arXivDaily arXiv每日学术速递 周一至周五更新
重置
全部学科分类 2029
2606.05991 2026-06-05 q-fin.GN econ.EM

Forecasting of volatility and risk premia in electricity markets

电力市场波动率与风险溢价的预测

Thomas K. Kloster, Fred Espen Benth

AI总结 研究电力市场已实现协方差的预测,通过构建简约矩阵HAR模型,发现纳入更长的时间跨度和可再生能源发电信息能显著提升预测能力,并利用方差预测改进远期市场价差风险溢价的预测。

详情
AI中文摘要

我们研究电力市场中已实现协方差的预测。在此背景下,已实现协方差是潜在无限维协方差算子的矩阵值表示,并构建了一个简约的矩阵HAR型模型以方便估计。我们在周度已实现协方差的一周前预测上测试该模型,发现纳入更长的时间跨度和可再生能源发电信息增加了重要的预测能力。我们还研究了电力远期市场中风险溢价的预测,发现与依赖回溯波动率的传统方法相比,我们的方差预测显著改进了价差风险溢价的预测。

英文摘要

We study forecasting of the realized covariation in electricity markets. The realized covariation in this context is a matrix-valued representation of the latent infinite-dimensional covariance operator and a parsimonious matrix-HAR type model is constructed to facilitate estimation. We test the model on one-week ahead forecasts of the weekly realized covariation and find that the inclusion of longer time horizons and renewable generation information adds important predictive power. We also investigate the prediction of risk premia in electricity forward markets and find that our variance forecasts provide substantially improved forecasts of spread risk premia compared to standard methods relying on backward looking volatility.

2606.05990 2026-06-05 math.AP

A Pohozaev-type neck proof of a conditional Harnack inequality in the critical $p$-Laplacian setting

临界 $p$-Laplace 设定中条件 Harnack 不等式的 Pohozaev 型颈部证明

Guolin Qin, Yi Ru-Ya Zhang

AI总结 通过 Pohozaev 颈部论证,在全局临界 Sobolev 增长和单调性条件下,将归一化颈部的初步奇异衰减率提升至尖锐的 $p$-调和基本速率,从而证明正弱解的 Schoen 型条件 Harnack 不等式。

Comments 26 pages

详情
AI中文摘要

我们证明了临界 $p$-Laplace 方程 $$ -\Delta_p u=g(u),\qquad 1<p<n, $$ 的正弱解在全局临界 Sobolev 增长假设和单调性条件 $s^{-(p^*-1)}g(s)$ 非增下的一个条件 Schoen 型 Harnack 不等式。该结果依赖于两个输入:有界正整体爆破解的分类为 Aubin--Talenti $p$-气泡,以及归一化颈部的初步奇异速率上界控制。在这两个假设下,$B_{3R}$ 中的解满足 $$ \Big(\sup_{B_R}u\Big)\Big(\inf_{B_{2R}}u\Big)^{p-1} \le C R^{p-n}. $$ 主要点在于一个 Pohozaev 颈部论证,它将初步奇异衰减率 $|x|^{-(n-p)/p}$ 提升至尖锐的 $p$-调和基本速率 $|x|^{-(n-p)/(p-1)}$。该论证替代了在共形不变半线性情形 $p=2$ 中可用但对于一般 $p$-Laplace 不可用的 Kelvin 变换和移动球面方法。

英文摘要

We prove a conditional Schoen-type Harnack inequality for positive weak solutions of the critical $p$-Laplace equation $$ -Δ_p u=g(u),\qquad 1<p<n, $$ under a global critical Sobolev growth assumption and the monotonicity condition that $s^{-(p^*-1)}g(s)$ is nonincreasing. The result is conditional on two inputs, the classification of bounded positive entire blow-up limits as Aubin--Talenti $p$-bubbles and a preliminary singular-rate upper control on the normalized necks. Under these two hypotheses, solutions in $B_{3R}$ satisfy $$ \Big(\sup_{B_R}u\Big)\Big(\inf_{B_{2R}}u\Big)^{p-1} \le C R^{p-n}. $$ The main point is a Pohozaev-neck argument which upgrades the preliminary singular decay rate $|x|^{-(n-p)/p}$ to the sharp $p$-harmonic fundamental rate $|x|^{-(n-p)/(p-1)}$. The argument replaces the Kelvin-transform and moving-sphere methods available in the conformally invariant semilinear case $p=2$, but unavailable for the general $p$-Laplacian.

2606.05987 2026-06-05 physics.optics physics.atom-ph

Laser fractional frequency instability at $\mathbf{4\times 10^{-17}}$ with a room temperature optical reference cavity

室温光学参考腔的激光分数频率不稳定性达到 $4\times 10^{-17}$

Adam L. Parke, Eve Clulow, Wei Huang, Namneet Kaur, Reinhard Karembera, Jacques-Olivier Gaudron, Xi Zhang, Matias Risaro, Jacob Tunesi, Henry Bourne, Marco Schioppo

AI总结 本文利用68厘米长的室温光学参考腔,实现了激光分数频率不稳定性为$4\times10^{-17}$、线宽为12 mHz,创下室温系统的最佳记录。

Comments Copyright 2026 Optica Publishing Group. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved

详情
AI中文摘要

超稳激光在光学频率计量中起着关键作用,它决定了测量速度,并最终影响光学频率标准的稳定性和准确性。本文利用一个在室温下工作的68厘米长光学参考腔,展示了激光分数频率不稳定性达到$4\times10^{-17}$,激光频率线宽为12 mHz(半高全宽)。据我们所知,该频率不稳定性和线宽是室温系统有报道以来的最低值。这项工作突显了在室温下实现最先进的频率稳定性和光谱纯度的可能性,使其能够被更广泛的用户所使用。

英文摘要

Ultrastable lasers play a key role in optical frequency metrology, setting measurement speed and ultimately impacting both stability and accuracy of optical frequency standards. Here we demonstrate laser fractional frequency instability at ${4}\times10^{-17}$ and laser frequency linewidth of $12\,$mHz full width at half maximum, employing a 68 cm long optical reference cavity operating at room temperature. To the best of our knowledge, both frequency instability and linewidth are the lowest ever reported for a room temperature system. This work highlights that state-of-the-art frequency stability and spectral purity are achievable at room temperature, making them accessible to a broader range of users.

2606.05984 2026-06-05 physics.bio-ph

Emergent swimming strategies of a smart three-bead swimmer

智能三珠游泳者的涌现游泳策略

Ruma Maity, Maximilian Huebl, Julian Lemmel, Benedikt Hartl, Gerhard Kahl

AI总结 通过强化学习训练一个简单的三珠模型微游泳者,发现了五种特征游泳步态,其中三种可实现高效定向运动,两种为旋转低效运动,且这些步态可由极简神经网络实现。

详情
AI中文摘要

低雷诺数微游泳者因其在生物学中的普遍性以及在生物技术和医学中的应用而近来引起了广泛兴趣。然而,人工微游泳者设计和部署的一个关键障碍在于其自主性:要在任何真实场景中成功执行任务,这些游泳者需要能够无需外部控制地与周围环境互动并适应环境。在此,我们训练了一个简单的二维模型微游泳者(由三个珠子组成),通过强化学习学习自主游泳策略,重点使用神经进化技术来推导具有最小复杂性的控制器架构。我们识别出五种不同的特征游泳步态:其中三种步态导致定向运动,效率各异;两种步态导致旋转、低效运动。值得注意的是,所有这些步态都可以由非常简单的神经网络(少于十个节点和权重)实现,表明低雷诺数游泳可以在仅需最小计算能力的情况下高效且鲁棒地实现。这些结果对人工微游泳者的实验设计特别有意义,并可能对建模如莱茵衣藻等生物微生物具有启示。

英文摘要

Low-Reynolds-number microswimmers have recently attracted much interest for their ubiquity in biology and their applications in biotechnology and medicine. However, a key obstacle for the design and deployment of artificial microswimmers lies in their autonomy: to successfully perform tasks in any real-world scenario, these swimmers need to be able to interact with and adapt to their environment without external control. Here, we train a simple two-dimensional model microswimmer (consisting of three-bead) to learn autonomous swimming strategies via Reinforcement Learning, focusing on neuroevolution techniques to derive controller architectures with minimal complexity. We identify five different, characteristic swimming gaits: three of these gaits lead to directed locomotion with varying grades of efficiency and two gaits result in a rotational, inefficient movement. Remarkably, all of these gaits can be achieved by very simple neural networks (with less than ten nodes and weights), showing that low-Reynolds-number swimming can be achieved efficiently and robustly while requiring only minimal computational power. These results are of particular interest to the experimental design of artificial microswimmers and may have implications for modeling biological microorganisms such as Chlamydomonas reinhardtii.

