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2605.14933 2026-05-15 math.NA cs.NA math.OC

Nyström Approximation on Manifolds

Hantao Nie, Bin Gao, Andi Han, Pratik Jawanpuria, Bamdev Mishra, Zaiwen Wen

AI总结 本文研究在流形上进行计算时如何高效近似切空间算子的问题,提出了一种基于子空间投影的黎曼尼斯特روم(Nyström)近似方法,能够在保持算子良好性质(如半正定性)的同时降低计算成本。该方法引入了基于哈尔-格拉斯曼投影的随机化技术,并结合随机牛顿型优化方法,有效提升了流形上优化任务的效率。数值实验表明,该近似方法在保持精度的同时显著减少了计算开销。

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英文摘要

Computations on a manifold often involve constructing an operator on the tangent space and computing its inverse, which can be time-consuming in many applications. In order to reduce the computational costs and preserve the benign properties of tangent operators, we develop the Riemannian Nyström approximation on manifolds, a low-rank approximation of tangent operators through subspace projections onto the tangent space. The developed approximation is intrinsically constructed and inherits desirable properties from the classical Nyström approximation, e.g., positive semidefiniteness and approximation errors. Instead of the Gaussian sketching, we introduce the Haar--Grassmann sketching condition with a coordinate-free representation, which remains compatible under isometric vector transport across tangent spaces. Moreover, we propose a randomized Newton-type method for optimization on manifolds in which the linear system is constructed via the Riemannian Nyström approximation. Numerical experiments on the SPD and Grassmann manifolds, together with principal geodesic analysis on real data, illustrate that the proposed approximation reduces the computational cost of operators while maintaining comparable accuracy.

2605.14932 2026-05-15 cs.CR

Toward Securing AI Agents Like Operating Systems

Lukas Pirch, Micha Horlboge, Patrick Großmann, Syeda Mahnur Asif, Klim Kireev, Thorsten Holz, Konrad Rieck

AI总结 本文从操作系统安全的角度出发,探讨基于大语言模型的自主代理系统的安全性问题,指出两者在资源隔离、权限划分和通信控制方面面临相似的挑战。研究分析了当前开源代理系统的架构与潜在攻击向量,并通过案例研究验证了现有保护机制在实践中存在的不足。研究发现,尽管部分能力设计上存在安全隐患,但许多漏洞可通过操作系统安全领域成熟的技术进行缓解,并提出了针对代理系统安全设计的建议。

Comments 17 pages, under submission

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英文摘要

Autonomous agents based on large language models (LLMs) are rapidly emerging as a general-purpose technology, with recent systems such as OpenClaw extending their capabilities through broad tool use, third-party skills, and deeper integration into user environments. At the same time, these agentic systems introduce substantial security risks by combining unconstrained capabilities with access to sensitive user data. In this work, we investigate the security of LLM-based agents through the lens of operating systems. We argue that both face strikingly similar challenges in isolating resources, separating privileges, and mediating communication. Guided by this perspective, we survey the current landscape of open-source agents, derive a unified agent architecture, and systematically analyze potential attack vectors. To validate this analysis, we conduct a case study evaluating four widely used OpenClaw-like agents. Even under modest attacker capabilities, we find that several protection mechanisms fail in practice and that secure operation requires detailed system knowledge and careful configuration. However, we also observe that while some agentic capabilities remain insecure by design, many vulnerabilities can be mitigated using well-established techniques from operating system security. We conclude with a set of recommendations for the secure design of agentic systems.

2605.14930 2026-05-15 astro-ph.GA

Identifying group galaxies merging with massive clusters using machine learning

Rhys Jordan, Meghan E. Gray, Alfonso Aragón-Salamanca, Steven P. Bamford, Frazer R. Pearce, Roan Haggar

AI总结 本研究利用机器学习方法,识别与大质量星系团合并的星系群,以探究星系在进入致密星团核心前的演化过程。研究基于星系的位置、视向速度和恒星质量等可观测属性,构建了一个监督学习框架,将星系分为主星团、星系群及其他三类,并在宇宙学模拟数据上验证了该方法的有效性。该模型在不同星团质量和动力学状态下的表现稳定,优于传统方法,为未来星系团外围区域的光谱巡天提供了可靠的统计工具。

