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2605.07573 2026-05-11 math.AT math.KT

Combinatorial Models for Linear Homotopy Theories

Atabey Kaygun

AI总结 本文研究了在特征为0的域 $k$ 上,线性同伦理论中不同组合模型之间的关系,包括链复形、半单形向量空间、增强半单形向量空间、半立方向量空间和树状向量空间。通过小微分范畴代数,作者证明了半单形模与增强半单形模在Gabriel–Zisman局部化和Quillen模型范畴层面上等价于适当的链复形同伦理论。此外,半立方符号嵌入引发了从半立方模到增强半单形模的自然比较,并诱导出一个Quillen伴随关系,但由于增强同调在-1度存在障碍,这一伴随关系并非Quillen等价。

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英文摘要

For a field $k$ of characteristic $0$, we compare $k$-linear chain complexes, semisimplicial vector spaces, augmented semisimplicial vector spaces, semicubical vector spaces, and arboreal vector spaces through small differential categorical algebras. We prove that semisimplicial modules and augmented semisimplicial modules are equivalent to appropriate chain-complex homotopy theories, both at the Gabriel--Zisman localization and the Quillen model-categorical level. The semicubical sign embedding gives a natural comparison from semicubical modules to augmented semisimplicial modules and induces a Quillen adjunction, but not a Quillen equivalence on the full semicubical category since there is an obstruction in augmented homology at degree $-1$.

2605.07571 2026-05-11 math.PR

On the Besov-Orlicz path regularity of some Gaussian processes

Rachid Belfadli, Brahim Boufoussi, Youssef Ouknine

AI总结 本文研究了一类高斯过程样本路径的Besov-Orlicz正则性,利用这些过程在律上的加法分解性质以及分数布朗运动的正则性结果,给出了统一且直接的证明方法。该方法适用于包括双分数布朗运动、次分数布朗运动以及某些自相似过程在内的广泛过程类,为理解这些过程的路径光滑性提供了新的理论工具。

Comments 13 pages

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英文摘要

In this paper, we rely on the additive decomposition in law satisfied by a class of stochastic processes, combined with the well-known regulariy properties of fractional Brownian motion, to establish Besov-Orlicz regularity of their sample paths. This provides a unified and direct proof for a broad class of processes, including bifractional Brownian motion with parameters $H\in (0, 1]$, $ K\in (0, 2)$ such that $HK \in (0, 1)$, subfractional Brownian motion with Hurst parameter $H\in (0, 1)$, and certain class of self-similar processes. %associated with the stochastic heat equation.

2605.07570 2026-05-11 cs.DS cs.CG

Coordinated Motion Planning is FPT on Discretized Simple Polygons

Argyrios Deligkas, Eduard Eiben, Robert Ganian, Iyad Kanj

AI总结 本文研究协调运动规划问题,目标是在图中为 $k$ 个机器人规划路径,使其从起点移动到目标点,同时避免碰撞,并最小化总移动距离。作者提出了一种基于机器人数量 $k$ 的固定参数算法,适用于由简单多边形离散化得到的图结构。这类图在现实应用中具有重要意义,且能推广到矩形网格,因此该成果为解决子网格乃至平面图上的协调运动规划参数化复杂性问题提供了重要进展。

Comments A short version of this manuscript appears in the proceedings of ICALP 2026

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英文摘要

In the coordinated motion planning problem, we are given a graph together with the starting and destination vertices of $k$ robots. At each time step, any subset of robots may move, each traversing an edge of the graph, provided that no two robots collide. The goal is to compute a schedule that routes all robots to their destinations while minimizing some objective function. In this paper, we focus on the well-studied objective of minimizing the total travel length of all robots. This problem is known to be NP-hard, and it has been shown to be fixed-parameter tractable (FPT), when parameterized by the number $k$ of robots, on full grids (SoCG 2023) and on bounded-treewidth graphs (ICALP 2024). We present a fixed-parameter algorithm for coordinated motion planning, parameterized by the number $k$ of robots, on graphs arising from discretizations of simple polygons. Such graphs are of particular interest in real-world applications, where planar motion is often constrained to discretized representations of polygonal environments. Moreover, these graphs generalize rectangular grids; consequently, our result constitutes a significant step toward resolving the parameterized complexity of coordinated motion planning on subgrids and, ultimately, planar graphs -- two prominent open problems in the field.

2605.07569 2026-05-11 cs.DC

HexiSeq: Accommodating Long Context Training of LLMs over Heterogeneous Hardware

Yan Liang, Youhe Jiang, Ran Yan, Binhang Yuan, Wei Wang, Chuan Wu

AI总结 本文研究了在异构硬件环境下进行大语言模型长上下文训练的问题,提出了HexiSeq系统,该系统通过根据设备计算、内存和通信能力分配序列分片和注意力头,实现了完全不对称的上下文并行与头并行划分。研究将异构CP-HP分配建模为约束优化问题,并设计了高效的分层调度器以寻找最优方案。实验表明,HexiSeq在多种真实和模拟的异构集群上显著提升了训练吞吐量,验证了其在异构硬件上高效训练长上下文大模型的可行性。

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英文摘要

Long-context training of large language models (LLMs) is commonly distributed with Context Parallelism (CP) and Head Parallelism (HP), but existing training systems largely assume homogeneous GPU meshes. This paper extends CP and HP to heterogeneous GPU clusters with mixed GPU models and non-uniform network bandwidths, a common setting in production training. We introduce HexiSeq, a system that supports fully asymmetric CP--HP partitioning by assigning sequence shards and attention heads according to device compute, memory, and communication capabilities. We formalize heterogeneous CP--HP allocation as a constrained optimization problem and develop an efficient hierarchical scheduler for finding optimal schedules. We evaluate HexiSeq against state-of-the-art CP and HP baselines on both real and simulated heterogeneous clusters. Across models from 3B to 70B parameters and context lengths up to one million tokens, HexiSeq improves throughput by $1.11\times$ on average and up to $1.19\times$ on mixed H100--A100 testbeds, and by $1.36\times$ on average and up to $1.72\times$ in simulations with 32--128 GPUs spanning up to four GPU models. On FLOP-comparable pairs against homogeneous clusters, HexiSeq reaches throughput close to the strongest homogeneous baseline, showing that heterogeneous clusters can be used efficiently for long-context LLM training.