2606.05982 2026-06-05 cs.NE math.AP math.PR

Quantifying Uncertainty In Wide Two-Layer Neural Networks: On The Law Of The Limiting Fluctuation Process

宽两层神经网络中的不确定性量化:关于极限波动过程的律

Arnaud Descours, Arnaud Guillin, Geoffrey Lacour, Manon Michel, Boris Nectoux, Paul Stos

AI总结 通过随机梯度下降训练的宽两层神经网络的预测不确定性,利用偏微分方程信息直接评估渐近方差,推导出极限波动过程为加权Sobolev空间对偶中的中心高斯过程,并给出协方差闭合表示。

详情
AI中文摘要

神经网络预测中的不确定性量化是实际应用中的一个主要问题。我们的方法旨在通过直接使用偏微分方程关于渐近方差的信息来评估不确定性,从而降低计算成本,而不是采用深度集成方法(可视为预测的蒙特卡洛估计,需要训练多个网络)。因此,我们研究了描述在弱噪声机制下由随机梯度下降训练的宽两层神经网络平均场极限周围随机波动的极限过程的律。基于最近的轨迹中心极限定理(其中该极限被刻画为线性随机发展方程的弱解),我们明确地识别了其律。更准确地说,我们证明它是加权Sobolev空间对偶中的一个中心高斯过程,并推导了通过将其与光滑函数测试获得的有限维分布的闭合协方差表示。该协方差通过一个具有非局部源项的后向输运方程的解来表达,其系数由平均场轨迹驱动。因此,通过在固定输入处与激活函数测试,我们获得了相应网络输出波动的极限方差的表达式。我们在一维回归示例上数值验证了这一结果。

英文摘要

Uncertainty quantification in neural networks prediction is a main issue for usual applications. Our approach seeks at reducing computation costs by directly evaluating uncertainty using PDE's information on the asymptotic variance, rather than the deep ensemble method which may be seen as a Monte Carlo estimation of the prediction, requiring the training of multiple networks. We thus study the law of the limiting process describing the random fluctuations around the mean-field limit of wide two-layer neural networks trained by stochastic gradient descent in a weak-noise regime. Building on a recent trajectorial central limit theorem, in which this limit is characterized as the weak solution of a linear stochastic evolution equation, we identify its law explicitly. More precisely, we show that it is a centered Gaussian process in the dual of a weighted Sobolev space, and we derive a closed covariance representation for the finite-dimensional distributions obtained by testing it against smooth functions. This covariance is expressed through the solution of a backward transport equation with a nonlocal source term, whose coefficients are driven by the mean-field trajectory. As a consequence, by testing against the activation function at a fixed input, we obtain an expression for the limiting variance of the corresponding network-output fluctuations. We illustrate this result numerically on a one-dimensional regression example.

2606.05980 2026-06-05 q-bio.QM

On the Promises and Limits of Multi-omics Integration for Deconvolution: The HADACA3 Benchmark

多组学整合用于去卷积的承诺与局限:HADACA3 基准测试

Hugo Barbot, Elise Amblard, Nicolas Homberg, Lucie Lamothe, Morgane Térézol, Hadaca Consortium, Mira Ayadi, Aurélia Baurès, Yasmina Kermezli, Carl Herrmann, Sebastien Dejean, Lionel Spinelli, David Causeur, Florent Chuffart, Anaïs Baudot, Yuna Blum, Magali Richard

AI总结 本文通过社区驱动的 HADACA3 基准测试,评估多组学整合(DNA甲基化与RNA)在细胞类型去卷积中的表现,发现单独DNA甲基化平均性能最优,但多组学整合可在特定设置下提升最佳性能。

详情
AI中文摘要

理解复杂组织(如肿瘤)的细胞组成是生物学和医学中的一个关键挑战。一种常见方法称为去卷积,旨在从批量分子测量中估计细胞组成。随着多种类型分子数据的日益可用,通常认为结合数据源应能提高去卷积性能。在此,我们提出 HADACA3,一个社区驱动的基准测试,旨在评估这一假设。我们进行了为期四天的协作竞赛,随后进行了大规模计算基准测试,在九个具有匹配DNA甲基化(DNAm)和RNA谱的数据集上测试了超过25万个分析流程,涵盖了广泛的生物学和实验条件。我们的框架联合评估了预处理、特征选择、建模和整合策略的影响。我们发现,单独DNAm在数据集间实现了最高的中位性能,使其成为最稳定可靠的单一模态方法。然而,多组学整合策略可以在特定数据集和流程配置中定期实现更高的顶级性能。在测试的策略中,基于误差加权平均的后期整合提供了一个强大且可靠的基线,而非线性早期整合方法(如最优传输)在真实生物数据集上显示出有希望的结果。总体而言,我们的结果表明,多组学整合并未系统性地提高相对于单独DNAm的平均性能,但可以在特定设置中提高最佳情况下的性能。这突显了稳健性与峰值性能之间的权衡,并强调了将整合策略与数据的统计特性对齐的重要性。所有数据、代码和评估工具均公开可用,以支持可重复研究和未来方法开发。

英文摘要

Understanding the cellular composition of complex tissues, such as tumors, is a key challenge in biology and medicine. A common approach, known as deconvolution, aims to estimate the cellular composition from bulk molecular measurements. With the growing availability of multiple types of molecular data, it is often assumed that combining data sources should improve deconvolution performance. Here, we present HADACA3, a community-driven benchmark designed to evaluate this assumption. We conducted a four-day collaborative competition followed by a large-scale computational benchmark, testing more than 250,000 analysis pipelines across nine datasets with matched DNA methylation (DNAm) and RNA profiles, representing a wide range of biological and experimental conditions. Our framework jointly evaluates the impact of preprocessing, feature selection, modeling, and integration strategies. We find that DNAm alone achieves the highest median performance across datasets, making it the most stable and reliable single-modality approach. However, multi-omics integration strategies can regularly achieve higher top performance in specific datasets and pipeline configurations. Among the tested strategies, late integration based on error-weighted averaging provides a strong and reliable baseline, while non-linear early integration methods, such as optimal transport, show promising results on real biological datasets. Overall, our results show that multi-omics integration does not systematically improve average performance over DNAm alone, but can improve best-case performance in specific settings. This highlights a trade-off between robustness and peak performance, and emphasizes the importance of aligning integration strategies with the statistical properties of the data. All data, code, and evaluation tools are publicly available to support reproducible research and future method development.

2606.05978 2026-06-05 hep-th gr-qc

Lecture notes: Introduction to the Off-shell Double Copy Program

讲义:离壳双拷贝程序导论

Eric Lescano

AI总结 本文为研究生课程讲义,基于经典场论基础,系统介绍离壳单拷贝和双拷贝的现代框架,并探讨T-对偶不变框架下的重新诠释。

Comments 3 Lectures with Exercices (40 hours course at UBA)

详情
AI中文摘要

本讲义基于为离壳双拷贝现代框架的八节入门课程所准备的一系列讲座。该课程于2026年4月16日至5月4日在布宜诺斯艾利斯大学(UBA)举行。这些讲座面向博士生和硕士生,内容自包含,仅需经典场论的基础知识。主要目标是回顾规范理论和引力理论的基本概念,以探索单拷贝和双拷贝的离壳框架。在课程的最后部分,我们探讨了在T-对偶不变框架下重新诠释单拷贝和双拷贝的现代方法。

英文摘要

The present notes are based on a series of lectures prepared for an introductory eight-class course on the modern framework of the off-shell double copy. The course was held from April 16 to May 4, 2026, at Universidad de Buenos Aires (UBA). These lectures, aimed at PhD and master's students, are self-contained and require only a basic knowledge of classical field theory. The main goal is to review the fundamental concepts of gauge and gravitational theories in order to explore the off-shell frameworks of the single and double copy. In the final part of the course, we explore modern approaches to reinterpreting the single and double copy within T-duality-invariant frameworks.

2606.05977 2026-06-05 math.NA cs.NA

Direct reconstruction for acoustic inverse Born scattering

声学逆Born散射的直接重建

Nuutti Hyvönen, Lisa Schätzle

AI总结 针对二维Helmholtz方程的弱散射逆介质问题,提出基于三角Zernike分解的直接重建公式,将对比度展开系数表示为远场数据展开系数的显式函数,并通过前向代入求解解耦的三角系统,数值实验表明该方法在Born近似失效时仍有效。

详情
AI中文摘要

我们考虑二维Helmholtz方程的逆介质散射问题,即从相关远场数据或等价地远场算子的完整知识中恢复紧支撑可穿透二维散射体的任务。尽管该问题唯一可解,但它是严重不适定且非线性的。在弱散射条件下,Born近似给出了对比度与远场数据之间的线性化关系,从而克服了第二个困难。这种线性设置允许借鉴最近关于线性化电阻抗断层扫描的工作(该工作依赖于三角Zernike分解),推导出一个显式重建公式,将对比度的展开系数表示为远场数据展开系数的函数。通过适当选择展开函数,所得系统矩阵解耦为对比度中空间角频率的独立(无限)三角系统。因此,每个系统可以通过前向代入独立求解。我们的数值实验表明,这种方法结合适当的正则化方法,即使在Born近似之外的完全非线性远场数据下仍然有效。

英文摘要

We consider the inverse medium scattering problem for the Helmholtz equation in two dimensions, i.e., the task to recover a compactly supported penetrable two-dimensional scatterer from full knowledge of the associated far field data or, equivalently, the far field operator. Although this problem is uniquely solvable, it is severely ill-posed and nonlinear. In the regime of weak scattering, the Born approximation yields a linearized relation between the contrast and the far field data, thus overcoming the second difficulty. This linear setting allows to build on recent work on linearized electrical impedance tomography, which relies on triangular Zernike decompositions, to derive an explicit reconstruction formula that expresses the expansion coefficients of the contrast in terms of those of the far field data. By choosing the expansion functions appropriately, the resulting system matrix decouples into separate (infinite) triangular systems for the spatial angular frequencies in the contrast. Consequently, each of these systems can be solved independently by performing forward substitutions. Our numerical experiments indicate that this approach, combined with an adequate regularization method, remains effective even when applied to full nonlinear far field data beyond the Born regime.