Comments Accepted for publication in MNRAS. 18 pages, 17 figures

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英文摘要

The environment plays a critical role in galaxy evolution, with galaxy clusters and their infall regions offering diverse conditions that shape galaxies before they enter the dense cluster core, a process known as ``pre-processing''. However, identifying environmental substructures, particularly galaxy groups in these transitional zones, remains challenging due to projection effects and ``fingers-of-god'' distortions. In this work, we present a supervised machine learning framework for classifying galaxies into three environmental categories: main cluster, group, and neither, using observable galaxy properties such as positions, line-of-sight velocities, and stellar mass. The model is trained on mock observations derived from cosmological simulations designed to replicate survey conditions and achieves an overall accuracy and class-size-weighted precision of 81%. The neither and main cluster populations are reliably recovered, whereas group galaxies remain the most challenging to identify, achieving 30% completeness and 76% purity. Within $1\times R_{200}$, classification performance is suppressed, but it improves beyond this radius, reaching 40% completeness and 80% purity. Resampling and thresholding strategies allow the model to be tuned toward either higher purity or higher completeness; in this study, we adopt first-past-the-post thresholding to emphasise purity. Model performance is consistent across cluster masses and dynamical states, and it outperforms both Friends-of-Friends and Gaussian Mixture Modelling. This flexibility makes it well suited to upcoming spectroscopic surveys of cluster infall regions, providing a robust statistical tool for disentangling environmental influences on galaxy evolution.

2605.14922 2026-05-15 astro-ph.GA

DREAMS. JWST Spectroscopy of a $z=8.3$ Galaxy with an ALMA Dust Continuum Detection: Early Dust, Very High $T_{\rm dust}$, and a Multi-wavelength [OIII] Ratio Discrepancy

Kana Takechi, Masami Ouchi, Kimihiko Nakajima, Tomokazu Kiyota, Yoichi Tamura, Yuichi Harikane, Yurina Nakazato, Tom J. L. C. Bakx, Akio K. Inoue, Hidenobu Yajima, Masato Hagimoto, Yoshiaki Ono, Yi Xu

AI总结 本文研究了红移 $z=8.312$ 的星系 MACS0416-Y1,利用 JWST/NIRSpec 谱和 ALMA 尘埃连续谱数据,揭示了其高尘埃温度、低尘埃质量比以及氧发射线在不同波段的显著差异。研究发现该星系可能包含一个宽线活动星系核,并具有中等偏低的金属丰度,其尘埃质量比和尘埃温度表明尘埃生长处于早期阶段。此外,[OIII]88μm 与 [OIII]5007 线的高通量比值显示光学与红外发射线区域存在显著差异,为多波段联合分析提供了新的见解。

Comments 18 pages, 18 figure, Submitted to ApJ

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英文摘要

We present a deep DREAMS JWST/NIRSpec MSA medium-grating spectrum of MACS0416-Y1, a galaxy at $z=8.312$ with the highest-redshift ALMA dust continuum detection to date, in order to characterize its properties together with archival IFU and ALMA data. The deep NIRSpec spectrum reveals a broad H$β$ line with a width of $\sim1100$ km s$^{-1}$. We interpret it as a broad-line AGN whose line diagnostics are consistent with AGN activity across its clumpy structure, given the absence of little red dot signatures. MACS0416-Y1 clearly shows [OIII]4363 emission, suggesting a moderately low metallicity of $12+\log(\mathrm{O/H})=7.86^{+0.09}_{-0.08}$ ($0.15~Z_\odot$). The combination of [CII]158$μ$m and dust continuum emission indicates low dust mass ratios of $\log (M_{\rm dust}/M_{\rm gas})=-3.60^{+0.29}_{-0.22}$ and $\log (M_{\rm dust}/M_{\rm metal})=-0.95^{+0.29}_{-0.20}$. Because the metallicity of MACS0416-Y1 is around the critical metallicity of $0.1\textrm{-}0.2~Z_\odot$, the system is expected to undergo dust growth, explaining these low dust mass ratios as well as its small dust mass, $M_{\rm dust}\sim10^6~M_\odot$. The intense UV radiation from the AGN may contribute to a high dust temperature of $T_{\rm dust}\simeq 91^{+62}_{-35}$ K, boosting the dust-continuum emission above the ALMA detection limit despite the small $M_{\rm dust}$ at $z>8$. We find a very high total flux ratio of [OIII]88$μ$m/[OIII]5007 = $0.26 \pm 0.06$ in MACS0416-Y1, above predictions from single ionized nebular models at any electron density. This discrepancy suggests that the [OIII]88$μ$m and [OIII]5007 trace largely distinct regions, with the optical line suppressed in dusty nebulae, and thus requires careful interpretation when combining optical and infrared emission lines in JWST+ALMA studies.

