然未来奇点宇宙模型,发现了一种新的宇宙奇点类型,称为有限时间伪撕裂奇点(FTPR)。与伪撕裂奇点不同,FTPR发生在宇宙的有限未来。通过研究能量条件,发现FTPR违反了所有能量条件,而SFS仅违反主导能量条件。应用Raychaudhuri平均显示,这些奇点在几何完整性的要求下是弱的。本文还研究了模型的性质,包括宇宙学视界的行为,并引入了一个包含标准辐射和尘埃流体的FTPR模型,可以模仿ΛCDM模型的过去膨胀历史,但面临未来的压力奇点。

Comments REVTEX4-2, 12 pages, 7 figures, strongly revised version, new section added, matches PLB published paper

Journal ref Phys. Lett. B 878 (2026) 140516

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AI中文摘要

通过研究一个新的减速突然未来奇点(SFS)宇宙模型,我们报告发现了一种新的宇宙学奇点类型,我们称之为有限时间伪撕裂奇点(FTPR),因为与伪撕裂奇点不同,它发生在宇宙的有限未来。与新的SFS模型不同,其中膨胀在达到压力奇点之前是减速的,FTPR场景之前有一个超加速的幻影阶段。我们的结论是基于对能量条件的深入研究,显示FTPR违反了所有能量条件,而SFS仅违反主导能量条件。应用所谓的Raychaudhuri平均显示,这些奇点在几何完整性的要求下是弱的。我们研究了模型的性质,包括在适当的Penrose图中呈现的宇宙学视界的行为。最后,我们介绍了一个包含标准辐射和尘埃流体的FTPR模型,可以模仿ΛCDM模型的过去膨胀历史,但面临未来的压力奇点。

英文摘要

By studying first a new decelerating sudden future singularity (SFS) universe we report finding a novel type of cosmological singularity which we dub a finite time pseudo-rip (FTPR) because unlike for a pseudo-rip, it happens in the finite future of the universe. In contrast to the new SFS model, where the expansion is decelerating before reaching the pressure singularity, the FTPR scenario is preceded by a super-accelerated phantom phase. Our claim is based on the thorough study of the energy conditions showing the violations of all of them for a FTPR, and only the dominant energy one for an SFS. Application of the so-called Raychaudhuri averaging shows that, alike within the requirement of geodesic completeness, these singularities are weak in the sense of this definition. We study the properties of the models including the behaviour of the cosmological horizons presented in the appropriate Penrose diagrams. Finally, we introduce a FTPR model containing standard radiation and dust fluids that can mimic the past expansion history of $Λ$CDM though facing a future pressure singularity.

2602.03436 2026-05-21 cs.DS

The Complexity of Maximal/Closed Frequent Tree Mining for Bounded Height Trees

最大/闭合频繁树挖掘的复杂性:针对有限高度树

Kenta Komoto, Kazuhiro Kurita, Hirotaka Ono

AI总结 本文研究了在有限高度树输入条件下,最大/闭合频繁树挖掘问题的复杂性,发现其难度取决于模型,对于高度不超过2的无序树可实现多项式延迟算法,而有序树则存在计算难题。

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AI中文摘要

频繁树挖掘要求我们列举出现在根树数据库中的频繁树模式。这个问题受到生物信息学中树状数据的启发,如糖类和无伪结RNA二级结构。直接枚举所有频繁树通常是高度冗余的,因为每个频繁树的子树再次频繁。闭合和最大频繁树是减少冗余的标准方法,但它们的枚举仍可能计算复杂。本文研究了对输入树的高度进行限制的影响。这是根树的自然限制,因为高度是层次的深度。我们询问在每个输入树具有小高度的情况下,闭合/最大频繁树挖掘是否仍困难。我们的结果表明,答案取决于模型。对于高度不超过2的无序根树,我们为枚举闭合频繁树提供了一种多项式延迟算法。另一方面,对于高度不超过2的有序根树,我们证明枚举闭合频繁树的输出多项式时间算法将导致Dualization问题的输出多项式时间算法。对于最大频繁树枚举,我们证明除非P=NP,否则不存在输出多项式时间算法,即使对于高度不超过2的有序根树或高度不超过3的无序根树。因此,即使非常小的高度限制,一般情况下枚举问题仍然困难。同时,高度不超过2的无序闭合情况允许多项式延迟枚举。这些结果给出了浅层根树上闭合和最大频繁树挖掘复杂性的高度分类。

英文摘要

Frequent tree mining asks us to enumerate tree patterns that occur frequently in a database of rooted trees. This problem is motivated by tree-structured data in bioinformatics, such as glycans and pseudoknot-free RNA secondary structures. A direct enumeration of all frequent trees is often highly redundant, because every subtree of a frequent tree is again frequent. Closed and maximal frequent trees are standard ways to reduce this redundancy, but their enumeration can still be computationally hard. In this paper, we study the effect of bounding the height of the input trees. This is a natural restriction for rooted trees, since the height is the depth of the hierarchy. We ask whether closed/maximal frequent tree mining remains hard when every input tree has a small height. Our results show that the answer depends sharply on the model. For rooted unordered trees of height at most 2, we give a polynomial-delay algorithm for enumerating closed frequent trees. On the other hand, for rooted ordered trees of height at most 2, we show that an output-polynomial time algorithm for enumerating closed frequent trees would imply an output-polynomial time algorithm for Dualization. For maximal frequent tree enumeration, we prove that no output-polynomial time algorithm exists unless P = NP already for rooted ordered trees of height at most 2 and for rooted unordered trees of height at most 3. Thus, even very small height bounds do not make the enumeration problems easy in general. At the same time, the unordered closed case of height at most 2 admits polynomial-delay enumeration. These results give a height-based classification of the complexity of closed and maximal frequent tree mining on shallow rooted trees.

2602.03433 2026-05-21 eess.SY cs.SY

When control meets large language models: From words to dynamics

当控制遇见大语言模型:从词语到动态

Komeil Nosrati, Aleksei Tepljakov, Juri Belikov, Eduard Petlenkov

AI总结 本文探讨了大语言模型与控制之间的双向关系,研究了LLM如何通过直接辅助控制器设计和间接增强研究流程来推动控制领域的发展,同时分析了控制理论如何帮助LLM偏离不良含义,提高可达性和对齐性,并通过状态空间框架将LLM视为动态系统,最后指出了关键挑战和未来研究方向。

Journal ref Engineering Applications of Artificial Intelligence 178(2), 115119 (2026)

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AI中文摘要

尽管大语言模型(LLMs)通过增强的控制能力和决策支持正在改变工程和技术,同时它们也在向复杂动态系统演变,其行为必须被调节。这种双重性突显了一种相互关联的关系,其中提示支持控制系统设计,而控制理论帮助塑造提示以高效实现特定目标。在本研究中,我们将LLM与控制之间的新兴联系视为双向连续体,从提示设计到系统动态。首先,我们研究LLM如何以两种不同的能力推动控制领域的发展:直接地,通过协助控制器的设计和综合;间接地,通过增强研究流程。其次,我们分析控制概念如何帮助LLM偏离不良含义,通过输入优化、参数编辑和激活层面干预来提高可达性和对齐性。第三,我们探讨更深入的整合,将LLM视为状态空间框架中的动态系统,其中其内部表示与外部控制回路紧密相连。最后,我们识别了关键挑战并概述了未来研究方向,以理解LLM行为并开发可解释和可控的LLM,使其如同其机电 counterparts一样可信和稳健,从而确保它们继续支持和保护社会。

英文摘要

While large language models (LLMs) are transforming engineering and technology through enhanced control capabilities and decision support, they are simultaneously evolving into complex dynamical systems whose behavior must be regulated. This duality highlights a reciprocal connection in which prompts support control system design while control theory helps shape prompts to achieve specific goals efficiently. In this study, we frame this emerging interconnection of LLM and control as a bidirectional continuum, from prompt design to system dynamics. First, we investigate how LLMs can advance the field of control in two distinct capacities: directly, by assisting in the design and synthesis of controllers, and indirectly, by augmenting research workflows. Second, we examine how control concepts help LLMs steer their trajectories away from undesired meanings, improving reachability and alignment via input optimization, parameter editing, and activation-level interventions. Third, we look into deeper integrations by treating LLMs as dynamic systems within a state-space framework, where their internal representations are closely linked to external control loops. Finally, we identify key challenges and outline future research directions to understand LLM behavior and develop interpretable and controllable LLMs that are as trustworthy and robust as their electromechanical counterparts, thereby ensuring they continue to support and safeguard society.