2605.07567 2026-05-11 physics.optics

Boundary-dominated optomechanics in silicon metamaterial membranes

David González-Andrade, Paula Nuño Ruano, Jianhao Zhang, Paul Joseph Robin, Hiba El Batoul Ferhat, Samson Edmond, Pavel Cheben, Daniele Melati, Eric Cassan, Laurent Vivien, Delphine Marris-Morini, Norberto Daniel Lanzillotti-Kimura, Carlos Alonso-Ramos

AI总结 该研究探讨了在硅超材料膜中由边界主导的光机械耦合机制,提出了一种基于横向磁光模式与垂直机械呼吸模式耦合的新方法,克服了传统波导中因光弹效应主导而导致的性能限制。通过优化膜结构与亚波长超材料包层设计,实现了由界面运动主导的强光声相互作用,在12 GHz频率下获得了创纪录的7200 W⁻¹m⁻¹ Brillouin增益与620的机械品质因数,为高频集成光声信号处理提供了可扩展的平台。

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英文摘要

Stimulated Brillouin scattering in integrated photonic waveguides enables coherent coupling between optical photons and gigahertz acoustic phonons, providing a powerful mechanism for on-chip microwave photonics and opto-acoustic signal processing. Despite theoretical predictions of ultra-strong Brillouin interactions arising from enhanced light-sound coupling at device boundaries, most state-of-the-art integrated demonstrations remain governed by bulk photoelastic effects. This limitation stems from trade-offs between optical loss, interaction with waveguide boundaries and accessible phonon frequencies associated with the use of transverse-electric optical modes coupled to horizontally breathing mechanical modes. Here we demonstrate a new approach based on transverse-magnetic optical modes coupled to vertically breathing mechanical modes in suspended silicon membranes engineered with subwavelength metamaterial claddings. In this geometry, the interaction is dominated by the moving-boundary effect occurring at smooth top and bottom interfaces, while the phonon frequency is set primarily by the membrane thickness rather than its width. We observe forward Brillouin interactions at a record frequency of 12 GHz with a gain of 7200 W$^{-1}$ m$^{-1}$ and a mechanical quality factor of 620, yielding the highest Brillouin gain-to-quality-factor ratio reported in silicon waveguides. The devices exhibit net Brillouin amplification in millimeter-scale waveguides with pump powers below 15 mW, establishing a scalable platform for high-frequency integrated opto-acoustic signal processing.

2605.07566 2026-05-11 hep-ex

NEXT Simulation Dataset for AI Summer School UC Irvine 2026

K. Mistry

AI总结 本文介绍了用于加州大学欧文分校2026年无中微子双β衰变人工智能暑期学校的模拟数据集,包含高气压氙气中$^{214}$Bi衰变产生的无中微子双β衰变信号及背景事件。该数据集旨在为研究者提供类似NEXT探测器实验条件下的仿真数据,用于相关算法的开发与验证,有助于推动无中微子双β衰变实验的分析技术进步。

Comments 6 pages, 2 figures

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英文摘要

This document details the dataset release of simulated $0νββ$ and background events originating from the decay of $^{214}$Bi in high-pressure xenon gas, describing events similar to those produced in the NEXT detector. This release is part of the Neutrinoless Double Beta Decay ($0νββ$) AI Summer School held on June 20-21 2026 at the University of California, Irvine.

2605.07564 2026-05-11 math.FA math.OA

Schur bounded patterns and submajorisation

Edward McDonald, Fedor Sukochev, Dmitriy Zanin

AI总结 本文研究了紧算子理想中不满足子主序闭包的Schur有界模式,特别关注Schatten理想$\mathcal{C}_p$(其中$0 < p < 1$)。作者给出了这些理想对应的Schur有界模式的刻画,并反过来通过Schur有界模式表征了不满足子主序闭包的算子理想,揭示了二者之间的深刻联系。

Comments 5 pages, comments welcome

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英文摘要

We characterise the Schur bounded patterns of ideals of compact operators that are not closed under submajorisation, in particular the Schatten ideals $\mathcal{C}_p$ with $0<p<1.$ Conversely we characterise the ideals that are not closed under submajorisation by their Schur bounded patterns.

2605.07563 2026-05-11 math.FA

On hypercyclic spaces and (common) $\mathscr{U}$-frequently hypercyclic spaces

Nacib G. Albuquerque, Thiago R. Alves, Geraldo Botelho, Vinícius V. Fávaro

AI总结 本文研究单侧加权后移算子在 $\ell_p$ 空间上的超循环子空间及其与 $\mathscr{U}$-频繁超循环子空间的关系。作者证明了若该算子存在 $\mathscr{U}$-频繁超循环子空间,则可以构造一个不含频繁超循环向量的 $\mathscr{U}$-频繁超循环子空间,并进一步解决了一个关于公共 $\mathscr{U}$-频繁超循环子空间存在的开放问题。

Comments 27 pages

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英文摘要

Let $B$ be an unilateral weighted backward shift on $\ell_p$, $1 \leq p < \infty$, that admits a $\mathscr{U}$-frequently hypercyclic subspace. We prove that $B$ admits such a subspace free of frequently hypercyclic vectors. The proof technique we develop also allows us to prove that $B$ admits a hypercyclic subspace free of $\mathscr{U}$-frequently hypercyclic vectors, and to solve a question posed by Bès and Menet in 2015 on the existence of common $\mathscr{U}$-frequently hypercyclic subspaces.

