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2410.02832 2026-05-18 cs.CR cs.AI

FlipAttack: Jailbreak LLMs via Flipping

Yue Liu, Xiaoxin He, Miao Xiong, Jinlan Fu, Shumin Deng, Yingwei Ma, Jiaheng Zhang, Bryan Hooi

AI总结 本文提出了一种简单而有效的黑盒大语言模型越狱攻击方法FlipAttack。该方法利用大语言模型从左到右理解文本的特性,通过在提示左侧添加噪声干扰模型理解,从而隐藏有害指令,并进一步扩展出四种翻转模式。实验表明,FlipAttack具有高度通用性、隐蔽性和简洁性,仅需一次查询即可成功越狱,对包括GPT-4o在内的多个模型均取得了高达约98%的攻击成功率。

Comments 43 pages, 31 figures

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英文摘要

This paper proposes a simple yet effective jailbreak attack named FlipAttack against black-box LLMs. First, from the autoregressive nature, we reveal that LLMs tend to understand the text from left to right and find that they struggle to comprehend the text when noise is added to the left side. Motivated by these insights, we propose to disguise the harmful prompt by constructing left-side noise merely based on the prompt itself, then generalize this idea to 4 flipping modes. Second, we verify the strong ability of LLMs to perform the text-flipping task, and then develop 4 variants to guide LLMs to denoise, understand, and execute harmful behaviors accurately. These designs keep FlipAttack universal, stealthy, and simple, allowing it to jailbreak black-box LLMs within only 1 query. Experiments on 8 LLMs demonstrate the superiority of FlipAttack. Remarkably, it achieves $\sim$98\% attack success rate on GPT-4o, and $\sim$98\% bypass rate against 5 guardrail models on average. The codes are available at GitHub\footnote{https://github.com/yueliu1999/FlipAttack}.

2407.08094 2026-05-18 stat.ML cs.LG physics.chem-ph physics.data-an

Density Estimation via Binless Multidimensional Integration

Matteo Carli, Alex Rodriguez, Alessandro Laio, Aldo Glielmo

AI总结 本文提出了一种名为无箱多维热力学积分(BMTI)的非参数密度估计方法,用于高效、稳健地估计高维数据的密度。该方法通过计算相邻数据点之间的对数密度差异,并结合最大似然框架对其进行加权积分,从而估计密度的对数。BMTI无需对数据进行分箱或空间划分,而是基于自适应带宽选择构建邻域图,利用流形假设在数据的内在流形上进行估计,有效克服了传统非参数密度估计方法的局限性,并在高维空间中表现出优越的性能。

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英文摘要

We introduce the Binless Multidimensional Thermodynamic Integration (BMTI) method for nonparametric, robust, and data-efficient density estimation. BMTI estimates the logarithm of the density by initially computing log-density differences between neighbouring data points. Subsequently, such differences are integrated, weighted by their associated uncertainties, using a maximum-likelihood formulation. This procedure can be seen as an extension to a multidimensional setting of the thermodynamic integration, a technique developed in statistical physics. The method leverages the manifold hypothesis, estimating quantities within the intrinsic data manifold without defining an explicit coordinate map. It does not rely on any binning or space partitioning, but rather on the construction of a neighbourhood graph based on an adaptive bandwidth selection procedure. BMTI mitigates the limitations commonly associated with traditional nonparametric density estimators, effectively reconstructing smooth profiles even in high-dimensional embedding spaces. The method is tested on a variety of complex synthetic high-dimensional datasets, where it is shown to outperform traditional estimators, and is benchmarked on realistic datasets from the chemical physics literature.

2605.16256 2026-05-18 cond-mat.quant-gas cond-mat.other

Polariton BECs: Theory and Concepts

极子玻色-爱因斯坦凝聚:理论与概念

Fabrice Laussy

AI总结 本文探讨极子凝聚的形成、相干性及动力学,强调其与原子凝聚体的区别及争议点,指出线性非相互作用效应在极子物理中被低估。

Comments This preprint will appear as a chapter in the Springer book entitled Short and Long Range Quantum Atomic Platforms -- Theoretical and Experimental Developments (provisional title), edited by P. G. Kevrekidis, C. L. Hung, and S. I. Mistakidis

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AI中文摘要

极子是光与物质的叠加,结合强干涉与弱相互作用,使其成为弱相互作用、强干涉的粒子。其凝聚是量子光学、凝聚态物理和驱动耗散系统非线性动力学交汇领域的核心。本文回顾了极子凝聚体形成、相干性和动力学的理论概念,强调其与原子凝聚体的区别及争议点,认为线性和非相互作用效应在极子物理中被低估,大部分现象,包括玻色子相关性和相干性建立,往往无需引入强相互作用或真实量子效应。

英文摘要

Polaritons are a superposition of light and matter, that combine Strong Interferences (of light) with Weak Interactions (of excitons), making them WISI (Weakly-Interacting, Strongly-Interfering) particles. Their condensation is the main highlight of a field which occupies a unique position at the intersection of quantum optics, condensed matter physics and nonlinear dynamics of driven, dissipative systems. This chapter surveys selected theoretical concepts of polariton condensates' formation, coherence and dynamics, with an emphasis on their distinctions from their atomic counterparts and on points of ongoing controversy. We argue that linear and non-interacting effects are undervalued in polariton physics, and that a significant part of the phenomenology -- including bosonic correlations and coherence buildup -- can often be understood without invoking strong interactions or genuine quantum effects.

2605.16253 2026-05-18 cs.AR

TTP: A Hardware-Efficient Design for Precise Prefetching in Ray Tracing

TTP:一种用于光线追踪中精确预取的高效硬件设计

Yavuz Selim Tozlu, Anshul Naithani, Huiyang Zhou

AI总结 本文提出TTP预取器,通过利用RT单元中的树遍历栈实现高效预取,减少内存延迟,提升光线追踪性能,实验显示平均加速1.48倍,硬件开销极低。

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AI中文摘要

光线追踪(RT)是一种3D图形技术,能提供高度逼真的视觉效果。随着GPU厂商集成专用光线追踪加速硬件,RT正变得越来越突出和易用。然而,实时通过包含大量三角形的3D场景追踪数百万条光线仍具挑战性,需要昂贵的硬件。RT工作负载的主要瓶颈是昂贵的包围盒层次结构(BVH)遍历任务,这是一个编码3D场景的大型树结构。BVH遍历是内存受限的问题,因为GPU线程大部分时间都在从内存中读取树节点数据。在本工作中,我们通过预取攻击光线追踪的内存延迟瓶颈。我们提出了一种新型的硬件预取器,称为树遍历预取器(TTP),用于光线追踪。主要思想是利用RT单元中已有的树遍历栈进行高精度预取。具体而言,TTP利用每个线程硬件遍历栈上已有的地址来预取节点。对于基于深度优先搜索(DFS)的遍历,当节点连续弹出遍历栈时生成预取,这可能对应于树中的向上遍历。我们在循环级模拟器Vulkan-sim 2.0上评估了TTP,并显示其在基准上平均加速1.48倍(最高1.89倍),硬件开销几乎可以忽略不计。TTP实现了98.92%的平均L1精度,即预取块被需求加载实际引用的比例。覆盖率,计算为L1缺失减少量与基准L1缺失量的比率,为31.54%,与所达到的加速率密切相关。

英文摘要

Ray tracing (RT) is a 3D graphics technique that offers highly realistic visuals. It is becoming prominent and accessible as GPU vendors have integrated dedicated ray tracing acceleration hardware. However, tracing millions of rays through 3D scenes consisting of high numbers of triangles in real time is challenging and requires expensive hardware. The main bottleneck in RT workloads is the expensive Bounding Volume Hierarchy (BVH) traversal task, which is a large tree structure that encodes the 3D scene. BVH traversal is a memory-bound problem, as the GPU threads spend most of their time reading tree node data from memory. In this work, we attack the memory latency bottleneck of ray tracing through prefetching. We propose a novel hardware prefetcher, named Tree Traversal Prefetcher (TTP), for ray tracing. The main idea is to leverage the existing tree traversal stack in the RT units for highly accurate prefetching. In particular, TTP prefetches nodes using the addresses already available on the hardware traversal stacks of each thread. For DFS (Depth-first search) based traversal, prefetches are generated when nodes are being popped consecutively from the traversal stack, potentially corresponding to upward traversal through the tree. We evaluate TTP on a cycle-level simulator, Vulkan-sim 2.0, and show that it achieves 1.48x speedup on average (up to 1.89x) compared to the baseline, with nearly negligible hardware overhead. TTP achieves 98.92% average L1 accuracy, which is the ratio of the prefetched blocks being actually referenced by demand loads. The coverage, computed as the ratio of L1 miss reduction over baseline L1 misses, is 31.54%, correlating well with the achieved speedup.

