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2306.01724 2026-05-27 math.CO

The Graph Minor Structure Theorem through Bidimensionality

通过双维度的图子结构定理

Dimitrios M. Thilikos, Sebastian Wiederrecht

AI总结 本文提出基于双维度概念的图子结构定理新版本,避免使用顶点和漩涡,并针对特定曲面Σ定义Σ-树宽,通过排除有限参数图族刻画其行为。

Comments We split the article into two volumes. The first volume, concerned with extracting surfaces from the GMST, has become the new version of this article, while the second volume will be a different upload. arXiv admin note: text overlap with arXiv:2304.04517

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AI中文摘要

图$G$中顶点集$X$的双维度是使得$G$包含以$X$为根的$(k \times k)$-网格作为子式的最大的$k$。这一概念允许图子结构定理(GMST)的如下版本,避免使用顶点和漩涡:$K_k$-子式自由图是那些允许树分解的图,其躯干包含有界双维度的集合,移除该集合后得到的图可嵌入到某个有界欧拉亏格的曲面$\Sigma$中。接下来,我们通过要求$\Sigma$是某个特定曲面来固定目标条件。这定义了树宽的“曲面扩展”,其中$\Sigma$-${\sf tw}$是最小的$k$,使得$G$允许一个树分解,其躯干在移除一个双维度至多为$k$的集合后可嵌入到$\Sigma$中。我们识别了一个有限的参数图族$\mathfrak{D}_\Sigma$,并证明对于每个曲面$\Sigma$,排除$\mathfrak{D}_\Sigma$中的图决定了$\Sigma$-${\sf tw}$的行为。由此可知,$\mathfrak{D}_\Sigma$与$\Sigma$的“曲面障碍”(即极小不包含在$\Sigma$中的曲面)一一对应。我们的结果是紧的,因为$\Sigma$-${\sf tw}$对于$\mathfrak{D}_\Sigma$中的所有参数图不能有界。

英文摘要

The bidimensionality of a set of vertices $X$ in a graph $G$ is the maximum $k$ for which $G$ contains as a $X$-rooted minor the $(k \times k)$-grid. This notion allows for the following version of the Graph Minors Structure Theorem (GMST) that avoids the use of apices and vortices: $K_k$-minor free graphs are those that admit tree decompositions whose torsos contain sets of bounded bidimensionality whose removal yield a graph embeddable in some surface $Σ$ of bounded Euler-genus. We next fix the target condition by demanding that $Σ$ is some particular surface. This defines a "surface extension" of treewidth, where $Σ$-${\sf tw}$ is the minimum $k$ for which $G$ admits a tree decomposition whose torsos become embeddable in $Σ$ after the removal of a set of bidimensionality at most $k$. We identify a finite collection $\mathfrak{D}_Σ$ of parametric graphs and prove that the minor-exclusion of the graphs in $\mathfrak{D}_Σ$ determines the behavior of $Σ$-${\sf tw},$ for every surface $Σ.$ It follows that the collection $\mathfrak{D}_Σ$ bijectively corresponds to the "surface obstructions" for $Σ,$ i.e., surfaces that are minimally non-contained in $Σ.$ Our results are tight in the sense that $Σ$-${\sf tw}$ cannot be bounded for all parametric graphs in $\mathfrak{D}_Σ$.

2305.01889 2026-05-27 eess.SP

A New Non-Negative Matrix Factorization Approach for Blind Source Separation of Cardiovascular and Respiratory Sound Based on the Periodicity of Heart and Lung Function

一种基于心肺功能周期性的心血管和呼吸音盲源分离的新非负矩阵分解方法

Yasaman Torabi, Shahram Shirani, James P. Reilly

AI总结 提出一种改进的仿射非负矩阵分解方法,利用信号周期性从数字听诊器记录的混合声音中盲分离心音和肺音,提高了分离精度。

Journal ref Biomedical Signal Processing and Control, 2026

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AI中文摘要

听诊为诊断心血管和呼吸系统疾病提供了丰富的信息。然而,由于噪声,声音听诊具有挑战性。本研究提出了一种改进的仿射非负矩阵分解(NMF)方法,用于盲分离由数字听诊器记录的肺音和心音。该方法采用一种新颖的NMF算法,该算法在输入信号上体现了多层单元的并行结构,以找到源信号的适当估计。另一个关键创新是利用信号的周期性特性,与以往工作相比提高了准确性。该方法在100个案例上进行了测试。每个案例包含两个真实测量的合成混合。讨论了不同参数的影响,并将结果与其他当前方法进行了比较。结果表明,心音和肺音的源失真比(SDR)、源干扰比(SIR)和源伪影比(SAR)分别得到了改善。

英文摘要

Auscultation provides a rich diversity of information to diagnose cardiovascular and respiratory diseases. However, sound auscultation is challenging due to noise. In this study, a modified version of the affine non-negative matrix factorization (NMF) approach is proposed to blindly separate lung and heart sounds recorded by a digital stethoscope. This method applies a novel NMF algorithm, which embodies a parallel structure of multilayer units on the input signal, to find a proper estimation of source signals. Another key innovation is the use of the periodic property of the signals which improves accuracy compared to previous works. The method is tested on 100 cases. Each case consists of two synthesized mixtures of real measurements. The effect of different parameters is discussed, and the results are compared to other current methods. Results demonstrate improvements in the source-to-distortion ratio (SDR), source-to-interference ratio (SIR), and source-to-artifacts ratio (SAR) of heart and lung sounds, respectively.

2501.16412 2026-05-27 hep-ph

Dynamic Neutrino Mass Ordering and Its Imprint on the Diffuse Supernova Neutrino Background

动态中微子质量顺序及其在弥散超新星中微子背景中的印记

Yuber F. Perez-Gonzalez, Manibrata Sen

AI总结 本文研究动态中微子质量谱对弥散超新星中微子背景(DSNB)通量的影响,发现电子中微子存活概率携带质量演变的特征,但当前DSNB模型谱形不确定性使直接探测超出近期实验能力。

Comments 10 pages, 4 figures. Accepted for publication in EPJC

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AI中文摘要

中微子质量可能在宇宙历史中动态演化,导致其质量谱不同于今天观测到的正常或反顺序。虽然宇宙学测量约束中微子的总能量密度,但除非未来巡天在探测每个质量本征态对大尺度结构的独特印记方面达到非凡精度,否则它们对动态变化的质量顺序并不直接敏感。在这项工作中,我们研究了动态中微子质量谱对弥散超新星中微子背景(DSNB)的影响,DSNB由宇宙历史上所有超新星爆发的中微子组成,正处于实验探测的边缘。中微子质量随红移的动态演化改变了中微子在超新星内部的传播。由于中微子振荡对质量谱高度敏感,我们展示了电子中微子存活概率携带了演化中微子质量谱的独特特征。我们的结果表明,动态中微子质量谱可以以能量依赖的方式修改DSNB通量。然而,我们发现当前DSNB建模中谱形不确定性的水平使得直接探测超出了当前和近期实验的能力。尽管如此,我们的研究强调了在控制天体物理系统误差后,DSNB可作为红移依赖中微子性质的探针。

英文摘要

Neutrino masses may have evolved dynamically throughout the history of the Universe, potentially leading to a mass spectrum distinct from the normal or inverted ordering observed today. While cosmological measurements constrain the total energy density of neutrinos, they are not directly sensitive to a dynamically changing mass ordering unless future surveys achieve exceptional precision in detecting the distinct imprints of each mass eigenstate on large-scale structures. In this work, we investigate the impact of a dynamic neutrino mass spectrum on the diffuse supernova neutrino background (DSNB), which is composed of neutrinos from all supernova explosions throughout cosmic history and is on the verge of experimental detection. The dynamic evolution of neutrino masses with redshift changes the propagation of neutrinos inside the supernova. Since neutrino oscillations are highly sensitive to the mass spectrum, we show that the electron neutrino survival probability carries distinct signatures of the evolving neutrino mass spectrum. Our results show that a dynamic neutrino mass spectrum can modify the DSNB flux in an energy-dependent way. However, we find that the current level of spectral shape uncertainty in DSNB modeling makes a direct detection beyond the reach of present and near-future experiments. Nonetheless, our study highlights the DSNB as a probe of redshift-dependent neutrino properties once the astrophysical systematics are brought under control.