2605.07558 2026-05-11 q-fin.MF

Stochastic Calculus and the Black-Scholes-Merton Model: A Simplified Approach

Kuo-Ping Chang

AI总结 本文挑战了传统观点,指出基础资产的预期收益率在布莱克-舒尔斯-默顿期权定价模型中并非无关紧要。通过引入随机微积分的简化方法,作者重新分析了模型中收益率的作用,并揭示了其对期权定价的影响机制。该研究为理解期权定价理论提供了新的视角,丰富了金融数学的相关理论基础。

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英文摘要

This paper refutes the claim that the expected rate of return of the underlying asset plays no role in the Black-Scholes-Merton option pricing model.

2605.07555 2026-05-11 math.RT math.RA

Limits and colimits in silting theory with applications to the wall and chamber structure of an algebra

Rosanna Laking, Alexandra Zvonareva

AI总结 本文研究了由倾斜对象(silting objects)所定义的一族嵌套的t-结构,通过同伦余极限构造了对应于这些t-结构心部交集的倾斜对象,并给出了余倾斜情况下的对偶构造——同伦极限。研究结果被应用于构造与数值挠对以及实格罗特end克群中极限墙对应的两类大倾斜对象,特别是在代数为温和(tame)情形下,可以借助该结果与Plamondon和Yurikusa的结果,描述所有的数值挠对。

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英文摘要

In this paper we consider a family of nested t-structures given by silting objects and construct a silting object corresponding to the intersection of aisles of these t-structures as a homotopy colimit. The dual construction for the cosilting case is given as a homotopy limit. The results are applied to construct two-term large silting objects corresponding to the numerical torsion pairs and the limiting walls in the wall and chamber structure of the real Grothendieck group of a finite dimensional algebra. In particular, in case the algebra is tame we can describe any numerical torsion pair in this way by combining our results with results of Plamondon and Yurikusa.

2605.07553 2026-05-11 physics.optics

Asynchronous Event-Based Spectroscopy for Microsecond-Resolved Spectral Reconstruction

Joana M. Teixeira, Tomas Lopes, Tiago D. Ferreira, Catarina S. Monteiro, Pedro A. S. Jorge, Nuno A. Silva

AI总结 许多物理和化学过程发生在微秒量级的时间尺度上,传统光谱仪的时序分辨率难以满足其观测需求。本文提出了一种基于事件驱动的异步光谱仪,结合Czerny-Turner光路结构和事件感知技术,实现了微秒级的光谱重建,其光谱分辨率为每像素约0.18纳米,覆盖可见光234纳米的带宽。实验表明,该方法在动态光照和微流控实验中均表现出比传统帧扫描光谱仪更高的时间分辨率和光谱保真度,为实时高精度光谱测量提供了新的解决方案。

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英文摘要

Many physical and chemical processes of interest evolve on timescales that push the limits of conventional spectroscopic instrumentation. Indeed, the temporal resolution of standard spectrometers is often insufficient to track these dynamics, which is connected to the fact that most systems rely on frame-based sensors, imposing fundamental constraints on acquisition speed, sensitivity, and data efficiency, frequently limiting practical operation to the kHz regime. In this work, we present an approach to circumvent this limitation by developing an event-based spectrometer to enable spectral reconstruction with microsecond temporal resolution by leveraging a Czerny-Turner configuration combined with asynchronous and event-driven sensing. A dedicated signal processing pipeline converts the resulting stream of binary events into calibrated spectra through temporal accumulation, geometric correction, and vertical spatial integration of the spectral line, covering a 234nm bandwidth in the visible range with a spectral resolution of approximately 0.18nm per pixel. Performance characterization under temporally modulated illumination demonstrates that the event-based spectrometer can reconstruct spectra at probing rates of up to tens of kilohertz, far exceeding the practical limits of a conventional frame-based spectrometer operated in parallel, while accurately preserving spectral peak positions and relative spectral features. Finally, to further illustrate its potential applications, the system is validated in a microfluidic experiment integrated into an inverted microscope, where spectral changes induced by an absorbing dye are tracked with higher temporal fidelity and resolution compared with the frame-based approach. These results establish event-based spectroscopy as a promising paradigm for real-time, high-temporal-resolution spectral measurements in dynamic and low-light applications.

2605.07548 2026-05-11 cs.CR

CCX: Enabling Unmodified Intel SGX Applications on Arm CCA

Matti Schulze, Thorsten Holz, Felix Freiling

AI总结 本文提出了一种名为CCX的框架,旨在使现有的Intel SGX应用程序无需修改源代码即可在基于Arm CCA的平台上运行。CCX通过重新设计SGX功能到Arm CCA固件中,实现了与原有SGX应用的完全兼容,并保持了相近的安全性。实验表明,CCX能够在QEMU模拟器和Nitrogen8M开发板上成功运行SGX应用,同时在性能上也有所提升。

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英文摘要

Novel confidential computing technologies such as Intel TDX, AMD SEV, and Arm CCA have recently emerged. In practice, due to its minimal trust boundaries, Intel SGX still remains widely used for enclave-based applications in cloud environments, including confidential cloud services, privacy-preserving communication, secure payment processing, and privacy-focused advertising. With the growing adoption of Arm CPUs in cloud systems, however, existing SGX applications face a significant portability challenge: they are tightly coupled to SGX-specific APIs and execution semantics. In this paper, we present the design and implementation of CCX, a framework that enables existing SGX applications to run on Arm CCA without source code modification. To this end, CCX redesigns SGX functionality within Arm CCA firmware, adapting SGX abstractions to CCA's architecture design while preserving full compatibility with existing applications originally developed for SGX. We implemented a prototype of CCX on both the QEMU emulator and a Nitrogen8M development board. Our evaluation shows that CCX is capable of executing existing SGX applications without requiring source code changes, while providing security guarantees comparable to Intel SGX and achieving performance improvements in our evaluated settings.