2602.02492 2026-05-21 math.NT math.AG math.RT

Spherical representations of unitary groups at ramified places and the arithmetic inner product formula

单位群在分歧处的球面表示及算术内积公式

Zhuoni Chi

AI总结 本文研究了局部域上偶单位群的可允许表示,其中二次扩张是分歧的,并考虑了在unimodular晶格稳定子作用下不变的向量以及相应单位Shimura品种积分模型的一些性质。作为直接应用,本文改进了算术内积公式,允许局部根数为(-1)的处为分歧。

Comments 74 pages, comments are welcome. arXiv admin note: text overlap with arXiv:2006.06139, arXiv:2101.09485 by other authors

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AI中文摘要

在本文中,我们研究了局部域上偶单位群的可允许表示,其中二次扩张是分歧的,并考虑了在unimodular晶格稳定子作用下不变的向量以及相应单位Shimura品种积分模型的一些性质。作为直接应用,我们能够改进算术内积公式,使得局部根数为(-1)的处允许为分歧。

英文摘要

In this article, we study admissible representations of even unitary groups over local fields, where the quadratic extension is ramified, with invariant vectors under the action of the stabilizer of a unimodular lattice and some properties of the corresponding integral model of unitary Shimura varieties. As a direct application, we are able to improve the arithmetic inner product formula so that the places with local root number \((-1)\) are allowed to be ramified.

2602.02111 2026-05-21 cond-mat.mes-hall cond-mat.mtrl-sci cond-mat.other

Intersubband electric dipole spin resonance in transition metal dichalcogenide heterobilayers

过渡金属二硫化物异双层间的亚带电偶极子自旋共振

K. K. Grigoryan, M. M. Glazov

AI总结 研究了过渡金属二硫化物异双层中电偶极子自旋共振现象,通过分析对称性发现异双层的降低对称性使电场能够耦合传导带自旋亚带,提出了光学选择规则,并揭示了自旋轨道耦合诱导的布洛赫态混合机制,导致非零动量矩阵元和有效哈密顿量中的自旋依赖项,即拉沙效应,且电偶极子自旋翻转速率远高于磁偶极子自旋翻转速率。

Comments 9 pages, 3 figures, 1 table

Journal ref Phys. Rev. B 113, 179605 (2026)

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AI中文摘要

本文提出了过渡金属二硫化物异双层中亚带电偶极子自旋共振的理论。我们的对称性分析表明,与单层相比,异双层的降低对称性使电场能够耦合传导带自旋亚带。我们为所有六个高对称性堆叠配置建立了光学选择规则。该效应的微观机制被确定为自旋轨道耦合诱导的来自不同传导带的布洛赫态混合,这会生成自旋分裂态之间的非零动量矩阵元。它还导致有效哈密顿量中的线性于波矢的自旋依赖项,即拉沙效应。我们的估算表明,在过渡金属二硫化物异双层中,电偶极子自旋翻转速率远高于磁偶极子自旋翻转速率。

英文摘要

The theory of inter-spin-subband electric dipole spin resonance in transition metal dichalcogenide heterobilayers is proposed. Our symmetry analysis demonstrates that, in contrast to monolayers, the reduced symmetry of heterobilayers enables coupling between conduction band spin subbands by an electric field. We establish the optical selection rules for all six high-symmetry stacking configurations. The microscopic mechanism of the effect is identified as the spin-orbit coupling induced mixing of Bloch states from different conduction bands, which generates a non-zero momentum matrix element between the spin-split states. It also leads to the linear-in-wavevector spin-dependent terms in the effective Hamiltonian, i.e., the Rashba effect. Our estimates show that the rate of electric-dipole spin-flip transitions exceeds by far that of the magnetic-dipole transitions in transition metal dichalcogenide heterobilayers.

2601.23230 2026-05-21 gr-qc

Detectability of Gravitational-Wave Memory with LISA: A Bayesian Approach

利用LISA进行引力波记忆效应的可探测性研究:一种贝叶斯方法

Adrien Cogez, Silvia Gasparotto, Jann Zosso, Henri Inchauspé, Chantal Pitte, Lorena Magaña Zertuche, Antoine Petiteau, Marc Besancon

AI总结 本文通过贝叶斯分析探讨LISA探测引力波记忆效应的能力,研究了单个大质量黑洞双星合并事件中该效应的检测条件,并讨论了其在广义相对论和替代理论测试中的应用。

Journal ref Phys. Rev. D 113, 104034 (2026)

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AI中文摘要

引力波天文开辟了探索宇宙的新途径。未来的观测站,如LISA(激光干涉空间天线),预计能够探测到由广义相对论预测的以前无法检测到的基本物理效应。特别有趣的一种信号是与位移记忆效应相关,这对应于由于引力辐射通过而引起的时间空间的永久变形。在本文中,我们探讨了LISA观测和表征这种效应的能力。为此,我们使用了最先进的LISA仪器模拟,并进行贝叶斯分析以评估其可探测性,并建立一般条件以声称从LISA中单个大质量黑洞双星合并事件中检测到位移记忆效应。我们进行了参数估计,以探索位移记忆效应的影响并重建其振幅。我们讨论了这种重建的精度,从而为广义相对论和替代理论的测试铺平了道路。为了提供天体物理学背景,我们将分析应用于黑洞双星种群模型,并估计在LISA计划寿命内位移记忆效应可能被观测到的速率。

英文摘要

Gravitational wave (GW) astronomy opens a new venue to explore the universe. Future observatories such as LISA, the Laser Interferometer Space Antenna, are expected to observe previously undetectable fundamental physics effects in signals predicted by General Relativity (GR).One particularly interesting such signal is associated to the displacement memory effect, which corresponds to a permanent deformation of spacetime due to the passage of gravitational radiation. In this work, we explore the ability of LISA to observe and characterize this effect. In order to do this, we use state-of-the-art simulations of the LISA instrument, and we perform a Bayesian analysis to assess the detectability and establish general conditions to claim detection of the displacement memory effect from individual massive black hole binary (MBHB) merger events in LISA. We perform parameter estimation both to explore the impact of the displacement memory effect and to reconstruct its amplitude. We discuss the precision at which such a reconstruction can be obtained thus opening the way to tests of GR and alternative theories. To provide astrophysical context, we apply our analysis to black hole binary populations models and estimate the rates at which the displacement memory effect could be observed within the LISA planned lifetime.

2601.22375 2026-05-21 cond-mat.stat-mech quant-ph

Non-Equilibrium Quantum Many-Body Physics with Quantum Circuits

非平衡量子多体物理与量子电路

Bruno Bertini

AI总结 本文探讨了量子电路在研究非平衡量子多体动力学中的应用,介绍了砖块量子电路的设置,并展示了其在局部相互作用存在时研究非平衡量子多体动力学的实用性。

Comments 49 pages, 6 figures; v2 minor changes

Journal ref SciPost Phys. Lect. Notes 124 (2026)

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AI中文摘要

这些笔记是我在2025年8月于勒·博斯夏季学校‘精确求解与量子信息’上以相同标题进行的4.5小时课程的讲义。在这些笔记中,我教人介绍了砖块量子电路的设置,并展示了它提供了一个有用的框架,用于在存在局部相互作用时研究非平衡量子多体动力学。我首先展示了砖块量子电路如何以本质上与本地哈密顿量相似的方式演化量子关联,然后给出了若干砖块量子电路的例子,在这些例子中,令人惊讶的是,可以在存在非平凡相互作用时精确计算几个相关的动力学和谱学性质。

英文摘要

These are the notes for the 4.5-hour course with the same title that I delivered in August 2025 at the Les Houches summer school ``Exact Solvability and Quantum Information''. In these notes I pedagogically introduce the setting of brickwork quantum circuits and show that it provides a useful framework to study non-equilibrium quantum many-body dynamics in the presence of local interactions. I first show that brickwork quantum circuits evolve quantum correlations in a way that is fundamentally similar to local Hamiltonians, and then present examples of brickwork quantum circuits where, surprisingly, one can compute exactly several relevant dynamical and spectral properties in the presence of non-trivial interactions.