2405.19809 2026-05-27 math.OC

Study of the behaviour of Nesterov Accelerated Gradient in a non convex setting: the strongly quasar convex case

Nesterov加速梯度在非凸环境中的行为研究:强类凸情况

Julien Hermant, Jean-François Aujol, Charles Dossal, Aude Rondepierre

AI总结 本文研究Nesterov加速梯度(NAG)算法在强类凸函数上的收敛性,通过高分辨率ODE分析证明在较低曲率假设下可实现加速收敛,并指出关键几何性质缺失会导致加速现象消失。

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AI中文摘要

我们研究了Nesterov加速梯度(NAG)最小化算法应用于一类称为强类凸函数的非凸函数的收敛性。我们证明NAG可以在较低曲率假设下实现加速收敛速度。我们通过高分辨率ODE进行连续分析,表明尽管可能出现负摩擦,系统解仍能以加速速率收敛到最小值。最后,我们确定了关键的几何性质,如果去掉该性质,理论上会取消加速现象。

英文摘要

We study the convergence of Nesterov Accelerated Gradient (NAG) minimization algorithmapplied to a class of non convex functions called strongly quasar convex functions. We show thatNAG can achieve an accelerated convergence speed at the cost of a lower curvature assumption.We provide a continuous analysis through high resolution ODEs, where we show that despite thatnegative friction may appear, the solution of the system achieves accelerated rate of convergenceto the minimum. Finally, we identify the key geometrical property that, if dropped, theoreticallycancels the acceleration phenomenon.

2404.13668 2026-05-27 math.FA math.AP math.MG math.PR

Contraction properties and differentiability of $p$-energy forms with applications to nonlinear potential theory on self-similar sets

$p$-能量形式的收缩性质与可微性及其在自相似集上非线性位势理论中的应用

Naotaka Kajino, Ryosuke Shimizu

AI总结 本文引入广义$p$-收缩性质,证明满足$p$-Clarkson不等式的$p$-能量形式是Fréchet可微的,并验证了分形上$p$-能量形式的该性质,进而引入$p$-电阻形式并研究$p$-调和函数的基本性质,获得了自相似$p$-能量形式尺度因子的新估计,并证明了广义Sierpiński地毯和$D$维$l$级Sierpiński垫片的$p$-游走维度严格大于$p$。

Comments 171 pages, 14 figures; a number of updates have been made throughout the paper, including correcting serious errors in the proof of Theorem 6.22, Subsection 6.3 and Subsection 8.4 and adding indexes of symbols, abbreviations, words and phrases

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AI中文摘要

我们引入了一种新的收缩性质,称为广义$p$-收缩性质,用于$p$-能量形式,作为许多著名不等式的推广,例如$p$-Clarkson不等式、强次可加性和非线性Dirichlet形式理论中的Markov性质,并证明任何满足$p$-Clarkson不等式的$p$-能量形式是Fréchet可微的。我们还验证了由Kigami [Mem. Eur. Math. Soc. 5 (2023)] 和Cao--Gu--Qiu [Adv. Math. 405 (2022), no. 108517] 构造的分形上$p$-能量形式的广义$p$-收缩性质。作为考虑广义$p$-收缩性质的$p$-能量形式的一般框架,我们引入了$p$-电阻形式的概念,并研究了关于$p$-电阻形式的$p$-调和函数的基本性质。特别地,通过建立$p$-调和函数的Hölder正则性估计,获得了自相似集上自相似$p$-能量形式尺度因子的新估计,并证明了任何广义Sierpiński地毯和$D$维$l$级Sierpiński垫片的$p$-游走维度严格大于$p$。

英文摘要

We introduce a new contraction property, which we call the generalized $p$-contraction property, for $p$-energy forms as generalizations of many well-known inequalities, such as $p$-Clarkson's inequality, the strong subadditivity and the Markov property in the theory of nonlinear Dirichlet forms, and show that any $p$-energy form satisfying $p$-Clarkson's inequality is Fréchet differentiable. We also verify the generalized $p$-contraction property for $p$-energy forms on fractals constructed by Kigami [Mem. Eur. Math. Soc. 5 (2023)] and by Cao--Gu--Qiu [Adv. Math. 405 (2022), no. 108517]. As a general framework of $p$-energy forms taking the generalized $p$-contraction property into consideration, we introduce the notion of $p$-resistance form and investigate fundamental properties of $p$-harmonic functions with respect to $p$-resistance forms. In particular, some new estimates on scaling factors of self-similar $p$-energy forms on self-similar sets are obtained by establishing Hölder regularity estimates for $p$-harmonic functions, and the $p$-walk dimensions of any generalized Sierpiński carpet and the $D$-dimensional level-$l$ Sierpiński gasket are shown to be strictly greater than $p$.

2408.08946 2026-05-27 cs.CY

Authorship Attribution in the Era of LLMs: Problems, Methodologies, and Challenges

LLM时代的作者身份归属:问题、方法与挑战

Baixiang Huang, Canyu Chen, Kai Shu

AI总结 本文系统综述了LLM时代作者身份归属的四个代表性问题和挑战,包括人类文本归属、LLM生成文本检测、LLM生成文本归属以及人机合著文本归属,并探讨了泛化性和可解释性等关键问题。

Comments ACM SIGKDD Exploration. 12 pages. Additional resources, including a regularly updated list of related papers, and LLM-generated text detectors, are available at https://llm-authorship.github.io

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AI中文摘要

准确的作者身份归属对于维护数字内容的完整性、改进法医调查以及减轻错误信息和抄袭的风险至关重要。解决对正确作者身份归属的迫切需求,对于维护真实作者身份的可信度和问责制至关重要。大型语言模型(LLMs)的快速发展模糊了人类与机器作者身份之间的界限,给传统方法带来了重大挑战。我们提出了一篇全面的文献综述,考察了LLM时代作者身份归属的最新研究。本综述通过分类四个代表性问题系统地探讨了该领域的格局:(1)人类撰写的文本归属;(2)LLM生成的文本检测;(3)LLM生成的文本归属;以及(4)人机合著文本归属。我们还讨论了与确保作者身份归属方法的泛化性和可解释性相关的挑战。泛化性要求跨不同领域泛化的能力,而可解释性则强调对这些模型做出的决策提供透明且易于理解的见解。通过评估现有方法和基准的优缺点,我们确定了该领域的关键开放问题和未来研究方向。这篇文献综述为有兴趣了解这一快速发展领域最新技术的研究人员和从业者提供了路线图。

英文摘要

Accurate attribution of authorship is crucial for maintaining the integrity of digital content, improving forensic investigations, and mitigating the risks of misinformation and plagiarism. Addressing the imperative need for proper authorship attribution is essential to uphold the credibility and accountability of authentic authorship. The rapid advancements of Large Language Models (LLMs) have blurred the lines between human and machine authorship, posing significant challenges for traditional methods. We present a comprehensive literature review that examines the latest research on authorship attribution in the era of LLMs. This survey systematically explores the landscape of this field by categorizing four representative problems: (1) Human-written Text Attribution; (2) LLM-generated Text Detection; (3) LLM-generated Text Attribution; and (4) Human-LLM Co-authored Text Attribution. We also discuss the challenges related to ensuring the generalization and explainability of authorship attribution methods. Generalization requires the ability to generalize across various domains, while explainability emphasizes providing transparent and understandable insights into the decisions made by these models. By evaluating the strengths and limitations of existing methods and benchmarks, we identify key open problems and future research directions in this field. This literature review serves as a roadmap for researchers and practitioners interested in understanding the state of the art in this rapidly evolving field.

2501.03912 2026-05-27 gr-qc

Pulsar timing in the Galactic Center

银河系中心的脉冲星计时

Riccardo Della Monica, Ivan de Martino

AI总结 提出一种将光子传播时间的相对论计算纳入脉冲星计时模型的新方法,并证明在强场构型中,仅使用最低阶后牛顿近似会导致显著误差,同时展示参数误估对残差的影响。

Comments 19 pages, 8 figures, 2 tables. Matches version accepted in PRD

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AI中文摘要

我们提出了一种新方法,将光子传播时间的相对论计算纳入一个稳健的、针对绕超大质量黑洞运行的脉冲星的计时模型。我们证明,依赖最低阶(1PN)后牛顿近似的计时模型在强场构型中会产生显著差异,影响在地球天文台预测的相对论到达时间。我们还展示了脉冲星参数的误估如何导致相位依赖残差的出现,这暗示了双星和内在参数对银河系中心潜在脉冲星计时观测的巨大约束能力。

英文摘要

We propose a novel approach which implements the relativistic calculations of the photon travel time into a robust timing model for pulsars orbiting supermassive black holes. We demonstrate that timing models relying on the lowest-order (1PN) post-Newtonian approximation can produce significant discrepancies in strong-field configurations, affecting the predicted relativistic times of arrival at an Earth-based observatory. We also show how a misestimation of the pulsar parameters can lead to the appearance of phase-dependent residual, which hints at a tremendous constraining power of the binary and intrinsic parameters for timing observations of potential pulsars at the Galactic Center.