2605.16252 2026-05-18 cond-mat.stat-mech

The fractal dimension of Brownian dynamics in liquids

液体中布朗动力学的分形维数

Michael C. Thumann, Jason Boynewicz, Giuseppe Procopio, Massimiliano Giona, Mark G. Raizen

AI总结 研究揭示液体中布朗运动速度波动的分形维数由非马尔可夫热噪声重新定义,实验和理论结合证明非平衡条件下速度分形维数为7/4。

Comments 14 pages, 13 figures

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AI中文摘要

经典Einstein-Langevin理论假设记忆less热浴,确立了粒子速度波动的通用分形维数d_v=3/2。本文通过实验和理论证明,流体惯性记忆效应根本地重新定义了这些波动的分形尺度。在分析高分辨率的布朗微球液体测量中,显示非马尔可夫流体热噪声建立了不同的速度分形维数d_v=7/4。结合非平衡短时间动力学和速度自相关函数初始尺度的理论分析,该结果确立了在具有有限非零密度的流体介质中布朗运动的非平衡普遍类。

英文摘要

The classical Einstein-Langevin theory of Brownian motion assumes a memoryless thermal bath, establishing a universal fractal dimension of $d_v = 3/2$ for the velocity fluctuations of a particle. In this Letter, we demonstrate experimentally and theoretically that fluid-inertial memory effects fundamentally redefine the fractal scaling of these fluctuations. In analyzing highly resolved measurements of Brownian microspheres in liquids, we show that the non-Markovian hydrodynamic thermal noise establishes a distinct velocity fractal dimension of $d_v = 7/4$. Coupled with theoretical analysis of non-equilibrium short-time dynamics and the initial scaling of the velocity autocorrelation function, this result establishes the non-equilibrium universality class of Brownian motion in fluid media possessing a finite non-vanishing density.

2605.16251 2026-05-18 eess.AS

Real-time Speech Restoration using Data Prediction Mean Flows

实时语音修复使用数据预测均流

Sebastian Braun

AI总结 本文提出一种结合数据预测均流的多步流匹配模型,以低延迟架构实现实时语音修复,相比现有方法,计算量减少120倍且音频质量相似。

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AI中文摘要

生成模型能够解决具有非唯一解的问题,如带宽扩展和空隙填充,去除编码器中的高度非线性伪影、 clipping 和失真,而不是去除线性加性成分如噪声和回声。尽管大型离线处理模型已取得显著成果,但这些任务尚未用具有低延迟和计算能力的实时模型解决。我们提出了一种使用数据预测均流的多步流匹配模型,结合合适的新型低延迟架构,使流匹配模型在这些约束下成为有吸引力的选择。与最先进方法相比,我们的所提均流模型使用120倍更少的计算,并且除了STFT外没有引入其他算法延迟,同时实现了相似的音频质量。

英文摘要

Generative models are capable to address difficult problems with non-unique solutions like bandwidth extension and gap filling, removing highly non-linear artifacts from codecs, clipping and distortion, as opposed to removing linear additive components like noise and reverb. While large offline processing models have shown impressive results, these tasks have not been solved with real-time capable models with low latency and compute. We propose a few-step flow matching model using Data Prediction Mean Flows in combination with suitable novel low-latency architecture to make flow matching models an attractive choice under theses constraints. Compared to state-of-the-art, our proposed mean flow model uses 120x less compute and introduces no algorithmic latency other than the STFT, while achieving similar audio quality.

2605.16249 2026-05-18 quant-ph cs.CC

The Collapse of Unentangled Stoquastic Merlin-Arthur Proof Systems

无纠缠的量子 Merlin-Arthur 证明系统崩溃

William Gay, Fernando Granha Jeronimo

AI总结 研究通过证明无纠缠无法提升stoquastic Merlin-Arthur验证能力,揭示了干涉在检测纠缠中的作用,并提出正的de Finetti定理作为核心方法,最终将StoqMa(k)纳入AM∩PP⊆PSPACE。

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AI中文摘要

量子力学中,纠缠和干涉是基本属性。本文从计算复杂性角度研究干涉在检测纠缠中的作用,证明无纠缠对stoquastic Merlin-Arthur验证无增益。对于任意多项式数量的证明者k=k(n),StoqMa(k)=StoqMa。证明将纠缠与干涉的作用分离:一旦通过stoquastic性排除破坏性干涉,乘积态约束可被多项式更大的单见证stoquastic验证吸收。主要分析成分是正的de Finetti定理,用于分别对称扩展。若M是正半定收缩矩阵,则其非负乘积值可被最大特征值近似到加性误差ε。随后,通过将对称投影中的均匀排列平均替换为逆多项式接近的双极逆不变平均,实现谱松弛作为实际的单见证stoquastic验证器。最终得出StoqMa(k)=StoqMa⊆AM∩PP⊆PSPACE。正的de Finetti定理作为独立技术,可能在其他非负张量优化和stoquastic验证场景中发挥作用。

英文摘要

Entanglement and interference are among the most fundamental properties of quantum mechanics. In this work, we investigate the role and power of interference in the context of detecting entanglement. We do so from a computational complexity lens by proving that unentanglement gives no additional power to stoquastic Merlin-Arthur verification. For every polynomial number of provers $k=k(n)$, \[ \text{StoqMa}(k)=\text{StoqMa} . \] Conceptually, the proof separates the role of entanglement from the role of interference: once destructive interference is ruled out by stoquasticity, the product-state constraint can be absorbed into a polynomially larger one-witness stoquastic verification. The main analytic ingredient is a positive, value-based de Finetti theorem for separately symmetric extensions. If $M$ is an entrywise nonnegative positive semidefinite contraction on $A_1\otimes\cdots\otimes A_k$, then the nonnegative product value of $M$ is approximated to additive error $ε$ by the largest eigenvalue of \[ Π_R^{<k} (M_{A_{1,1}\cdots A_{k-1,1}A_k}\otimes I) Π_R^{<k}, \qquad R=O\!\left(\frac{k^2\sum_i\log\dim A_i}{ε^3}\right), \] where $Π_R^{<k}$ is the operator on $A_1^{\otimes R} \otimes \cdots \otimes A_{k-1}^{\otimes R} \otimes A_k$ projecting to the subspace $\mathrm{Sym}^R(A_1) \otimes \cdots \otimes \mathrm{Sym}^{R}(A_{k-1}) \otimes A_k$. The spectral relaxation is then realized as an actual one-witness stoquastic verifier. After replacing the uniform permutation averages in the symmetric projectors by inverse-polynomially close dyadic inverse-invariant averages. Consequently, \[ \text{StoqMa}(k)=\text{StoqMa}\subseteq\text{AM}\cap\text{PP}\subseteq\text{PSPACE} . \] The positive de Finetti theorem is isolated as a standalone technique and may be useful in other nonnegative tensor-optimization and stoquastic-verification settings.

2605.16248 2026-05-18 quant-ph

Local Softmax and Global Weights in Non-Boolean Event Structures

局部Softmax与非布尔事件结构中的全局权重

Karl Svozil

AI总结 研究非布尔事件结构中局部Softmax与全局权重的关系,揭示单值性对共享原子的影响,以及严格正可接受权重的表示方法。

Comments 12 pages, 1 figure, 1 table

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AI中文摘要

Softmax及相关归一化响应函数广泛应用于选择理论、机器学习和认知科学。然而在具有重叠上下文的非布尔事件结构中,局部归一化并不自动产生全局概率权重。本文表明,对共享原子施加单值性——等价于无干扰或一致连通性——会将广义Softmax规则归约为严格正部分可接受权重多面体的坐标参数化。任何严格正的可接受权重都可以以这种方式表示,而边界权重则作为极限出现。因此,超出经典或量子界限的奇异权重是事件结构和所选权重的属性,而非归一化链接的属性。所得到的层次结构将局部归一化、跨上下文粘合、Cauchy-Gleason线性以及物理或认知可实现性区分开来。

英文摘要

Softmax and related normalized response functions are widely used in choice theory, machine learning, and cognitive science. In non-Boolean event structures with overlapping contexts, however, local normalization does not automatically yield a global probability weight. We show that imposing single-valuedness on shared atoms -- equivalently, no-disturbance or consistent connectedness -- collapses generalized softmax rules to coordinate parametrizations of the strictly positive part of the admissible-weight polytope. Any strictly positive admissible weight can be represented in this way, while boundary weights arise as limits. Exotic weights that exceed classical or quantum bounds are therefore properties of the event structure and the chosen weight, not of the normalizing link. The resulting hierarchy separates local normalization, cross-context gluing, Cauchy--Gleason linearity, and physical or cognitive realizability.