2605.07547 2026-05-11 cs.DC cs.NI cs.SY eess.SY

Deadline-Driven Hierarchical Agentic Resource Sharing for AI Services and RAN Functions in AI-RAN

Haiyuan Li, Yulei Wu, Dimitra Simeonidou

AI总结 本文研究了AI-RAN中AI服务与无线接入网络(RAN)功能在边缘计算平台上的计算资源共享问题,提出了一种分层智能代理框架(HAF),通过结合基于大语言模型的代理进行慢时间尺度的服务与功能部署,以及基于凸优化的快速时间尺度资源分配算法,有效协调了不同时间尺度的调度决策。该框架还引入了预测性评判模块,以减少因服务迁移带来的性能损失,实验表明HAF在服务等级目标(SLO)达成率方面优于现有方法,显著提升了AI服务请求的满足率。

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英文摘要

AI-RAN consolidates AI services and Radio Access Network (RAN) functions onto a unified, GPU-accelerated infrastructure at the network edge. However, compute sharing between real-time RAN functions and highly heterogeneous AI services requires coordination of scheduling decisions at mismatched timescales, and placement adaptation may require service migration across nodes with non-negligible interruptions. This paper proposes a hierarchical agentic framework (HAF) for compute sharing in AI-RAN that combines a large language model (LLM)-based agent for slow-timescale placement of AI services and RAN functions with a closed-form, deadline-aware convex algorithm for fast-timescale GPU/CPU allocation. The LLM agent is further equipped with a predictive critic that filters out migrations when the induced service interruption outweighs the expected service-level objective (SLO) benefit. Experimental results show that HAF reaches 90.0% overall SLO fulfillment, a 20.5% improvement over the strongest baseline, and raises AI service request fulfillment from 51% to 85.3%. Further evaluations show that HAF retains its advantage under diverse load conditions, while the critic consistently improves SLO fulfillment across multiple open-source LLM agents.

2605.07543 2026-05-11 math.AP

Stability of the ball in isoperimetric inequalities between two fractional perimeters

G. Alberti, G. Cozzi, A. Massaccesi, J. Mirmina

AI总结 本文研究了涉及分数周长的等周不等式,考虑了 $s$-周长与 $t$-周长(其中 $0<s<t<1$)之间的关系,证明了在近似球形的集合中,球是该尺度不变等周比 $\mathcal{F}(E)$ 的局部极小值点。作者将 $\mathcal{F}$ 表示为单位球面上标量函数 $u$ 的泛函,并在 $u=0$ 附近证明了关于适当 Sobolev 范数的定量稳定性结果,这一结果与将 $s$-周长替换为体积的情形相类似。

Comments 24 pages

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英文摘要

We consider the isoperimetric inequality involving the $s$-perimeter and the $t$-perimeter with $0<s<t<1$, and show that the ball is a local minimizer of the (scale-invariant) isoperimetric ratio $\mathcal{F}(E):=P_t(E)^{\frac{1}{n-t}}/ P_s(E)^{\frac{1}{n-s}}$ among sets $E$ that are nearly spherical. To this end, we rewrite $\mathcal{F}$ as a functional of $u$, where $u$ is a scalar function on the unit sphere in $\mathbb{R}^n$ that parametrizes the boundary of $E$, and prove a quantitative stability result for $\mathcal{F}$ around $u=0$ with respect to a suitable Sobolev norm. This parallels known results where the $s$-perimeter is replaced by the volume.

2605.07542 2026-05-11 math.CO cs.DM cs.FL math.NT

Brik's sequence: a strange recursion

Jeffrey Shallit

AI总结 本文研究了一个特殊的二进制序列 $ \bf b $,其前缀由递归定义的单词序列 $ (B_i) $ 构成。该序列具有递归生成的结构,研究发现它满足递归性但不满足一致递归性,其因子复杂度呈指数增长,并且该序列不是由形态映射生成的。此外,该序列中1的密度存在且为超越数。

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英文摘要

We study the properties of the sequence of words $(B_i)$, where $B_1 = 101$ and $B_{i+1} = B_i C_i$ for $i \geq 1$, where $C_i$ is $B_i$ with the first $i$ symbols removed, and the infinite binary sequence ${\bf b} = 10101101011011101 \cdots$ of which all the $B_i$ are prefixes. We show that $\bf b$ is recurrent, but not uniformly recurrent; it has exponential factor complexity; it is not morphic; and the density of $1$'s exists and is transcendental.

2605.07541 2026-05-11 eess.SY cs.SY

Learning Neural Hybrid Surrogates for Gradient-Based Falsification

Lasse Kötz, Knut Åkesson

AI总结 本文提出了一种基于神经网络的混合替代模型方法,用于解决具有模式依赖动态和离散切换的混合动态系统的形式化验证问题。该方法通过从数据中学习可微分的混合自动机模型,扩展了传统仅适用于连续动态的替代验证方法,能够同时学习隐含模式编码器和对应模式条件下的向量场。实验表明,该方法在多数基准规范上能够有效发现反例,并在样本效率方面优于其他工具。

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英文摘要

Falsification of hybrid dynamical systems remains challenging due to mode-dependent dynamics and discrete transitions. In this work, we propose a surrogate-based falsification approach that enables hybrid systems by learning a differentiable hybrid automaton model from data. This extends previous surrogate-based falsification methods, which were limited to purely continuous dynamics. Specifically, we employ neural hybrid automata to learn both a latent mode encoder and the corresponding mode-conditioned vector fields. Once the surrogate has paired each mode with an associated vector field, the transition guards are inferred using existing trajectory data. The learned surrogate is subsequently subjected to a gradient-based optimal control formulation, which minimizes a smooth approximation of the safety specification to find safety violations. In the last step, an experiment with the optimal control solution is carried out on the original system to ensure soundness. The proposed method consistently uncovers counterexamples on a majority of evaluated benchmark specifications; on these cases, it achieves competitive or improved sample efficiency than other tools while using a reduced simulation budget.