2601.18354 2026-05-21 hep-lat nucl-th

Chiral Properties of $(2\!+\!1)$-Flavor QCD in Magnetic Fields at Zero Temperature

(2+1)味QCD在零温度下的磁场中的手性性质

Heng-Tong Ding, Dan Zhang

AI总结 本文研究了在零温度下,具有物理质子质量的(2+1)味QCD在背景磁场中的手性性质,通过高改进的 staggered 轻子作用在四个不同的晶格间距上进行模拟,计算了磁场强度eB范围内介子的质量和衰变常数,揭示了手性凝聚物的磁催化效应以及中性介子衰变常数的增强效应。

Comments 22 pages, 18 figures

Journal ref Phys. Rev. D 113, 094503 (2026)

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AI中文摘要

我们呈现了一项关于在零温度下具有物理质子质量的(2+1)味QCD在背景磁场中的手性性质的晶格QCD研究。使用高改进的staggered轻子作用在四个不同的晶格间距上进行模拟,以实现受控的连续极限。我们计算了磁场强度eB范围内介子的质量和衰变常数,包括π,K以及虚构的η^0_{sar{s}}伪标量。手性凝聚物表现出明显的磁催化效应,随着磁场强度单调增加。在介子领域,中性伪标量质量随着eB下降,而带电伪标量质量则表现出非单调响应:在小磁场下上升,与最低朗德- level的期望一致,但随后饱和并略微下降,表明内部结构效应显著。同时,中性伪标量衰变常数被磁场强烈增强。为了量化偏离手性对称关系的偏差,我们分离了磁场诱导的Gell-Mann-Oakes-Renner校正的偏移,并发现对于中性π子,这种偏移保持较小,但对于中性K子则变得显著。为了阐明磁场响应的起源,我们分别分析了海夸克和价夸克对中性及带电介子质量的贡献,发现零温度下价效应占主导地位。这些结果提供了关于QCD手性对称破缺和强磁场相互作用的新见解。

英文摘要

We present a lattice QCD study of the chiral properties of $(2\!+\!1)$-flavor QCD in background magnetic fields at zero temperature with physical pion masses. Simulations are performed using the highly improved staggered quark action across four different lattice spacings to enable a controlled continuum extrapolation. We compute the renormalized chiral condensates together with pseudoscalar meson masses and decay constants for pions, kaons, and the fictitious $η^0_{s\bar{s}}$ pseudoscalar as functions of the magnetic-field strength $eB$ up to $eB\simeq1.2$ $\mathrm{GeV}^2$. The chiral condensates exhibit clear magnetic catalysis, increasing monotonically with the field strength. In the meson sector, neutral pseudoscalar masses decrease steadily with $eB$, whereas charged pseudoscalar masses display a nonmonotonic response: They rise at small fields, consistent with the lowest-Landau-level expectation, but then saturate and slightly decrease at larger fields, signaling sizable internal-structure effects. At the same time, neutral pseudoscalar decay constants are strongly enhanced by the magnetic field. To quantify deviations from chiral symmetry relations, we isolate the magnetic-field-induced shift in the Gell-Mann--Oakes--Renner corrections and find it to remain small for the neutral pion but to become sizable for the neutral kaon. To elucidate the origin of the magnetic response, we separately analyze the sea- and valence-quark contributions to both neutral and charged meson masses, finding that valence effects dominate at zero temperature. These results provide new insights into the interplay between QCD chiral symmetry breaking and strong magnetic fields.

2601.16908 2026-05-21 cond-mat.str-el cond-mat.supr-con

Doping-dependent orbital magnetism in Chromium pnictides

铬基氮化物中掺杂依赖的轨道磁性

Henri G. Mendonça, George B. Martins, Lauro B. Braz

AI总结 研究通过矩阵随机相位近似方法探讨了LaCrAsO母体化合物在电子掺杂下的相图,发现低掺杂时系统稳定于反铁磁态,高掺杂时出现条纹型反铁磁相,不同磁序向量与Cr的d轨道局域性有关。

Comments 20 pages (single column), 5 figures

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AI中文摘要

我们通过矩阵随机相位近似方法给出了LaCrAsO母体化合物在电子掺杂下的相图结果。在低掺杂水平下,系统稳定于反铁磁态,其中不同的Cr亚晶格携带相反的自旋,这与实验观测一致。随着掺杂浓度的增加,条纹型反铁磁相变得更有利。在更高的掺杂水平下,系统重复前两种磁性相,但具有不协调的磁序向量。协调的磁性相与Cr的d_{3z²−r²}轨道中更局域化的电子有关,而不协调的磁性相则与d_{xy}轨道有关,其更强的重叠有利于它inerant电子磁性。

英文摘要

We present results for the phase diagram of the parent compound LaCrAsO under electron doping using the matrix random-phase approximation. At low doping levels, the system stabilizes an antiferromagnetic state in which different Cr sublattices carry opposite spins, consistent with experimental observations. As the doping concentration increases, a stripe-type antiferromagnetic phase becomes favored. At even higher doping, the system repeats the two former magnetic states, but with incommensurate magnetic ordering vectors. The commensurate magnetic phases are associated with more localized electrons in the Cr $d_{3z^2-r^2}$ orbital, whereas the incommensurate phases are linked to the $d_{xy}$ orbital, whose stronger overlap favors itinerant-electron magnetism.

2601.14991 2026-05-21 stat.ME stat.ML

Consistency of Honest Decision Trees and Random Forests

诚实决策树与随机森林的一致性

Martin Bladt, Rasmus Frigaard Lemvig

AI总结 本文研究了回归设置中诚实决策树和随机森林的不同一致性类型,通过简单证明和经典平滑方法的论证,建立了诚实树和诚实森林平均值对真实回归函数的弱一致性和几乎必然收敛,并在紧致协变量域上获得一致收敛。该框架自然支持基于分层采样的集成变体和两阶段bootstrap采样方案,简化了现有分析并恢复了多个结果。

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AI中文摘要

我们研究了回归设置中诚实决策树和随机森林的各种一致性类型。与相关文献不同,我们的证明是简单的,并遵循用于平滑方法的经典论证。在回归函数和数据分布的温和正则性条件下,我们建立了诚实树和诚实森林平均值对真实回归函数的弱一致性和几乎必然收敛,并且还获得了在紧致协变量域上的统一收敛。该框架自然地容纳了基于分层采样的集成变体以及两阶段bootstrap采样方案。我们的处理综合并简化了现有的分析,特别是恢复了多个结果作为特殊情况。论证的简单性澄清了数据自适应分区与核型方法之间的紧密关系,为理解基于树的方法的渐近行为提供了可访问的方法。

英文摘要

We study various types of consistency of honest decision trees and random forests in the regression setting. In contrast to related literature, our proofs are elementary and follow the classical arguments used for smoothing methods. Under mild regularity conditions on the regression function and data distribution, we establish weak and almost sure convergence of honest trees and honest forest averages to the true regression function, and moreover we obtain uniform convergence over compact covariate domains. The framework naturally accommodates ensemble variants based on subsampling and also a two-stage bootstrap sampling scheme. Our treatment synthesizes and simplifies existing analyses, in particular recovering several results as special cases. The elementary nature of the arguments clarifies the close relationship between data-adaptive partitioning and kernel-type methods, providing an accessible approach to understanding the asymptotic behavior of tree-based methods.

2601.13970 2026-05-21 quant-ph

A Converse Bound via the Nussbaum-Szkoła Mapping for Quantum Hypothesis Testing

通过Nussbaum-Szkoła映射获得的量子假设检验的反向界

Jorge Lizarribar-Carrillo, Gonzalo Vazquez-Vilar, Tobias Koch

AI总结 本文提出了一种基于Nussbaum-Szkoła映射的新下界,用于不对称量子假设检验,该下界在大偏差、中等偏差和小偏差等所有主要渐进行 regime 中统一恢复了反向结果,且无需复杂的信息谱论证或固定预因子,同时在某些情况下可以直接应用经典结果。

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AI中文摘要

量子假设检验涉及区分量子态。本文介绍了一种新颖的下界,用于不对称量子假设检验,该下界基于Nussbaum-Szkoła映射。该下界在大偏差、中等偏差和小偏差等所有主要渐进行 regime 中统一恢复了反向结果。与现有下界不同,现有下界要么依赖于技术复杂的信息谱论证,要么在非渐进行 regime 中存在固定预因子和有限适用性。所提出的下界来源于单一表达式,并在某些情况下允许直接使用经典结果。进一步证明,所提出的下界在小块长中提供了对最优量子误差权衡函数的准确近似。与现有下界(包括基于保真度和信息谱方法的下界)的数值比较突显了其改进的紧度。

英文摘要

Quantum hypothesis testing concerns the discrimination between quantum states. This paper introduces a novel lower bound for asymmetric quantum hypothesis testing that is based on the Nussbaum-Szkoła mapping. The lower bound provides a unified recovery of converse results across all major asymptotic regimes, including large-, moderate-, and small-deviations. Unlike existing bounds, which either rely on technically involved information-spectrum arguments or suffer from fixed prefactors and limited applicability in the non-asymptotic regime, the proposed bound arises from a single expression and enables, in some cases, the direct use of classical results. It is further demonstrated that the proposed bound provides accurate approximations to the optimal quantum error trade-off function at small blocklengths. Numerical comparisons with existing bounds, including those based on fidelity and information spectrum methods, highlight its improved tightness.