2605.16247 2026-05-18 cond-mat.stat-mech

Brownian motion: non-equilibrium states from equilibrium trajectories -- recovering hydrodynamic regimes from prepared displacement measurements

布朗运动:从平衡轨迹中获得非平衡态——通过准备位移测量恢复流体动力学 regime

Jason Boynewicz, Michael C. Thumann, Giuseppe Procopio, Massimiliano Giona

AI总结 通过分析单个布朗轨迹的非平衡性质,揭示流体-粒子相互作用的微尺度细节,并连接到流体动力学,利用粒子位置的低阶矩确定短时间位移统计,验证了流体惯性效应的t^{5/2}定律,并指出在考虑随机力相关性时可能被t^4尺度取代。

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AI中文摘要

由于马尔可夫动力学的 Chapman-Kolmogorov 方程,布朗粒子在流体中的任何平衡轨迹均可视为非平衡态的叠加。这一性质允许通过分析单个布朗轨迹来揭示微尺度的流体-粒子相互作用细节,并将其与流体的流体动力学联系起来,仅需考虑被捕获条件下的粒子位置的低阶(第二)矩。通过这种方式,热-流体波动力的加速度可从其他因素中分离出来,短时间位移统计完全由波动热-流体力的相关性质决定。该方法不仅验证了 Boynewicz 等人 (2026) 所获得的与流体惯性效应相关的 t^{5/2} 法则,还表明在考虑随机力的相关性时,该尺度可能被 t^4 的尺度所取代。后者结果与粒子速度实现实的正则性性质有关。

英文摘要

Owing to the Chapman-Kolmogorov equation for Markovian dynamics,any equilibrium trajectory of a Brownian particle in a solvent fluid can be viewed as the superposition of an uncountable number of non-equilibrium states. This property permits the unraveling of fine details of fluid-particle interactions at microscales defined by its non-equilibrium properties from the analysis of a single Brownian trajectory and to connect them to the hydrodynamics of the solvent fluid, simply considering the lower-order (second) moments of particle position in trapped conditions. In this way, the acceleration due to thermal-hydrodynamic fluctuational forces is isolated from the other factors and the short-time displacement statistics is completely determined by the correlation properties of the fluctuational thermal-hydrodynamic force. This approach not only confirms the $t^{5/2}$-law obtained by Boynewicz et al. (2026), related to fluid inertial effects, but indicates that this scaling may be superseded by a $t^4$-scaling at very short times once the correlated nature of the stochastic forcings is taken into account. The latter result is related to the regularity properties of particle velocity realizations.

2605.16246 2026-05-18 stat.ME stat.ML

FRESH: Information-Geometric Calibration of Patient-Level Models to Aggregate Evidence

FRESH:信息几何校准患者级模型以聚合证据

Franklin Fuller, Daniele Bertolini, Samantha Liang, Jason Christopher, Aaron M. Smith

AI总结 FRESH通过信息几何方法将群体层面结果与患者层面数据结合,提升临床决策模型的效率与准确性。

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AI中文摘要

本文介绍FRESH(近期证据与患者历史融合),一种将群体层面总结结果——已发表的临床试验、注册摘要、先前自然史研究和同行评审的间接比较——纳入基于患者层面数据训练的预测模型中的方法。该方法提供了一种系统地将患者层面和汇总层面数据类型结合到统一的、数据高效的模型中的方法,用于临床决策。FRESH假设可以访问一个基于患者层面数据源(例如临床试验或真实世界数据)训练的生成模型。该方法通过重新校准的模型产生患者层面的预测,该模型匹配目标人群指定的汇总统计量。这可以理解为对汇总源的患者层面重演——其关键特性是重新校准是对原始联合分布在特定信息几何意义上的最小扰动。生成的样本可以直接分析或结合到后训练过程中以更新原始生成模型。这种方法使在需要严格纳入患者层面数据与汇总信息的多个应用中变得可行,包括(i)将单臂试验结果与最近的标准化护理进行上下文化,(ii)用于临床试验设计和技术成功概率估计的临床试验模拟,以及(iii)对上市药物的比较有效性分析。

英文摘要

This note introduces FRESH (Fusion of Recent Evidence and Subject Histories), a method for incorporating population-level summary results -- published clinical trials, registry summaries, prior natural-history studies, and peer-reviewed indirect comparisons -- into predictive models trained on patient-level data. This method provides a principled means of combining both patient-level and aggregate-level data types into a unified data-efficient model for clinical decision making. FRESH assumes access to a generative model trained on patient-level data sources (e.g. clinical trial or real-world data). The method produces patient-level predictions from a re-calibrated model that matches a set of specified aggregate statistics for a target population. This can be understood as a patient-level recapitulation of the aggregate source -- with the key property that the recalibration is a minimal perturbation of the original joint distribution in a specific information-geometric sense. The resulting samples can be analyzed directly or combined into a post-training procedure to update the original generative model. This approach enables several applications where rigorously incorporating patient-level data with summary information is valuable, including (i) contextualizing single-arm trial results with respect to recent standard-of-care, (ii) clinical-trial simulations for design and probability-of-technical-success estimation, and (iii) comparative-effectiveness analyses of on-market therapies.

2605.16244 2026-05-18 math.PR math.CO

Burnside process on parking functions and Dyck paths

Burnside过程与停车函数及Dyck路径

Ivan Z. Feng, J. E. Paguyo

AI总结 本文研究了Catalan结构上的Burnside过程,通过置换坐标和标签,提出新的近似均匀采样停车函数和Dyck路径的算法,并证明两者具有O(n log n)的快速混合性。

Comments 17 pages, 2 figures

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AI中文摘要

设G为有限群,作用于有限集X上。该群作用将X分成不相交的轨道。Burnside过程是X上的马尔可夫链,当投影到轨道时具有均匀的平稳分布。本文首次研究Catalan结构上的Burnside过程。考虑两种特殊情况:第一种状态空间为长度为n的停车函数集,G=S_n作用于坐标;第二种状态空间为长度为2n的标记Dyck路径集,G=S_n作用于标签。所得Burnside过程分别给出近似均匀采样递增停车函数和Dyck路径的新型算法。主要结果表明,这两种过程具有快速混合性,混合时间上界为O(n log n)。作为应用,本文展示如何利用Burnside过程近似均匀采样(n+2)边形的三角剖分。

英文摘要

Let $G$ be a finite group acting on a finite set $X$. This group action splits $X$ into disjoint orbits. The Burnside process is a Markov chain on $X$ which has a uniform stationary distribution when the chain is projected to orbits. We initiate the study of the Burnside process on Catalan structures. We consider two special cases: the first where the state space is the set of parking functions of length $n$ and $G = S_n$ is the symmetric group on $[n]$, such that $G$ acts by permuting coordinates, and the second where the state space is the set of labeled Dyck paths of length $2n$ and $G = S_n$ acts by permuting labels. The resulting Burnside processes give novel algorithms for sampling, respectively, an increasing parking function and a Dyck path approximately uniformly at random. Our main result shows that both processes are rapidly mixing, with mixing times upper bounded by $O(n \log n)$. As an application, we show how our Burnside process can be used to sample triangulations of an $(n+2)$-gon approximately uniformly at random.

2605.16243 2026-05-18 physics.plasm-ph astro-ph.HE

Stern--Gerlach Spin Sorting in Relativistic Magnetic Reconnection

斯图尔德-格尔克Spin排序在相对论性磁重联中

K. Nykyri

AI总结 本文提出一个斯图尔德-格尔克spin-kinetic控制参数用于磁重联,通过分析不同环境中的参数,揭示了在磁力尾、日冕等环境中SG传输可忽略,而在磁星电流片中则显著,为强场spin-kinetic重联提供了研究框架。

Comments 4 pages includiing two figures, supplementary material with 3 figures

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AI中文摘要

我们引入了一个斯图尔德-格尔克(SG)spin-kinetic控制参数用于磁重联。完全投影分支参数,$Ξ_0=<Z>/r_L$比较了SG横穿片位移在扩散区域传输期间积累的量与相对论性劳伦兹半径。对于一个群体或部分参与的群体,相关有效参数是$Ξ_{\ m Eff}=P_{\ m eff}Ξ_0$,其中$P_{\ m eff}$代表存活分支权重或有效spin/动量投影。评估$Ξ_{\ m Eff}$在代表性的空间和天体物理环境中揭示出一个稳健的层级:在磁力尾、日冕、活动星系核(AGN)/blazar喷流、脉冲星风 nebula 中SG传输可忽略,但在磁星电流片和极端近磁星表面则变为过渡到强的。我们进一步通过电子-正电子粒子-细胞模拟显示,SG力将粒子按磁动量投影分为电流片的两侧而不显著改变重联率。这表明磁星是强场spin-kinetic重联($Ξ_{\ m eff}\gg 1$)的最清晰自然目标,而在外磁osphere中则是过渡的,而SG传输在所有考虑的太阳物理和喷流环境中都是安全可忽略的($Ξ_{\ m eff}\ll 1$),并提供了一个可检验的框架来评估SG物理的相关性。

英文摘要

We introduce a Stern--Gerlach (SG) spin-kinetic control parameter for magnetic reconnection. The fully projected branch parameter, $Ξ_0=<Z>/r_L$ compares the SG cross-sheet displacement accumulated during a diffusion-region transit with the relativistic Larmor radius. For an ensemble or partially participating population the relevant effective parameter is $Ξ_{\rm Eff}=P_{eff}Ξ_0$, where $P_{eff}$ represents the surviving branch weight or effective spin/moment projection. Evaluating $Ξ_{\rm Eff}$ across representative space and astrophysical environments reveals a robust hierarchy: SG transport is negligible in the magnetotail, solar corona, active galactic nuclei (AGN)/blazar jets, and pulsar-wind nebulae, but becomes transitional to strong in magnetar current sheets and extreme near magnetar surfaces. We further show, using electron--positron particle-in-cell simulations, that the SG force sorts particles by magnetic-moment projection into opposite sides of a Harris current sheet without measurably changing the global reconnection rate in the tested regime. This identifies magnetars as the clearest natural target for strong-field spin-kinetic reconnection ($Ξ_{\rm eff}\gg 1$) near the surface; transitional in the outer magnetosphere), while SG transport is safely negligible ($Ξ_{\rm eff}\ll 1$) in all heliophysical and jet environments considered, and provides a falsifiable framework for assessing where SG physics is relevant.