2605.07540 2026-05-11 cond-mat.str-el cond-mat.mtrl-sci cond-mat.supr-con

Noncollinear antiferromagnetic structure and physical properties of CrRhAs with distorted kagome lattice

Chenglin Shang, Daye Xu, Bingxian Shi, Xuejuan Gui, Zhongcen Sun, Juanjuan Liu, Jinchen Wang, Hongxia Zhang, Hongliang Wang, Lijie Hao, Peng Cheng

AI总结 本文研究了具有扭曲克罗内克晶格的CrRhAs材料的非共线反铁磁结构及其物理性质。通过粉末中子衍射实验,发现其反铁磁序的传播矢量为k = (1/3, 1/3, 1/2),并在克罗内克平面内表现出不同于理论预测的二阶最近邻铁磁耦合。该材料展现出异常的输运特性,包括磁序转变附近的电阻行为变化和霍尔系数的双符号反转,表明其具有多带效应和强自旋涨落的特征,是研究强关联克罗内克金属的理想候选体系。

Comments 8 pages, 5 figures. Published in PHYSICAL REVIEW B 113, 184430 (2026)

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Journal ref
Phys. Rev. B 113, 184430 (2026)
英文摘要

CrRhAs was theoretically proposed to be a kagome metal with unusual magnetic ground states; however, little is known about its magnetic structure and physical properties experimentally. Here, we present an experimental investigation of CrRhAs with ZrNiAl-type structure and a distorted Cr kagome lattice. CrRhAs is an antiferromagnet with TN = 149 K. Powder neutron diffraction analysis reveals a noncollinear antiferromagnetic structure with propagation vector k = (1/3, 1/3, 1/2), which features a ferromagnetic second nearest neighbor coupling in the kagome plane that is different from the prediction in previous density functional theory calculations. Furthermore, CrRhAs exhibits anomalous electrical transport properties which are possibly related to multiband effects and strong spin fluctuations. For the temperature-dependent longitudinal resistivity \r{ho}xx, it is semiconductinglike above TN and becomes metallic below TN . The Hall coefficients exhibit two sign changes near 70 and 300 K. Combined with the results of heat capacity measurements, a large Kadowaki-Woods ratio α = 33.9 μΩ cm mol2 K2/J2 is obtained. The above results suggest CrRhAs is a strongly correlated kagome metal with multiband and noncollinear magnetic structure features.

2605.07539 2026-05-11 cond-mat.mes-hall cond-mat.soft physics.optics

Exciton-mediated optical control of liquid-solid friction

Timur Pryadilin, Alexey Kavokin, Baptiste Coquinot

AI总结 该研究探讨了液固界面摩擦在纳米流体系统中的光调控机制,提出了一种基于激子与水分子电荷涨落耦合的微观理论模型。通过区分静态和动态激子的作用,研究得出了可实验调控的激子摩擦公式,能够显著降低纳米通道的滑移长度和液压渗透性。研究还成功再现了碳纳米管中光激发下扩散行为的实验结果,表明激子可作为调控纳米流体传输的光学手段,并为利用激子荧光探测纳米通道内流速提供了新思路。

Comments 6 pages, 2 figures

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英文摘要

Interfacial friction in nanofluidic systems can arise from fluctuation-induced coupling between liquid charge fluctuations and the internal excitations of the confining solid. Here, we develop a microscopic theory of exciton-mediated solid-liquid friction based on the coupling between optically generated excitons and charge fluctuations in water. We distinguish between static excitons, localized by disorder or functionalization, and dynamic excitons, which interact with water through polarization fluctuations. In both cases, we derive analytical formulas for the excitonic friction, which is experimentally tunable and can significantly reduce the slip length and thereby the hydraulic permeability of nanochannels. Applying our framework to carbon nanotubes, we quantitatively reproduce the recent measurements of Kistwal et al., showing a reduction of nanotube diffusion under optical excitation, without fitting parameters. More broadly, our results establish excitons as a mechanism to optically control nanofluidic transport and suggest that excitonic photoluminescence could provide an optical probe of flow velocity inside nanochannels.

2605.07538 2026-05-11 math.AP

Nonlinear stability threshold for 3D compressible Couette flow

Rui Li, Fei Wang, Lingda Xu, Zeren Zhang

AI总结 本文研究了三维可压缩库埃特流在可压缩Navier-Stokes方程下的非线性稳定性阈值,证明其为$O(ν^{3/2})$。相比二维及不可压缩三维情况,三维可压缩情形因结构复杂、模态耦合强烈而尚未有明确结论。作者通过改进频率-空间方法,分离并精确估计扩散波、声波及提升机制的非线性耦合效应,并引入新的乘子估计与系统结构分解,有效追踪耗散与声学效应的相互作用,从而系统地解决了该问题。

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英文摘要

We establish the nonlinear stability threshold $O(ν^{3/2})$ for the three-dimensional Couette flow governed by the compressible Navier--Stokes equations. While stability thresholds are well understood in two dimensions for both compressible and incompressible flows, and in three dimensions for incompressible flows, the three-dimensional compressible case remains open due to additional structural features, strong mode interactions, and wave coupling. The proof is based on a refined frequency-space approach. For zero modes, we improve upon two-dimensional methods by clearly separating and precisely estimating the main contributions from diffusion waves, acoustic waves, and the lift-up mechanism, leading to a systematic way to handle their nonlinear coupling. For the non-zero modes, we introduce new multiplier estimates and a decomposition based on the structure of the compressible system, which allows us to track the interaction between dissipation and acoustic effects.