2605.14921 2026-05-15 math.CO math.RT

Anchored Dyck Paths

Jimmy Dillies

AI总结 本文针对Simental提出的问题,给出了一个推广了有理Catalan数的公式的组合解释,该公式出现在Springer纤维的研究中。作者提出了两种解释方式,分别基于二元项链和锚定Dyck路径,为相关组合结构提供了新的视角和工具。

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英文摘要

We answer a question of Simental by providing a combinatorial interpretation of a formula which generalizes rational Catalan numbers and which appears in the study of Springer fibers. We provide an interpretation in terms of binary necklaces as well as anchored Dyck paths.

2605.14919 2026-05-15 eess.SP

Transmit Beamforming for High-Rate Underwater Acoustic Communications

Diego A. Cuji, Andrew C. Singer, Milica Stojanovic

AI总结 本文研究了用于高速水声通信的发射波束成形技术,旨在减少对信道完全先验知识的依赖。通过利用传播场中几何结构的稳定成分,提出了一种基于角度的波束成形策略,特别适用于存在时间相对稳定的主传播路径的场景。实验结果表明,该方法在数据检测均方误差和误码率方面表现优异。

Comments 5 pages, 5 figures, conference

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英文摘要

Transmit beamforming for underwater acoustic communication is challenging because it requires perfect knowledge of the channel to the receiver in advance. In practice, channel estimates must be learned through feedback and are often noisy or outdated because of feedback delay and channel variation. In this paper, we investigate angle-based beamforming strategies for a single-user link that reduce dependence on full channel knowledge by exploiting stable components of the geometric structure in the propagation field. In particular, we focus on scenarios in which there exists a dominant path that remains relatively stable over time, making it a suitable candidate for transmit beamforming. Experimental results using the SPACE and MACE data sets demonstrate the effectiveness of the proposed method in terms of data-detection mean-squared error and bit error rate.

2605.14918 2026-05-15 cs.SI cs.CY

Static and Dynamic Strategies for Influencing Opinions in Social Networks

Paolo Tarantino, Fabio Mazza, Carlo Piccardi, Francesco Pierri

AI总结 本文研究了在网络社交平台中,少量协调行动者如何通过静态或动态策略影响群体意见的问题。通过基于赫塞尔曼-克劳斯(Hegselmann-Krause)有限信任动态模型的实验,比较了静态干预(固定极端意见)和动态干预(意见从温和逐渐转向极端)的效果,发现动态策略在扩大影响力方面更为有效。研究还表明,尽管某些中心性指标在静态干预中表现较好,但动态干预即使使用简单或随机选择节点也能取得良好效果,揭示了干预策略设计与目标选择在塑造集体意见中的相互作用。

Comments 19 pages, 18 figures

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英文摘要

The ability of a small set of coordinated actors to manipulate opinions in online social networks poses a serious challenge to the fairness and integrity of public debate. We investigate this problem by studying how targeted stubborn agents can shift the average opinion of a network governed by the Hegselmann-Krause bounded-confidence dynamics. Experiments are conducted on weighted LFR benchmark networks with community structure, using multiple node-selection strategies based on degree, strength, PageRank, betweenness, k-coreness, s-coreness, and salience. We compare static interventions, in which stubborn agents keep a fixed extreme opinion, with dynamic interventions, in which their opinion gradually evolves from moderate to extreme values. Results show that dynamic strategies are substantially more effective than static ones, as they exploit bounded-confidence dynamics to progressively recruit intermediate agents and extend influence across the network. In contrast, static strategies tend to create early opinion separation and therefore have a more limited reach. We also find that while some centrality measures offer advantages in static settings, dynamic interventions can achieve strong performance even with simple or random node selection. Overall, the study clarifies how intervention design and target selection interact in shaping collective opinions, with implications for understanding and countering manipulation in social networks.

2605.14916 2026-05-15 cond-mat.dis-nn

From Chaos to Synchrony in Recurrent Excitatory-Inhibitory Networks with Target-Specific Inhibition

Carles Martorell, Rubén Calvo, Alessia Annibale, Miguel A. Muñoz

AI总结 本研究探讨了具有目标特异性抑制的兴奋-抑制递归网络中的动态行为转变问题,分析了从混沌到同步的过渡机制。通过动力学平均场理论,作者推导了网络宏观活动和自相关性的自洽方程,并提出了区分均值驱动与波动驱动不稳定性的稳定性判据。研究发现,目标特异性抑制能够将网络的动力学相图划分为三个主要类别,揭示了抑制与兴奋平衡对网络动态行为的调控作用,为理解神经网络中计算与行为变化的机制提供了新的理论框架。

Comments Supplemental Material is added as an additional PDF file at the end of the main text