2605.16242 2026-05-18 cond-mat.mtrl-sci cond-mat.mes-hall cond-mat.str-el

Near-degenerate competing magnetic orders in EuAgAs: a tunable route to altermagnetism

近退简的 competing 磁序在 EuAgAs 中:一种可调的 alternate 磁性路线

Mohamed El Gazzah, Daniel Kaplan, Zachary Morgan, Abhijeet Nayak Resham Regmi, Sk Jamaluddin, Huibo Cao, Igor I. Mazin, Nirmal J. Ghimire

AI总结 研究揭示 EuAgAs 中 AFM 结构与近退简的 FM/AM 磁序,通过 DFT 计算显示其磁序可调,压力下可转为 alternate 磁性,为拓扑 alternate 磁性提供平台。

Comments 9 pages + supplementary

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AI中文摘要

Alternate 磁体 (AMs) 近年来作为一种独特的磁性类别出现,连接 ferromagnets (FMs) 和 antiferromagnets (AFMs) 的核心特征,为基于自旋的电子学提供新机会。尽管它们像 collinear AFMs 一样具有零净磁化,但同时表现出依赖动量的自旋分裂,这曾被认为是 FMs 的专属特性。尽管理论兴趣浓厚,但能同时容纳 alternate 磁性和非平凡带拓扑的实验材料仍很少。EuAgAs,属于空间群 $P6_3/mmc$,之前通过密度泛函理论 (DFT) 被识别为 bulk alternate 磁性 Dirac 半金属。与这些预测相反,我们的中子衍射实验显示,bulk 基态采用 $\mathbf{q} = (0,0,\tfrac{1}{2})$ 的 AFM 结构,具有平面内的 $\uparrow\uparrow\downarrow\downarrow$ 自旋序列。然而,系统性的 DFT 计算揭示了 competing 磁序之间的显著近退简:FM 和 AM 配置分别仅比 AFM 基态高 $0.11$ 和 $0.40~\text{meV/f.u.}$。我们进一步表明,虽然简单的 Heisenberg 模型倾向于 spin-spiral 基态,但加入非 Heisenberg 的 biquadratic 耦合稳定了观察到的 commensurate AFM 相。这种近退简使磁态高度可调,DFT 预测在约 $14 \text{ GPa}$ 的静水压力下可转为 alternate 磁性相,使 EuAgAs 成为可调节的平台,用于访问拓扑 alternate 磁性。

英文摘要

Altermagnets (AMs) have recently emerged as a distinct magnetic class bridging central features of ferromagnets (FMs) and antiferromagnets (AFMs), offering new opportunities for spin-based electronics. While they possess zero net magnetization like collinear AFMs, they simultaneously exhibit momentum-dependent spin splitting long thought exclusive to FMs. Despite intense theoretical interest, experimentally accessible materials hosting both altermagnetism and nontrivial band topology remain scarce. EuAgAs, crystallizing in space group $P6_3/mmc$, was previously identified via density functional theory (DFT) as a bulk altermagnetic Dirac semimetal. Contrary to these predictions, our neutron diffraction experiments reveal that the bulk ground state adopts a $\mathbf{q} = (0,0,\tfrac{1}{2})$ AFM structure with an in-plane $\uparrow\uparrow\downarrow\downarrow$ spin sequence. Systematic DFT calculations, however, uncover a remarkable near-degeneracy among competing magnetic orders: the FM and AM configurations lie only $0.11$ and $0.40~\text{meV/f.u.}$ above the AFM ground state, respectively. We further show that while a simple Heisenberg model favors a spin-spiral ground state, the inclusion of non-Heisenberg biquadratic coupling stabilizes the observed commensurate AFM phase. This near-degeneracy renders the magnetic state highly tunable, with DFT predicting a transition to the altermagnetic phase under hydrostatic pressure at approximately $14 \text{ GPa}$, establishing EuAgAs as a controllable platform for accessing topological altermagnetism.

2605.16236 2026-05-18 cond-mat.mes-hall physics.optics

Acoustic spin resonance in polariton condensates

极子凝聚体中的声子自旋共振

D. A. Saltykova, A. Kudlis, A. V. Yulin, I. A. Shelykh

AI总结 研究极子凝聚体中声子自旋共振现象,通过声波产生有效磁场驱动极化振荡,揭示自旋依赖相互作用和非线性特性,以及非平衡态下的双稳态行为。

Comments 8 pages + 13 pages of Supplementary Materials

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AI中文摘要

我们理论上研究了均匀极子凝聚体中的声子自旋共振。纵向声波产生时间周期性的应变诱导有效磁场,作用于凝聚体赝自旋。当该磁场垂直于静态平面线极化分裂时,它共振驱动极化振荡。我们显示自旋依赖相互作用改变共振并产生非线性线形,而增益、储层动力学和自旋弛豫使响应耗散且历史依赖,产生振幅滞后。在寿命各向异性存在下,凝聚体可以发展出具有有限圆极化率的双稳态,共振声波驱动可以在对应的垂直分支间切换。Zeeman分裂提供额外的保守调节共振频率的手段。我们的结果识别出相干声波驱动作为实现共振、非线性和可切换控制极子赝自旋动力学的途径。

英文摘要

We theoretically investigate acoustic spin resonance in a spatially homogeneous spinor polariton condensate. A longitudinal acoustic wave generates a time-periodic strain-induced effective magnetic field acting on the condensate pseudospin. When this field is transverse to the static in-plane linear-polarization splitting, it resonantly drives polarization oscillations. We show that spin-dependent interactions shift the resonance and produce nonlinear line shapes, while gain, reservoir dynamics, and spin relaxation make the response dissipative and history-dependent, producing amplitude hysteresis. In the presence of lifetime anisotropy, the condensate can develop a bifurcated stationary state with finite circular polarization, and a resonant acoustic drive can switch between the corresponding out-of-plane branches. A Zeeman splitting provides an additional conservative knob for tuning the resonance frequency. Our results identify coherent acoustic driving as a route to resonant, nonlinear, and switchable control of polariton pseudospin dynamics.

2605.16235 2026-05-18 gr-qc math-ph math.AP math.MP

Nonlinear stability of continuously self-similar naked singularities for the Einstein-scalar field equations I: main results

非线性稳定性的连续自相似裸奇点对于爱因斯坦-标量场方程I:主要结果

Weihao Zheng

AI总结 本文研究了爱因斯坦-标量场方程中连续自相似裸奇点的非线性稳定性,通过局部Hölder拓扑证明了小扰动下的稳定性,挑战了Christodoulou关于裸奇点不稳定性的结论。

Comments 54 pages

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AI中文摘要

本文是关于证明爱因斯坦-标量场方程中一个参数族连续自相似$C^{1,α}$裸奇点解的非线性稳定性的一系列论文中的第一部分。稳定性适用于初始扰动位于生成这些裸奇点解数据的小开邻域内,以局部Hölder拓扑度量。这些连续自相似裸奇点时空此前由Christodoulou构造,并证明了在足够粗糙扰动下对黑洞形成的不稳定性。本文首次在相同正则性下证明了这些裸奇点时空的非线性稳定性,依赖于前文建立的线性化稳定性结果。我们的结果强调了函数框架在提出弱宇宙 censorship 猜想中的关键作用。

英文摘要

This is the first part of a series of papers proving the nonlinear stability of a one-parameter family of continuously self-similar $C^{1,α}$ naked singularity solutions, with $0<α\ll1$, to the spherically symmetric Einstein-scalar field equations. The stability holds for initial perturbations lying in a small open neighborhood of the data generating these naked singularity solutions, measured in a localized Hölder topology. These continuously self-similar naked singularity spacetimes were previously constructed by Christodoulou [D. Christodoulou, Examples of naked singularity formation in the gravitational collapse of a scalar field, Ann. of Math. 140 (1994), 607--653], who also proved their instability to black hole formation under sufficiently rough perturbations [D. Christodoulou, The instability of naked singularities in the gravitational collapse of a scalar field, Ann. of Math. 149 (1999), 183--217], thereby verifying weak cosmic censorship within a rough functional framework. In complete contrast, in this paper, we obtain the first nonlinear stability of these naked singularity spacetimes under general perturbations of the same regularity as the background. We rely on the linearized stability result established in the companion paper [J. Singh and W. Zheng, Nonlinear stability of continuously self-similar naked singularities for the Einstein--scalar field equations II: linearized stability]. Our result underscores the decisive role of the functional framework in formulating the Weak Cosmic Censorship conjecture.