2606.05974 2026-06-05 cond-mat.mtrl-sci physics.app-ph

The KNN rollercoaster: from bulk ceramics to phase engineered wafer-scale thin films

KNN 过山车:从块体陶瓷到相工程晶圆级薄膜

Giulia Pavese, Federico Orlando, Fabio Melzi, Walter Piazzi, Andrea Pescarolo, Federico Maspero, Marco Asa, Riccardo Gianola, Andrea Picco, Andrea Serafini, Kui Yao, Silvia Picozzi, Laura Castoldi, Miguel-Ángel Badillo-Ávila, Riccardo Bertacco

AI总结 本研究通过系统研究 Mn 掺杂 K1-xNaxNbO3 薄膜在 8 英寸晶圆上的生长,发现富钠成分(>70 at.%)可克服衬底约束,抑制焦绿石相和化学偏析,实现高取向 (001) 柱状生长,从而获得优异的铁电和压电性能,为 KNN 在微系统中的应用提供了明确路径。

Comments 27 pages, 5 figures

详情
AI中文摘要

自从钾钠铌酸盐(KNN)在近等摩尔块体陶瓷中展现出非凡的压电系数以来,其发展轨迹犹如过山车,由于热力学稳定性问题和较差的平面工艺兼容性,其在微电子领域的集成严重滞后。在本工作中,我们重新审视了针对集成在硅上的薄膜这一特定情况的块体衍生相图。通过系统研究在 8 英寸晶圆上生长的 Mn 掺杂 K1-xNaxNbO3 薄膜,我们证明了薄膜的最佳化学计量比与块体等摩尔标准存在根本性差异。需要富钠成分(>70 at.%)来克服衬底诱导的约束,有效抑制焦绿石相形成和化学相分离,同时促进具有完全 (001) 面外极性取向的致密柱状生长。因此,富钠薄膜展现出卓越的功能特性,剩余极化强度高达 14 μC cm-2,压电系数 d33f = 79 pm/V 和 e31f = 10 C/m2。在密度泛函理论模拟的支持下,我们将这种增强归因于稳定性的提高以及应变驱动的结构重取向,形成具有倾斜极化的低对称单斜相。通过重新定义晶圆级薄膜的相工程规则,我们的结果为 KNN 在微系统中的集成建立了清晰的路线。

英文摘要

Since the initial disclosure of the extraordinary piezoelectric coefficients of Potassium sodium niobate (KNN) in near-equimolar bulk ceramics, its development trajectory has resembled a rollercoaster, with its integration into microelectronics severely lagging due to thermodynamic stability issues and poor planar process compatibility. In this work, we revisit the bulk-derived phase diagram for the specific case of thin films integrated on silicon. By systematically investigating Mn-doped K1-xNaxNbO3 films grown on 8-inch wafers, we demonstrate that the optimal stoichiometry for thin films fundamentally diverges from the bulk equimolar standard. A Na-rich composition (> 70 at.%) is required to overcome substrate-induced constraints, effectively suppressing pyrochlore formation and chemical phase segregation while promoting dense columnar growth with a complete (001) out-of-plane polar orientation. Consequently, Na-rich films deliver outstanding functional properties, reaching remanent polarizations up to 14 uC cm-2, with piezoelectric coefficients of d33f= 79 pm/V and e31f = 10 C/m2. Supported by Density Functional Theory simulations, we correlate this enhancement with improved stability and a strain-driven structural reorientation toward a lower-symmetry monoclinic phase with tilted polarization. By redefining the phase engineering rules for wafer-scale thin films, our results establish a clear route toward KNN integration in microsystems.

2606.05973 2026-06-05 math-ph math.DS math.MP

Liouville-Preserving Hamiltonian Scattering on Finite Metric Graphs

有限度量图上的保Liouville哈密顿散射

Philip Hierhager

AI总结 研究在有限度量图上,通过在每个顶点指定能量保持的Borel同构,将边上的哈密顿动力学拼接成全局保测度流,并证明其保Liouville测度。

Comments Submitted to Journal of Mathematical Physics

详情
AI中文摘要

每条边上具有力学哈密顿量的度量图本身并不能通过分支顶点定义确定性的经典运动:能量守恒只固定了出射速度,而非出射边端。我们研究在补充了缺失的顶点数据后得到的确定性问题。在每条边$e$上,坐标为$q\in[0,\ell_e]$,哈密顿量为$H_e(q,p)=p^2/2+V_e(q)$,其中$V$在图上是连续的,在每条边上$C^2$光滑。在每个顶点,我们指定一个从入射非零边界余切向量到出射非零边界余切向量的能量保持的Borel同构。得到的相空间是可测商空间,它将每个入射边界余切向量与其指定的出射向量等同。在排除有限个能量水平$V(v)$后,边上的哈密顿方程和顶点法则拼接成一个全局的单参数双可测变换群。该群保持能量以及由边上Liouville测度$dq\,dp$诱导的商测度。证明中未使用商空间上的光滑辛结构;不变性源于通常的边上Liouville不变性、紧致正则能量窗口上的均匀无Zeno估计,以及由速度方向顶点置换保持的横向Liouville流$r\,dr$。如果顶点法则与动量反转相容,则商动力学是可逆的。在满足通常正则值条件的正则能量曲面上,诱导的时间参数化测度也是不变的。

英文摘要

A metric graph with a mechanical Hamiltonian on each edge does not, by itself, define a deterministic classical motion through a branching vertex: conservation of energy fixes only the outgoing speed, not the outgoing edge-end. We study the deterministic problem obtained after this missing vertex datum is supplied. On each edge $e$, with coordinate $q\in[0,\ell_e]$, the Hamiltonian is $H_e(q,p)=p^2/2+V_e(q)$, where $V$is continuous on the graph and $C^2$ on every edge. At each vertex we prescribe an energy-preserving Borel isomorphism from incoming to outgoing nonzero boundary covectors. The resulting phase space is the measurable quotient that identifies each incoming boundary covector with its prescribed outgoing one. After excluding the finitely many energy levels $V(v)$, the edgewise Hamilton equations and the vertex laws concatenate to a global one-parameter group of bimeasurable transformations. The group preserves energy and the quotient measure induced by the edgewise Liouville measures $dq\,dp$. The proof uses no smooth symplectic structure on the quotient; the invariance follows from ordinary edgewise Liouville invariance, a uniform no-Zeno estimate on compact regular energy windows, and preservation of the transverse Liouville flux $r\,dr$ by the speedwise vertex permutations. If the vertex laws are compatible with momentum reversal, then the quotient dynamics is reversible. On regular energy surfaces satisfying the usual regular-value condition, the induced time-parametrization measure is invariant as well.

2606.05971 2026-06-05 astro-ph.GA

The quenching time and timescale distribution of z~2 quiescent galaxies from precise colour distribution analysis

基于精确颜色分布分析的z~2静止星系的熄灭时间和时标分布

Vivienne Wild, Ho-Hin Leung, Adam Carnall, Maya Skarbinski

AI总结 利用模拟推断方法,通过分析z~2大质量星系的宽波段测光颜色分布,直接约束其形成时间、熄灭时间和熄灭时标的分布,发现熄灭时标中位数为182 Myr,完全静止所需中位时间约400 Myr。

Comments Submitted to OJA, comments welcome. Code will be made available on acceptance

详情
AI中文摘要

理解星系何时以及如何熄灭其恒星形成对于理解主导的物理过程至关重要。星系的光谱能量分布(SED)编码了其过去历史的显著信息:不同物理过程的相对重要性影响了星系群中SED形状的观测分布。我们采用基于模拟的推断(SBI)方法,通过1.7<z<2的宽波段测光颜色分布,直接约束z>~2大质量星系群中形成时间、熄灭时间和熄灭时标的分布。我们证明,一个简单的双幂律恒星形成历史分布能够准确拟合log10(M*/Msol)>10.3的星系的SED形状分布。我们测量得到静止星系比例为0.24±0.02,在大爆炸后2.5 Gyr(z<~2.6)时静止星系的数量密度迅速上升。为了实现精确的双峰颜色分布,星系必须快速熄灭:将熄灭时标定义为从峰值恒星形成率(SFR_peak)到0.5×SFR_peak的时间,熄灭时标分布的众数为97_{-25}^{+31} Myr,中位数为182±16 Myr,尾部延伸至~700 Myr。达到完全静止所需的中位时间约为400 Myr。与z>2处静止星系的直接数量密度测量相比,从化石记录推断出的近期快速熄灭表明,在z>3.5直接观测到的静止星系存在显著的再活跃和/或并合率。

英文摘要

Understanding when and how galaxies quench their star formation is crucial for understanding the dominant physical processes at play. The spectral energy distribution (SED) of galaxies encodes significant information on their past histories: the relative importance of different physical processes influences the observed distribution of SED shapes in the galaxy population. We use a simulation based inference (SBI) approach to directly constrain the distribution of formation times, quenching times and quenching timescales within the massive galaxy population at z >~ 2 from their broad band photometric colour distribution at 1.7<z<2. We demonstrate that a simple distribution of double power-law star formation histories accurately fits the distribution of SED shapes of galaxies with log10(M*/Msol)>10.3. We measure a quenched galaxy fraction of 0.24+/-0.02, with the number density of quenched galaxies rising rapidly 2.5Gyr after the Big Bang (z<~2.6). Galaxies must quench rapidly to achieve the precise bimodal colour distribution: defining the quenching timescale as the time from peak star formation rate (SFR_peak) -> 0.5xSFR_peak, the quenching timescale distribution has a mode at 97_{-25}^{+31}Myr, a median of 182+/-16Myr and a tail to ~700Myr. To achieve full quiescence takes a median time of ~400Myr. Comparing to direct number density measurements of quenched galaxies at z>2 the combination of recent and rapid quenching inferred from the fossil record suggests a substantial rejuvenation and/or merger rate for quenched galaxies observed directly at z>3.5.