2601.13595 2026-05-21 cond-mat.stat-mech

Macroscopic localization and collective memory in Poisson renewal resetting

泊松重置下的宏观定位与集体记忆

Ohad Vilk

AI总结 本文研究了泊松重置下连续时间刷新过程如何产生混合离散-连续结构,并展示了集体相互作用如何在所有重置事件无记忆的情况下保留记忆,揭示了从弱集体偏置到强集体偏置的相变过程。

Comments 11 pages, 5 figures

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AI中文摘要

随机刷新过程在物理、生物和社会科学中普遍存在。本文表明,连续时间刷新动力学可以自然产生混合离散-连续结构,其中宏观分数的粒子占据离散状态。对于受泊松刷新重置影响的连续时间随机游走集体,我们开发了一个年龄结构框架,显示该离散成分对应于重置配置的定位。我们进一步表明,集体相互作用可以在所有重置事件无记忆的情况下保留记忆。值得注意的是,集体记忆向的转变是不连续的,我们识别出从弱集体偏置到强集体偏置的不连续动力学相变,其中动力学从平稳到非平稳且表现出有限尺寸效应的衰老。我们明确讨论了本研究的生态意义,展示了连续时间刷新动力学如何塑造宏观结构和集体组织的长期记忆。

英文摘要

Stochastic renewal processes are ubiquitous across physics, biology, and the social sciences. Here, we show that continuous-time renewal dynamics can naturally produce a mixed discrete-continuous structure, with a macroscopic fraction of particles occupying a discrete state. For ensembles of continuous-time random walkers subject to Poissonian renewal resets, we develop an age-structured framework showing this discrete component corresponds to localization at the reset configuration. We next show that collective interactions can retain memory although all reset events are memoryless. Remarkably, the transition to collective memory is discontinuous, and we identify a discontinuous dynamical phase transition from weak collective bias, where the dynamics are stationary, to strong collective bias where the dynamics are nonstationary and display aging up to finite-size effects. We explicitly discuss ecological implications of our work, illustrating how continuous-time renewal dynamics shape macroscopic structure and collective organization with long-term memory.

2601.13202 2026-05-21 eess.SY cs.SY math.OC

Emissions and cost tradeoffs of time-matched clean electricity procurement under inter-annual weather variability -- case study of hydrogen production

时间匹配清洁能源采购的排放与成本权衡——以氢气生产案例研究

Michael Giovanniello, Dharik S. Mallapragada

AI总结 本文研究了在年度和小时级时间匹配要求下,清洁能源采购的排放与成本权衡,通过德克萨斯州连接电网的氢气生产案例,分析了天气变化对基础设施成本、构成和排放的影响。

Comments 7 Figures, 1 table (main text)

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AI中文摘要

监管机构和自愿的企业可持续发展努力正越来越多地采用时间匹配要求(TMRs)来采购清洁能源,用于大型负载如数据中心,以及电力密集型燃料生产如氢气。我们使用随机容量扩展模型(CEM)框架,评估了年度和小时级TMRs在满足年度和小时级TMRs时,天气变化对采购驱动基础设施的成本、构成和排放的影响,以德克萨斯州连接电网的氢气生产案例研究为例。我们的方法依赖于在九种天气情景下共同优化投资和小时级操作,发现小时级TMRs相比年度TMRs带来了更高的成本溢价,但排放结果方向一致。需求灵活性和部分小时级TMRs(80-90%)降低了成本溢价,同时保持排放效益。我们进一步研究了可再生能源组合标准(RPS)与TMRs成本和排放结果的相互作用。当将RPS应用于非H2电力需求时,年度TMRs在较低成本下与小时级TMRs产生相似的排放减少。将H2相关电力需求直接纳入RPS约束,而不是单独施加TMRs,可以实现相似的排放结果,但成本更低,表明在严格的电网脱碳政策地区,基于TMRs的清洁能源采购,特别是小时级匹配,提供了有限的额外价值。

英文摘要

Regulators and voluntary corporate sustainability efforts are increasingly adopting time-matching requirements (TMRs) for clean electricity procurement for large loads, such as data centers, and electricity-intensive fuel production, such as hydrogen. We use a stochastic capacity expansion model (CEM) framework to assess how inter-annual weather variability affects the cost, composition, and emissions of procurement-driven infrastructure to meet annual and hourly TMRs using the case study of a grid-connected hydrogen producer in Texas. Our approach, which relies on co-optimizing investments and hourly operations over nine weather scenarios, reveals that hourly TMR comes at a higher cost premium compared to annual TMR than previously estimated by single-scenario deterministic modeling, while emissions outcomes remain directionally consistent. Demand flexibility and partial hourly TMR (80-90%) lower the cost premium while preserving emissions benefits. We further examine how binding renewable portfolio standards (RPS) interact with TMR costs and emissions outcomes. When an RPS is applied to non-H2 electricity demand, annual TMR reduces emissions comparably to hourly TMR at a lower cost. Incorporating H2-related electricity demand directly into the RPS constraint, rather than imposing a separate TMR, achieves similar emissions outcomes at still lower cost, suggesting that TMR-based clean electricity procurement, particularly hourly matching, offers limited additional value in regions with stringent grid decarbonization policies.

2601.11986 2026-05-21 hep-ph hep-ex

Prospects for discovering strongly decaying doubly heavy $T_{bc}$ tetraquark states at LHCb

在LHCb发现强衰变的双重重子T_{bc}四夸克态的前景

Mingjie Feng, Yiming Li, Hua-Sheng Shao

AI总结 研究重点在于通过LHCb在13 TeV中心对撞能下质子-质子碰撞中发现J^P=0^+的T_{bc}态的前景,探讨其衰变通道T_{bc}→B^-D^+,并评估不同生产截面下的发现可能性。

Journal ref Chin. Phys. C 50 (2026) 073102

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AI中文摘要

我们研究了在LHCb在13 TeV中心对撞能下质子-质子碰撞中发现J^P=0^+的T_{bc}态的前景。研究重点在于衰变通道T_{bc}→B^-D^+。采用现象学方法构建背景模型,基于B和D介子的关联产生,结合之前发表的LHCb结果。背景过程使用MadGraph5_aMC@NLO和Pythia8.3模拟。我们探索了T_{bc}质量、宽度、生产截面以及与B D介子背景相关的有效双夸克散射截面(σ_{eff})参数空间。评估了不同假设下所需的积分亮度以在LHCb实现5σ发现。特别地,我们考虑了三种代表性的T_{bc}生产截面情景:乐观估计的103 nb,通过T_{cc}^+生产截面缩放得到的中间值18 nb,以及保守的下限0.3 nb。我们发现,生产截面为103 nb时可以实现5σ发现,预计在Run 4期间内可达。相比之下,更现实的截面估计18 nb需要完整的Run 5数据集(300 fb^{-1})在最有利的参数选择下。对于保守情景,即使使用300 fb^{-1},也不会观察到显著信号。此外,我们还估计了不同亮度情景下实现5σ发现所需的最小可观测σ(T_{bc})×BR(T_{bc}→B^-D^+),为LHCb未来的实验搜索提供指导。

英文摘要

We investigate the discovery potential of the $T_{bc}$ state with $J^P = 0^+$ in proton-proton ($pp$) collisions at LHCb at a center-of-mass energy of $\sqrt{s} = 13~\mathrm{TeV}$. The study focuses on the decay channel $T_{bc} \to B^- D^+$. A phenomenological approach is employed to construct the background model based on the associated production of $B$ and $D$ mesons, incorporating previously published LHCb results. Background processes are simulated using $\texttt{MadGraph5\_aMC@NLO}$ and $\texttt{Pythia8.3}$. We explore the parameter space of the $T_{bc}$ mass, width, production cross section, and the effective double-parton scattering cross section ($σ_{\mathrm{eff}}$) relevant for the $B D$ meson background. The integrated luminosity required for a $5σ$ discovery at LHCb is evaluated under various assumptions. In particular, we consider three representative $T_{bc}$ production cross section scenarios: an optimistic estimate of $103~\mathrm{nb}$, an intermediate value of $18~\mathrm{nb}$ obtained by scaling from the $T_{cc}^+$ production cross section, and a conservative lower bound of $0.3~\mathrm{nb}$. We find that a $5σ$ observation is achievable for a production cross section of $103~\mathrm{nb}$, which is expected to be within reach during Run~4. In contrast, the more realistic cross section estimate of $18~\mathrm{nb}$ requires the full Run~5 dataset ($300~\mathrm{fb}^{-1}$) under the most favorable parameter choices. For the conservative scenario, no significant signal would be observable even with $300~\mathrm{fb}^{-1}$. In addition, we estimate the minimum observable $σ(T_{bc}) \times BR(T_{bc} \to B^- D^+)$ for a $5σ$ discovery under different luminosity scenarios, providing guidance for future experimental searches at LHCb.