2605.16231 2026-05-18 hep-ph

Scheme-invariant stratified factorization algebras for inclusive deep inelastic scattering

包容深非弹性散射中不变分层因子化代数方案

Dustin Keller

AI总结 本文提出一种结合渐近重构和方案不变性的因子化代数结构,用于描述深非弹性散射中的物理测量,通过类型化和过滤结构整合了主干分析、重叠减除、Wilson线缩减等方法。

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AI中文摘要

包容深非弹性散射因子化结合了两个通常分开处理的特征:从硬和长距离数据中对电流-电流矩阵元的渐近重构,以及在有限变化的共线方案或算子基下不变性。我们将其作为单一证明对象。该构造将主导区域分析、重叠减除、Wilson线缩减、有限方案核和物理测量整合为一种类型化和过滤的结构,在紧缩的渐近区域空间上。其核心载体是平衡的硬-共线核心,其上覆盖有限方案变换的界面代数。硬QCD输入是将此核心与区域代数的共线边缘之间的方案平衡比较映射的构造。一旦此比较通过所选幂次精度成为等价,且测量降维到卷积,标准DIS卷积公式就形式上成立且不依赖所选方案表示。我们分离了这一形式推论与构造边缘等价所需的分析QCD义务,描述Collins式减除为区域格上的下降和莫比乌斯反演,并给出与$\overline{\mathrm{MS}}$和DIS表示相关的有限检验。该框架旨在作为证明基础设施而非新的DIS系数函数计算。它提供了诊断缺失区域、非闭合算子扇区、非平衡测量和失败边缘等价的工具,并为未来证明助手和机器学习实现因子化工作流提供类型化接口。

英文摘要

Inclusive deep inelastic scattering factorization combines two features that are often treated separately: an asymptotic reconstruction of the current-current matrix element from hard and long-distance data, and an invariance under finite changes of collinear scheme or operator basis. We formulate these two features as a single proof object. The construction packages the leading-region analysis, overlap subtraction, Wilson-line reduction, finite scheme kernels and physical measurement into a typed, filtered structure on a compactified space of asymptotic regimes. Its central carrier is the balanced hard-collinear core over the interface algebra of finite scheme transformations. The hard QCD input is the construction of a scheme-balanced comparison map from this core to the collinear collar of the regime algebra. Once this comparison is an equivalence through the chosen power accuracy and the measurement descends to convolution, the standard DIS convolution formula follows formally and independently of the chosen scheme presentation. We separate this formal implication from the analytic QCD obligations needed to construct the collar equivalence, describe Collins-style subtraction as descent and Möbius inversion on the region poset, and give a finite check relating $\overline{\mathrm{MS}}$ and DIS presentations. The framework is intended as proof infrastructure rather than as a new calculation of DIS coefficient functions. It supplies diagnostics for missing regions, nonclosed operator sectors, nonbalanced measurements and failed collar equivalences, and it gives a typed interface for future proof-assistant and machine-learning implementations of factorization workflows.

2605.16229 2026-05-18 cs.IT math.IT math.ST stat.ML stat.TH

Breaking the Finite-Sample Barrier in Entropy Coupling

突破有限样本障碍的熵耦合

Shahab Asoodeh, Jun Chen

AI总结 本文提出最小列表熵耦合,研究依赖性观测如何突破有限样本限制,通过条件熵分析揭示独立观测指数减少不确定性,而依赖观测可有限样本消除不确定性。

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AI中文摘要

边际受限观测间的依赖可以打破有限样本障碍。为形式化这一现象,我们引入最小列表熵耦合H(P∥Q₁,…,Qₘ),即所有具有给定离散边际分布P和Yᵢ∼Qᵢ的联合分布中最小的条件熵H(X|Y₁,…,Yₘ)。与基于独立观测的经典方法不同,我们的模型允许Y₁,…,Yₘ任意依赖,同时保持每个边际固定。扩大耦合空间揭示了明确二元性:独立观测使残余不确定性指数级减少,而依赖观测可在有限样本后精确消除。我们通过必要充分条件刻画零熵区域,并给出具体结构准则。特别地,在温和的支持假设下,零熵可通过O(log(1/Pₘin))观测实现,其中Pₘin是P的最小非零质量。我们还开发了具有单调近似保证的贪心算法以计算H(P∥Q₁,…,Qₘ)。最后,我们展示相同框架可形式化有限样本限制在分布匹配表示学习和随机性提取中,其中零熵对应于精确恢复和提取。

英文摘要

Dependence among marginally constrained observations can break a finite-sample barrier. To formalize this phenomenon, we introduce the \emph{minimum list entropy coupling} $H(P\|Q_1,\dots,Q_m)$, the minimum conditional entropy $H(X|Y_1,\dots,Y_m)$ over all joint distributions with prescribed discrete marginals $X\sim P$ and $Y_i\sim Q_i$. Unlike classical formulations based on independent observations, our model allows $Y_1,\dots,Y_m$ to be arbitrarily dependent while keeping each marginal fixed. This enlarged coupling space reveals a sharp dichotomy: independent observations reduce residual uncertainty exponentially, whereas dependent observations can eliminate it exactly after finitely many samples. We characterize this zero-entropy regime through necessary and sufficient conditions and give concrete structural criteria under which it occurs. In particular, under mild support assumptions, zero entropy is achieved with $O(\log(1/P_{\min}))$ observations, where $P_{\min}$ is the minimum nonzero mass of $P$. We also develop a greedy algorithm with monotone approximation guarantees for computing $H(P\|Q_1,\dots,Q_m)$. Finally, we show that the same framework formalizes finite-sample limits in distribution-matching representation learning and randomness extraction, where zero entropy corresponds to exact recovery and exact extraction.

2605.16228 2026-05-18 hep-ex

Observation of a $B_c^{*+}$ meson with the ATLAS detector

观测 $B_c^{*+}$ 强子

ATLAS Collaboration

AI总结 本研究首次观测到一种新强子态,其衰变为$B_c^+$和光子,通过三缪子最终态重建,质量差测量为64.5±1.4 MeV,符合$B_c^{*+}$作为$\bar{b}c$系统最低矢量态的理论预期。

Comments 32 pages in total, author list starting page 15, 2 figures, 1 table, submitted to PRL. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/BPHY-2022-03/

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AI中文摘要

利用在大型强子对撞机上由ATLAS探测器收集的13 TeV质心能下的pp碰撞数据集(对应140 fb$^{-1}$的积分亮度),首次观测到一种新强子态,其衰变为 $B_c^+$ 和光子。$B_c^+$ 强子通过三缪子最终态($B_c^+\to J/ψ(μ^+μ^-)μ^+ν_μX$)重建,同时利用光电转换在探测器材料中重建光子。新态的显著性超过8个标准差。新强子态与基态 $B_c^+$ 强子的质量差测量为64.5±1.4(stat.)±1.0~−1.4(syst.) MeV。这对应观测态的质量为6339.0±1.4(stat.)±1.0~−1.4(syst.)±0.3(m_{B_c^+}) MeV,其中最后一个不确定性源于 $B_c^+$ 强子质量的最佳精度。低质量差值符合 $B_c^{*+}$ 强子作为 $\bar{b}c$ 轻子对强子系统最低矢量态的理论预期。

英文摘要

The first observation of a new meson state decaying into $B_c^+$ and a photon is presented using a dataset of $pp$ collisions at a centre-of-mass energy $\sqrt{s} = 13$ TeV collected by the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb$^{-1}$. The $B_c^+$ mesons are reconstructed from a three-muon final state from $B_c^+\to J/ψ(μ^+μ^-)μ^+ν_μX$ decays, along with photons reconstructed via conversions to electron-positron pairs in the detector material. The new state is observed with a significance that exceeds 8 standard deviations. The mass difference between the new meson state and the ground-state $B_c^+$ meson is measured to be $64.5 \pm 1.4\text{(stat.)}^{+1.0}_{-1.4}\text{(syst.)}$ MeV. This corresponds to a mass for the observed state of $6339.0 \pm 1.4\text{(stat.)}^{+1.0}_{-1.4}\text{(syst.)}\pm 0.3(m_{B_c^+})$ MeV, where the last uncertainty is due to the precision of the best knowledge of the $B_c^+$ meson mass. The low mass difference value matches the theory expectations for the lowest vector state of the $\bar{b}c$ quarkonium system, the $B_c^{*+}$ meson.