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英文摘要

Biological neural networks can operate in qualitatively distinct dynamical regimes, and transitions between these regimes are thought to underlie changes in computation and behavior. The seminal work of Sompolinsky, Crisanti, and Sommers (SCS) showed that random recurrent networks undergo a transition from quiescence to asynchronous chaos, establishing a paradigmatic link between random connectivity, dynamical instability, and internally generated fluctuations in neural circuits. Here, we extend this framework to two-population firing-rate networks with segregated excitatory and inhibitory neurons and target-specific inhibitory couplings that break excitation--inhibition balance. Using dynamical mean-field theory, we derive self-consistent equations for the macroscopic mean activities and autocorrelations, together with stability criteria distinguishing mean-driven and fluctuation-driven instabilities. We show that target-specific inhibition organizes the phase diagram into three qualitative classes: inhibition-dominated or strictly balanced networks display only quiescent activity and asynchronous chaos; excitation-dominated networks display persistent activity together with either synchronous chaos with non-vanishing mean activity or coherent oscillations, depending on the stability-matrix eigenvalues. Crucially, coherent oscillations do not coexist with chaotic fluctuations around the periodic mean trajectory; rather, their onset suppresses the chaotic component, reminiscent of input-induced suppression of chaos. These results generalize SCS theory to recurrent networks with explicit excitatory--inhibitory structure and identify target-specific inhibition as a key control parameter for large-scale neural dynamics.

2605.14914 2026-05-15 cond-mat.dis-nn cond-mat.stat-mech math.AP

FKPP fronts in quenched random media

Ulysse Marquis, Henri Berestycki, Marc Barthelemy

AI总结 该研究数值分析了一维FKPP前沿在淬火随机增长率背景下的演化行为,发现与均匀情况和确定性杂乱相比,淬火随机性会增加前沿的平均传播速度。研究显示,速度相对于均匀情况的偏移与杂乱方差成线性关系,且比例因子具有普适性;同时,前沿位置在不同杂乱实现中表现出扩散性波动,其有效扩散系数与方差平方成正比。这些结果揭示了FKPP前沿对淬火异质性的普适统计响应。

Comments 7 pages, 7 figures

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英文摘要

We study numerically the evolution of one-dimensional FKPP fronts initiated from steep initial conditions in the presence of a quenched random growth rate. Compared to both the homogeneous case (with velocity $v_0$) and deterministic disorder, quenched randomness increases the average propagation speed. We show that the velocity shift relative to the homogeneous case scales linearly with the disorder variance $σ^2$, with a universal prefactor -- independent of the specific distribution of the disorder -- such that $v = v_0 + a σ^2$, with $a \approx 0.02432 \pm 0.00002$. Moreover, the front position exhibits diffusive fluctuations across disorder realizations. The corresponding effective diffusion coefficient scales quadratically with $σ$, $D = \frac{b^2 σ^2}{2}$, with $b \approx 0.223 \pm 0.002$. These results suggest a universal statistical response of FKPP fronts to quenched heterogeneity.

2605.14910 2026-05-15 math.PR

Sharp Phase Transition for the Formation of Infinite Tubes

Shu Kanazawa, Omer Bobrowski, Primoz Skraba

AI总结 本文研究了高维随机图中“管状渗流”的形成问题,即一个固定环(或拓扑球面)是否能通过由随机面片构成的“管”逃逸至无穷远。作者引入了管状渗流的概念,并将其与已有高维渗流模型进行比较,建立了其临界概率与有限簇渗流及屏蔽渗流之间的关系。通过引入管状单臂事件并证明其在临界点处具有尖锐阈值,结合探索算法与OSSS不等式,最终证明了管状盒交叉性质也具有尖锐阈值,从而揭示了管状渗流的相变特性。

Comments 40 pages, 7 figures

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英文摘要

Classical bond percolation theory studies the conditions for a given point in a random graph to be connected to infinity, or "escape" to infinity, via a sequence of random edges. In this work, we present a higher-dimensional generalization of this question, asking whether a fixed loop (or, more generally, a topological sphere) can escape to infinity via a tube formed by random plaquettes. We refer to this phenomenon as tube percolation. We first compare tube percolation with previously studied higher-dimensional percolation phenomena, including face and cycle percolation. For tubes of codimension one, we further relate the critical probability for tube percolation to those for percolation of finite clusters and shielded percolation in the dual bond percolation model. Next, we introduce a tubular analogue of the classical one-arm event, the tubular one-arm event, and prove that it exhibits a sharp threshold at criticality: below criticality, its probability decays exponentially in scale, whereas above criticality, it admits a mean-field-type lower bound. The proof relies on the O'Donnell-Saks-Schramm-Servedio (OSSS) inequality together with an exploration algorithm adapted to the topology of tubes. Finally, we study the tubular box-crossing property. Unlike ordinary path connectedness, "tube connectedness" is not transitive, and thus there is no natural notion of clusters. Nevertheless, we establish an analogue of the uniqueness of the infinite cluster from classical bond percolation. Combining this result with the sharp threshold for the tubular one-arm event, we prove that the existence of a box-crossing tube also exhibits a sharp threshold.