2606.05969 2026-06-05 math.DG physics.class-ph

Minimal surfaces: A Lagrangian derivation of first and second variations

极小曲面:第一和第二变分的拉格朗日推导

Romain Lloria, Boris Kolev

AI总结 本文通过拉格朗日方法,利用拉回协变导数,严格推导了极小曲面的第一和第二变分,并证明所有切向变分为零。

详情
AI中文摘要

本文利用拉回协变导数的概念,建立了极小曲面变分计算的严格拉格朗日形式。特别地,通过几何论证表明所有切向变分为零,然后推导了第一和第二法向变分。

英文摘要

This article develops a rigorous Lagrangian formulation of variational calculus for minimal surfaces, using extensively the concept of pullback covariant derivative. It is shown, in particular, using a geometric argument that all tangential variations vanish. First and second normal variations are then derived.

2606.05968 2026-06-05 quant-ph

Shattering the Symmetry Trap in Fixed-Ansatz VQE: An Accelerated ADAPT-VQE Study of Three Pillar Molecules under Bravyi-Kitaev Mapping

打破固定拟设VQE中的对称性陷阱:Bravyi-Kitaev映射下三种支柱分子的加速ADAPT-VQE研究

Hermawan Kresno Dipojono

AI总结 针对固定拟设VQE在非局域Bravyi-Kitaev映射下出现的初始化瘫痪和零梯度陷阱,本文采用ADAPT-VQE框架,通过解析交换子梯度动态选择对称性破缺算子,并在三种分子(LiH、HF、H2O)的拉伸或非对称多参考构型下实现即时精确的全组态相互作用收敛。

Comments 8 pages, including raw algorithmic telemetry logs

详情
AI中文摘要

固定拟设变分量子本征求解器(VQE),例如单双激发幺正耦合簇(UCCSD)框架,在使用非局域Bravyi-Kitaev(BK)费米子到量子比特映射进行评估时,经常遭受严重的初始化瘫痪和零梯度陷阱。在这项工作中,我们系统地展示了自适应导数组装伪Trotter(ADAPT-VQE)框架如何在三种不同的电子和几何分子支柱:氢化锂($\text{LiH}$)、氟化氢($\text{HF}$)和水($\text{H}_2\text{O}$)在高度拉伸或不对称多参考构型下打破这些结构限制。虽然传统的UCCSD-VQE由于BK树结构固有的全局相位抵消,在零能量偏移($0.000000$~Ha)处完全平坦化,我们的动态ADAPT-VQE循环通过解析交换子梯度成功分离了主要的对称性破缺算子。为了绕过较大寄存器上密集矩阵指数化和奇异值分解的严重$\mathcal{O}(N^3)$计算瓶颈,我们实现了一个高度优化的、基于向量的泰勒级数展开状态演化引擎。我们的数值结果表明,加速的ADAPT-VQE框架在所有三个分子系统的第一个宏周期内实现了即时、精确的全组态相互作用(FCI)收敛,并在高达12量子比特的寄存器空间中保持绝对数值稳定性。这项研究为在近期局域架构上模拟强相关、高度极化的三原子化学环境建立了一条稳健、硬件高效的路径。

英文摘要

Fixed-ansatz Variational Quantum Eigensolvers (VQE), such as the Unitary Coupled Cluster with Singles and Doubles (UCCSD) framework, frequently suffer from severe initialization paralyzation and zero-gradient traps when evaluated using the non-local Bravyi-Kitaev (BK) fermion-to-qubit mapping. In this work, we systematically demonstrate how the Adaptive Derivative-Assembled Pseudo-Trotter (ADAPT-VQE) framework shatters these structural limitations across three distinct electronic and geometric molecular pillars: Lithium Hydride ($\text{LiH}$), Hydrogen Fluoride ($\text{HF}$), and Water ($\text{H}_2\text{O}$), under heavily stretched or asymmetric multi-reference configurations. While conventional UCCSD-VQE flatlines completely at a zero energy shift ($0.000000$~Ha) due to global phase cancellations inherent to the BK tree structures, our dynamic ADAPT-VQE loop successfully isolates the dominant symmetry-breaking operators using analytical commutator gradients. To bypass the severe $\mathcal{O}(N^3)$ computational bottlenecks of dense matrix exponentiation and Singular Value Decomposition on larger registers, we implement a highly optimized, vector-based Taylor series expansion state-evolution engine. Our numerical results show that the accelerated ADAPT-VQE framework achieves instant, exact Full Configuration Interaction (FCI) convergence within the very first macro-cycle across all three molecular systems, maintaining absolute numerical stability up to a 12-qubit register space. This study establishes a robust, hardware-efficient path for simulating strongly correlated, highly polarized triatomic chemical environments on near-term local architectures.

2606.05965 2026-06-05 math.QA math.RT

On strong identities of almost-canonically seminormed rings

关于几乎典范半赋范环的强恒等式

Xu Gao, Jianqi Liu

AI总结 本文研究几乎典范半赋范环的强恒等式条件,通过发展表示论(包括Zhu型代数、诱导模、理性条件、张量积兼容性和模式转移代数的端公式),将该条件刻画为正交展开、典范模投射性和Zhu型代数诱导的Morita型等价,并应用于顶点算子代数中节点曲线的光滑化。

Comments 65 pages

详情
AI中文摘要

我们研究了几乎典范半赋范环的强恒等式条件,这是一类拓扑分次环,包括顶点算子代数的包络代数。该条件在共形块的代数几何理论中被引入,用于控制节点曲线的光滑化。为了理解强恒等式的表示论意义,我们发展了几乎典范半赋范环的表示论,包括Zhu型代数、诱导模、理性条件、张量积兼容性以及模式转移代数的端公式。我们的主要结果用正交展开、典范模的投射性以及Zhu型代数诱导的Morita型等价刻画了强恒等式条件。作为应用,我们证明对于CFT型顶点算子代数,光滑化性质等价于Zhu代数诱导与容许模范畴的Morita型等价。因此,强恒等式条件识别了将代数光滑化扩展到半单情形之外的精确表示论障碍。我们进一步通过显式例子说明该理论,包括Weyl代数和几个强恒等式条件不成立的非有理顶点算子代数。

英文摘要

We investigate the strong identity condition (SIC) for almost-canonically seminormed rings, a class of topological graded rings that includes enveloping algebras of vertex operator algebras. This condition was introduced in the algebro-geometric theory of conformal blocks, where it governs the smoothing of nodal curves. To understand the representation-theoretic meaning of SIC, we develop the representation theory of almost-canonically seminormed rings, including Zhu-type algebras, induced modules, rationality conditions, tensor product compatibility, and an end formula for the mode transition algebra. Our main result characterizes the strong identity condition in terms of orthogonal expansions, projectivity of canonical modules, and Morita-type equivalences induced by Zhu-type algebras. As an application, we show that for vertex operator algebras of CFT type, the smoothing property is equivalent to the Zhu algebra inducing a Morita-type equivalence with the category of admissible modules. Consequently, the strong identity condition identifies the precise representation-theoretic obstruction to extending algebraic smoothing beyond the semisimple setting. We further illustrate the theory through explicit examples, including the Weyl algebra and several irrational vertex operator algebras where the strong identity condition fails.

2606.05963 2026-06-05 math.OC

Combining diffuse and sharp interface methods in shape optimisation

形状优化中扩散界面与尖锐界面方法的结合

Philip J. Herbert, Michael Hinze, Christian Kahle

AI总结 提出一种结合相场(扩散界面)和尖锐界面方法的形状优化数值策略,通过两阶段过程实现拓扑灵活性与界面精度的平衡。

详情
AI中文摘要

我们开发了一种基于相场和尖锐界面方法相结合的形状优化问题数值处理概念。一方面,相场方法非常适合数值确定所求区域的形状、尺寸和拓扑,但另一方面,它们在锐化出区域(例如应发展出角点)方面存在问题。然而,这正是我们小组开发的尖锐界面方法的优势所在,该方法在Lipschitz拓扑中提供形状更新。这导致了一个两阶段过程:首先使用相场方法确定优化形状,得到的区域作为尖锐界面形状优化方法的初始解。两种方法均采用有限元法离散化。尖锐方法的初始网格由最优相场解的有限元网格通过适当后处理的零水平集构造而成。我们详细描述了这一构造过程,并在来自文献和应用的若干测试问题上研究了方法的性能。

英文摘要

We develop a concept for the numerical treatment of shape optimization problems based on the combination of phase field and sharp interface methods. On the one hand, phase field methods are very well suited to numerically determine the shape, size and topology of a sought domain, but on the other hand they have problems to sharpen out domains where they e.g. should develop corners. However, this is the strength of a sharp-interface approach developed in our group, which provides shape updates in the Lipschitz topology. This leads to a two-stage process that first determines an optimized shape using the phase field method. The resulting domain is the starting solution for the sharp interface shape optimization method. Both methods are discretized with the finite element method. The starting mesh for the sharp method is constructed from the finite element mesh of the optimal phase field solution using its properly post processed zero-level set. We describe this construction process in detail and investigate the performance of our method on a selection of test problems from the literature and from applications.