2605.16227 2026-05-18 cs.CR

LymphNode: A Plug-and-Play Access Control Method for Deep Neural Networks

LymphNode: 一种用于深度神经网络的即插即用访问控制方法

Hanyu Pei, Shang Liu, Zeyan Liu

AI总结 LymphNode提出一种新型后处理防御框架,通过注入通用稀疏通用对抗扰动阻止模型提取和逆向攻击,实现轻量级且高效的访问控制。

Comments Accepted by the 56th Annual IEEE/IFIP International Conference on Dependable Systems and Networks (DSN 2026). Author accepted manuscript. 14 pages, 6 figures

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AI中文摘要

深度神经网络(DNN)是高价值知识产权,但部署到边缘环境会暴露于无限制的oracle访问,导致模型提取和逆向攻击。现有防御措施无法有效解决这一问题:被动水印仅提供事后溯源,而主动防御则导致延迟过高或需要持续访问敏感训练数据。为此,我们提出LymphNode,一种新的后处理防御框架,作为模型内在的『免疫系统』。LymphNode实施严格『默认拒绝』策略:通过注入通用稀疏通用对抗扰动,主动中和未经授权查询的模型效用,有效阻止梯度估计和数据推断。只有授权输入携带隐秘的特征域凭证时,效用才会被选择性恢复。我们的框架高度实用:它具有数据高效性,仅需少于100个样本(<1%的训练数据)即可建立稳健保护,并具有跨数据集适应性,允许使用公开的替代数据集进行保护。LymphNode因此为高风险场景提供了一种轻量级、可立即部署的防御措施,其中原始训练数据受限或不可用。

英文摘要

Deep Neural Networks (DNNs) are high-value intellectual property (IP), yet deploying them to edge environments exposes them to \textbf{unrestricted oracle access}, rendering them vulnerable to model extraction and inversion attacks. Existing defenses fail to address this practically: passive watermarking only offers post-hoc provenance, while active defenses impose prohibitive latency or require persistent access to sensitive training data. To bridge this gap, we propose \textit{LymphNode}, a novel post-hoc defense framework that acts as an intrinsic ``immune system" within the model. \textit{LymphNode} enforces a strict ``default-deny'' policy: it actively neutralizes model utility for unauthorized queries via \textbf{Generalized Sparse Universal Adversarial Perturbations (GSUAP)} injected into the feature space, effectively blocking gradient estimation and data inference. Utility is selectively restored only for authorized inputs carrying a stealthy feature-domain credential. Our framework is highly practical: it is \textbf{data-efficient}, establishing robust protection with fewer than 100 samples ($<1\%$ of training data), and \textbf{cross-dataset adaptable}, enabling protection using public surrogate datasets. \textit{LymphNode} thus provides a lightweight, immediately deployable defense for high-stakes scenarios where original training data is restricted or unavailable.

2605.16225 2026-05-18 cs.IT cs.NI cs.SY eess.SY math.IT

Preemption Revisited: Multi-Threshold Preemption Policies for AoI Minimization

重新审视预emption:用于最小化信息年龄的多阈值预emption策略

Sahan Liyanaarachchi, Sennur Ulukus, Nail Akar

AI总结 本文研究了随机更新到达系统的多阈值预emption策略,通过分析框架评估信息年龄,并展示其在信息年龄优化中的有效性。

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AI中文摘要

在信息年龄(AoI)文献中,最优预emption策略的研究一直是热点问题,阈值结构在生成-at-will更新生成模型下被证明是优化的。本文研究了随机更新到达系统的阈值策略有效性,引入了评估多阈值预emption策略信息年龄的分析框架,并展示了最优预emption策略的结构特性。我们证明了这些阈值策略在传统概率预emption策略和单阈值策略上更有效,通过结合数据包年龄和系统年龄设计策略,可显著降低信息年龄。

英文摘要

The study of optimal preemption policies for status update systems has been a recurring topic in the age of information (AoI) literature, where threshold-based structures have been shown to be optimal under a generate-at-will update generation model under certain assumptions. In this work, we study the effectiveness of threshold-based policies for a system with random update arrivals. In this regard, we introduce an analytical framework for evaluating the AoI of multi-threshold preemption policies and present interesting characteristics of the structure of the optimal preemption policy. We show the effectiveness of these threshold-based policies over the traditional probabilistic preemption policies and single-threshold policies, where we observe that significant gains in terms of AoI can be obtained by utilizing both the age of the packet and the age of the system when designing these preemption policies.

2605.16224 2026-05-18 math.CO

The Facial Common Neighbourhood Graph

面部共同邻域图

Riccardo W. Maffucci

AI总结 研究多面体的共同邻域图的平面性,引入面部共同邻域图概念,并解决极值图论问题。

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AI中文摘要

给定一个多面体(平面、3-连通图)G,我们研究其共同邻域图con(G)。对于立方(3-正则)多面体,我们证明con(G)的平面性取决于G中奇数面的数量及其相邻情况。我们证明对于其他多面体,con(G)是非平面的。我们引入了多面体(更一般地说,平面图)G的新概念,即'面部共同邻域图'facecon(G)。其定义考虑了具有相同面上的共同邻居的顶点对。它是con(G)的生成子图,对于立方多面体与con(G)相同。它还推广了径向图的反向构造。作为研究的一部分,我们证明了一个技术结果:如果一个极大平面图(球面三角剖分)恰好有两个奇数度顶点,则它们不相邻。我们还回答了极值图论中的几个问题。固定顶点数,我们刻画了con(G)为平面且边数最小/最大时的多面体G。我们针对facecon(G)解决了相同问题,并证明如果facecon(G)是极大平面图,则G没有长度大于6的面。我们特别刻画并明确构造了所有多面体G的最大面长为4且facecon(G)为极大平面图的实例。

英文摘要

Given a polyhedron (planar, $3$-connected graph) $G$, we investigate its common neighbourhood graph con($G$). For cubic ($3$-regular) polyhedra, we show that the planarity of con($G$) depends on the number of odd faces of $G$, and on their adjacency. We then prove that for all other polyhedra, con($G$) is non-planar. We introduce a novel concept for polyhedra (and more generally, for plane graphs) $G$, namely the `facial common neighbourhood graph' facecon($G$). Its definition takes into account pairs of vertices with a common neighbour on the same face of $G$. It is a spanning subgraph of con($G$), that coincides with con($G$) for cubic polyhedra. It also generalises the reverse construction of the radial graph. As part of our investigation, we also prove a technical result of independent interest: if a maximal planar graph (triangulation of the sphere) has exactly two vertices of odd degree, then they are not adjacent. We also answer several questions in extremal graph theory. Fixing the number of vertices, we characterise the polyhedra $G$ such that con($G$) is planar and the number of edges in con($G$) is minimal/maximal. We address the same problem for facecon($G$), and prove that if it is maximal planar, then $G$ has no face of length greater than $6$. We notably characterise and explicitly construct all polyhedra $G$ of maximal face length $4$ such that facecon($G$) is maximal planar.

2605.16221 2026-05-18 stat.ME stat.AP

Why Empirical p-Values Are Not Uniform: Reference Samples, Dependence, and PIT Backtesting

为什么经验p值不遵循均匀分布:参考样本、依赖性和PIT回测

Jakub Lis

AI总结 研究指出经验p值因参考样本和依赖性影响,不遵循均匀分布,需改进回测方法以考虑两阶段采样结构。

Comments 16 pages, 5 figures

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AI中文摘要

概率积分变换(PITs)和经验p值广泛用于评估预测分布的校准。尽管精确PIT值在模型正确规范下服从均匀分布,但实际应用依赖于有限样本构建的经验估计。本文显示,这一估计步骤从根本上改变了问题的统计结构。特别是,共同样本和滚动窗口实现引入了依赖性和方差扭曲,使经典单样本均匀性检验失效。当经验分位数基于共享参考样本时,所得统计量趋向于双样本Kolmogorov-Smirnov情形,而滚动窗口则诱导自相关和方差抑制。研究发现,将经验分位数视为独立均匀抽样会扭曲统计推断,基于PITs的回测程序需采用修正的校准方法以考虑底层两阶段采样结构。

英文摘要

Probability integral transforms (PITs) and empirical $p$-values are widely used to assess the calibration of predictive distributions. While exact PIT values are uniformly distributed under correct model specification, practical implementations rely on empirical estimates constructed from finite samples. We show that this estimation step fundamentally alters the statistical structure of the problem. In particular, common-sample and rolling-window implementations introduce dependence and variance distortions that invalidate classical one-sample uniformity tests. When empirical percentiles are conditioned on a shared reference sample, the resulting statistics converge towards a two-sample Kolmogorov--Smirnov regime, while rolling windows induce autocorrelation and variance suppression. Our findings indicate that treating empirical percentiles as independent uniform draws can distort statistical inference and that backtesting procedures based on PITs require revised calibration methods accounting for the underlying two-stage sampling structure.