2501.00863 2026-05-27 econ.GN q-fin.EC

Paternalism and Deliberation: An Experiment on Making Formal Rules

家长主义与深思熟虑:关于制定正式规则的实验

Max R. P. Grossmann

AI总结 通过炸弹风险诱发任务实验,研究强制性等待期作为软家长主义政策是否替代硬性限制,以及延迟决策是否更受尊重,发现等待期是附加限制而非替代。

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AI中文摘要

强制性等待期已被用于医疗程序、枪支购买和其他高风险决策。这些软家长主义政策是否是更严格限制的替代品?延迟决策是否更受尊重?在一项一般人群调查实验中,选择架构师为面临高风险炸弹风险诱发任务的决策者制定规则。实验处理变量是决策时间:当场或一天后,以及初始决策是否可以修改。选择架构师设定决策者风险承担的上限;在一个处理中,他们还可以实施强制性等待期。外生深思熟虑对上限于无影响;等价检验(TOST)和贝叶斯分析($\text{BF}_{01} \approx 12$)为无效应提供了强有力的正面证据。内生规定的等待期是附加限制,并不替代上限。选择架构师相信,随着时间的推移,平均决策者将承担更少的风险,并且——由于选择架构师理想点的分布——更接近选择架构师的主观理想选择;由此导致的预测误差减少很小。软和硬的家长主义工具并非替代品:等待期被用作附加限制。

英文摘要

Mandatory waiting periods have been instituted for medical procedures, gun purchases, and other high-stakes decisions. Are these softly paternalistic policies substitutes for harder restrictions, and are delayed decisions more respected? In a general population survey experiment, Choice Architects make rules for decision-makers facing a high-stakes Bomb Risk Elicitation Task. Treatments vary when the decision is made: on the spot or after one day, and whether the initial decision can be revised. Choice Architects set a cap on the decision-maker's risk taking; in one treatment, they can additionally implement a mandatory waiting period. Exogenous deliberation has no effect on the cap; equivalence testing (TOST) and Bayesian analysis ($\text{BF}_{01} \approx 12$) provide strong positive evidence for the absence of an effect. Endogenously prescribed waiting periods are add-on restrictions that do not substitute for the cap. Choice Architects believe that, with time, the average decision-maker will take less risk and -- because of the distribution of Choice Architects' bliss points -- come closer to Choice Architects' subjective ideal choice; the resulting reduction in forecasted errors is small. Soft and hard paternalistic instruments are not substitutes: waiting periods are deployed as add-on restrictions.

2410.07079 2026-05-27 cs.SE

Automated and Complete Generation of Traffic Scenarios at Road Junctions Using a Multi-level Danger Definition

使用多级危险定义自动完整生成道路交叉口交通场景

Aren A. Babikian, Attila Ficsor, Oszkár Semeráth, Gunter Mussbacher, Dániel Varró

AI总结 提出一种基于多级危险定义的方法,通过枚举交叉口处参与者抽象路径的重叠排列,自动生成完整且潜在危险的交通场景,用于自动驾驶车辆仿真测试。

Journal ref Softw. Syst. Model., Online First (2026)

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AI中文摘要

为确保安全使用,自动驾驶车辆(AV)必须满足严格的认证标准,这些标准涉及在(任意)场景中安全执行操作,其中其他参与者执行其预期操作。为此,现有的场景生成方法优化搜索以推导出具有高概率危险情况的场景。在本文中,我们假设在道路交叉口,潜在危险主要源于执行指定高级操作的个体参与者的路径重叠。作为迈向AV认证的一步,我们提出了一种方法,用于在任意给定道路交叉口推导出一组完整的(潜在危险的)抽象场景,即对于一组给定的可能抽象路径,分配给参与者(包括AV)的所有重叠抽象路径的排列。从这些抽象场景中,我们推导出参与者必须遵循的精确路径,以引导基于仿真的测试朝向潜在碰撞。我们进行了大量实验,评估了一个最先进的基于学习的AV控制器在两个现实道路交叉口上生成的场景中的行为,这些场景具有不断增加的外部参与者数量。结果表明,被测AV在仿真中涉及的不安全行为百分比不断增加,这些行为根据功能和逻辑级别的场景属性而变化。

英文摘要

To ensure their safe use, autonomous vehicles (AVs) must meet rigorous certification criteria that involve executing maneuvers safely within (arbitrary) scenarios where other actors perform their intended maneuvers. For that purpose, existing scenario generation approaches optimize search to derive scenarios with high probability of dangerous situations. In this paper, we hypothesize that at road junctions, potential danger predominantly arises from overlapping paths of individual actors carrying out their designated high-level maneuvers. As a step towards AV certification, we propose an approach to derive a complete set of (potentially dangerous) abstract scenarios at any given road junction, i.e. all permutations of overlapping abstract paths assigned to actors (including the AV) for a given set of possible abstract paths. From these abstract scenarios, we derive exact paths that actors must follow to guide simulation-based testing towards potential collisions. We conduct extensive experiments to evaluate the behavior of a state-of-the-art learning-based AV controller on scenarios generated over two realistic road junctions with increasing number of external actors. Results show that the AV-under-test is involved in increasing percentages of unsafe behaviors in simulation, which vary according to functional- and logical-level scenario properties.

2412.05581 2026-05-27 hep-th hep-ph

Canonical formulation of the plasmon - hard particle scattering process in a quark-gluon plasma

等离子体-硬粒子散射过程的规范形式:在夸克-胶子等离子体中

Yu. A. Markov, M. A. Markova

AI总结 本文通过哈密顿形式主义,将软激发非线性动力学推广到描述无色等离子体与热夸克-胶子等离子体中硬色荷粒子的散射,并推导了自洽的玻尔兹曼型动力学方程。

Comments 42 pages, 1 figure. The text of the article has been reduced and the title changed. This version was published in IJMPA

Journal ref Int. J. Mod. Phys. A 41 (2026) 08, 2650005

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AI中文摘要

本文表明,先前在[1]中提出的用于描述仅软费米子和玻色子激发非线性动力学的哈密顿形式主义,包含的信息比最初假设的多得多。我们详细证明,它在描述一系列其他物理现象方面也非常适用和强大,包括无色等离子体与在热夸克-胶子等离子体中运动的硬热(或外部)色荷粒子的散射。针对连续介质情况,提出了泊松超括号的推广,其中包含硬模式的反交换变量和软玻色场的正常变量。定义了相应的哈密顿方程,并以正常玻色场变量和夸克-胶子等离子体的硬动量模式写出了三阶和四阶相互作用哈密顿量的最一般形式。讨论了涉及所考虑系统的玻色子和硬模式自由度的正则变换。推导了基于泊松超括号的这些变换的正则性条件。给出了以新正常场变量和新硬模式变量展开至六阶的积分-幂级数形式的正则变换的最一般结构。针对夸克-胶子等离子体激发的硬动量模式,提出了分离颜色和动量自由度的ansatz。考虑了当硬激发动量远大于等离子体软激发动量时总有效散射振幅的近似问题。得到了考虑硬粒子颜色电荷平均值时间演化的自洽玻尔兹曼型动力学方程组。

英文摘要

It is shown that the Hamiltonian formalism proposed previously in [1] to describe the nonlinear dynamics of only {\it soft} fermionic and bosonic excitations contains much more information than initially assumed. In this paper, we have demonstrated in detail that it also proved to be very appropriate and powerful in describing a wide range of other physical phenomena, including the scattering of colorless plasmons off {\it hard} thermal (or external) color-charged particles moving in a hot quark-gluon plasma. A generalization of the Poisson superbracket including both anticommuting variables for hard modes and normal variables of the soft Bose field, is presented for the case of continuous medium. The corresponding Hamilton equations are defined, and the most general form of the third- and fourth-order interaction Hamiltonians is written out in terms of the normal boson field variables and hard momentum modes of the quark-gluon plasma. The canonical transformations involving both bosonic and hard mode degrees of freedom of the system under consideration, are discussed. The canonicity conditions for these transformations based on the Poisson superbracket, are derived. The most general structure of canonical transformations in the form of integro-power series up to sixth order in a new normal field variable and a new hard mode variable, is presented. For the hard momentum mode of quark-gluon plasma excitations, an ansatz separating the color and momentum degrees of freedom, is proposed. The question of approximation of the total effective scattering amplitude when the momenta of hard excitations are much larger than those of soft excitations of the plasma, is considered. The self-consistent system of Boltzmann-type kinetic equations taking into account the time evolution of the mean value of the color charge of the hard particle is obtained.