2601.10275 2026-05-21 math.CO

A general identity for umbral operators and a special subclass

一个通用的影子算子恒等式及其一个特殊子类

Kei Beauduin

AI总结 本文证明了一个新的通用影子算子恒等式,并定义了一个满足简化恒等式的子类,对其进行了完整刻画,通过常见的影子微积分理论示例进行了说明。

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AI中文摘要

我们证明了一个新的通用影子算子恒等式。这促使我们定义了一个满足简化恒等式的子类,我们对其进行了完整刻画。结果通过常见的影子微积分理论示例进行了说明。

英文摘要

We prove a new universal identity for umbral operators. This motivates the definition of a subclass satisfying a simplified identity, which we fully characterize. The results are illustrated with common examples of the theory of umbral calculus.

2601.10174 2026-05-21 cond-mat.mtrl-sci

A Neuroevolution Potential for Gallium Oxide: Accurate and Efficient Modeling of Polymorphism and Swift Heavy-Ion Irradiation

镓氧化物的神经进化潜力:对多形性和快速重离子辐照的准确高效建模

Yaohui Gu, Binbo Li, Lingyang Jiang, Yuhui Hu, Wenqiang Liu, Lijun Xu, Pengfei Zhai, Jie Liu, Jinglai Duan

AI总结 本文提出了一种基于神经进化势(NEP)框架结合能量依赖加权策略的机器学习互原子势(MLIP),用于准确高效建模镓氧化物的多形性和快速重离子辐照行为,该势在精度和计算效率上优于现有最先进的tabGAP势,并通过物理过程导向的采样策略提升MLIP性能。

Comments 13 pages, 9 figures

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AI中文摘要

镓氧化物(Ga2O3)是一种宽禁带半导体,具有在高功率和高频电子器件中的应用前景。然而,其复杂的多形性本质给基础研究带来了重大挑战,特别是在非平衡条件下的相变行为理解方面。本文开发了一种稳健、准确且计算高效的机器学习互原子势(MLIP),该势基于神经进化势(NEP)框架结合能量依赖加权策略。所得NEP势在精度和计算效率方面均优于现有最先进的tabGAP势。此外,我们引入了一种以物理过程为导向的采样策略,系统地扩展训练数据集,从而提升MLIP对特定物理现象的性能。作为代表性应用,专门构建了一个用于快速重离子(SHI)辐照模拟η-Ga2O3的NEP势。模拟结果与实验观测量值一致,并为报告的实验不一致现象提供了一致的物理解释。

英文摘要

Gallium oxide (Ga2O3) is a wide-bandgap semiconductor with promising applications in high-power and high-frequency electronics. However, its complex polymorphic nature poses substantial challenges for fundamental studies, particularly in understanding phase-transformation behaviors under nonequilibrium conditions. Here, we develop a robust, accurate, and computationally efficient machine-learning interatomic potential (MLIP) for Ga2O3 based on the neuroevolution potential (NEP) framework combined with an energy-dependent weighting strategy. The resulting NEP potential demonstrates clear advantages over the state-of-the-art tabGAP potential with respect to both accuracy and computational efficiency. Furthermore, we introduce a physically process-oriented sampling strategy to systematically augment the training dataset, thereby enhancing the MLIP performance for targeted physical phenomena. As a representative application, a dedicated NEP potential is constructed for swift heavy-ion (SHI) irradiation simulations of \b{eta}-Ga2O3. The simulated results are in quantitative agreement with experimental observations and provide a consistent physical explanation for the reported experimental discrepancies regarding phase transformations in the ion track of \b{eta}-Ga2O3.

2601.08647 2026-05-21 math.AP

A selection principle for 2D steady Euler flows via the vanishing viscosity limit

通过消粘性极限原理选择二维稳态欧拉流

Changfeng Gui, Chunjing Xie, Huan Xu

AI总结 本文研究了二维稳态欧拉流的消粘性极限,发现有限域内仅存在常涡量流,且在无限长带状域中,周期性粘性速度的极限仅包括常流、Couette流和Poiseuille流,证明依赖于对粘性和无粘流流线的细致分析和一个强大的刚性定理。

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AI中文摘要

二维欧拉系统, governing 无粘不可压缩流体流动,可以在给定的领域内允许无限多个稳态解,在滑动边界条件下。为了选择物理经典解,我们研究了稳态纳维-斯托克斯系统的消粘性极限。在周期性条带或有界连通域中的消粘性极限被完全刻画,即使当强边界层可能出现时也是如此。更确切地说,我们证明在有界连通域中唯一的消粘性极限是涡量常数的流。这一结果的重要性在于近似纳维-斯托克斯解不需要具有嵌套的闭合流线,这是世纪以来Prandtl-Batchelor定理的一个基本假设。对于无限长条状域中的流体,如果粘性速度(但不是压力)在条状方向上是周期性的,我们证明唯一的消粘性极限是常流、Couette流和Poiseuille流。证明依赖于对粘性和无粘流流线的细致分析,在其中一个关键观察是欧拉流的混沌流线集相对于二维勒贝格测度是零集。第二个结果不仅依赖于第一个结果,还依赖于一个强大的刚性定理,即任何非剪切的稳态经典欧拉流在周期性条状域中必须具有闭合流线,该定理通过流线分析和新的总曲率估计建立。

英文摘要

The 2D Euler system, which governs inviscid incompressible fluid flow, can admit infinitely many steady solutions in a given domain with slip boundary conditions. To select physical classical solutions, we investigate the vanishing viscosity limits of the steady Navier-Stokes system. The vanishing viscosity limits in periodic strips or bounded connected domains are completely characterized, even when strong boundary layers may appear. More precisely, we show that the only vanishing viscosity limits in a bounded connected domain are flows with constant vorticity. The significance of this result is that the approximating Navier-Stokes solutions are not required to have nested closed streamlines, an essential assumption in the century-old Prandtl-Batchelor theorem. For flows in an infinitely long strip, if the viscous velocity (but not the pressure) is periodic in the strip direction, we show that the only vanishing viscosity limits are constant flows, Couette flows, and Poiseuille flows. The proof relies on a delicate analysis of the streamlines for both viscous and inviscid flows, in which a key observation is that the set of chaotic streamlines for the Euler flow is null with respect to two-dimensional Lebesgue measure. The second result depends not only on the first but also on a powerful rigidity theorem that any non-shear steady classical Euler flow in a periodic strip must have closed streamlines, established via an analysis of streamlines and a novel total curvature estimate.

2601.08416 2026-05-21 math.NT

On the variance of the digits of $1/p$

关于1/p的数字方差

Kurt Girstmair

AI总结 本文研究了当周期长度q=(p-1)/2时,1/p在基b下的数字方差,发现其公式涉及德迪金求和和可能的伯努利数,尤其当p≡3 mod 4时还涉及二次域的类数。

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AI中文摘要

设p>3为素数,b≥2为整数且p不整除b。则1/p在基b下有周期数字展开,其周期长度q是b模p的乘法阶。当q=p-1时,已给出周期数字方差的公式,该公式涉及德迪金求和。本文确定了当q=(p-1)/2时的方差公式。若p≡3 mod 4,则公式中出现德迪金求和和二次域Q(√-p)的类数。若p≡1 mod 4,则公式可能更为复杂,因为它涉及多个奇特征伯努利数的线性组合。

英文摘要

Let $p>3$ be a prime and $b\ge 2$ an integer such that $p$ does not divide $b$. Then $1/p$ has a periodic digit expansion with respect to the basis $b$. The length $q$ of the period is the (multiplicative) order of $b$ mod $p$. In the case $q=p-1$ a formula for the variance of the digits of a period was given previously. This formula involves a Dedekind sum. We determine the variance in the case $q=(p-1)/2$. If $p\equiv 3$ mod 4 a Dedekind sum and the class number of $\mathbb Q(\sqrt{-p})$ occur in the respective formula. If $p\equiv 1$ mod 4, the formula may be much more complex since it involves linear combinations of (possibly many) products of two Bernoulli numbers attached to odd characters.