2605.16220 2026-05-18 gr-qc math-ph math.MP

Non-minimal fluid Lagrangian couplings

非最小流体拉格朗日耦合

Christian G. Boehmer, Erik Jensko, Eissa Al-Nasrallah

AI总结 本文研究非最小耦合引力模型,通过直接耦合物质拉格朗日量与引力拉格朗日量,探讨暗能量和暗物质的解释方法,并推导流体方程及热力学量,揭示非最小耦合的影响。

Comments 22 pages

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AI中文摘要

具有非最小耦合的引力模型,涉及物质拉格朗日量和曲率的函数,在近年来变得流行。通过直接耦合物质拉格朗日量与引力拉格朗日量,希望构建能解释暗能量或暗物质而不引入额外源的理论。当此物质拉格朗日量描述完美流体时,其变分公式涉及一些技术细节。我们给出了引力场方程的详细推导以及完整的流体方程集。流体方程允许我们定义温度、化学势和数密度等热力学量,从而理解非最小耦合对这些量的影响。我们展示了Schutz和Brown对这类模型的拉格朗日公式的非等价性,并提供了结果的详细解释。

英文摘要

Gravitational models with non-minimal couplings involving functions of the matter Lagrangian and curvature have become popular in recent decades. By coupling the matter Lagrangian directly to the gravitational Lagrangian, one hopes to construct theories that can explain dark energy or dark matter without introducing additional sources. When this matter Lagrangian describes a perfect fluid, some technicalities are involved in its variational formulation. We present a careful derivation of the gravitational field equations together with the complete set of fluid equations. The fluid's equations allow us to define thermodynamic quantities such as temperature, chemical potential and number density and thus allow us to understand the effects of the non-minimal couplings on these quantities. We demonstrate the non-equivalence of the Lagrangian formulations of Schutz and Brown for these types of models and provide a detailed interpretation of our results.

2605.16218 2026-05-18 cond-mat.str-el cond-mat.mes-hall

Lattice Relaxation Flattens Chern Bands in Rhombohedral Graphene Stacks

晶格弛豫使菱形石墨烯堆叠中的陈数带变平

Luca Nashabeh, Héctor Ochoa

AI总结 研究揭示晶格弛豫通过长程库仑相互作用与晶格弛豫的交织效应,使石墨烯异质结构中的陈数带变平并隔离,挑战了传统观点。

Comments 8 + 5 pages, 5 + 3 figures

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AI中文摘要

受近期在菱形石墨烯堆叠与六方氮化硼对齐中观察到的整数和分数陈绝缘体的启发,我们提出并研究了一个模型,其中莫尔势由这些异质结构中由晶格弛豫产生的层剪切应变场模式定义。尽管这些应变场随层数指数衰减,但其对远离接触层的电子的影响不可忽视。在无位移场的情况下,晶格弛豫效应放大了两种不同堆叠中与hBN的电子差异。这些差异虽然在单电子水平上被削弱,但在所谓的莫尔远处区域得以保留,并进一步通过电子相互作用增强。我们发现晶格弛豫在平化和隔离具有|C|=1陈数的谷极化Hartree-Fock电子带中起关键作用。我们的结果通过展示长程库仑相互作用和晶格弛豫的交织效应,挑战了这些异质结构中莫尔效应的传统观念,并为探索不同扭角和位移场的 regime 以寻找拓扑态打开了大门。

英文摘要

Motivated by recent observations of integer and fractional Chern insulators in rhombohedral graphene stacks aligned with hexagonal boron nitride (hBN), we propose and study a model in which the moiré potential is defined by the pattern of layer-shear strain fields produced by lattice relaxation in these heterostructures. Although these strain fields decrease exponentially with the number of layers, their imprints on electrons residing away from the contact layer are non-negligible. In the absence of a displacement field, lattice relaxation effects amplify the electronic differences among the two different stackings with hBN. These differences, although attenuated at the single-electron level, survive in the so-called moiré-distant regime and are further enhanced with the inclusion of electron interactions. We find that lattice relaxation plays a crucial role in flattening and isolating a valley-polarized Hartree-Fock electron band with $|C|=1$ Chern number. Our results challenge the conventional wisdom on moiré effects in these heterostructures by illustrating the intertwined effects of long-range Coulomb interactions and lattice relaxation, and opens the door to explore different regimes of twist angles and displacement fields for the search for topological states.

2605.16216 2026-05-18 math.NT math.CO

Extensions of the Furstenberg-Sárközy theorem via the arithmetic level-$d$ inequality

通过算术水平-d不等式扩展Furstenberg-Sárközy定理

Carlo Francisco E. Adajar, Rishika Agrawal, Mukul Rai Choudhuri, Chian Yeong Chuah, Steve Fan, Swaroop Hegde, Andrew Lott, Krishnamohan Nandakumar, Nagendar Reddy Ponagandla

AI总结 本文基于Green和Sawhney的方法,通过算术水平-d不等式,为不含非零交集多项式差的集合提供了一个准多项式上界,改进了密度增量方案。

Comments 34 pages

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AI中文摘要

最近,Green和Sawhney在Furstenberg-Sárközy定理中通过证明一个

英文摘要

Very recently, Green and Sawhney obtained a quasipolynomial bound in the Furstenberg--Sárközy theorem for square differences by proving an ''arithmetic level-$d$'' inequality, thereby yielding a greatly improved density increment scheme. We adapt their method to general intersective polynomials $h\in\mathbb{Z}[x]$ and obtain an analogous quasipolynomial upper bound for the largest subset of $\{1,2,\dots,X\}$ whose difference set contains no nonzero element of the form $h(n)$ with $n\in \mathbb{Z}$. This is the best quantitative upper bound presently known for sets lacking intersective polynomial differences. In contrast to the square case, extending the method to general intersective polynomials requires performing a density increment iteration in which the underlying polynomial changes at each step; a key contribution of this paper is to show that the arithmetic level-$d$ inequality remains effective uniformly across all auxiliary polynomials arising in the iteration. We also develop smoothly weighted versions of the exponential sum estimates of Rice.

2605.16214 2026-05-18 cond-mat.mtrl-sci

Bridging Atomistic Simulation and Experimental Processing Timescales with Goal-Directed Deep Reinforcement Learning

通过目标导向的深度强化学习弥合原子模拟与实验处理时间尺度

Wonseok Jeong, Francesca Tavazza, Brian DeCost

AI总结 本文提出一种目标导向的深度强化学习框架,用于发现材料形成路径,无需人工设计反应坐标,通过障碍意识奖励保持动力学合理性,解决传统原子动力学方法在稀有事件路径模拟中的不足。

Comments 35 pages, 9 figures

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AI中文摘要

原子尺度建模通过机器学习的整合已迅速发展,但关键瓶颈仍然存在。即使具有准确的势能面和明确的目标材料,我们仍缺乏一个实用的原子动力学框架,可以模拟材料在现实合成和处理条件下的形成过程。许多加工转变由非理想化演变环境中罕见事件控制,而直接分子动力学受限于飞秒时间步和短访问轨迹。现有加速方法通常需要先验机理知识,包括反应坐标、集体变量、事件表或路径猜测,这在真实实验中很少可用。本文提出一个E(3)-等变的深度强化学习框架,使目标导向的路径发现无需人工设计反应坐标。该框架引入了一种互补的操作模式,使现实、非理想化的环境可以直接处理,同时通过障碍意识奖励保持动力学合理性。作为具有挑战性的基准,我们针对硅干氧化,其中非晶SiO2中的稀有事件路径对传统原子动力学方法而言是难以接近的。我们将O2分子视为一个代理,在Si/a-SiO2环境中执行连续刚体平移和旋转。代理通过episode级目标进行训练,奖励已验证的O2解离同时偏好低有效激活能垒。我们证明学习的策略在无序Si/a-SiO2环境中发现动力学有利的O2扩散和解离路径,随着训练逐步提高成功率并降低有效激活能垒。我们还讨论了该方法如何推广到其他加工和合成问题。

英文摘要

Atomic-scale modeling has advanced rapidly through integration of machine learning, yet a key bottleneck remains. Even with an accurate potential energy surface and a clear target material, we still lack a practical atomistic dynamics framework that can simulate how materials form under realistic synthesis and processing conditions. Many processing transformations are governed by rare events in non-idealized evolving environments, while direct molecular dynamics is limited by femtosecond timesteps and short accessible trajectories. Existing acceleration methods often require prior mechanistic knowledge, including reaction coordinates, collective variables, event tables, or pathway guesses, which is rarely available in real experiments. Here we present an E(3)-equivariant deep reinforcement learning framework that enables goal-directed pathway discovery without hand-crafted reaction coordinates. The framework introduces a complementary operating mode for atomistic simulation in which realistic, non-idealized environments can be addressed directly while retaining kinetic plausibility through barrier-aware rewards. As a challenging benchmark, we target silicon dry oxidation, where rare-event pathways in amorphous SiO2 are effectively inaccessible to conventional atomistic methods. We treat an O2 molecule as an agent that performs continuous rigid-body translations and rotations in a Si/a-SiO2 environment. The agent is trained with an episode-level objective that rewards verified O2 dissociation while preferring low effective activation barriers. We demonstrate that the learned policy discovers kinetically favorable O2 diffusion and dissociation pathways in a disordered Si/a-SiO2 environment, progressively improving success rate while reducing effective activation barriers over training. We also discuss how the approach can be generalized to other processing and synthesis problems.