2606.05962 2026-06-05 hep-ph

Search for heavy Majorana neutrinos at muon-proton colliders via lepton-number-violating signals

在缪子-质子对撞机上通过轻子数破坏信号寻找重Majorana中微子

Yao-Bei Liu

AI总结 提出在缪子-质子对撞机上利用轻子数破坏过程μ⁻p→jN→j(ℓ⁺W⁻)搜索重Majorana中微子的新策略,通过分析特征末态(一个带电轻子和三个分辨喷注或一个胖喷注)并考虑探测器效应,得到对混合参数|VℓN|²的排除界限,证明该策略在200-3000 GeV质量范围内灵敏度优于LHC等现有实验。

Comments 19 pages, 8 figures

详情
AI中文摘要

我们提出了一种基于轻子数破坏过程$μ^{-}p \to jN \to j(\ell^{+}W^{-})$的新搜索策略,用于在未来的缪子-质子($μp$)对撞机上寻找重Majorana中微子。该对撞机配备1 TeV缪子束和7 TeV质子束,质心能量约为5.3 TeV。对于质量在$200~\text{GeV} \lesssim m_N \lesssim 1000~\text{GeV}$范围内的重中微子,本分析针对衰变链$N \to \ell^{+}W^{-} \to \ell^{+}jj$,产生由单个带电轻子和三个良好分辨的喷注组成的特征末态。对于TeV量级的Majorana中微子,$W$玻色子被高度增强,其强子衰变产物合并成一个显著的胖喷注($J$)信号。我们进行了全面的信号和本底分析,考虑了真实的探测器效应,以评估搜索灵敏度。基于$100~\text{fb}^{-1}$和$1~\text{ab}^{-1}$两种典型积分亮度场景,我们推导了中微子混合参数$|V_{\ell N}|^2$的预期$2\sigma$排除界限。结果表明,所提出的搜索策略能够实现比LHC和其他高能对撞机现有界限显著优越的约束。本研究证明,未来的$μp$对撞机在质量范围$200~\text{GeV} \leq m_N \leq 3000~\text{GeV}$内探测重Majorana中微子具有竞争性灵敏度。

英文摘要

We propose a novel search strategy for heavy Majorana neutrinos based on the lepton-number-violating process $μ^{-}p \to jN \to j(\ell^{+}W^{-})$ at future muon-proton ($μp$) colliders equipped with 1 TeV muon beams and 7 TeV proton beams, yielding a center-of-mass energy of approximately 5.3 TeV. For heavy neutrinos with masses in the range $200~\text{GeV} \lesssim m_N \lesssim 1000~\text{GeV}$, this analysis targets the decay chain $N \to \ell^{+}W^{-} \to \ell^{+}jj$, producing a characteristic final state consisting of one charged lepton and three well-resolved jets. For TeV-scale Majorana neutrinos, the $W$ boson is highly boosted, such that its hadronic decay products coalesce into a prominent fat-jet ($J$) signature. We conduct comprehensive signal and background analyses that account for realistic detector effects to assess the search sensitivity. We derive the projected $2σ$ exclusion limits on the neutrino mixing parameter $|V_{\ell N}|^2$ based on two typical integrated luminosity scenarios of $100~\text{fb}^{-1}$ and $1~\text{ab}^{-1}$. The results demonstrate that the proposed search strategy can achieve constraints substantially superior to the existing bounds from the LHC and other high-energy colliders. This study demonstrates that future $μp$ colliders can provide competitive sensitivity for probing heavy Majorana neutrinos over the mass range $200~\text{GeV} \leq m_N \leq 3000~\text{GeV}$.

2606.05961 2026-06-05 cs.CY physics.soc-ph

Political Persuasion and Endorsement in Large Language Models

大型语言模型中的政治说服与支持

Alessia Antelmi, Alessia Galdeman, Lucio La Cava, Arianna Pera, Giovanni Da San Martino

AI总结 研究大型语言模型是否支持包含说服技巧的信息,以及党派角色提示如何调节这种支持,发现无政治条件时模型通常不支持,但党派提示加剧极化。

Comments 9 pages, 4 figures, 3 tables

详情
AI中文摘要

大型语言模型(LLMs)越来越多地被用作计算社会科学中人类行为的代理。然而,它们从训练数据中内化偏见的趋势引发了对其在政治敏感领域可靠性的担忧,特别是它们对说服性语言的敏感性。在这项工作中,我们考察了LLMs是否支持注入说服技巧的信息,以及党派角色提示是否调节这种支持。我们评估了来自不同地理区域的六个LLMs,这些模型基于来自真实世界媒体来源的、标注了说服技巧的内容,并使用五点李克特量表测量支持的可能性。模型被提示为中立社交媒体用户或具有左倾或右倾政治观点的用户。结果表明,在没有政治条件的情况下,LLMs通常不支持包含说服技巧的信息,尽管模型层面存在差异,而党派角色提示增加了支持的两极分化,特别是对于注入说服技巧的内容。支持进一步因说服技巧和主题而异。这些发现引发了对在政治敏感环境中部署代理型LLMs的担忧,并使其作为人类政治认知的可靠模拟器的使用复杂化。

英文摘要

Large Language Models (LLMs) are increasingly employed as proxies for human behavior in computational social science. However, their tendency to internalize biases from training data raises concerns about their reliability in politically sensitive domains, specifically in regard to their susceptibility to persuasive language. In this work, we examine whether LLMs endorse persuasion-infused messages and whether partisan persona prompting modulates such endorsement. We evaluate six LLMs from different geographic regions on content annotated with persuasion techniques drawn from real-world media sources, measuring the likelihood of endorsement using a five-point Likert scale. The models are prompted as either a neutral social media user or as a user with left- or right-leaning political views. Results show that without political conditioning, LLMs generally do not endorse messages containing persuasion techniques, though model-level differences emerge, and that partisan persona prompting increases polarization of endorsement, particularly for persuasion-infused content. Endorsement further varies by persuasion technique and topic. These findings raise concerns about agentic LLM deployments in politically sensitive environments and complicate their use as reliable simulators of human political cognition.

2606.05959 2026-06-05 astro-ph.IM gr-qc

Narrow spectral artifact investigation and mitigation in LIGO data from the fourth LIGO-Virgo-KAGRA observing run

第四次LIGO-Virgo-KAGRA观测运行中LIGO数据的窄谱伪影调查与缓解

E. Goetz, A. Neunzert, A. M. Knee, A. Calafat, X. Fan, J-R. Mérou, K. A. Pham, T. Starkman, N. Aggarwal, Z. Bhalla, P. Baxi, J. Bayley, Y. Bu, J. B. Carlin, P. Charlton, X. Chen, G. Cheng, T. Cheunchitra, N. Christensen, A. Claveus, C. M. Compton, M. W. Coughlin, F. De Lillo, L. Dunn, S. E. Dwyer, A. Effler, T. A. Ferreira, B Finkel, P. Goodarzi, A. E. Granados, H. Guo, C. Hsiung, K. Janssens, S. Kandhasamy, K. Kawabe, Y. -M. Kim, T. Kimpson, R. Krismer, M. Lalleman, Y. S. C. Lee, N. K. Y. Low, J. C. Martins, H. Middleton, C. -A. Miritescu, D. Nykamp, J. O'Leary, A. Renzini, K. Riles, A. Romero-Rodríguez, J. R. Sanders, R. M. S. Schofield, D. Singh, D. Singh, R. Slocum, Q. Song, J. Suresh, S. Suyamprakasam, J. D. Tasson, A. Tripathee, A. F. Vargas, A. Wang, K. Wu, J. Yee, J. Yi, Z. Zhang, O4 LIGO Detector authors

AI总结 本文针对LIGO探测器在第四次观测运行中的窄谱伪影,更新了软件工具并成功识别和缓解了多个窄带伪影,以提升引力波搜索效率。

Comments 37 pages, 15 figures

详情
AI中文摘要

我们介绍了在第四次LIGO-Virgo-KAGRA观测运行期间,识别、表征和缓解LIGO探测器数据中窄谱伪影的工作。引力波探测器中的窄谱伪影是非天体物理噪声源,会降低对窄带持续引力波的搜索效率。识别并尽可能缓解这些噪声源是LIGO探测器表征小组的核心工作之一。为便于调查和数据监测,第四次LIGO-Virgo-KAGRA观测运行更新了关键软件工具并部署了新工具。我们讨论了这些工具升级,并介绍了在LIGO数据中成功调查和缓解的几个已识别窄带伪影。无论伪影是否被缓解,窄带持续引力波搜索都需要知道哪些频段包含非天体物理伪影。最小化包含非天体物理伪影的频段数量对于最大化发现新类型引力波信号的可能性至关重要。

英文摘要

We present efforts to identify, characterize, and mitigate narrow spectral artifacts in LIGO detector data during the fourth LIGO-Virgo-KAGRA observing run. Narrow spectral artifacts in gravitational-wave detectors are non-astrophysical noise sources that can degrade searches for narrowband persistent gravitational waves. Identifying and, where possible, mitigating these noise sources is one of the core efforts of the LIGO Detector Characterization group. Key software tools have been updated and new tools deployed for the fourth LIGO-Virgo-KAGRA observing run to facilitate investigations and data monitoring. We discuss these tool upgrades, and present several identified narrowband artifacts that have been successfully investigated and mitigated in LIGO data. Regardless of whether artifacts are mitigated or not, narrowband persistent gravitational-wave searches require information on which frequency bands contain non-astrophysical artifacts. Minimizing the number of bands containing non-astrophysical artifacts is essential to maximize the potential for discovery of a new class of gravitational-wave signals.

2606.05955 2026-06-05 quant-ph

Magnetic flux as a quantized Lorentz pseudoscalar and its relation to electric charge quantization

磁通量作为量子化的洛伦兹赝标量及其与电荷量子化的关系

Cyril Belardinelli

AI总结 通过重新审视带电粒子在载流螺线管周围无场区域的运动,求解薛定谔方程得到磁通量与电荷的同时量子化条件,并证明该条件的洛伦兹不变性。

Comments 9 pages, 2 figures

详情
AI中文摘要

在本文中,我们重新审视了为什么电荷只以量子化形式存在的著名问题。在此背景下,我们重新考察了带电粒子在载流螺线管周围无场区域的运动。求解相应的薛定谔方程得到了磁通量和电荷的同时量子化条件。我们还通过证明磁通量在洛伦兹变换下表现为赝标量,展示了该条件的洛伦兹不变性。

英文摘要

In this paper, we re-examine the well-known question of why electric charges exist only in quantized portions. In this context, we revisit the motion of a charged particle in a field-free region around a current-carrying solenoid. Solving the corresponding Schrödinger equation leads to a simultaneous quantization condition for the magnetic flux and the electric charge. We also demonstrate the Lorentz invariance of this condition by showing that the magnetic flux behaves like a pseudoscalar under Lorentz transformations.