2410.21536 2026-05-27 cs.CY

Intelligent Environmental Empathy (IEE): A new power and platform to fostering green obligation for climate peace and justice

智能环境共情(IEE):促进气候和平与正义的绿色义务的新动力与平台

Saleh Afroogh, Ali Mostafavi, Junfeng Jiao

AI总结 本文提出智能环境共情(IEE)作为大数据时代推动气候和平与正义的新动力,通过分析气候不公的根源,构建了结合环境共情与去中心化AI的操作模型。

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AI中文摘要

在本文中,我们提出智能环境共情(IEE)作为气候和平与正义的新驱动力,这是大数据时代的一个新兴议题。我们首先表明,通过国际组织(如UNEP)进行的自上而下的威权政府间合作,迄今为止未能克服环境问题和裂痕。我们阐述了气候不公的四个根源(即目的论根源、价值论根源、形成原因和社会认知原因),并解释了全球范围内共情和环境动机的缺失如何导致所有自上而下的威权政府间合作的失败。解决这些问题需要一种新的自下而上的气候和平与正义方法。其次,聚焦于人工智能、环境共情和气候正义的交叉点,我们在操作层面提出了一个用于气候和平与正义的智能环境共情(IEE)模型。IEE由环境共情的新力量(作为气候正义绿色义务的驱动力)和假定的去中心化AI平台(作为对抗搭便车者的操作系统)赋能,最初影响公民和部分中产阶级决策者(如城市规划者和地方行政人员),但最终也会影响全球决策者。

英文摘要

In this paper, we propose Intelligent Environmental Empathy (IEE) as a new driver for climate peace and justice, as an emerging issue in the age of big data. We first show that the authoritarian top-down intergovernmental cooperation, through international organizations (e.g., UNEP) for climate justice, could not overcome environmental issues and crevices so far. We elaborate on four grounds of climate injustice (i.e., teleological origin, axiological origin, formation cause, and social epistemic cause), and explain how the lack of empathy and environmental motivation on a global scale causes the failure of all the authoritarian top-down intergovernmental cooperation. Addressing all these issues requires a new button-up approach to climate peace and justice. Secondly, focusing on the intersection of AI, environmental empathy, and climate justice, we propose a model of Intelligent Environmental Empathy (IEE) for climate peace and justice at the operational level. IEE is empowered by the new power of environmental empathy (as a driver of green obligation for climate justice) and putative decentralized platform of AI (as an operative system against free riders), which Initially, impact citizens and some middle-class decision makers, such as city planners and local administrators, but will eventually affect global decision-makers as well.

2412.12930 2026-05-27 math.OC cs.NA math.NA

Certified Model Predictive Control for Switched Evolution Equations using Model Order Reduction

基于模型降阶的切换演化方程认证模型预测控制

Michael Kartmann, Mattia Manucci, Benjamin Unger, Stefan Volkwein

AI总结 针对抛物型偏微分方程导出的线性切换演化方程,提出一种结合模型降阶的模型预测控制框架,推导最优性条件,给出递归后验估计并设计两种带闭环认证的降阶模型预测控制算法。

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AI中文摘要

我们提出了一种针对由抛物型偏微分方程导出的线性切换演化方程的模型预测控制(MPC)框架。推导了所得有限时域最优控制问题的一阶最优性条件。该分析允许纳入凸控制约束和稀疏正则化。然后,为减轻MPC过程的计算负担,我们采用Galerkin降阶建模(ROM)技术来获得状态-伴随系统的低维代理。我们推导了ROM反馈律和ROM-MPC闭环状态的递归后验估计,并表明ROM-MPC轨迹在真实MPC轨迹的邻域内演化,该邻域的大小可以显式计算并由ROM的质量控制。这些估计随后被用于制定两种具有闭环认证的ROM-MPC算法。

英文摘要

We present a model predictive control (MPC) framework for linear switched evolution equations arising from a parabolic partial differential equation (PDE). First-order optimality conditions for the resulting finite-horizon optimal control problems are derived. The analysis allows for the incorporation of convex control constraints and sparse regularization. Then, to mitigate the computational burden of the MPC procedure, we employ Galerkin reduced-order modeling (ROM) techniques to obtain a low-dimensional surrogate for the state-adjoint systems. We derive recursive a-posteriori estimates for the ROM feedback law and the ROM-MPC closed-loop state and show that the ROM-MPC trajectory evolves within a neighborhood of the true MPC trajectory, whose size can be explicitly computed and is controlled by the quality of the ROM. Such estimates are then used to formulate two ROM-MPC algorithms with closed-loop certification.

2412.09808 2026-05-27 eess.SY cs.SY

V2Sim: An Open-Source Microscopic V2G Simulation Platform in Urban Power and Transportation Network

V2Sim:城市电力和交通网络中开源微观V2G仿真平台

Tao Qian, Mingyu Fang, Qinran Hu, Chengcheng Shao, Junyi Zheng

AI总结 提出V2Sim开源仿真平台,通过集成微观城市交通网络与配电网,实现电动汽车充电负荷和动态V2G操作的精确建模,支持自定义V2G策略和并行仿真,以南京实际交通网络案例验证其分析空间-时间分布及评估V2G影响的能力。

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AI中文摘要

本文提出V2Sim,一个基于Python的开源仿真平台,专为耦合城市电力和交通网络中的高级车辆到电网(V2G)分析而设计。通过将微观城市交通网络(MUTN)与配电网(PDN)集成,V2Sim能够精确建模电动汽车充电负荷(EVCL)和动态V2G操作。该平台独特地结合了用于MUTN仿真的SUMO和用于PDN分析的优化DistFlow模型,并针对快速充电站(FCS)和慢速充电站(SCS)建立了专用模型,捕捉了现有仿真工具中常被忽略的详细充电动态。V2Sim支持一系列可定制的V2G策略、充电站高级故障检测以及通过多处理加速大规模案例研究的并行仿真。使用中国南京真实MUTN的案例研究表明,V2Sim能够以前所未有的细节分析EVCL的空间-时间分布,并评估V2G影响(如故障传播和定价变化)。与传统的均衡模型不同,V2Sim在微观层面捕捉单车行为和充电交互,为评估V2G兼容系统的运行和规划需求提供了无与伦比的准确性。该平台为旨在优化综合电力和交通网络的研究人员和城市规划者提供了一个全面的工具。

英文摘要

This paper proposes V2Sim, an open source Pythonbased simulation platform designed for advanced vehicle-to-grid (V2G) analysis in coupled urban power and transportation networks. By integrating a microscopic urban transportation network (MUTN) with a power distribution network (PDN), V2Sim enables precise modeling of electric vehicle charging loads (EVCL) and dynamic V2G operations. The platform uniquely combines SUMO for MUTN simulations and an optimized DistFlow model for PDN analysis, with dedicated models for fast charging stations (FCS) and slow charging stations (SCS), capturing detailed charging dynamics often overlooked in existing simulation tools. V2Sim supports a range of customizable V2G strategies, advanced fault-sensing in charging stations, and parallel simulation through multi-processing to accelerate large-scale case studies. Case studies using a real-world MUTN from Nanjing, China, demonstrate V2Sim's capability to analyze the spatial-temporal distribution of EVCL and evaluate V2G impacts, such as fault dissemination and pricing variations, in unprecedented detail. Unlike traditional equilibrium models, V2Sim captures single-vehicle behavior and charging interactions at the microscopic level, offering unparalleled accuracy in assessing the operational and planning needs of V2G-compatible systems. This platform serves as a comprehensive tool for researchers and urban planners aiming to optimize integrated power and transportation networks.

2412.07876 2026-05-27 quant-ph cond-mat.quant-gas

Measurement-Induced Local Dephasing Generates Symmetrically Located Entangled Sites in a Fermionic Tight-Binding Lattice

测量诱导的局域退相干在费米子紧束缚晶格中产生对称分布的纠缠位点

Aitijhya Saha, Srijani Das, Debraj Rakshit

AI总结 研究在奇数尺寸费米子紧束缚链中心位点进行随机投影测量导致的局域退相干,发现系统在特定初始条件下会演化到具有长程量子关联的非平庸稳态,形成对称分布的成对纠缠位点,且增加粒子数可增强纠缠。

Comments 19 pages, 5 figures

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AI中文摘要

我们研究了一个奇数尺寸的费米子开放紧束缚链,在其中心位点进行随机投影测量,有效诱导了局域退相干。最初关注单粒子区域,我们证明当系统制备在偶宇称态时,中心位点退相干下的动力学将其驱动到一个非平庸稳态,我们通过解析和数值方法对其进行了表征。值得注意的是,该稳态以对称分布、成对纠缠的位点形式展现出长程量子关联。我们进一步证明,如果系统在与一个潜在强对称算子相关的特定对称扇区内初始化,通过增加粒子数可以显著增强成对纠缠的程度。我们的结果确定了产生对称选择的长程成对纠缠的最小测量诱导途径,对量子通信和分布式量子信息处理具有潜在意义。

英文摘要

We investigate an odd-sized fermionic open tight-binding chain subjected to stochastic projective measurements at its central site, effectively inducing localized dephasing. Focusing initially on the single-particle regime, we demonstrate that when the system is prepared in an even-parity state, the dynamics under central-site dephasing drive it toward a nontrivial steady state, which we characterize through both analytical and numerical approaches. Remarkably, this steady state exhibits long-range quantum correlations in the form of symmetrically positioned, pairwise entangled sites across the chain. We further show that the degree of pairwise entanglement can be significantly enhanced by increasing the particle number, provided the system is initialized within a specific symmetry sector associated with an underlying strong symmetry operator. Our results identify a minimal measurement-induced route for generating symmetry-selected long-range pairwise entanglement, with possible implications for quantum communication and distributed quantum information processing.