2605.07535 2026-05-11 cs.CR cs.SY eess.SY

Resilience of IEC 61850 Sampled Values-Based Protection Systems Under Coordinated False Data Injections

Denys Mishchenko, Irina Oleinikova, Laszlo Erdodi

AI总结 本文评估了基于IEC 61850采样值(SV)协议的数字化变电站在协同虚假数据注入攻击(FDIA)下的鲁棒性。研究通过实验分析了在变电站层级同时具备物理和网络访问权限的攻击场景,展示了攻击者如何协调操纵多个电气参数,实现隐蔽的多向量攻击,导致保护系统误动作或失效。实验结果揭示了SV保护机制在真实攻击条件下的关键脆弱性,并提出了一种涵盖威慑、预防、检测、缓解和恢复的防御策略,以及基于可信独立通道和数据交叉验证的增强防护方法。

Comments 11 pages, 8 figures

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英文摘要

This paper assesses the resilience of IEC 61850 digital substations under False Data Injection Attacks (FDIAs) targeting the Sampled Values (SV) protocol. The multicast nature of SV, while enabling time-critical automation, exposes substations to cyber intrusions capable of disrupting protection functions and causing large-scale outages. To evaluate these risks, coordinated attack vectors involving both physical and cyber access at the bay level are experimentally analyzed using an advanced setup based on industrial-grade intelligent electronic devices (IEDs). The proposed attacks simultaneously manipulate multiple electrical parameters in a coordinated and physically consistent manner. Experimental results confirm the feasibility of stealthy multi-vector FDIAs that can trigger false protection actions, conceal real faults, or block protection mechanisms while maintaining realistic signal behavior. The Power Hardware-in-the-Loop (PHIL) testbed enables closed-loop evaluation under strict timing, communication, and protection logic constraints, reflecting real device behavior beyond simulation and controller-level HIL environments. The findings reveal critical vulnerabilities in SV-based protection schemes that directly affect grid reliability, particularly under realistic attacker positioning. To address these challenges, a defense strategy covering deterrence, prevention, detection, mitigation, and resilience is analyzed, with emphasis on bay-level infrastructure. Furthermore, a resilience-oriented method based on trusted independent channels and cross-verification of SV data within the protection logic is outlined as a complementary countermeasure for scenarios where existing standardized security mechanisms are insufficient.

2605.07534 2026-05-11 cs.SE

System Test Generation for Virtual Reality Applications using Scenario Models

Gerry Longfils, Maxime Cauz, Arnaud Blouin, Xavier Devroey

AI总结 本文提出了一种名为UltraInstinctVR的新方法,用于生成虚拟现实(VR)应用的系统测试用例。该方法基于预定义的VR场景模型,自动化生成和执行具体的系统测试,以提高测试的系统性和可重复性。实验结果表明,与现有最先进的VR自动化测试工具相比,UltraInstinctVR在测试覆盖率和缺陷检测方面表现更优,能够更有效地发现VR应用中的独特错误和实际问题。

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英文摘要

Virtual Reality (VR) applications are increasingly being integrated across a wide range of domains, including surgical training and industrial marketing. However, the long-term adoption and maintenance of VR applications remain limited, particularly due to the lack of effective, systematic, and reproducible software testing approaches tailored to their unique characteristics. To address this issue, we introduce UltraInstinctVR, a novel testing approach for VR applications. Relying on predefined VR models (scenarios), it automates the generation and execution of concrete VR system tests. In our empirical evaluation, we compare UltraInstinctVR with state-of-the-art automated VR testing approaches in terms of coverage and failure detection on 10 open-source VR applications. The results show that UltraInstinctVR outperforms existing automated tools for detecting unique failures and provides valuable insights for identifying real-world bugs in VR applications.

2605.07532 2026-05-11 nlin.SI math.AP

The Korteweg-de Vries limit for the global dynamics of the Toda lattice

Ruoyuan Liu, Herbert Koch

AI总结 本文研究了在连续极限下,Toda晶格的动力学行为如何由Korteweg-de Vries(KdV)方程描述的问题。通过引入KdV尺度和适当的平移,作者证明了在H¹初始条件下,Toda晶格的解在长时间内收敛于KdV方程的解。该结论基于调和分析工具以及Toda晶格的质量和能量守恒性质,这些性质源于其完全可积结构,从而得到了Toda晶格的长波KdV极限。

Comments 44 pages

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英文摘要

It has been observed that the dynamics of the Toda lattice can be well described by solutions of the Korteweg-de Vries (KdV) equation in the continuum limit. We show that, under the KdV scaling and a suitable translation, the solution of the Toda lattice with H^1 initial data converges to that of the KdV equation globally in time. Our proof relies on tools from harmonic analysis and also on the construction and the conservation of mass and energy of the Toda lattice, the latter of which are derived from the completely integrable structure of the Toda lattice. As a consequence, we obtain long-wave KdV limits for the Toda lattice.

2605.07528 2026-05-11 econ.TH

Aggregate Stable Matching with Money Burning

Alfred Galichon, Yu-Wei Hsieh, Antoine Jacquet

AI总结 本文研究了具有固定价格的去中心化匹配市场中的非转移效用(NTU)稳定性问题,提出了一种基于“金钱销毁”机制的聚合稳定性概念,该机制可解释为等待时间。文章将代理分为可观测类型,并在类型层面定义均衡,使得同一类型内的代理具有相等的间接效用。研究引入了两种NTU模型,分别在确定性和随机效用框架下分析了均衡的存在性、唯一性,并提出了一个基于交替约束离散选择问题的广义延迟接受算法,证明其收敛于唯一均衡。

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英文摘要

We propose an aggregate notion of non-transferable utility (NTU) stability for decentralized matching markets with fixed prices, where market clearing is achieved through one-sided money burning, which can be interpreted as waiting. Agents are grouped into observable types and are indifferent among individuals within type; equilibrium is defined at the type level and delivers equal indirect utility within each type. We introduce money burning into two types of NTU models: In a deterministic model, we relate our notion to classical Gale--Shapley stability and show how money burning decentralizes stable outcomes under aggregation. We then introduce separable random utility, obtaining an NTU counterpart to Choo and Siow (2006). We prove the existence and uniqueness of equilibrium and provide a stationary queueing interpretation. Finally, we develop a generalized deferred acceptance algorithm based on alternating constrained discrete-choice problems and prove its convergence to the unique equilibrium.