2605.14905 2026-05-15 math.DG

$κ$-solutions with the round cylinder as an asymptotic shrinker

Aprameya Girish Hebbar

AI总结 本文研究了在维度 $n \geq 4$ 下以圆柱体 $\mathbb{S}^{n-1} \times \mathbb{R}$ 为渐近收缩里奇流形的 $\kappa$-解的结构。通过证明这类解必须满足统一的正截面曲率条件(PIC),结合先前的分类结果,得出任何非紧解只能是圆柱收缩解或Bryant稳态解,而任何紧解则必为佩雷尔曼的古老解。这一结果进一步完善了里奇流解的分类理论。

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英文摘要

We show that $κ$-solutions to the Ricci flow in dimensions $n\geq 4$ whose asymptotic shrinking Ricci soliton is the round cylinder $\mathbb{S}^{n-1}\times\mathbb{R}$ must be uniformly PIC. Combined with earlier classification results, this implies that any such noncompact solution is either the round shrinking cylinder or the Bryant steady soliton, and any such compact solution is Perelman's ancient solution.

2605.14903 2026-05-15 math.CO

Twins and Co-Twins in Circulant graphs

Sally Cockburn, Ryhory Hatavets, Will Swartz

AI总结 本文研究循环图中“双生顶点”和“共双生顶点”的性质,探讨它们对图的自同构群结构的影响。通过分离双生顶点的排列作用与在双生商图上的操作,简化了自同构群的分析。特别地,对于具有共双生顶点的顶点传递图,作者展示了如何利用这些结构特性深入理解循环图的对称性参数和自同构群的结构。

Comments 22 pages; 8 figures

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英文摘要

Circulant graphs are a widely studied family of graphs whose members possess varying amounts of symmetry. Although considerable progress has been made in finding the automorphism groups of circulant graphs under certain restrictions, a complete classification is elusive. In general, the structure of the automorphism group of a graph with twins can be simplified by separating the effect of automorphisms that permute mutually twin vertices and those that operate on the twin quotient graph. Further simplification can be achieved in twin-free, vertex-transitive graphs that have co-twins, which we define to be vertices whose neighborhoods are complementary. In this paper, we demonstrate how the these simplifications can be used provide insight into the automorphism groups and symmetry parameters of vertex-transitive graphs in general and circulant graphs in particular.

2605.14902 2026-05-15 math.CO cs.DM cs.DS

Optimal Bounds for the k-Disjoint Paths Problem

Dario Cavallaro, Maximilian Gorsky, Stephan Kreutzer, Dimitrios M. Thilikos, Sebastian Wiederrecht

AI总结 本文研究了图论中$k$-不相交路径问题的最优界,提出了一个适用于$k$-不相交路径与根连通子图检测问题的通用无关顶点定理。通过引入双向度的概念,作者给出了一个关于树宽的阈值,当图的树宽超过该阈值时,可以找到一个无关顶点以简化问题求解。该结果不仅改进了连通函数的指数界,还为基于图小生成算法提供了更优的参数依赖性。

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英文摘要

The Graph Minors Series of Robertson and Seymour forms the foundation of algorithmic structural graph theory, yielding fixed-parameter algorithms for problems such as Disjoint Paths, Rooted Minor Checking, and Folio. A key ingredient behind the fixed-parameter tractability of the $k$-Disjoint Paths problem is the irrelevant-vertex technique. This machinery is governed by the Vital Linkage Theorem and the so-called Linkage Function $\ell$. However, despite its foundational role, the best known bounds on the Linkage Function are enormous and are only implicitly understood. The quantitative bounds behind these results have traditionally been so large that the resulting algorithms are regarded as "galactic". Our main result is a general irrelevant-vertex theorem for a common generalisation of $k$-Disjoint Paths and Rooted Minor Checking for graphs of size at most $d,$ commonly called the $(k,d)$-Folio problem. Specifically, we show that for any graph $G$ in which the $k$ terminals are chosen from some set $R,$ if the treewidth of $G$ exceeds $β(k,b,d)\in$ $2^{{\bf poly}(b + d)}$ $\cdot {\bf poly}(k)$ then we can locate an irrelevant vertex for the $(k,d)$-Folio problem. Here, the quantity $b$ is the bidimensionality of $R,$ that is, the largest $b$ for which a $(b\times b)$-grid minor in $G$ can be rooted on $R$. Thus, the exponential component of the irrelevant-vertex threshold is driven by the bound on the bidimensionality, rather than by the number of terminals, and we argue that this dependence is essentially optimal up to polynomial factors. As a consequence, the Linkage Function satisfies $\ell(k) \in 2^{{\bf poly}(k)}$. Beyond its structural significance, our result yields improved parameter dependencies for algorithms for Disjoint Paths and Rooted Minor Checking}, and provides a quantitative improvement for a broad range of graph-minor-based algorithmic frameworks.