2601.07707 2026-05-21 math.NT

A note on extensions of $p$-adic representations of $\mathrm{GL}_2(\mathbb{Q}_p)$

关于 $p$-adic 表示扩展的注记

Debargha Banerjee, Srijan Das

AI总结 本文研究 $ \mathrm{GL}_2(\mathbb{Q}_p) $ 的 $ p $-adic 表示的扩展,通过 $ p $-adic 局部朗兰兹对应中通用伽罗瓦表示得到的表示进行分类,并应用于证明有限层级德林费尔德空间上étale上同调中可约表示与超 cuspidal 异型分量之间扩展的消失。

Comments Final Version. To appear in Canadian Math Bulletin

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AI中文摘要

我们计算了 $ p $-adic Banach 空间表示范畴中延伸群。聚焦于由 $ p $-adic 局部朗兰兹对应中通用伽罗瓦表示产生的表示,我们完全分类了这些延伸。这些结果随后应用于证明有限层级德林费尔德空间上étale上同调中可约表示与超 cuspidal 异型分量之间延伸的消失。

英文摘要

We compute extension groups in the category of duals of $p$-adic Banach space representations of $\mathrm{GL}_2(\mathbb{Q}_p)$. Focusing on representations arising from the $p$-adic local Langlands correspondence for generic Galois representations, we classify these extensions completely. These results are then applied to prove the vanishing of extensions between the duals of reducible representations and supercuspidal isotypic components of the ètale cohomology of the finite level Drinfeld spaces.

2601.07572 2026-05-21 math.OA

Exactness and Fell bundles with the approximation property over inverse semigroups

精确性与具有逼近性质的Fell包 over逆半群

Changyuan Gao, Julian Kranz

AI总结 本文研究了具有逼近性质的Fell包 over逆半群的减少横截代数的精确性,证明其等价于Fell包的单位纤维的精确性,并扩展了作者关于局部紧豪斯多夫第二可数群oid作用于可分C*-代数的结果。

Comments 18 pages. Minor changes. Adjusted the title to avoid terminological conflicts with Kwaśniewski--Meyer's definition of exact Fell bundles

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AI中文摘要

我们证明,具有逼近性质的Fell包 over逆半群的减少横截代数是精确的当且仅当Fell包的单位纤维是精确的。这扩展了作者最近关于局部紧豪斯多夫第二可数群oid作用于可分C*-代数的结果。在此过程中,我们重新证明了Kwaśniewski--Meyer关于Fell包理想的一些结果。

英文摘要

We prove that the reduced cross-sectional algebra of a Fell bundle with the approximation property over an inverse semigroup is exact if and only if the unit fiber of the Fell bundle is exact. This generalizes a recent result of the first-named author for actions of second countable locally compact Hausdorff groupoids on separable $C^*$-algebras. Along the way, we reprove some results of Kwaśniewski--Meyer on Fell bundle ideals.

2601.07169 2026-05-21 math.PR cond-mat.stat-mech cs.DM math.CO math.ST stat.TH

Approximate FKG inequalities for phase-bound spin systems, with applications to central limit theorems for exponential random graphs

相位边界自旋系统的近似FKG不等式,及其在指数随机图模型中心极限定理中的应用

Satyaki Mukherjee, Vilas Winstein

AI总结 本文研究了相位边界自旋系统中近似的FKG不等式,证明了在相变共存区域中,每个相内部确实满足近似的FKG不等式,并利用此结果完成了各个相内的中心极限定理证明,回答了Bianchi等人提出的问题。

Comments 28 pages, 1 figure. Title, abstract, and introduction updated to clarify the focus of the article

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AI中文摘要

Fortuin-Kasteleyn-Ginibre(FKG)不等式是单调自旋系统中满足FKG晶格条件的重要工具,它为所有坐标递增的自旋函数提供正相关性。该不等式在各种中心极限定理(CLTs)的证明中发挥了重要作用,包括最近关于铁磁性指数随机图模型(ERGMs)的研究,其中哈密顿量倾斜促进了小子图如三角形的存在。然而,当将自旋系统限制在特定相中时,在低温参数下FKG晶格条件会失效。因此,不清楚每个相内部是否对递增函数具有正相关性,或者整体模型(即相的混合)中的正相关性是否主要来自全局相的选择。在本文中,我们证明ERGMs中的各个相确实满足近似的FKG不等式。我们利用此结果完成各个相内的中心极限定理证明,回答了Bianchi、Collet和Magnanini提出的问题。我们展示了ERGMs中的FKG不等式是更一般结果的推论,该结果在某些与元稳态混合相关的输入条件下成立;我们预计该一般结果将具有广泛的应用性,并专门用一节来阐述其在一类广义高阶铁磁性居里-魏斯模型中的应用细节,其中所需的输入相对明确。

英文摘要

The Fortuin-Kasteleyn-Ginibre (FKG) inequality is an invaluable tool in monotone spin systems satisfying the FKG lattice condition, which provides positive correlations for all coordinate-wise increasing functions of spins. This inequality has numerous applications and plays an integral role in the proof of various central limit theorems (CLTs), including recent work on ferromagnetic exponential random graph models (ERGMs) wherein a Hamiltonian tilt promotes the presence of small subgraphs like triangles. However, the FKG lattice condition fails to hold when confining a spin system to a particular phase in the low-temperature regime of parameters. Thus it is not a priori clear if each phase internally has positive correlations for increasing functions, or if the positive correlations in the overall model (which is a mixture of phases) arise primarily from the global choice of phase. In this article, we show that the individual phases in ERGMs do indeed satisfy an approximate form of the FKG inequality internally. We use this to finish the proof of various CLTs within each individual phase in the phase-coexistence regime, answering a question posed by Bianchi, Collet, and Magnanini. We present the FKG inequality for ERGMs as a consequence of a more general result which holds under certain inputs related to metastable mixing; we expect this general result to be widely applicable, and we devote a section to spelling out the details of its application to a class of generalized higher-order ferromagnetic Curie-Weiss models where the necessary inputs are relatively transparent.

2601.07157 2026-05-21 quant-ph

Strong coupling of virtual negative states in the Kapitza-Dirac effect

Kapitza-Dirac效应中虚拟负态的强耦合

Qianlong Wang, Sven Ahrens, Baifei Shen

AI总结 研究了Kapitza-Dirac效应中虚拟负态对双光子动力学衍射振幅的主要贡献,并通过时间依赖微扰理论的解验证了负态耦合在强激光场和任意低幅射场中的主导作用。

Comments 14 pages, 5 figures

Journal ref Physical Review A 113, 052221 (2026)

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AI中文摘要

负态是相对论量子理论中的固有属性,与Dirac海概念中的反粒子相关。我们证明负态在双光子Kapitza-Dirac效应的量子动力学中主导衍射振幅。我们通过研究时间依赖微扰理论的解得出结论,其中微扰解与相对论量子系统的数值解以及经典点状电子在外部驻波光场中的相对论运动方程的数值和解析解相一致。尽管我们的数值解假设了强激光场,解析解表明负态耦合在任意低幅射场中仍占主导地位,在单光子情况下(康普顿散射)负态耦合可以与旧式微扰理论中虚电子-正电子对的相互作用相关联。

英文摘要

Negative states are an intrinsic property of relativistic quantum theory and related to anti-particles in the context of the Dirac sea concept. We show that negative states can dominantly contribute to the diffraction amplitude in the quantum dynamics of the two-photon Kapitza-Dirac effect. We draw our conclusion by investigating solutions from time-dependent perturbation theory, where the perturbative solutions are in match with numeric solutions of the relativistic quantum system and also with the numeric and analytic solutions from the relativistic equations of motion of a classical point-like electron in an external standing wave light field. While our numeric solutions assume a strong laser field, the analytic solutions indicate that negative state coupling remains dominant for arbitrary low field amplitudes, where in the single-photon case (Compton scattering) negative state coupling can be mathematically associated with the interaction of a virtual electron-positron pair in the context of a quantized theory in old-fashioned perturbation theory.