2309.04449 2026-05-27 math.DS

Formal first integrals and higher variational equations

形式首次积分与高阶变分方程

Sergi Simon

AI总结 本文通过微分伽罗瓦理论将高阶变分方程形式化为无限线性系统,利用其对偶性求解非哈密顿系统的首次积分,并应用于Dixon系统、SIR流行病模型和Van der Pol振荡器。

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AI中文摘要

代数如何用于求解动力系统和表征混沌的问题最初由Ziglin、Morales、Ramis和Simó利用微分伽罗瓦理论在丰富的数学背景下提出。他们的研究针对哈密顿系统的一阶,后来是高阶变分方程。本文作者最近的工作将高阶变分方程紧凑而全面地表达为一个无限线性系统,从而简化了方法。更重要的是,该线性系统的对偶包含了与首次积分相关的所有信息,无论原始系统是否为哈密顿系统。这种对守恒量形式计算的适用性是本文的核心,在介绍必要的背景之后,本文处理了三个重要例子,即Dixon系统的特例、具有生命动力的SIR流行病模型和Van der Pol振荡器,并为前两个提供了显式收敛的首次积分。

英文摘要

The question of how Algebra can be used to solve dynamical systems and characterize chaos was first posed in a fertile mathematical context by Ziglin, Morales, Ramis and Simó using differential Galois theory. Their study was aimed at first-order, later higher-order, variational equations of Hamiltonian systems. Recent work by this author formalized a compact yet comprehensive expression of higher-order variationals as one infinite linear system, thereby simplifying the approach. More importantly, the dual of this linear system contains all information relevant to first integrals, regardless of whether the original system is Hamiltonian. This applicability to formal calculation of conserved quantities is the centerpiece of this paper, following an introduction to the requisite context. Three important examples, namely particular cases of Dixon's system, the SIR epidemiological model with vital dynamics and the Van der Pol oscillator, are tackled, and explicit convergent first integrals are provided for the first two.

2411.17862 2026-05-27 astro-ph.GA

Exploring effects of IMF sampling and SN feedback injection on star formation and metallicity in ultra-faint dwarf galaxies

IMF采样和SN反馈注入对超暗弱矮星系恒星形成和金属丰度影响的探究

Myoungwon Jeon, Minsung Go

AI总结 通过高分辨率宇宙学流体动力学模拟,研究不同初始质量函数采样和超新星反馈注入方法对超暗弱矮星系恒星形成历史和金属增丰的影响,发现个体IMF采样导致更连续的恒星形成和更高的恒星金属丰度。

Comments 21 pages, 19 figures, Accepted for publication in MNRAS

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AI中文摘要

我们研究了各种初始质量函数(IMF)采样和超新星(SN)反馈注入方法对超暗弱矮星系(UFD)类似体的恒星形成和金属增丰历史的影响。这些类似体在z=0时具有M_vir~10^8太阳质量和M_star < 10^4.5太阳质量的特征,使用气体粒子质量分辨率约为63太阳质量的高分辨率宇宙学流体动力学zoom-in模拟进行模拟。我们比较了三种方法:爆发模型、随机IMF采样和个体IMF采样。这些方法不仅在星粒子如何按照IMF采样方面不同,而且在SN反馈能量的注入方式上也不同——特别是在时间和空间离散度上,其中个体IMF采样方法具有最离散的SN反馈,因此物理上最真实。我们的发现表明,尽管采样和SN反馈注入存在差异,但不同方法最终的恒星质量总体相似。然而,在个体采样运行中,由于离散SN事件的抑制较弱,恒星形成更为连续,这使得在更致密的环境中能够形成恒星。这种持续的恒星形成导致恒星形成气体更频繁地自增丰,使得个体采样运行中的恒星金属丰度比爆发模型和随机模型高0.2到0.5 dex。这些发现强调了在模拟UFD星系的恒星形成和化学演化时,考虑IMF采样和SN反馈实现的重要性。

英文摘要

We examine the impact of various Initial Mass Function (IMF) sampling and supernova (SN) feedback injection methods on the star formation and metal enrichment histories of Ultra-Faint Dwarf (UFD) galaxy analogs. These analogs, characterized by M_vir~10^8 solar mass and M_star < 10^4.5 solar mass at z=0, are simulated using high-resolution cosmological hydrodynamic zoom-in simulations with a gas particle mass resolution of ~63 solar mass. We compare three approaches: the burst model, stochastic IMF sampling, and individual IMF sampling. These methods differ not only in how star particles are sampled following the IMF, but also in how SN feedback energy is injected -- specifically in the degree of temporal and spatial discreteness, with the individual IMF sampling method being the most discrete SN feedback and thus the most physically realistic. Our findings indicate that, despite variations in sampling and SN feedback injection, the final stellar masses across methods are generally similar. However, star formation is notably more continuous in the individual sampling runs due to the weaker suppression from discrete SN events, which enables star formation in denser environments. This sustained star formation leads to more frequent self-enrichment of star-forming gas, resulting in stellar metallicities that are 0.2 to 0.5 dex higher in individual sampling runs compared to burst and stochastic models. These findings highlight the importance of considering both IMF sampling and SN feedback implementation when modeling the star formation and chemical evolution of UFD galaxies.

2411.10652 2026-05-27 quant-ph cond-mat.quant-gas hep-lat

String-Breaking Dynamics in Quantum Adiabatic and Diabatic Processes

量子绝热和含时过程中的弦断裂动力学

Federica Maria Surace, Alessio Lerose, Or Katz, Elizabeth R. Bennewitz, Alexander Schuckert, De Luo, Arinjoy De, Brayden Ware, William Morong, Kate Collins, Christopher Monroe, Zohreh Davoudi, Alexey V. Gorshkov

AI总结 本文通过量子伊辛链中的畴壁约束,研究弦张力逐渐增大诱导的动态弦断裂现象,发现短弦和慢演化下类似Landau-Zener两态跃迁,长弦则出现气泡叠加的复杂时空模式,并证明长程相互作用可实现纯量子涨落驱动的弦断裂。

Comments 21 pages, 17 figures

Journal ref PRX Quantum 7, 020331 (2026)

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AI中文摘要

禁闭通过称为弦断裂的过程阻止自然界中色荷(如夸克)的孤立:两个色荷的分离导致连接这些色荷的色通量(可视化为弦)的能量增加。最终,产生额外的色荷在能量上更有利,从而断裂弦。这种现象可以在更简单的模型中探测,包括量子自旋链,从而增强对弦断裂动力学的理解。一个具有挑战性的任务是理解在非平衡设置中弦断裂如何随时间发生。本工作建立了由弦张力随时间逐渐增加引起的动态弦断裂的现象学。因此,它超越了瞬时淬火过程,并能够在更受控的设置中追踪弦的实时演化。我们专注于一系列量子伊辛链中的畴壁约束。我们的结果表明,对于足够短的弦和缓慢的演化,弦断裂可以用类似于Landau-Zener过程的两态量子系统的跃迁动力学来描述。对于更长的弦,出现更复杂的时空模式:弦通过形成气泡(不同大小的翻转自旋畴)的叠加而断裂,这些气泡涉及高度激发态。最后,我们证明仅由量子涨落驱动的弦断裂可以在存在足够长程相互作用的情况下实现。本工作对量子模拟实验中研究弦断裂具有直接意义。

英文摘要

Confinement prohibits isolation of color charges, e.g., quarks, in nature via a process called string breaking: the separation of two charges results in an increase in the energy of a color flux, visualized as a string, connecting those charges. Eventually, creating additional charges is energetically favored, hence breaking the string. Such a phenomenon can be probed in simpler models, including quantum spin chains, enabling enhanced understanding of string-breaking dynamics. A challenging task is to understand how string breaking occurs as time elapses, in an out-of-equilibrium setting. This work establishes the phenomenology of dynamical string breaking induced by a gradual increase of string tension over time. It, thus, goes beyond instantaneous quench processes and enables tracking the real-time evolution of strings in a more controlled setting. We focus on domain-wall confinement in a family of quantum Ising chains. Our results indicate that, for sufficiently short strings and slow evolution, string breaking can be described by the transition dynamics of a two-state quantum system akin to a Landau-Zener process. For longer strings, a more intricate spatiotemporal pattern emerges: the string breaks by forming a superposition of bubbles (domains of flipped spins of varying sizes), which involve highly excited states. We finally demonstrate that string breaking driven only by quantum fluctuations can be realized in the presence of sufficiently long-ranged interactions. This work holds immediate relevance for studying string breaking in quantum-simulation experiments.