2605.14901 2026-05-15 math.OC math.PR

Non--exchangeable mean field games with moderate interactions and common noise

Mao Fabrice Djete

AI总结 本文研究具有中等强度相互作用和公共噪声的非交换型平均场博弈问题,考虑了大规模异质群体中的有限玩家系统。该系统通过图论结构和局部核函数描述异质的宏观交互和密度依赖的微观交互。文章引入了适用于公共噪声的松弛型平均场博弈框架,证明了在一般连续性和非退化条件下解的存在性,并在凸性条件下展示了松弛均衡可以转化为严格均衡。研究还建立了有限玩家博弈与极限平均场博弈之间的渐近关系,证明了有限玩家近似纳什均衡的极限点对应于松弛解,并实现了均衡收益的收敛性,从而完整刻画了该类非交换型博弈的均衡行为。

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英文摘要

We study mean field games for large non--exchangeable populations with moderate local interactions and common noise. The finite--player system is driven by two complementary interaction mechanisms : a graphon--type structure, which encodes heterogeneous large--scale interactions between agents, and a rescaled local kernel, which produces a density-dependent interaction term in the limit. The limiting model is a non--exchangeable mean field game in which the representative player is indexed by a label \(u\in[0,1]\), interacts through a graphon--weighted local density, and is affected by a graphon--induced environment law. We introduce a relaxed formulation of the limiting mean field game, adapted to the presence of common noise, and prove existence under general continuity and non--degeneracy assumptions. Under additional convexity assumptions, relaxed equilibria can be realized in strict form. In the deterministic case without common noise, we obtain deterministic equilibria and provide a probabilistic characterization of strict equilibria through a nonlinear Feynman--Kac representation. We then establish the asymptotic connection with the finite--player game. We prove that every limit point of approximate closed--loop Nash equilibria is a relaxed solution of the limiting mean field game, and that the corresponding averaged equilibrium payoffs converge. Conversely, every relaxed mean field game equilibrium can be approximated by Markovian approximate Nash equilibria of the finite--player systems. These results give a complete asymptotic characterization of equilibrium behavior for non--exchangeable games with moderate interactions and common noise.

2605.14899 2026-05-15 hep-ph

CP asymmetries in $D\to K^0_{S,L}P$ and $D\to K^0_{S,L}V$ decays

Ying-Xin Lai, Di Wang

AI总结 本文研究了 $D$ 介子衰变到中性K介子与伪标量或矢量介子的CP不对称性,分析了时间依赖和时间积分的CP不对称性公式,并首次考虑了 $D^0-\overline{D}^0$ 混合效应和 $K^0_L$ 模式的影响。通过拓扑图方法对分枝比进行全局拟合,提取了决定CP不对称性的强子参数,显著缓解了理论预测与实验数据在 $D^0\to K_{S,L}^0ω$ 和 $D^0\to K_{S,L}^0ϕ$ 模式中的张力。研究还指出,在某些衰变模式中,CP破坏效应可达到 $10^{-3}$ 量级,并预计LHCb和Belle II实验将在不久的将来观测到相关CP不对称性的差异。

Comments 18 pages, 5 figures

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英文摘要

$D$ meson decays into neutral kaons involve both Cabibbo-favored and doubly Cabibbo-suppressed amplitudes as well as final-state kaon mixing, providing abundant sources of CP violation. In this work, we analyze CP asymmetries in the $D\to K^0_{S,L}P$ and $D\to K^0_{S,L}V$ decays, where $P$ and $V$ denote pseudoscalar and vector mesons respectively. The formulas of the time-dependent and time-integrated CP asymmetries in these modes are derived, in which the $D^0-\overline D^0$ mixing effects and the $K^0_L$ modes are considered for the first time. The hadronic parameters that determine CP asymmetries are extracted by the global fit of branching fractions within the topological diagram approach. A significant result is that the tension between theoretical predictions and experimental data for the $K_S^0-K_L^0$ asymmetries in $D^0\to K_{S,L}^0ω$ and $D^0\to K_{S,L}^0ϕ$ modes is mitigated. The CP-violating effects arising from the interference between Cabibbo-favored and doubly Cabibbo-suppressed amplitudes with neutral kaon mixing could reach to $\mathcal{O}(10^{-3})$ order in the $D^+\to K^0_Sπ^+$, $D^+_s\to K^0_SK^+$, $D^0\to K^0_Sρ^0$, and $D^0\to K^0_Sϕ$ modes. The difference between the CP asymmetries in the $D^+\to K^0_Sπ^+$ and $D^+_s\to K^0_SK^+$ modes is available on LHCb and Belle II in the near future.