2605.07526 2026-05-11 hep-ph

The study of $K^{*0}$ meson production using a multi-phase transport model at RHIC BES energies

Pranjal Barik, Kadambini Menduli, Aswini Kumar Sahoo, Md. Nasim

AI总结 该研究利用多阶段输运模型(AMPT)在RHIC BES能量下分析了Au+Au碰撞中$K^{*0}$介子的产生特性,包括产额、平均横向动量和集体流。研究发现,由于强子再散射作用,$K^{*0}$的衰变产物在介质中与其它粒子相互作用,导致可重建的$K^{*0}$产额在低横向动量区域显著下降。研究还表明,$K^{*0}/K$比值对强子相寿命不敏感,而横向动量和定向流($v_1$)则对强子再散射高度敏感,表明$K^{*0}$的定向流可以作为探测晚期强子介质的重要探针。

Comments 9 pages, 11 figures

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英文摘要

We present the yield, average transverse momentum, and collective flow measurement of $K^{*0}$ resonances in Au+Au collisions at $\sqrt{s_{NN}} = 19.6$, 14.5, and 7.7~GeV using the AMPT model. It is found that, due to hadronic rescattering, the decay daughters of $K^{*0}$ interact with other particles in the medium, causing the yield of reconstructable $K^{*0}$ to be significantly suppressed, especially at low transverse momentum. The model results are compared with recent experimental data from Phase-II of the Beam Energy Scan (BES-II) program at the Relativistic Heavy-Ion Collider. The string-melting version of the AMPT model successfully reproduces the measured $K^{*0}/K$ ratios at all three analysed collision energies. Interestingly, AMPT calculations that exclude the hadronic phase nevertheless provide a reasonable description of the data, thereby challenging the conventional interpretation that hadronic rescattering is the primary mechanism responsible for suppressing the $K^{*0}/K$ ratio in central heavy-ion collisions. In addition, we find that the $K^{*0}/K$ ratio appears to be largely insensitive to the lifetime of the hadronic phase, whereas the average transverse momentum, $\langle p_{T} \rangle$, of the $K^{*0}$ shows a strong dependence, increasing significantly as the lifetime of the hadronic phase becomes longer. We further show that the directed flow ($v_1$) of $K^{*0}$ mesons is strongly influenced by hadronic rescattering, whereas the elliptic flow ($v_2$) exhibits only weak sensitivity to hadronic effects. These results establish $K^{*0}$ directed flow as a sensitive probe of the late-stage hadronic medium in heavy-ion collisions. These model calculations therefore provide valuable insight into the underlying physics governing the observed experimental results at RHIC.

2605.07519 2026-05-11 cs.IT math.IT

A Log-Domain Approximation of SOCS Decoding for Turbo Product Codes

Oleg Nesterenkov, Kirill Andreev, Alexey Frolov, Pavel Rybin

AI总结 本文研究了基于扩展Bose-Chaudhuri-Hocquenghem码的涡轮乘积码的低复杂度软输出译码方法。为了解决现有SOCS译码在概率域实现中硬件实现困难的问题,作者提出了一种基于最大对数近似的对数域SOCS译码方法,通过可靠性差距的分段线性函数替代概率域运算,保持与标准迭代译码流程的兼容性。实验结果表明,该方法在相同列表规模下性能优于传统Chase-Pyndiah译码器,并接近原SOCS译码器的性能。

Comments This work has been submitted to the IEEE for possible publication

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英文摘要

This paper studies low-complexity soft-output decoding of turbo product codes with extended Bose--Chaudhuri--Hocquenghem component codes. Recent soft-output from covered space (SOCS) decoding substantially improves the quality of extrinsic information compared with the conventional Chase--Pyndiah decoder, but its probabilistic-domain implementation is less attractive for hardware-oriented realizations. We therefore propose a log-domain approximation of SOCS based on max-log approach. The proposed soft-input soft-output rule replaces probability-domain operations with a piecewise-linear function of reliability gaps between competing Chase-II decoding list and out of the list hypotheses, which preserves compatibility with the standard iterative TPC decoding loop. Numerical results for a TPC built from (256,239) eBCH component codes show that the proposed decoder clearly outperforms the baseline Chase--Pyndiah decoder with the same list size and approaches the performance of SOCS decoder.

2605.07518 2026-05-11 quant-ph cs.DS

Loop Composition in Quantum Algorithms

Stacey Jeffery, Manideep Mamindlapally, Alex Baudoin Nguetsa Tankeu

AI总结 本文研究了量子算法中循环结构的建模问题,指出传统量子线路模型将算法视为直线程序,难以有效处理包含不同长度子程序的叠加分支结构。通过引入量子行走形式化方法,作者提出了支持分支和循环的组合方式,改进了量子算法的结构表达。该方法应用于Grover搜索算法,展示了如何通过引入循环机制获得与先前工作一致的复杂度,突显了正确建模程序控制流对设计高效量子算法的重要性。

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英文摘要

The quantum circuit model essentially treats every quantum algorithm as a straight-line program. While this view is universal, recent work has shown that it is inconvenient for using different-length quantum subroutines in superposition. Using the quantum walk formalism of quantum algorithms, it is possible to model such branching behaviour, and get better composition in this setting. We apply the above branching composition to Grover's algorithm, which gives a variable-time quantum search algorithm that is worse than previous work. The reason it is worse is because branching composition does not take into account another deviation from straight-line programs: looping. We show that by modifying branching composition to also include looping, we can get a complexity that matches previous work. This highlights the importance of properly modeling the program control flow when designing quantum algorithms.