2606.05954 2026-06-05 physics.soc-ph cs.SI nlin.AO stat.ME

Network model selection: A review of methods

网络模型选择:方法综述

Zoran Levnajić

AI总结 本文系统综述了网络模型选择的方法,将方法按核心原理分为四类,并探讨了未来方向,旨在为开发统一最优方法奠定基础。

Comments This is an Accepted Manuscript version of the book: Zoran Levnajic, Network model selection: A review of methods, 2026, Springer. This version has been accepted for publication, but is not the Version of Record and does not reflect post-acceptance improvements (such as copyediting or typesetting), or any corrections. The final authenticated version is available online at ISBN 978-3-032-30448-3

详情
AI中文摘要

理解复杂网络演化背后的过程是网络科学的一个关键目标。应对这一挑战的有效框架是网络模型选择,即从一组候选模型中找到最能解释给定网络的模型。本书是对此目的方法的系统综述。每种方法分三部分概述:其核心原理(用于将方法分为四类)、其他相关细节(包括我自己的观察)以及软件可用性。本书全面概述了网络模型选择的最新进展,并探讨了未来方向。一种统一的最优方法可能比任何现有方法更精确地识别塑造现实网络的机制。这项工作代表了朝着开发这种最优方法迈出的第一步。它将成为网络科学学生和研究人员的宝贵资源。

英文摘要

Understanding the processes behind the evolution of complex networks is a key objective in network science. An effective framework for tackling this challenge is network model selection, which involves finding the model from a set of candidates that best explains a given network. This book is a systematic review of methods for this purpose. Each method is outlined in three parts: its core principle (used to organize methods into four categories), other relevant details including my own observations, and software availability. The book provides a comprehensive overview of the state-of-the-art in network model selection and concludes by exploring future directions. A unified, optimal method could identify the mechanisms that shape real-world networks more precisely than any current approach. This work represents the first step toward developing such an optimal method. It will be a valuable resource for students and researchers in network science.

2606.05951 2026-06-05 cs.DC

Demystifying NVSHMEM: A System-Level Analysis on Symmetric Memory and Device-Initiated Operations in GPU Communication

揭秘NVSHMEM:GPU通信中对称内存和设备发起操作的系统级分析

Yijun Ma, Siyuan Shen, Tiancheng Chen, Akhil Langer, Jiri Kraus, Benjamin Glick, Craig Belusar, Jeff Hammond, Torsten Hoefler

AI总结 本文系统分析了NVSHMEM的编程模型、实现和性能特征,聚焦对称内存、单边操作和设备端集合通信,并通过DeepEP案例研究展示了其在性能关键的稀疏深度学习工作负载中的应用,揭示了其作为系统构建块的作用和设计权衡。

详情
AI中文摘要

NVSHMEM是NVIDIA基于OpenSHMEM的PGAS通信库,用于GPU集群,通过对称内存实现GPU发起的单边通信。尽管其应用日益广泛,但其设计和行为的系统级理解仍分散在文档、源代码和应用经验中。本文对NVSHMEM的编程模型、实现和性能特征进行了简明研究,重点关注对称内存、单边操作和设备端集合通信。我们还以DeepEP为例,研究了NVSHMEM在性能关键的稀疏深度学习工作负载中的应用。我们的分析表明,NVSHMEM开创了一种设备端对称内存编程模型,支持细粒度的GPU驱动通信,对于接近硬件性能极限至关重要。总体而言,本文定义了NVSHMEM作为系统构建块的角色,突出了其设计权衡,并识别了改进GPU通信运行时的机会。

英文摘要

NVSHMEM is NVIDIA's OpenSHMEM-based PGAS communication library for GPU clusters, enabling GPU-initiated, one-sided communication through symmetric memory. Despite its growing adoption, a system-level understanding of its design and behavior remains scattered across documentation, source code, and application experience. This paper presents a concise study of NVSHMEM's programming model, implementation, and performance characteristics, focusing on symmetric memory, one-sided operations, and device-side collectives. We also examine DeepEP as a case study of NVSHMEM in performance-critical sparse deep learning workloads. Our analysis shows that NVSHMEM pioneered a device-side symmetric-memory programming model that enables fine-grained GPU-driven communication and is important for approaching the hardware performance limit. Overall, this work defines NVSHMEM's role as a systems building block, highlights its design tradeoffs, and identifies opportunities for improving GPU communication runtimes.

2606.05948 2026-06-05 physics.plasm-ph

Optimization of EUV output by experimentally validated radiation-hydrodynamic simulations across a broad laser parameter space

通过实验验证的辐射流体动力学模拟优化宽激光参数空间下的EUV输出

Nozomi Tanaka, Yu Yamamoto, Akira Sasaki, Katsunobu Nishihara, Atsushi Sunahara, Tomoyuki Johzaki, Yuji Takagi, Kentaro Tomita, Shinsuke Fujioka, Masashi Yoshimura

AI总结 使用辐射流体动力学代码STAR-1D对超过14万种参数组合进行网格搜索,揭示了激光波长对最佳脉冲宽度和目标尺寸的系统性依赖关系,预测了EUV转换效率的全局最大值,并为2微米驱动的EUV光源开发提供了指导。

Comments The following article has been submitted to/accepted by Applied Physics Letters. After it is published, it will be found at https://pubs.aip.org/aip/apl

详情
AI中文摘要

随着极紫外(EUV)光刻技术进入高容量半导体制造,提高插头效率和减小系统占地面积等实际需求变得越来越重要。这些需求促使开发固态中红外激光器作为当前CO2激光器的替代品。当改变驱动激光波长时,由于EUV转换效率(EUV-CE)以复杂方式依赖于激光参数,因此在宽参数空间内系统探索激光到EUV的转换效率至关重要。在这项工作中,我们使用经过EUV源实验验证的辐射流体动力学代码STAR-1D,对激光产生的锡等离子体EUV源进行了超过14万种参数组合的大规模网格搜索。最佳脉冲宽度和目标尺寸的系统性波长依赖性由同时实现EUV发射的最佳电子温度和密度、保持高效激光吸收以及抑制EUV自吸收的要求决定。得到的转换效率图预测在5.5 μm处全局最大值为5.63%。对于实际相关的2 μm固态驱动器,获得的最大转换效率为4.64%,与最近的实验结果吻合良好。在宽脉冲参数范围内确定了多个工作点,为2 μm驱动的EUV光源开发提供了指导。

英文摘要

Practical requirements such as improving wall-plug efficiency and reducing system footprint have become increasingly important with the introduction of extreme ultraviolet (EUV) lithography into high-volume semiconductor manufacturing. These demands motivate the development of solid-state mid-infrared lasers as alternatives to current CO2 lasers. Systematic exploration of laser-to-EUV conversion efficiency (EUV-CE) over a broad parameter space is essential when altering the drive laser's wavelength, because the EUV-CE depends on the laser parameters in a complex manner. In this work, we performed a large-scale grid search of more than 140,000 parameter combinations for laser-produced tin plasma EUV sources using the radiation-hydrodynamics code STAR-1D, which is validated against EUV source experiments. The systematic wavelength dependence of the optimum pulse width and target size is governed by the requirement to simultaneously achieve the electron temperature and density optimal for EUV emission, maintain efficient laser absorption, and suppress EUV self-absorption. The resulting CE map predicts a global maximum of 5.63% at 5.5 μm. For the practically relevant 2 μm solid-state driver, a maximum CE of 4.64% is obtained, in good agreement with recent experimental results. Multiple operating points are identified over a broad range of pulse parameters, providing guidance for 2 μm-driven EUV source development.

2606.05947 2026-06-05 quant-ph

Double-bracket quantum algorithms for thermal state preparation

用于热态制备的双括号量子算法

Andrew Wright, Reyhaneh Aghaei Saem, Supanut Thanasilp, Yudai Suzuki, Zoë Holmes

AI总结 提出利用双括号量子算法模拟热场双态以实现热态制备,包括两种变体,其复杂度在实用范围内随逆温度指数增长,并在量子玻尔兹曼机中展现优于变分虚时演化的性能。

详情
AI中文摘要

我们提出了通过模拟热场双态来制备热态的量子算法。关键思想是利用双括号量子算法在热场双态上实现虚时演化,其约化态实现吉布斯态。我们的方法称为双括号热场双态(DB-TFD),引入了两种变体。第一种是朴素DB-TFD算法,直接使用双括号量子虚时演化实现虚时演化。第二种是多项式DB-TFD,采用双括号量子信号处理通过多项式变换逼近虚时演化算子。我们证明,在广泛的实用范围内,多项式DB-TFD算法的复杂度随逆温度指数增长。这一缩放与现有方法一致,数值模拟支持相应的理论界限。我们进一步展示了DB-TFD在用于生成建模的量子玻尔兹曼机中的实用性,与变分虚时演化方法相比实现了改进的性能。这些结果确立了DB-TFD作为近期和早期容错体制下热态制备的有前途的途径。

英文摘要

We propose quantum algorithms for preparing thermal states via the simulation of the thermofield double states. The key idea is to leverage double-bracket quantum algorithms to implement imaginary-time evolution on thermofield double states, whose reduced state realizes the Gibbs state. Our method, termed double-bracket thermofield double (DB-TFD), introduces two variants. The first, the vanilla DB-TFD algorithm, directly implements imaginary-time evolution using double-bracket quantum imaginary-time evolution. The second, poly DB-TFD, employs double-bracket quantum signal processing to approximate the imaginary-time evolution operator via a polynomial transformation. We demonstrate that the complexity of the poly DB-TFD algorithm scales exponentially with the inverse temperature in a broad practical regime. This scaling is consistent with existing methods, and numerical simulations support the corresponding theoretical bound. We further demonstrate the utility of DB-TFD in quantum Boltzmann machines for generative modeling, achieving improved performance compared with variational imaginary-time evolution approaches. These results establish DB-TFD as a promising route for thermal state preparation in the near-term and early-fault-tolerant regimes.