2601.06259 2026-05-21 hep-ph astro-ph.CO

Temperature-Dependent CPT Violation: Constraints from Big Bang Nucleosynthesis

温度依赖的CPT违反:来自大爆炸核合成的约束

Gabriela Barenboim, Anne-Katherine Burns

AI总结 研究通过电子-正电子质量不对称性探讨大爆炸核合成中温度依赖的CPT违反,利用$b_0(T) = αT^2$参数化,发现该模型在早期宇宙的MeV尺度上允许显著的CPT违反,同时通过修改的BBN代码约束了电子-正电子质量差异,提出了三种玩具模型解释$b_0(T) \propto T^2$的场论机制。

Comments 29 pages, 5 figures, updated version which was accepted to PRD

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AI中文摘要

在本研究中,我们通过电子-正电子质量不对称性参数化$b_0(T) = αT^2$,探讨了大爆炸核合成(BBN)期间温度依赖的CPT违反。$T^2$的缩放自然地规避了实验室在零温度下的严格界限,同时允许早期宇宙在MeV尺度上存在显著的CPT违反。使用修改后的BBN代码PRyMordial,通过动态求解化学势和适当的有限质量修正,我们从观测到的氦-4、氘和$N_{ m eff}$丰度约束了电子-正电子质量差异。我们发现,对于BBN中keV尺度的质量差异,$α$必须大于或约等于$10^{-6}$ GeV$^{-1}$。尽管三个可观测值显示没有同时的$1σ$重叠,但成对组合允许参数空间的受约束区域。我们提出了三种玩具模型,展示了如何通过场论机制产生$b_0(T) \propto T^2$,包括温度驱动的相变。这些结果为该领域提供了最严格的早期宇宙CPT违反约束,探测了实验室实验无法触及的参数空间。

英文摘要

In this study, we explore temperature-dependent CPT violation during Big Bang Nucleosynthesis (BBN) through electron-positron mass asymmetries parametrized by $b_0(T) = αT^2$. The $T^2$ scaling naturally evades stringent laboratory bounds at zero temperature while allowing for significant CPT violation at MeV scales in the early universe \cite{ParticleDataGroup:2024cfk}. Using a modified version of the BBN code \faGithub \href{https://github.com/vallima/PRyMordial}{\,\texttt{PRyMordial}} with dynamically-solved chemical potentials and appropriate finite-mass corrections, we constrain electron-positron mass differences from observed abundances of Helium-4, Deuterium, and $N_{\rm eff}$. We find that $α$ must be greater than or approximately equal to $10^{-6}$ GeV$^{-1}$ for keV-scale mass differences at BBN. All three observables show no simultaneous $1σ$ overlap, though pairwise combinations allow for constrained regions of parameter space. We present three toy models demonstrating how $b_0(T) \propto T^2$ arises from field-theoretic mechanisms, including temperature-driven phase transitions. These results provide the most stringent constraints on early-universe CPT violation in this regime, probing parameter space inaccessible to laboratory experiments.

2601.06256 2026-05-21 quant-ph cond-mat.quant-gas cond-mat.stat-mech cond-mat.str-el

Universal Predictors for Mixing Time more than Liouvillian Gap

通用预测混合时间超过李普希兹间隙

Yi-Neng Zhou

AI总结 本文研究了开放量子系统混合时间的决定因素,发现不仅由李普希兹间隙决定,还受每个衰减李普希兹本征模的迹范数影响。通过利用这些作为通用预测器,建立了快速和快速混合的一般条件。具体而言,推导了强弱耗散情况下快速混合的条件,以哈密顿量和本地李普希兹算符的稀疏性约束形式呈现。研究为计算混合时间提供了通用框架,并为设计耗散以实现所需混合速度提供了指导,对高效实验态制备有重要意义。

Comments 5 pages, 2 tables

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AI中文摘要

我们分析了由李普希兹主方程支配的开放量子系统混合时间,证明其不仅由李普希兹间隙决定,还受每个衰减李普希兹本征模的迹范数因子影响。通过将其作为通用混合时间预测器,我们建立了快速和快速混合的一般条件。具体而言,我们为强和弱耗散情形推导了快速混合条件,形式为哈密顿量和本地李普希兹算符的稀疏性约束。我们的发现提供了一个计算混合时间的通用框架,并为设计耗散以实现所需混合速度提供了指导,这对高效实验态制备具有重要意义。

英文摘要

We analyze the mixing time of open quantum systems governed by the Lindblad master equation, showing that it is determined not only by the Liouvillian gap, but also by the trace-norm factor of each decaying Liouvillian eigenmode. By utilizing them as universal predictors of mixing time, we establish general conditions for the fast and rapid mixing, respectively. Specifically, we derive rapid mixing conditions for both the strong and weak dissipation regimes, formulated as sparsity constraints on the Hamiltonian and the local Lindblad operators. Our findings provide a general framework for calculating mixing time and offer a guide for designing dissipation to achieve desired mixing speeds, which has significant implications for efficient experimental state preparation.

2601.05147 2026-05-21 cond-mat.supr-con quant-ph

Low-loss Material for Infrared Protection of Cryogenic Quantum Applications

用于低温量子应用红外防护的低损耗材料

Markus Griedel, Max Kristen, Biliana Gasharova, Yves-Laurent Mathis, Alexey V. Ustinov, Hannes Rotzinger

AI总结 本研究提出了一种低损耗材料,通过优化Mie散射效应,在光学范围内有效阻挡辐射,同时在低GHz频率下实现低损耗传输,用于保护低温量子应用免受红外辐射影响。

Journal ref Appl. Phys. Lett. 128, 204003 (2026)

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AI中文摘要

低温量子应用中的脆弱量子态需要防护来自高温阶段或其他来源的红外辐射。我们提出了一种材料系统,能够在光学范围内高效阻挡辐射,同时在低GHz频率下传输光子。该系统基于以下效应:当入射光子的波长与嵌入弱吸收介质中的粒子尺寸相当时,光子会被强烈散射(Mie散射)。本工作旨在通过模拟其对尺寸分布的依赖性,优化非磁性环氧树脂中含刚玉球体的吸收和传输光谱。此外,我们还制备了几种材料组成,对其以及其它材料在光学、红外和GHz频率下进行了表征。在红外区域(阻带)中,优化的Mie散射材料具有高衰减,与其它常用滤波材料相当。在GHz频率(通带)下,原型滤波器在毫开尔文温度下表现出高传输,插入损耗低于0.4 dB,在10 GHz以下。

英文摘要

The fragile quantum states of low-temperature quantum applications require protection from infrared radiation caused by higher-temperature stages or other sources. We propose a material system that can efficiently block radiation up to the optical range while transmitting photons at low gigahertz frequencies. It is based on the effect that incident photons are strongly scattered when their wavelength is comparable to the size of particles embedded in a weakly absorbing medium (Mie-scattering). The goal of this work is to tailor the absorption and transmission spectrum of an non-magnetic epoxy resin containing sapphire spheres by simulating its dependence on the size distribution. Additionally, we fabricate several material compositions, characterize them, as well as other materials, at optical, infrared, and gigahertz frequencies. In the infrared region (stop band) the attenuation of the Mie-scattering optimized material is high and comparable to that of other commonly used filter materials. At gigahertz frequencies (pass-band), the prototype filter exhibits a high transmission at millikelvin temperatures, with an insertion loss of less than $0.4\,$dB below $10\,$GHz.