2605.14898 2026-05-15 cond-mat.mtrl-sci

Generative reconstruction of 2D and 3D polycrystalline microstructures using symmetrized hyperspherical harmonics

Ali R. Safi, Paul Seibert, Santiago Benito, Alexander Raßloff, Markus Kästner, Benjamin Klusemann

AI总结 该研究提出了一种基于方向的可微分微结构表征与重建框架,用于从有限的二维数据生成具有目标统计特性的二维和三维多晶微结构。通过结合四元数和对称化超球谐函数,克服了传统欧拉角方法中的数值奇点和不连续性问题,实现了晶体取向的连续对称不变表示。该方法结合两点空间相关性、新型混合三点变异图和均值变化正则化项,有效捕捉了全局纹理和局部界面拓扑结构,成功用于从铝合金热力学处理后的二维取向数据重建三维微结构,为多晶材料的数字合成提供了高效且开源的解决方案。

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英文摘要

Establishing structure-property linkages in polycrystalline materials requires representative two- (2D) and three- (3D) dimensional microstructural inputs for full-field simulations. A core objective of microstructure characterization and reconstruction is the generative synthesis of 2D and 3D microstructures that reflect a target statistical ensemble using limited 2D data as a reference. This work introduces an orientation-based differentiable microstructure characterization and reconstruction framework, implemented in MCRpy, to perform reconstructions of voxelized images. Unit quaternions in combination with symmetrized hyperspherical harmonics are utilized to derive a continuous, symmetry-invariant representation of crystallographic orientations to overcome the numerical singularities and discontinuities associated with traditional Euler-based methods. The descriptor-based reconstructions are driven by a set combining two-point spatial correlations, a novel hybrid three-point variogram, and a mean variation regularizer to capture both global texture and local interfacial topology. The framework's efficiency is demonstrated by reconstructing 3D realizations from 2D orientation data of an aluminum alloy after thermo-mechanical processing, successfully recovering both morphological features and crystallographic distribution. Systematic benchmarking indicates that second-order gradient-based optimization, utilizing the L-BFGS-B algorithm, effectively navigates the complex loss landscape to generate high-fidelity realizations with minimal residuals. This methodology provides a versatile, open-source framework for the digital synthesis of polycrystalline representative volume elements to facilitate the rapid development of microstructure-informed materials design workflows.

2605.14895 2026-05-15 math.CO

Nonexistence results of generalized bent functions from $\mathbb{Z}_3^n$ to $ \mathbb{Z}_m$

Priya Dhankhar, Sanjay Kumar Singh

AI总结 本文研究从 $\mathbb{Z}_3^n$ 到 $\mathbb{Z}_m$ 的广义 bent 函数(GBFs)的存在性问题。研究发现,当 $m$ 能被 3 整除时,此类函数存在,而当 $m$ 不能被 3 整除时,得到若干不存在性结果。特别地,对于 $n=1,2$ 且 $m$ 为奇数且不被 3 整除的情形,证明不存在广义 bent 函数;对于 $n=3$,进一步证明从 $\mathbb{Z}_3^3$ 到 $\mathbb{Z}_{5\cdot11^r}$ 的广义 bent 函数也不存在。此外,还证明了从 $\mathbb{Z}_3$ 到 $\mathbb{Z}_{2m'}$ 和从 $\mathbb{Z}_3^2$ 到 $\mathbb{Z}_{2m'}$ 的广义 bent 函数在 $m'$ 为奇数且不被 3 整除时也不存在。

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英文摘要

In this paper, we investigate generalized bent functions (GBFs) from $\mathbb{Z}_3^n$ to $\mathbb{Z}_m$. We show that GBFs exist whenever $3$ divides $m$, while several nonexistence results are obtained when $3\nmid m$. In particular, we prove that no GBFs exist for $n=1,2$ when $m$ is odd and not divisible by $3$. For the case $n=3$, we establish the nonexistence of GBFs $f:\mathbb{Z}_3^3 \rightarrow \mathbb{Z}_{5\cdot11^r}$ for all nonnegative integers $r$. Finally, we show that no GBF exists from $\mathbb{Z}_3$ to $\mathbb{Z}_{2m'}$ and $\mathbb{Z}_3^2$ to $\mathbb{Z}_{2m'}$, where $m'$ is odd and not divisible by $3$.