2606.05945 2026-06-05 cs.CR

Exploring the connection between coding habits and cognitive styles in malware developers

探索恶意软件开发者编码习惯与认知风格之间的联系

Vasilis Vouvoutsis, Constantinos Patsakis, Fran Casino

AI总结 通过分析泄露的恶意软件源码与良性开源软件,应用静态安全测试和软件度量,基于认知心理学和犯罪学理论,揭示恶意软件开发者在代码结构、质量、漏洞模式上的独特行为特征,表明其开发风格优先考虑便捷性、操作保密性和规避性而非长期可维护性。

详情
AI中文摘要

恶意软件研究主要关注结果、方法和影响。即使从进攻性安全的角度来看,所考察的是方法,而非攻击者的开发策略。本研究调查了恶意软件源码中嵌入的行为特征和编码模式。通过分析大量泄露的恶意软件代码,并与精心挑选的良性开源软件进行比较,我们应用静态应用安全测试并计算多个软件度量。基于认知心理学和犯罪学理论,我们的工作将代码结构和质量的差异解释为行为指标,反映了恶意软件作者与良性软件开发者在动机结构、风险容忍度和开发策略上的不同。我们的发现表明,恶意软件代码通常更小、文档更少,每个函数的圈复杂度更高,并且较少使用类和闭包等抽象机制。漏洞分析进一步揭示,恶意软件表现出更多良性代码通常避免的问题类型,表明在安全开发实践上的投入极少。这些模式暗示了一种开发风格,优先考虑便捷性、操作保密性和规避性,而非长期可维护性。尽管如此,代码质量指标表明,它并未显著偏离良性软件到足以区分的地步。通过将代码度量作为行为信号和策略选择的代理,我们展示了定量软件分析如何丰富行为网络安全研究,为恶意软件开发者的实践和优先级提供新见解。我们的结果为网络犯罪者行为画像的进一步研究铺平了道路。

英文摘要

Malware research primarily studies the results, the methods, and the impact. Even from an offensive security perspective, what is examined is the method, not the development strategy of the offender. This study investigates the behavioral signatures and coding patterns embedded in the malware source code. By analyzing a large corpus of leaked malware code and comparing it with carefully selected benign open-source software, we apply static application security testing and compute multiple software metrics. Based on cognitive psychology and criminological theories, our work interprets differences in code structure and quality as behavioral indicators, reflecting distinct motivational structures, risk tolerances, and development strategies of malware authors compared to benign software developers. Our findings reveal that malware code is generally smaller, less documented, and exhibits higher cyclomatic complexity per function, with reduced use of abstraction mechanisms such as classes and closures. Vulnerability analysis further reveals that malware exhibits more issues of the types that benign code typically avoids, suggesting a minimal investment in secure development practices. These patterns imply a development style optimized for expedience, operational secrecy, and evasion rather than long-term maintainability. Nonetheless, the code quality metrics indicate that it does not deviate significantly from benign software enough to be distinctive. By framing code metrics as proxies for behavioral signals and strategic choices, we demonstrate how quantitative software analysis can enrich behavioral cybersecurity research, offering new insights into the practices and priorities of malware developers. Our results pave the way for further research in the behavioral profiling of cyber offenders.

2606.05944 2026-06-05 astro-ph.HE

Simulations of interaction between outflow and surrounding broken power-law circumnuclear medium: implications for different radio light curves of TDEs

外流与周围破碎幂律核周介质相互作用的模拟:对TDE不同射电光变曲线的启示

Xiangli Lei, Qingwen Wu, Chang Zhou, Wei-Hua Lei, Ya-Ping Li, Jiancheng Wu, Weibo Yang

AI总结 通过三维流体动力学模拟,研究外流与具有Bondi半径附近过渡的破碎幂律密度轮廓的核周介质相互作用,解释潮汐瓦解事件中不同射电光变曲线的起源。

Comments Submitted to ApJ

详情
AI中文摘要

潮汐瓦解事件(TDEs)复杂的射电光变曲线挑战了我们对超大质量黑洞周围外流和核周介质(CNM)性质的理解。在这项工作中,我们采用三维流体动力学模拟,在广泛的参数空间中探索外流-CNM相互作用,采用在Bondi半径附近具有过渡的破碎幂律CNM密度轮廓。Bondi半径内的外流-CNM相互作用在发射区域变得光学薄后产生早期射电耀发(≲2年)。如果外流在Bondi半径之外减速,几年后可能出现第二次射电再增亮。我们还发现,要么非常致密的内CNM(导致快速减速),要么稀薄的外CNM会抑制晚期再增亮,从而产生单一的早期峰值耀发。相反,Bondi半径内的稀薄CNM抑制早期耀发,产生单一的晚期峰值事件。对于大半径处非常致密的CNM,相互作用会触发尖锐的晚期上升,如在一些TDEs中观测到的那样。我们进一步探索了相对论性喷流与破碎幂律CNM的相互作用,这可以再现喷流TDEs中观测到的特征光变曲线,而无需调用复杂的喷流结构。

英文摘要

The complex radio light curves of tidal disruption events (TDEs) challenge our understanding of the properties of both the outflows and the circumnuclear medium (CNM) surrounding supermassive black holes. In this work, we explore outflow-CNM interactions across a broad parameter space using three-dimensional hydrodynamic simulations, adopting a broken power-law CNM density profile with a transition near the Bondi radius. The outflow-CNM interaction inside Bondi radius produces an early radio flare (\(\lesssim 2\) yr) once the emitting region becomes optically thin. A second radio rebrightening can appear a few years later if the outflow decelerates beyond Bondi radius. We also find that either a very dense inner CNM, which causes rapid deceleration, or a rarefied outer CNM suppresses the late rebrightening that will produces a single early-peaked flare. In contrast, a rarefied CNM inside the Bondi radius suppresses the early flare and yields a single late-peaked event. For the case of very dense CNM at large radii, the interaction will trigger a sharp late-time rise as observed in some TDEs. We further explore the interaction of a relativistic jet with a broken power-law CNM, which can reproduce the characteristic light curves as observed in jetted TDEs without invoking complex jet structure.

2606.05943 2026-06-05 math.FA

Antilinar Normal Operators on Hilbert Space

希尔伯特空间上的反线性正规算子

Konrad Schmüdgen

AI总结 研究稠定无界反线性算子,特别是反线性正规算子的刻画与结构,得到无界反线性正规算子的结构定理。

详情
AI中文摘要

若复希尔伯特空间 $\Hh$ 上的算子 $A$ 满足 $A(x+y)=Ax+Ay$ 且 $A(λx)=\ovλ Ax$,其中 $x,y\in \cD(A)$,$λ\in \dC$,则称 $A$ 为反线性算子。我们研究一些稠定无界反线性算子类,特别是反线性正规算子。我们给出了反线性正规算子的多种刻画,并详细研究了一类这样的算子。我们的主要结果是关于无界反线性正规算子的结构定理。

英文摘要

An operator $A$ on a complex Hilbert space $\Hh$ is called antilinear if $A(x+y)=Ax+Ay$ and $A(λx)=\ovλ Ax$ for $x,y\in \cD(A)$ and $λ\in \dC$. We investigate some classes of densely defined antilinear unbounded operators, especially antilinear normal operators. We give various characterizations of antilinear normal operators and study a class of such operators in detail. Our main result is a structure theorem for unbounded antilinear normal operators.

2606.05941 2026-06-05 physics.data-an

The BRUIT-FM "open data" noise reduction challenge

BRUIT-FM“开放数据”降噪挑战

Wayne C Crawford, Stephan Ker, Simon Rebeyrol, Laurent Duval

AI总结 BRUIT-FM挑战赛要求参与者在开放的真实和合成宽带海底地震学数据集上降低“噪声”,通过分离信号以优化地震和海底顺应信号。

详情
AI中文摘要

BRUIT-FM挑战赛要求参与者在开放的真实和合成宽带海底地震学数据集上降低“噪声”。该数据集包括来自地震、海洋次重力波和海底洋流的信号。它还包含带有解决方案的合成数据训练集。参与者被要求移除或分离这些信号,以获得最佳的地震和海底顺应信号。作者将基于降噪效果和易用性进行初步评估。参与者受邀参加社区研讨会,在研讨会上他们将验证初步评估,并合作撰写一篇描述结果、识别有前景的路径并提出新方向的社区论文。最佳结果将被添加到数据集的新版本中,该版本将作为未来发展的基准。

英文摘要

The BRUIT-FM Challenge asks participants to reduce ''noise'' on an open dataset of real and synthetic broadband seafloor seismology data. The dataset includes signals from earthquakes, ocean infragravity waves and seafloor currents. It also includes training datasets of synthetic data with solutions. Participants are asked to remove or separate these signals to obtain the best earthquake and seafloor compliance signals. The authors will make a first assessment of the noise reduction, based on noise reduction and ease of use. Participants are invited to a community workshop, in which they will validate the preliminary assessment and collaborate on a community paper describing the results, identifying promising pathways and proposing new directions. The best results will be added to a new version of the dataset, which will persist as a benchmark for future developments.