2601.05141 2026-05-21 gr-qc cond-mat.quant-gas

Superluminal modes in a quantum field simulator for cosmology from analog trans-Planckian physics

量子场模拟器中类光模式的超光速特性:从类普朗克物理的类比宇宙学

Christian F. Schmidt, Stefan Floerchinger

AI总结 本文研究了通过类比超普朗克物理构建的量子场模拟器中,标量玻色-爱因斯坦凝聚体的U(1)金石子的超光速模式,发展了超越声学近似的量子场理论描述,并探讨了其在宇宙学中的应用与贡献。

Comments (17 + 6) pages, 12 figures, matches journal version

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AI中文摘要

针对标量玻色-爱因斯坦凝聚体中具有时间依赖接触相互作用的U(1)金石子的量子场理论描述,在Bogoliubov理论框架下发展了超越声学近似的描述。所得有效作用量被映射到具有超光速Corley-Jacobson色散关系的相对论量子场论上,该色散关系对应于色散(或雨伞)宇宙学时空。时间依赖的s波散射长度的变化用于模拟宇宙学粒子产生,伴随时间依赖的愈合长度,可解释为共动框架中的类比普朗克长度。非绝热转变获得色散特征,进行了深入讨论。该框架应用于指数膨胀或幂律收缩的(2+1)维时空,已知能产生标量不变的宇宙学功率谱。研究了这些场景对Bogoliubov色散时间依赖性的敏感性:发现当截止尺度不明显分离于视界穿越尺度时,通过可分析的Transplanckian阻尼效应违反标量不变性。在指数膨胀的情况下,这些阻尼效应显著趋于稳定,收敛到另一个标量不变的平台,在远紫外区域,非绝热转变被高色散抑制。所发展的框架使能够定量研究更具极端的类比宇宙学场景,在紫外区域具有改进的可预测性,最终可能在实验室中观测到标量不变的宇宙学功率谱。

英文摘要

The quantum-field-theoretic description for the U(1)-Goldstone boson of a scalar Bose-Einstein condensate with time-dependent contact interactions is developed beyond the acoustic approximation in accordance with Bogoliubov theory. The resulting effective action is mapped to a relativistic quantum field theory on a dispersive (or rainbow) cosmological spacetime which has a superluminal Corley-Jacobson dispersion relation. Time-dependent changes of the s-wave scattering length to quantum-simulate cosmological particle production are accompanied by a time-dependent healing length that can be interpreted as an analog Planck length in the comoving frame. Non-adiabatic transitions acquire a dispersive character, which is thoroughly discussed. The framework is applied to exponentially expanding or power-law contracting $(2+1)$-dimensional spacetimes which are known to produce scale-invariant cosmological power spectra. The sensitivity of these scenarios to the time-dependence of the Bogoliubov dispersion is investigated: We find a violation of scale-invariance via analytically trackable Transplanckian damping effects if the cut-off scale is not well separated from the horizon-crossing scale. In case of the exponential expansion, these damping effects remarkably settle and converge to another scale-invariant plateau in the far ultraviolet regime where non-adiabatic transitions are suppressed by the high dispersion. The developed framework enables quantitative access to more drastic analog cosmological scenarios with improved predictability in the ultraviolet regime that ultimately may lead to the observation of a scale-invariant cosmological power spectrum in the laboratory.

2601.03859 2026-05-21 cs.SI cs.CY

Fairness in Opinion Dynamics

意见动态中的公平性

Stanisław Stępień, Michalina Janik, Mateusz Nurek, Akrati Saxena, Radosław Michalski

AI总结 本文研究了意见动态中算法对少数群体的歧视问题,通过分析NetSense数据集和CoDiNG模型,探讨了基于人口统计学、拓扑学和混合方法的分类器在预测算法不准确时的表现,并识别了四种算法偏见模式,强调了需要结合个体属性和网络结构的多维方法来促进公平的社会网络分析。

详情
AI中文摘要

人们意见变化的方式无疑受到多种不同影响的复杂交织。影响一个人形成意见的因素反映了他们一生所经历的环境、教育、物质状况、所信仰的体系以及所属于的社会经济少数群体。这种已经复杂的系统还因社交网络的不断变化而进一步扩展。因此,许多模型倾向于对大多数人口表现最佳,而对属于各种边缘化群体的人则表现出歧视。这种偏见以及如何对抗它的研究属于快速发展的社会网络分析(SNA)公平性领域。本文的重点是探讨最先进的模型如何歧视某些少数群体,以及是否有可能可靠地预测它对谁表现更差。此外,这种预测是否仅基于一个人的种族或拓扑特征?为此,NetSense数据集和最先进的CoDiNG意见预测模型被采用。我们的工作探讨了三种分类器模型(基于人口统计学、基于拓扑学和混合模型)在评估该算法对谁提供不准确预测时的表现。最后,通过全面分析这些实验结果,我们识别了四种算法偏见模式。我们的发现表明,没有单一范式能提供最佳结果,公平导向的社会网络分析需要真正的上下文感知策略。我们得出结论,一种结合个体属性和网络结构的多维方法对于减少算法偏见和促进包容性决策是至关重要的。

英文摘要

Ways in which people's opinions change are, without a doubt, subject to a rich tapestry of differing influences. Factors that affect how one arrives at an opinion reflect how they have been shaped by their environment throughout their lives, education, material status, what belief systems are they subscribed to, and what socio-economic minorities are they a part of. This already complex system is further expanded by the ever-changing nature of one's social network. It is therefore no surprise that many models have a tendency to perform best for the majority of the population and discriminating those people who are members of various marginalized groups . This bias and the study of how to counter it are subject to a rapidly developing field of Fairness in Social Network Analysis (SNA). The focus of this work is to look into how a state-of-the-art model discriminates certain minority groups and whether it is possible to reliably predict for whom it will perform worse. Moreover, is such prediction possible based solely on one's demographic or topological features? To this end, the NetSense dataset, together with a state-of-the-art CoDiNG model for opinion prediction have been employed. Our work explores how three classifier models (Demography-Based, Topology-Based, and Hybrid) perform when assessing for whom this algorithm will provide inaccurate predictions. Finally, through a comprehensive analysis of these experimental results, we identify four key patterns of algorithmic bias. Our findings suggest that no single paradigm provides the best results and that there is a real need for context-aware strategies in fairness-oriented social network analysis. We conclude that a multi-faceted approach, incorporating both individual attributes and network structures, is essential for reducing algorithmic bias and promoting inclusive decision-making.

2601.03720 2026-05-21 math.GN math.DS

On generalized Namioka spaces and joint continuity of functions on product of spaces

关于广义Namioka空间和乘积空间上函数的联合连续性

Xiongping Dai, Congying Lv, Yuxuan Xie

AI总结 本文研究了广义Namioka空间的性质,并探讨了在乘积空间上函数的联合连续性问题,主要贡献在于证明了在某些条件下乘积空间为Namioka空间或广义Namioka空间,并讨论了右拓扑群作用的联合连续性条件。

Comments 45 pages

详情
AI中文摘要

一个空间X被称为广义Namioka空间(gN-space),如果对于每一个紧空间Y和每一个分别连续的函数f:X×Y→R,存在至少一个点x∈X,使得f在{x}×Y中的每个点上都是联合连续的。我们主要证明了以下结果:(1) 如果X=∏_{α∈A}X_α是非meager的,并且每个因子是可分空间或每个因子是伪度量空间,则X是gN-space。(2) 如果X是可分空间,Y是伪度量空间,并且X×Y是Baire空间(resp.非meager),则X×Y是N-space(resp. gN-space)。(3) 如果X=∏_{α∈A}X_α,每个因子都是可分的,并且对于每个可数子集A′⊂A,∏_{α∈A′}X_α是非meager空间,则X是非meager的gN-space。(4) 如果X=∏_{α∈A}X_α,每个因子具有可数π-基,则X中的每个尾集具有Baire性质时,该集要么是meager要么是residual。如果G是gN右拓扑群,X是局部紧正则空间,或者如果G是可分第一可数非meager右拓扑群,且X×X是可数紧完全正则空间,则任何分别连续的作用G→X都是联合连续的。

英文摘要

A space $X$ is called a generalized Namioka space (g$\mathcal{N}$-space), if for every compact space $Y$ and every separately continuous function $f\colon X\times Y\rightarrow\mathbb{R}$, there exists at least one point $x\in X$ such that $f$ is jointly continuous at each point of $\{x\}\times Y$. We principally prove the following results: (1) If $X=\prod_{α\in A}X_α$ is non-meager such that each factor is a separable space or each factor is a pseudo-metric space, then $X$ is a g$\mathcal{N}$-space. (2) If $X$ is a separable space and $Y$ a pseudo-metric space such that $X\times Y$ is Baire (resp. non-meager), then $X\times Y$ is an $\mathcal{N}$-space (resp. a g$\mathcal{N}$-space). (3) If $X=\prod_{α\in A}X_α$ such that each factor is separable and $\prod_{α\in A^\prime}X_α$ is a non-meager space for each countable subset $A^\prime$ of $A$, then $X$ is a non-meager g$\mathcal{N}$-space. (4) If $X=\prod_{α\in A}X_α$ such that each factor has a countable $π$-base, then each tail set having the property of Baire in $X$ is either meager or residual. If $G$ is a g$\mathcal{N}$ right-topological group and $X$ a locally compact regular space, or, if $G$ is a separable first countable non-meager right-topological group and $X\times X$ a countably compact completely regular space, then any separately continuous action $G\curvearrowright X$ is jointly continuous.