2605.16213 2026-05-18 cs.AR

ADS-IMC: Accelerating Data Sorting with In-Memory Computation

ADS-IMC:利用内存计算加速数据排序

Narendra Singh Dhakad, Santosh Kumar Vishvakarma

AI总结 本文提出在内存fabric中直接执行排序操作的新型架构,通过减少内存与处理单元间的数据传输,降低延迟和能耗,首次利用6T SRAM实现内存排序,相比基于memristor的IMC排序延迟降低3.4倍。

Comments 5 Pages, 8 Figures

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AI中文摘要

排序是众多计算领域中的基本操作。传统方法涉及将数据从主内存传输到处理单元进行排序,然后将排序后的数据写回内存,这种传统方法由于内存与处理组件之间大量数据传输导致显著的延迟和能耗。为缓解这些开销,本文引入了在内存fabric中直接执行排序操作的新架构,消除了离芯片数据传输的需要。据我们所知,这项工作是首次利用6T SRAM进行内存排序的探索。所提出的架构设计用于处理以数字系统中常用的标准化加权二进制基数格式表示的数据。所提出的架构在延迟方面相比基于memristor的IMC排序实现了显著的3.4倍减少。

英文摘要

Sorting is a fundamental operation across numerous computational domains. Traditionally, this process involves transferring data from main memory to a processing unit for sorting, followed by writing the sorted data back to memory. This conventional approach incurs substantial latency and energy overheads due to the extensive data movement between memory and processing components. To mitigate these overheads, this paper introduces novel architectures for executing sorting operations directly within the memory fabric, eliminating the need for off-chip data transfer. To our knowledge, this work represents the first exploration of in-memory sorting using 6T SRAM. The proposed architecture is designed to operate on data represented in the standard weighted binary radix format commonly used in digital systems. The proposed architecture achieves a significant 3.4x reduction in latency compared to memristor-based IMC sorting.

2605.16210 2026-05-18 math.DS cs.NA math.NA math.OC

The Wolf and the Cello: Modelling and design of multiple resonance suppressors in large string instruments

狼与大提琴:大型弦乐器中多重共振抑制器的建模与设计

Simone Cacace, Emiliano Cristiani, Francesca L. Ignoto

AI总结 本文提出了一种数学模型,描述弦与带有一个或两个共振抑制器的二维体的耦合动力学,通过三个性能指标评估共振抑制器的优化调谐与放置,以有效抑制狼音并保持整体音色平衡。

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AI中文摘要

狼音是大型弓弦乐器中由于强体共振与振动弦相互作用产生的声学不稳定性,会产生幅度调制和音色控制丧失。本文提出了一种数学模型,描述弦与带有一个或两个共振抑制器的二维体的耦合动力学。弦和体均包含弹性(二次)和刚度(四次)贡献,可被拨弦或弓弦激发。引入了三个性能指标:第一个感知狼音的出现,第二个量化可能由狼音抑制器引起的音调衰减,第三个测量与原始乐器相比的声学保真度(以频谱为衡量标准)。所提出的数值测试提供了关于一个或两个抑制器最佳调谐和放置的见解,能够在有效抑制狼音的同时尽可能保持整体音色平衡。

英文摘要

The wolf note is an acoustic instability that occurs in large bowed string instruments when a strong body resonance interacts with the vibrating string, producing amplitude modulation and loss of tonal control. Various wolf suppressors - tuned mass dampers attached to the string or to the instrument body - are used in practice to mitigate this effect. In this paper, we propose a mathematical model describing the coupled dynamics of a string and a two-dimensional body equipped with one or two wolf suppressors. Both string and body include elastic (second-order) and stiffness (fourth-order) contributions and can be excited either by plucking or bowing. Three performance indicators are introduced: The first one perceives the wolf-tone appearance, the second one quantifies the attenuation of the notes possibly caused by the wolf suppressor, and the third one measures the acoustic fidelity (in terms of spectrum) with respect to the original instrument. The proposed numerical tests give insights about optimal tuning and placement of one or two suppressors, achieving effective wolf-note suppression while preserving as much as possible the global tonal balance.

2605.16209 2026-05-18 cond-mat.stat-mech

An agitated oscillator chain

一个激动的振子链

Aaron Beyen, Christian Maes, Ion Santra

AI总结 研究振子链在与游动粒子浴耦合时的稳态动力学变化,推导了诱导的Langevin链动力学,并发现反阻尼效应在长时尺度因非线性效应而被抑制,导致振子链产生自维持波动。

Comments Comments welcome

详情
AI中文摘要

我们研究了振子链在与游动粒子浴耦合时稳态动力学的修改。首先,假设时间尺度分离,我们推导了诱导的Langevin链动力学,明确给出了流项、摩擦系数和噪声幅度的表达式。在游动粒子浴高持续性下,线性摩擦系数变为负值,产生不稳定性。其次,我们发现这种反阻尼效应在长时尺度因非线性效应而被抑制,类似于Rayleigh振子。我们得出结论:被动谐振链通过与主动物质的耦合可以转变为具有多体Rayleigh动力学的自维持波动介质。这种活动的转移导致位移脉动、空间振荡以及链上速度持续性的出现。

英文摘要

We study how the stationary dynamics of an oscillator chain is modified when coupled to a bath of run-and-tumble particles. First, assuming time-scale separation, we derive the induced Langevin chain dynamics with explicit expressions for the streaming term, friction coefficient, and noise amplitude. At high persistence of the run-and-tumble particle bath, the linear friction turns negative, creating an instability. Second, we find that this anti-damping is arrested at long times due to nonlinear effects, reminiscent of a Rayleigh oscillator. We conclude that a passive harmonic chain can be transformed by its coupling to active matter into a self-sustained fluctuating medium with many-body Rayleigh-like dynamics. That transfer of activity results in pulsations of the displacements, spatial oscillations, and the emergence of persistence in velocities along the chain.

2605.16206 2026-05-18 physics.plasm-ph physics.comp-ph

Kinetic Simulations of Laser-Driven Compression and Heating of Magnetised Cryogenic Hydrogen Targets using PIConGPU

利用PIConGPU进行激光驱动压缩和加热磁化液化氢靶体的动力学模拟

Filip Optołowicz, Klaus Steiniger, David Blaschke, Michael Bussmann, Brian Marre

AI总结 本文通过PIConGPU模拟研究了激光驱动压缩和加热磁化液化氢靶体的过程,揭示了非热机制在加速中的主导作用,并探讨了外部轴向磁场对压缩效果的影响。

Comments 24 pages, 17 figures. Submitted to Particles

详情
AI中文摘要

我们展示了利用PIConGPU进行的完全动能二维、三速度分量(2D3V)模拟,研究了三束直接驱动相互作用与15μm固密度液化氢圆柱体的相互作用,为DRACO(τ=30 fs)和即将来临的PENELOPE(τ=150 fs)激光设施提供了预测性数值基准。模拟结果揭示了电荷分离场可达3 TV/m,并展示了加速粒子群体的稳健运动 bifurcation 分为快速(1-5 MeV)离子束和较慢的总体流(1-100 keV)。我们证明了电荷分离前沿(v_hb)本质上是非准中性静电双电层,位于辐射流体动力学模型的闭合假设之外。一个简单的2v_hb反射缩放,直接从前沿轨迹推导出,在脉冲30 fs驱动下追踪恒定能量快速离子带的质心,在持续150 fs驱动下追踪时间变化的快速离子带上边缘,跨过两种强度(a0=12.7和22.0),确立了这一非热机制作为主导加速路径。然后我们扫描了外部轴向磁场从0 T到10 kT。实验室可实现的20 T磁场使所有宏观观测不变;kT尺度的磁场逐步磁化MeV热电子群体,抑制激光驱动的电荷分离机制,抑制快速离子带,并使短脉冲驱动的净向内压缩时间超过一倍,同时延长了靶的外边缘。几何等价性论证将这些kT尺度的结果映射到更大直径的液化氢喷射流上。

英文摘要

We present fully kinetic two-dimensional, three-velocity-component (2D3V) PIConGPU simulations of a three-beam direct-drive interaction with a 15 $μ$m solid-density cryogenic hydrogen cylinder, establishing a predictive numerical baseline for the operational DRACO ($τ=30$ fs) and upcoming PENELOPE ($τ=150$ fs) laser facilities at HZDR. The simulations resolve charge-separation fields on the order of 3 TV/m and reveal a robust kinematic bifurcation of the accelerated population into a fast (1-5 MeV) ion beam and a slower bulk (1-100 keV) flow. We demonstrate analytically and numerically that the charge-separation front ($v_{hb}$) is an intrinsically non-quasi-neutral electrostatic double layer that lies outside the closure assumptions of radiation-hydrodynamic models. A simple $2v_{hb}$ reflection scaling derived directly from the front trajectory tracks the centroid of the constant-energy fast-ion band under the impulsive 30 fs driver and the time-varying upper edge of the swept fast-ion band under the sustained 150 fs driver, across both intensities ($a_{0}=12.7$ and 22.0), establishing this non-thermal mechanism as the dominant acceleration pathway. We then scan an external axial magnetic field from 0 T to 10 kT. Laboratory-achievable 20 T fields leave all macroscopic observables unchanged; fields at the kT scale progressively magnetise the MeV hot-electron population, quench the laser-driven charge-separation mechanism, suppress the fast-ion band, and more than double the net-inward compression time of the short-pulse driver-while extending the outer target envelope. A geometric equivalence argument maps these kT-scale results onto larger-diameter cryogenic hydrogen jets.