2411.08403 2026-05-27 math.AG math.RT

Purity of the anisotropic affine Springer fibers for $\mathbf{GL}_{n}$

$\mathbf{GL}_{n}$ 的各向异性仿射 Springer 纤维的纯度

Zongbin Chen

AI总结 对于 $\mathrm{GL}_{n}$ 群和各向异性元素,证明了 Goresky-Kottwitz-MacPherson 的纯度猜想,即仿射 Springer 纤维在 Grothendieck-Deligne 意义上是上同调纯的。

Comments As pointed out by Zhiwei Yun, there is a gap in the final step of the proof of theorem 3.9. Indeed, when we make the intermediate extension from plane curve singularities to complete intersection curve singularities, extra singular support might appear

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AI中文摘要

对于群 $\mathrm{GL}_{n}$ 和各向异性元素,我们确认了 Goresky、Kottwitz 和 MacPherson 的纯度猜想,该猜想指出仿射 Springer 纤维在 Grothendieck-Deligne 意义上是上同调纯的。

英文摘要

For the group $\mathrm{GL}_{n}$ and the anisotropic elements, we confirm the purity hypothesis of Goresky, Kottwitz and MacPherson, which states that the affine Springer fibers are cohomologically pure in the sense of Grothendieck-Deligne.

2411.00657 2026-05-27 stat.ML cs.NA math.NA

Fast Spectrum Estimation of Some Kernel Matrices

某些核矩阵的快速谱估计

Mikhail Lepilov

AI总结 提出一种无需显式构造完整核矩阵即可估计其所有特征值量级的框架,适用于均匀分布点集上快速衰减核函数生成的矩阵,并给出理论保证和实验验证。

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AI中文摘要

在数据科学中,通常假设单个观测值独立地来自一个潜在的概率空间。由大量此类观测值构成的核矩阵经常出现,例如在分类任务中。在不显式构造这些矩阵的情况下了解其特征值衰减特性是可取的,例如在确定低秩近似是否可行时。在这项工作中,我们为某些核矩阵引入了一种新的特征值分位数估计框架。该框架为核矩阵的所有特征值提供了有意义的界,同时避免了构造完整矩阵的成本。所考虑的核矩阵来自一个在远离对角线处快速衰减的核函数,应用于任意维欧几里得空间中均匀分布的点集。我们证明了在核函数满足某些界限时该框架的有效性,并提供了其准确性的经验证据。在此过程中,我们还证明了有限数集的一个一般交错型定理。此外,我们指出了该框架在数据内在维度研究中的应用,以及推广本工作的几个其他方向。

英文摘要

In data science, individual observations are often assumed to come independently from an underlying probability space. Kernel matrices formed from large sets of such observations arise frequently, for example during classification tasks. It is desirable to know the eigenvalue decay properties of these matrices without explicitly forming them, such as when determining if a low-rank approximation is feasible. In this work, we introduce a new eigenvalue quantile estimation framework for some kernel matrices. This framework gives meaningful bounds for all the eigenvalues of a kernel matrix while avoiding the cost of constructing the full matrix. The kernel matrices under consideration come from a kernel with quick decay away from the diagonal applied to uniformly-distributed sets of points in Euclidean space of any dimension. We prove the efficacy of this framework given certain bounds on the kernel function, and we provide empirical evidence for its accuracy. In the process, we also prove a general interlacing-type theorem for finite sets of numbers. Additionally, we indicate an application of this framework to the study of the intrinsic dimension of data, as well as several other directions in which to generalize this work.

2410.23527 2026-05-27 astro-ph.GA

Exploring Galactic open clusters with Gaia. II Dynamical Evolution and Stellar Population Properties in Fifteen Nearby Open Clusters

利用Gaia探索银河疏散星团。II 十五个邻近疏散星团的动力学演化和星族性质

Jeison Alfonso, Alejandro Garcia-Varela, Katherine Vieira

AI总结 利用Gaia DR3数据,通过最小生成树技术和幂律拟合,研究了十五个邻近疏散星团的质量分层和现今质量函数,发现所有星团均存在显著质量分层,且质量分层强度与最分层恒星质量相关,为质量分层的原初起源和动力学演化提供了证据。

Comments Accepted for publication in PASP. 21 pages, 8 figures

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AI中文摘要

恒星质量主导恒星演化,恒星质量分布对星团的动力学演化起着核心作用。利用Gaia DR3的高精度天体测量和测光数据,我们研究了十五个邻近疏散星团的质量分层和现今质量函数(PDMF)。从颜色-星等图中识别出单星和双星,单星的质量通过三次样条关系与G波段星等推导,双星成分质量则通过基于模拟的推断方法估计。基于这些质量估计,使用最小生成树技术量化质量分层,并通过幂律拟合表征PDMF。我们在所有星团中检测到显著的质量分层。缺乏大质量恒星的系统表现出较弱的分层,影响更大比例的星族,而拥有少量大质量恒星的星团则显示出这些天体的强中心聚集。PDMF遵循斜率为2.01的幂律,与经典的Kroupa初始质量函数一致。质量分层的强度与最分层恒星的质量相关。在非常年轻的星团中观测到的强分层支持原初起源,而较老的星团在低质量端显示出动力学质量分层的特征以及双星瓦解的证据。大多数星团中观测到的PDMF低质量断裂,如果不是由于不完整性,可能反映了最初质量分层系统中早期的气体抛射。

英文摘要

Stellar mass governs stellar evolution and the distribution of stellar masses plays a central role in the dynamical evolution of stellar clusters. Using high-precision astrometry and photometry from Gaia DR3, we investigate mass segregation and the present-day mass function (PDMF) in fifteen nearby open clusters. Single and binary stars are identified from the color magnitude diagram, and stellar masses for single stars are derived from a cubic spline relation with G-band magnitude, while binary component masses are estimated via a simulation-based inference method. Based on these mass estimates, mass segregation is quantified using the minimum spanning tree technique, and the PDMF is characterized through power-law fitting. We detect significant mass segregation in all clusters. Systems lacking very massive stars exhibit weaker segregation affecting a larger fraction of the population, whereas clusters hosting a small number of very massive stars show strong central concentration of these objects. The PDMF follows a power law with a slope of 2.01, consistent with the canonical Kroupa initial mass function. The strength of mass segregation correlates with the mass of the most segregated stars. Strong segregation observed in very young clusters supports a primordial origin, while older clusters display signatures of dynamical mass segregation at lower masses and evidence of binary disruption. A low-mass break in the PDMF observed in most clusters, if not due to incompleteness, may reflect early gas expulsion in initially mass-segregated systems.

2410.22507 2026-05-27 math.NT

Universality criterion sets for quadratic forms over number fields

数域上二次型的泛准则集

Vitezslav Kala, Jakub Krásenský, Giuliano Romeo

AI总结 本文通过最小准则集的新刻画,证明在完全实代数数域上,二次型表示所有完全正整数的有限准则集总是存在且唯一,并推广到给定整数子集的表示。

Comments 23 pages, to appear in Adv. Math

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AI中文摘要

类比Bhargava-Hanke的290-定理,准则集是给定完全实代数数域中完全正整数的有限子集$C$,使得如果一个二次型表示$C$的所有元素,则它必然表示所有完全正整数,即它是泛的。我们利用最小准则集的新刻画证明它们总是存在且唯一,并且必须包含某些显式元素。我们还将唯一性结果推广到给定整数子集的表示这一更一般的设定。

英文摘要

In analogy with the 290-Theorem of Bhargava-Hanke, a criterion set is a finite subset $C$ of the totally positive integers in a given totally real number field such that if a quadratic form represents all elements of $C$, then it necessarily represents all totally positive integers, i.e., is universal. We use a novel characterization of minimal criterion sets to show that they always exist and are unique, and that they must contain certain explicit elements. We also extend the uniqueness result to the more general setting of representations of a given subset of the integers.