2606.05940 2026-06-05 nucl-th

Seed-Robust PINN Determination of $s$-Wave Bound States and Jost-Function-Based vertex constants in $_Λ^{208}$Pb

基于种子鲁棒PINN的$_Λ^{208}$Pb中$s$波束缚态确定及Jost函数顶点常数

J. T Tshipi, A. S Cornell

AI总结 采用物理信息神经网络(PINN)结合Rayleigh-Ritz变分商计算$_Λ^{208}$Pb超核的$s$波束缚态,通过归一化残差损失实现种子鲁棒性,并基于Jost函数提取渐近归一化常数和核顶点常数。

详情
AI中文摘要

我们研究了物理信息神经网络(PINN)用于计算超核$_Λ^{208}$Pb的$s$波束缚态,该超核被建模为由$Λ$超子和$^{207}$Pb核组成的二体系统。相互作用由无自旋-轨道耦合的Woods-Saxon势描述。在PINN公式中,径向束缚态波函数由人工神经网络表示,本征能量通过Rayleigh-Ritz变分商获得。由于PINN本征值计算可能依赖于残差损失公式和随机种子初始化,我们在四个独立随机种子上比较了两种残差损失。使用本征值精度、变异系数、信噪比、偏差-方差分解和厄米谱序一致性评估其性能。对于所考虑的四个种子,归一化残差损失给出了最稳定且物理一致的束缚态谱。使用该损失,计算得到的束缚态能量和均方根半径与相应的理论值非常吻合。得到的波函数用于通过Wronskian与入射和出射Riccati-Hankel函数构造Jost函数。从这些Jost函数中,提取了分波$S$矩阵在束缚态极点处的留数、渐近归一化常数和核顶点常数。这些量与理论值显示出合理的一致性,尽管其标准差大于本征能量和半径的标准差。结果表明,Rayleigh-Ritz公式与种子鲁棒的归一化残差损失相结合,为超核二体系统中的束缚态和基于Jost函数的计算提供了稳定的PINN框架。

英文摘要

We investigate physics-informed neural networks (PINNs) for computing the $s$-wave bound states of the hypernucleus $_Λ^{208}$Pb, modeled as a two-body system composed of a $Λ$ hyperon and a $^{207}$Pb core. The interaction is described by a Woods--Saxon potential without spin--orbit coupling. In the PINN formulation, the radial bound-state wave function is represented by an artificial neural network, and the eigenenergies are obtained from the Rayleigh--Ritz variational quotient. Because PINN eigenvalue calculations can depend on the residual-loss formulation and random-seed initialization, two residual losses are compared across four independent random seeds. Their performance is assessed using eigenvalue accuracy, coefficient of variation, signal-to-noise ratio, bias--variance decomposition, and Hermitian spectral-ordering consistency. The normalized residual loss gives the most stable and physically consistent bound-state spectrum for the four seeds considered. With this loss, the computed bound-state energies and root-mean-square radii are in very good agreement with the corresponding theoretical values. The resulting wave functions are used to construct the Jost functions through the Wronskian with incoming and outgoing Riccati--Hankel functions. From these Jost functions, the residue of the partial-wave $S$-matrix at the bound-state pole, the Asymptotic Normalization and the Nuclear Vertex Constants are extracted. These quantities show reasonable agreement with theoretical values, although with larger standard deviations than those obtained for the eigenenergies and radii. The results indicate that the Rayleigh--Ritz formulation combined with a seed-robust normalized residual loss provides a stable PINN framework for bound-state and Jost-function-based calculations in hypernuclear two-body systems.

2606.05939 2026-06-05 cs.FL

Correct-by-Construction Design of Timed Systems in Event-B

Event-B中定时系统的正确性构造设计

Guillaume Dupont, Jun Sun

AI总结 提出一种非侵入式的、受时间自动机启发的Event-B时间与时钟嵌入方法,支持复杂实时系统的逐步正确性构造设计,并通过案例展示其应用。

Comments This work was supported by ANR grant ANR-24-CE25-5742 (TAPAS project)

详情
AI中文摘要

实时系统需要在其模型中仔细处理时间方面。对于关键应用,这需要使用时间感知的形式化方法。目前,大多数这些形式化方法通过归约到时间自动机或时间转换系统来表达其语义,并与基于模型检验的验证技术相关联。在这方面,它们旨在作为后验分析方法,用于已经开发的系统。相比之下,诸如Event-B之类的方法旨在使用正确性构造方法逐步构建系统,但不具备表达时间方面和约束的能力。我们提出了一种非侵入式的、工具支持的Event-B中时间和时钟的嵌入,其灵感来自时间自动机的特征和语义,使得能够设计复杂的实时系统,同时受益于该方法的整个生态系统和工具支持。精化被扩展以考虑时间,使得能够以正确性构造的方式逐步设计复杂系统,同时从顶层集成时间方面。通过一个案例研究说明了该嵌入和相关方法,展示了如何从时间自动机推导出定时Event-B模型,以及Event-B核心的一阶逻辑和集合论的扩展表达能力如何实现更精细的建模。

英文摘要

Real-time systems require the careful handling of timing aspects in their models. For critical applications, this entails the use of time-aware formal methods. Currently, most of these formal methods express their semantics by reduction to timed automata or timed transition systems, and are associated with model-checking-based verification techniques. In this regard, they are intended to be used as a posteriori analysis methods, on systems that have already been developed. In contrast, methods such as Event-B have been designed to build systems incrementally using a correct-by-construction approach, but are not equipped with the ability to express timing aspects and constraints. We propose a non-intrusive, tool-supported embedding of time and clocks in Event-B inspired by the features and semantics of timed automata, that enables the design of complex real-time systems while benefiting from the entire ecosystem and tooling support of the method. Refinement is extended to also take time into account, making it possible to design complex systems gradually in a correct-by-construction manner while integrating timing aspects from the top level. The embedding and associated methodology are illustrated on a case study, showcasing both how timed Event-B models may be derived from timed automata, and also how the extended expressivity of first-order logic and set theory at the core of Event-B enables finer modelling.

2606.05938 2026-06-05 physics.flu-dyn

High-order thermodynamic nonequilibrium in three-dimensional compressible flows: Kinetic moment closure and multigradient coupling

三维可压缩流中的高阶热力学非平衡:动力学矩封闭与多梯度耦合

Huilin Lai, Qinghong Guo, Yanbiao Gan, Bin Yang, Hailong Liu, Pengfei Lin

AI总结 本文通过Chapman-Enskog分析识别描述三维可压缩流中高阶热力学非平衡所需的动力学矩约束,构建了超Burnett级离散玻尔兹曼模型(D3V91),揭示了高阶TNE的多梯度起源及不同阶中心矩的主导梯度依赖性。

Comments 42 pages, 15 figures

详情
AI中文摘要

三维可压缩流中的高阶热力学非平衡(TNE)反映了强梯度区域中低阶动力学矩封闭的失效。利用Chapman-Enskog分析,我们识别了描述三阶TNE所需的动力学矩约束。该分析给出了粘性应力和热通量的三阶本构关系及演化方程,以及它们相关高阶通量的二阶表达式。这些约束使得构建具有91个离散速度的三维超Burnett级离散玻尔兹曼模型成为可能。由此得到的D3V91模型再现了激波管波结构,并解析了低阶DBM无法可靠捕捉的高阶TNE贡献。这些结果表明,高阶TNE具有多梯度而非单梯度的起源。对于本文考虑的四个TNE量,奇数阶中心矩(包括热通量和粘性应力通量)主要受温度梯度支配,而偶数阶中心矩(包括粘性应力和热通量相关通量)主要受速度梯度支配。这些主导梯度依赖性并非唯一;它们通过高阶导数项、梯度乘积和交叉耦合受到密度梯度、次级梯度和过渡层宽度的显著修正。当次级贡献与主导梯度项相当时,非平衡响应从近线性区域过渡到近似指数区域。本工作建立了一个一致处理动力学矩封闭和多梯度耦合的超Burnett级DBM框架,为解析和解释三维可压缩流中的高阶TNE提供了基础。

英文摘要

High-order thermodynamic nonequilibrium (TNE) in three-dimensional compressible flows reflects the breakdown of low-order kinetic moment closure in strong-gradient regions. Using Chapman-Enskog analysis, we identify the kinetic moment constraints required to describe third-order TNE. The analysis yields the third-order constitutive relations and evolution equations for the viscous stress and heat flux, together with second-order expressions for their associated higher-order fluxes. These constraints enable the construction of a three-dimensional super-Burnett-level discrete Boltzmann model with 91 discrete velocities. The resulting D3V91 model reproduces shock-tube wave structures and resolves high-order TNE contributions that lower-order DBMs do not capture reliably. These results demonstrate that high-order TNE has a multigradient, rather than single-gradient, origin. For the four TNE quantities considered here, odd-order central moments, including the heat flux and the viscous-stress flux , are primarily governed by temperature gradients, whereas even-order central moments, including the viscous stress and the heat-flux-related flux , are dominated by velocity gradients. These leading-gradient dependences are not exclusive; they are substantially modified by density gradients, secondary gradients and transition-layer widths through higher-order derivative terms, gradient products and cross-couplings. When the secondary contributions become comparable to the leading-gradient terms, the nonequilibrium response transitions from a near-linear regime to an approximately exponential regime. This work establishes a super-Burnett-level DBM framework that treats kinetic moment closure and multigradient coupling consistently, providing a basis for resolving and interpreting high-order TNE in three-dimensional compressible flows.