2605.07437 2026-05-11 cond-mat.mtrl-sci

Spin-lattice coupling enables adaptive adsorption in magnetically-driven electrocatalysts

Arnold Gaje, Lulu Li, Felipe A. Garcés-Pineda, Camilo A. Mesa, Ghazaleh Abdolhosseini, Aditya K. Kushwaha, Dora Zalka, Elzbieta Trzop, Nicolas Godin, Raffaella Torchio, María Escudero-Escribano, Eric Collet, Sixto Giménez, Niels Keller, José Ramón Galán-Mascarós, Núria López, Ernest Pastor

AI总结 本文研究了如何通过磁性驱动调控电催化反应中的吸附过程,以优化催化中间体的能量。研究发现,施加外部磁场能够改变镍铁氧化物在析氧反应中的表面吸附行为,并通过调控自旋-晶格耦合引入结构灵活性,从而打破中间体之间的能量关联。这一成果为通过外部刺激调控多态能态提供了新思路,拓展了电催化和传感应用的设计策略。

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英文摘要

A major challenge in electrochemistry is to decouple the reactive intermediates of a catalytic cycle to optimise their energies independently. During the oxygen evolution reaction (OER), such energy interdependence results from the need to generate multiple adsorbates at the same site and sets the minimum overpotential. Here, we show that an external stimulus, such as a magnetic field, can relax the scaling relationships between intermediates during the OER. Spectroscopic measurements and Density Functional Theory simulations in Ni-Fe oxyhydroxides reveal that applying a magnetic field alters surface chemisorption and injects structural flexibility at the interface. We interpret these observations as a consequence of stimulated changes in the spin-lattice coupling, which allow access to quasi-degenerate oxygenated intermediates that modulate the reaction energy demands. Our findings redefine the scaling limitations as state-projected rather than intrinsic and establish external stimulation as a strategy to navigate multi-state energy landscapes in electrocatalysis and sensing applications.

2605.06616 2026-05-11 cs.DM math.CO

Adjacency labelling for proper minor-closed graph classes

Vida Dujmović, Cyril Gavoille, Gwenaël Joret, Piotr Micek, Pat Morin, David R. Wood

AI总结 本文研究了适当小图类的邻接标签方案问题,证明了每个适当小图类都存在一个接近 $\log_2 n$ 位的邻接标签方案。该结果等价于表明对于每个适当小图类和每个正整数 $n$,都存在一个顶点数为 $n^{1+o(1)}$ 的图 $U$,使得该类中所有 $n$ 顶点图都是 $U$ 的诱导子图。该结论在忽略低阶项的情况下是最佳的。

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英文摘要

We show that every proper minor-closed class of graphs admits a $(1+o(1))\log_2 n$-bit adjacency labelling scheme. Equivalently, for every proper minor-closed class $\mathcal{G}$ and every positive integer $n$ there exists an $n^{1+o(1)}$-vertex graph $U$ such that every $n$-vertex graph in $\mathcal{G}$ is isomorphic to an induced subgraph of $U$. Both results are optimal up to the lower order term.

2605.06603 2026-05-11 cond-mat.mtrl-sci

Moire based strain analysis in wurtzite GaAs -- rock-salt (Pb,Sn)Te core-shell nanowires grown by molecular beam epitaxy

Maciej Wojcik, Sania Dad, Piotr Dziawa, Slawomir Kret, Wojciech Pacuski, Janusz Sadowski

AI总结 本研究利用分子束外延技术制备了具有纤锌矿结构GaAs核心和拓扑晶体绝缘体(Pb,Sn)Te壳层的核壳纳米线结构,通过高分辨透射电镜和几何相位分析等手段,观察到了由于晶格失配引起的错配位错和莫尔条纹,并利用莫尔条纹分析估算了壳层中的应变。该方法为研究核壳纳米线结构中的应变分布提供了一种新的分析手段。

Comments 11 pages, 5 figures

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英文摘要

We investigate core/shell GaAs/(Pb,Sn)Te nanowire nanoheterostructures with wurtzite (wz) GaAs cores and (Pb,Sn)Te topological crystalline insulator shells. The nanostructures have been grown by molecular beam epitaxy using two distinct MBE systems dedicated to III-V, and IV-VI semiconductors. The interface structure of wz-GaAs/(Pb,Sn)Te nanowires is investigated using high resolution transmission electron microscopy, scanning transmission electron microscopy and geometric phase analysis. Misfit dislocations and moiré fringes are observed as a direct result of the lattice mismatch between the core and the shell materials, and used to estimate strain in crystalline topological insulator shells. Our results point to a possibility of using moiré patterns analysis as an alternative, for estimating strain in the core-shell nanowire structures.

2605.06558 2026-05-11 physics.med-ph

John Equation Constraints for the 3D X-ray Transform under a Cylindrical-Spherical Mixed Parameterization: Theoretical Derivation, Experimental Validation, and Application Analysis

Shaojie Tang, Zhiwei Qiao, Xuanqin Mou

AI总结 本文在三维欧几里得空间中提出了一种混合参数化方案,用于描述X射线变换的几何结构,并在此基础上系统推导了约翰方程的具体形式。通过坐标变换和代数简化,得到了一组完整的约束方程,并在特定几何条件下简化为具有明确物理意义的微分关系。该研究不仅建立了数学理论与实际成像几何之间的桥梁,还为三维CT系统中的数据一致性验证、几何参数标定和不完整数据重建提供了严格的数学工具,对CT成像的理论发展和应用具有重要意义。

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The John equation serves as the mathematical foundation of the X-ray transform, describing the intrinsic compatibility conditions that projection data must satisfy. In this paper, within three-dimensional (3D) Euclidean space, an innovative mixed parameterization scheme is adopted: the source point is represented using cylindrical coordinates a=(s cosθ,s sinθ,z_0), and the ray direction is represented using spherical coordinates d=\{rho}(-cos\{beta}sinα,cos\{beta}cosα,sin\{beta}). The specific form of the John equation under this geometric parameterization is systematically derived. Through detailed partial differential operator transformations, application of -1 homogeneity, and algebraic simplification, a complete system of constraint equations is obtained. In particular, under the special configurations where the ray direction is perpendicular to the radial direction of the source point in the horizontal plane (i.e., the so-called alignment condition:α = θ) and the ray has no tilt (\{beta} = 0), the constraint equations simplify to differential relations with clear physical meanings. This paper not only establishes a bridge between abstract mathematical theory and concrete imaging geometry, but also provides rigorous mathematical tools for data consistency verification, geometric parameter calibration, and incomplete-data reconstruction in 3D Computed Tomography (CT) systems. The research results are of great significance for advancing the mathematical theory and practical applications of CT imaging.