2410.22416 2026-05-27 astro-ph.GA astro-ph.CO

ERGO-ML: A continuous organization of the X-ray galaxy cluster population in TNG-Cluster with contrastive learning

ERGO-ML: 基于对比学习的TNG-Cluster中X射线星系团群体的连续组织

Urmila Chadayammuri, Lukas Eisert, Annalisa Pillepich, Katrin Lehle, Mohammadreza Ayromlou, Dylan Nelson

AI总结 利用最近邻对比学习(NNCLR)从TNG-Cluster模拟的X射线图像中提取低维表示,揭示了星系团从松弛到合并、从中心峰值到平坦发射的连续分布,并能预测多种物理性质。

Comments Please see more results from TNG-Cluster on astro-ph this week from Rohr+ and Prunier+

Journal ref Mon Not R Astron Soc (2026)

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AI中文摘要

星系团内介质(ICM)的物理性质反映了底层引力势、并合及与其他晕和卫星星系的强相互作用,以及超新星和超大质量黑洞(SMBH)的星系反馈的印记。传统上,星系团通过汇总统计量(如晕质量、X射线光度、冷核状态、AGN光度和并合成分数量)来表征。在本文(ERGO-ML系列)中,我们转而考虑ICM的X射线发射图中可用的完整信息内容。我们采用最近邻对比学习(NNCLR)来识别并填充此类图像的低维表示空间。利用TNG-Cluster宇宙磁流体动力学模拟套件中352个星系团的理想化X射线图,我们在红移范围$0\leq z<1$内的八个快照中取每个星系团的三个正交投影,得到约8000张图像的数据集。我们的发现表明,这个表示空间形成了从松弛到并合天体、从中心峰值到平坦发射轮廓的连续分布。该表示还显示出与红移、晕质量、气体质量、恒星质量、SMBH质量、自上次主要并合以来的时间以及动力学状态指标的清晰趋势。我们证明,一个8维表示可用于预测多种星系团性质、寻找相似体以及识别物理性质之间的相关性,从而暗示因果关系。我们的分析表明,对比学习是仅从图像表征星系团的强大工具,使我们能够利用宇宙流体动力学星系模拟推导出其物理性质和形成历史的约束。

英文摘要

The physical properties of the intracluster medium (ICM) reflect signatures of the underlying gravitational potential, mergers and strong interactions with other halos and satellite galaxies, as well as galactic feedback from supernovae and supermassive black holes (SMBHs). Traditionally, clusters have been characterized in terms of summary statistics, such as halo mass, X-ray luminosity, cool-core state, luminosity of AGN, and number of merging components. In this paper of the Extracting Reality from Galaxy Observables with Machine Learning series (ERGO-ML), we instead consider the full information content available in maps of X-ray emission from the ICM. We employ Nearest Neighbour Contrastive Learning (NNCLR) to identify and populate a low-dimensional representation space of such images. Using idealized X-ray maps of the 352 clusters of the TNG-Cluster cosmological magnetohydrodynamical simulation suite, we take three orthogonal projections of each cluster at eight snapshots within the redshift range $0\leq z<1$, resulting in a dataset of $\sim$8,000 images. Our findings reveal that this representation space forms a continuous distribution from relaxed to merging objects, and from centrally-peaked to flat emission profiles. The representation also exhibits clear trends with redshift, with halo, gas, stellar, and SMBH mass, with time since a last major merger, and with indicators of dynamical state. We show that an 8-dimensional representation can be used to predict a variety of cluster properties, find analogs, and identify correlations between physical properties, thereby suggesting causal relationships. Our analysis demonstrates that contrastive learning is a powerful tool for characterizing galaxy clusters from their images alone, allowing us to derive constraints on their physical properties and formation histories using cosmological hydrodynamical galaxy simulations.

2402.17617 2026-05-27 eess.IV

Quantifying the Resolution of a Template after Image Registration

图像配准后模板分辨率的量化

Matthias Glock, Thomas Hotz

AI总结 提出首个模板分辨率度量(TRM),通过确定使配准图像一致所需平滑量来量化模板各位置的空间未对齐程度,并增强模板可视化。

Comments This is a post-peer-review, pre-copyedit version of an article published in Pattern Analysis and Applications. The final authenticated version is available online at: https://doi.org/10.1007/s10044-026-01652-9

Journal ref Pattern Anal Applic 29, 87 (2026)

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AI中文摘要

在许多图像处理应用(例如计算解剖学)中,对图像样本进行组配准并同时生成模板图像。仅从模板通常不清楚配准后的图像在空间上仍有多大程度的未对齐。配准后留下的局部空间变化可视为所得模板的分辨率。在此意义上,我们开发了第一个模板分辨率度量(TRM),用于量化模板每个位置处的未对齐程度。TRM基于关键洞察:此类未对齐的大小可确定为使配准图像一致所需的平滑量。该关系从一维特征示例中数学推导得出。这样,TRM以模板的长度单位量化剩余的空间变化。此外,我们建议通过有效可视化其分辨率度量来增强模板。最后,我们展示了TRM的适用性,并验证了其在二维和三维示例数据集上的可解释性。相应代码已在GitHub上公开。

英文摘要

In many image processing applications (e.g. computational anatomy) a groupwise registration is performed on a sample of images and a template image is simultaneously generated. From the template alone it is in general unclear to which extent the registered images are still spatially misaligned. The local spatial variation left after registration may be seen as the resolution of the resulting template. In this sense we develop the first template resolution measure (TRM) quantifying the misalignment at each location of the template. The TRM is based on the key insight that the size of such misalignments can be determined as the amount of smoothing required to bring the registered images in agreement. This relationship is mathematically derived from characteristic examples in one dimension. This way, the TRM quantifies the remaining spatial variation in the template's units of length. Furthermore we propose to enhance the template by an effective visualization of its resolution measure. Finally we demonstrate the TRM's applicability and validate its interpretability for example datasets in two and three dimensions. The corresponding code is publicly available on GitHub.

2409.02643 2026-05-27 math.DG

On the Focal Locus of Submanifolds of a Finsler Manifold

关于Finsler流形中子流形的焦点轨迹

Aritra Bhowmick, Sachchidanand Prasad

AI总结 本文研究正向完备Finsler流形中闭子流形的焦点轨迹,证明法指数映射在F.W. Warner意义下是正则的,并利用正则焦点轨迹的连通分量识别出开稠密集,使得焦点时间映射光滑,最后将切共轭轨迹表示为分离切共轭点的闭包。

Comments 38 Pages. Final version. Comments are welcome!

Journal ref J. Geom. Anal. (2026), Vol 36 (3), No. 117, Pg. 46

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AI中文摘要

本文研究了正向完备Finsler流形中闭(不一定紧)子流形的焦点轨迹。主要目标是证明相关的法指数映射在F.W. Warner(Am. J. of Math., 87, 1965)意义下是\emph{正则的}。作为推论,我们证明了法指数映射在任意切焦点附近是非单射的。扩展Warner的思想,我们研究了正则焦点轨迹的连通分量。这使我们能够识别出一个开稠密集,在该集合上焦点时间映射是光滑的,只要它们是有限的。我们显式计算了可微点处的导数。作为法指数映射局部形式的一个应用,遵循R.L. Bishop的工作(Proc. Amer. Math. Soc., 65, 1977),我们将切共轭轨迹表示为某个点集(称为分离切共轭点)的闭包。这加强了本文作者先前工作(J. Geom. Anal., 34, 2024)的结果。

英文摘要

In this article, we investigate the focal locus of closed (not necessarily compact) submanifolds in a forward complete Finsler manifold. The main goal is to show that the associated normal exponential map is \emph{regular} in the sense of F.W. Warner (Am. J. of Math., 87, 1965). As a consequence, we show that the normal exponential is non-injective near any tangent focal point. Extending the ideas of Warner, we study the connected components of the regular focal locus. This allows us to identify an open and dense subset, on which the focal time maps are smooth, provided they are finite. We explicitly compute the derivative at a point of differentiability. As an application of the local form of the normal exponential map, following R.L. Bishop's work (Proc. Amer. Math. Soc., 65, 1977), we express the tangent cut locus as the closure of a certain set of points, called the separating tangent cut points. This strengthens the results from the present authors' previous work (J. Geom. Anal., 34, 2024).

2409.18019 2026-05-27 math.AG

Injectivity and Vanishing for the Du Bois Complexes of Isolated Singularities

孤立奇点的 Du Bois 复形的单射性与消没性

Mihnea Popa, Wanchun Shen, Anh Duc Vo

AI总结 本文证明了具有孤立奇点的簇的 Du Bois 复形上同调的单射定理,并推导出更高阶 Du Bois 复形上同调的消没性,同时讨论了非孤立情形下的推广、猜想以及交复形的类似结果。

Comments 26 pages; small corrections and additions made

Journal ref Alg. Number Th. 20 (2026) 1235-1262

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AI中文摘要

我们证明了具有孤立奇点的簇的 Du Bois 复形上同调的单射定理。利用该定理,我们推导出此类簇的更高阶 Du Bois 复形上同调的消没性。除了非孤立情形下的一些推广和猜想外,我们还提供了交复形的类似结果。

英文摘要

We prove an injectivity theorem for the cohomology of the Du Bois complexes of varieties with isolated singularities. We use this to deduce vanishing statements for the cohomologies of higher Du Bois complexes of such varieties. Besides some extensions and conjectures in the non-isolated case, we also provide analogues for intersection complexes.

1908.10681 2026-05-27 gr-qc

A Treatise on Differential Geometry and its role in Relativity Theory

微分几何及其在相对论中的作用专论

Subenoy Chakraborty

AI总结 本文作为讲义,旨在通过几何直观方式介绍现代微分几何术语,并展示其在相对论中的广泛应用。

Comments 307 pages and many figures; A lecture note for Graduate and Post Graduate students; comments are welcome

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AI中文摘要

本讲义希望对理论物理和应用数学的本科生、研究生或博士生有所帮助。书中以几何或图像思维的方式讨论了现代微分几何术语。本讲义致力于教授微分几何,并展示其在相对论中的广泛适用性。其中的问题可能对学生有用。

英文摘要

This lecture note is hopefully helpful to undergraduate and postgraduate students or beginning Ph.D students both in theoretical physics and in applied mathematics. Modern terminology in differential geometry has been discussed in the book with the motivation of geometrical or pictorial way of thinking. This note is an effort of teaching differential geometry and shows its wide applicability to relativity theory. The problems in this lecture note may be useful to the students

2410.02648 2026-05-27 math.QA hep-th math-ph math.MP

Convergence and operadic compatibility of bulk and boundary OPEs in two-dimensional conformal field theory

二维共形场论中体与边界OPE的收敛性和Operadic相容性

Yuto Moriwaki

AI总结 本文证明了具有局部C1-共有限手征对称性的二维共形场论中迭代体与边界算子乘积展开的收敛性和相容性,通过括号置换-辫子Operad在顶点算子代数C1-共有限模范畴上的作用,给出了配置空间上的单值实解析相关函数。

Comments 54 pages, v2: revised title, abstract, and introduction; corrected typos

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AI中文摘要

我们证明了具有局部$C_1$-共有限手征对称性的二维共形场论中迭代体与边界算子乘积展开(OPE)的收敛性和相容性。对于每棵树,我们给出了相应迭代OPE的显式收敛域。这些局部展开粘合为配置空间上的单值实解析函数,即理论的相关函数。证明使用了括号置换-辫子Operad在顶点算子代数的$C_1$-共有限模范畴上的作用。该Operad模拟了二维瑞士奶酪Operad的基本群胚,在此作用下,Operadic生成元对应于边界CFT的亏格零自举方程。

英文摘要

We prove convergence and compatibility of iterated bulk and boundary operator product expansions (OPEs) in two-dimensional conformal field theory with locally $C_1$-cofinite chiral symmetry. For each tree, we give an explicit domain of convergence for the corresponding iterated OPE. These local expansions glue to single-valued real analytic functions on the configuration spaces, which are the correlation functions of the theory. The proof uses an action of the parenthesized permutation-braid operad on $C_1$-cofinite module categories of a vertex operator algebra. This operad models the fundamental groupoid of the two-dimensional Swiss-cheese operad, and under this action the operadic generators correspond to the genus-zero bootstrap equations of boundary CFT.

2409.13207 2026-05-27 nucl-th hep-ph

Theoretical study of the $Ξα$ correlation function

$Ξα$ 关联函数的理论研究

Yuki Kamiya, Asanosuke Jinno, Tetsuo Hyodo, Akira Ohnishi

AI总结 通过高能核碰撞中 $Ξ$-$^4{\mathrm{He}}$ ($α$) 动量关联函数的研究,利用基于格点 QCD $ΞN$ 相互作用的折叠 $Ξα$ 势,探讨 $ΞN$ 相互作用的性质,发现关联函数对 $Ξα$ 相互作用中束缚态的存在及排斥芯敏感。

Comments 7 pages, 6 figures, published version

Journal ref Phys. Rev. C 113, 055205 (2026)

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AI中文摘要

我们研究高能核碰撞中的 $Ξ$-$^4{\mathrm{He}}$ ($α$) 动量关联函数,以探究 $ΞN$ 相互作用的性质。我们采用基于格点 QCD $ΞN$ 相互作用的折叠 $Ξα$ 势来计算关联函数。$Ξα$ 势在 $Ξ^-α$ 道中支持一个库仑辅助的束缚态 ${}^5_Ξ\mathrm{H}$,而 $Ξ^0α$ 道则无束缚。为了检验关联函数对 $Ξα$ 相互作用性质的敏感性,我们通过模拟更强和更弱的相互作用来改变势强度。关联函数的结果对 $Ξ^0 α$ 道中束缚态的存在敏感,并且束缚态的特征行为在带有库仑相互作用的 $Ξ^-α$ 关联中仍然存在。$Ξα$ 势排斥芯的影响可以在小源关联中体现为中间动量区域的显著凹陷。

英文摘要

We study $Ξ$-$^4{\mathrm{He}}$ ($α$) momentum correlation functions in the high-energy nuclear collisions to investigate the nature of the $ΞN$ interactions. We employ the folding $Ξα$ potential based on the lattice QCD $ΞN$ interactions to compute the correlation function. The $Ξα$ potential supports a Coulomb-assisted bound state ${}^5_Ξ\mathrm{H}$ in the $Ξ^-α$ channel, while the $Ξ^0α$ channel is unbound. To examine the sensitivity of the correlation function to the nature of the $Ξα$ interaction, we vary the potential strength simulating stronger and weaker interactions. The result of the correlation function is sensitive to the existence of the bound state in the $Ξ^0 α$ channel, and the characteristic behavior of the bound state remains also in the $Ξ^-α$ correlation with the Coulomb interaction. The effect of the repulsive core of the $Ξα$ potential can be found in the correlation from the small source as the distinctive dip in the intermediate momentum region.

2409.18076 2026-05-27 math.DG gr-qc math.AP

On the existence and properties of solutions of the generalized Jang equation with respect to asymptotically anti-de Sitter initial data

关于渐近反德西特初始数据的广义Jang方程解的存在性与性质

Benjamin Meco

AI总结 在$3\leq n\leq 7$维反德西特时空的恒定时间切片上,针对一类非常一般的渐近行为,严格分析了广义Jang方程,并讨论了其在渐近反德西特初始数据集时空正质量定理中的潜在应用。

Comments 43 pages

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AI中文摘要

我们提供了在渐近反德西特背景下广义Jang方程的严格分析,该背景建模于$3\leq n\leq 7$维反德西特时空的恒定时间切片上,适用于一类非常一般的渐近行为。讨论了其在渐近反德西特初始数据集时空正质量定理中的潜在应用。

英文摘要

We provide a rigorous analysis of the generalized Jang equation in the asymptotically anti-de Sitter setting modelled on constant time slices of anti-de Sitter spacetimes in dimensions $3\leq n \leq 7$ for a very general class of asymptotics. Potential applications to spacetime positive mass theorems for asymptotically anti-de Sitter initial data sets are discussed.

2407.13204 2026-05-27 econ.GN q-fin.EC

The Pay and Non-Pay Content of Job Ads

招聘广告中的薪酬与非薪酬内容

Richard Audoly, Manudeep Bhuller, Tore Adam Reiremo

AI总结 通过挪威雇主的招聘广告数据,开发系统分类方法,验证广告中薪酬与非薪酬属性对雇主质量的信号作用,并量化其对劳动力市场不平等的影响。

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AI中文摘要

招聘广告对雇主实际提供的薪酬和非薪酬属性的信息量有多大?利用挪威雇主发布的招聘广告综合数据库,我们开发了一种系统分类方法,对空缺文本中广告的薪酬和非薪酬工作属性进行分类。约60%的招聘广告提供薪酬相关信息,几乎所有广告都包含非薪酬属性信息。我们将这些广告属性与发布广告的雇主联系起来,并针对雇主质量的显示性偏好度量、实现属性以及调查实验中的选择来验证这些信息。所有三种策略都证实,招聘广告提供了雇主质量的可靠信号。然后,我们将详细的工作属性纳入一个垄断框架,并量化它们对劳动力市场不平等的贡献。

英文摘要

How informative are job ads about the actual pay and non-pay attributes offered by employers? Using a comprehensive database of job ads posted by Norwegian employers, we develop a methodology to systematically classify the pay and non-pay job attributes advertised in vacancy texts. About 60% of job ads provide pay-related information and nearly all ads feature information on non-pay attributes. We link these advertised attributes to the employers posting the ads and validate this information against revealed-preference measures of employer quality, realized attributes, and choices from a survey experiment. All three strategies confirm that job ads provide reliable signals of employer quality. We then incorporate the detailed job attributes in a monopsony framework and quantify their contribution to labor market inequality.