2605.14887 2026-05-15 astro-ph.SR

Self-Interacting Dark Matter in Brown Dwarfs

A. Pérez-Garrido

AI总结 该研究探讨了棕矮星内部暗物质对天体结构和动力学特性的影响。通过建立一个包含普通物质和暗物质流体的自洽两流体模型,研究了暗物质在棕矮星核心积累如何改变其质量-半径关系和动力学特性。研究发现,暗物质的存在会重塑普通物质的密度分布,并影响半径及二阶Love数,为利用棕矮星探测暗物质性质提供了新的途径。

Comments 20 pages, 7 figures

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英文摘要

Brown dwarfs, being transitional objects between giant planets and low-mass stars, possess dense, cool interiors that provide optimal conditions to explore non-standard physics. Capture and accumulation of dark-matter particles can alter the thermal, structural and dynamic of these substellar objects. We aim to apply a self-consistent two-fluid framework to model the internal structure of self-gravitating brown dwarfs and to quantify how the presence of a dark-matter component modifies their mass--radius relations and dynamical properties. The brown dwarf is modeled as a composite system of a baryonic fluid, described by a polytropic equation of state, and an independent dark-matter fluid. Both components are coupled through their shared gravitational potential in hydrostatic equilibrium. We solve numerically the coupled Lane-Emden equations for a range of dark-matter mass fractions. We find that dark matter accumulating in the core reshapes the baryonic density profile, modifying both the radius and the second-order Love number. Radius and dynamical anomalies in brown dwarfs can serve as diagnostic tools to constrain dark-matter properties. Future high-precision astrometric missions could identify these structural signatures, establishing brown dwarfs as possible detectors of dark matter in the Galaxy.

2605.14882 2026-05-15 math.CO

Perturbation of the largest matching root of hypergraphs

Jiang-Chao Wan, Yi Wang

AI总结 本文研究了$k$-图的最大匹配根在扰动下的变化情况,其中最大匹配根是指匹配多项式的最大实根。作者确定了在给定边数和环数的情况下,所有$k$-树状图和线性$k$-树状图中使最大匹配根达到最大的$k$-图结构。通过证明Erdős、Ko和Rado引入的移位操作不会减小最大匹配根,推广了Csikvári关于Kelmans变换不减小图的最大匹配根的经典结果。

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英文摘要

The largest matching root of a $k$-graph is the largest real root of its matching polynomial, which is equal to the maximum modulus of all the zeros of the matching polynomial. In this paper, we investigate the perturbation of the largest matching root of $k$-graphs. We determine all $k$-graphs whose largest matching root attains the maximum among all $k$-cacti and linear $k$-cacti with a given number of cycles and edges, where a $k$-cactus is a $k$-graph in which every two distinct cycles have at most one vertex in common. To achieve this, we prove that the celebrated shifting operation of $k$-graphs, introduced by Erdős, Ko and Rado, does not decrease the largest matching root. This result extends a classical result by Csikvári (Electron. J. Combin. {\bf 18} (2011) $\#$P182) stating that the Kelmans transformation does not decrease the largest matching root of graphs.

2605.14881 2026-05-15 quant-ph cs.LO

QSeqSim: A Symbolic Simulator for Qiskit While Loops Using Sequential Quantum Circuits

Zihao Li, Ji Guan, Mingsheng Ying

AI总结 本文提出了一种名为 QSeqSim 的工具,用于在 Qiskit 中对包含 while 循环的量子程序进行符号化仿真。该工具通过将 Qiskit 量子电路转换为 OpenQASM 3 代码,并将其组织为组合、动态和时序电路的组合,为 while 循环提供了精确的时序电路语义。基于这一语义,QSeqSim 采用二进制决策图(BDD)进行符号化表示,并结合加权模型计数技术高效计算测量概率,实验表明该工具能够有效处理包含大量 qubit 和多轮循环的复杂量子电路。

Comments This is the full arXiv version of the paper accepted at FM 2026. The paper has 26 pages and 4 figures. Proceedings version: FM 2026, LNCS 16556, Springer, 2026

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Journal ref
FM 2026, LNCS 16556, Springer, 2026
英文摘要

We present a tool QSeqSim, a Qiskit-integrated symbolic backend that fills the current gap of having no Qiskit-native support for simulating while-loop quantum programs and their induced sequential quantum circuits. QSeqSim takes Qiskit QuantumCircuit objects, translates them into OpenQASM 3 code, and organises the resulting program into a combination of combinational, dynamic, and sequential circuits, thereby assigning while-loops a precise sequential circuit semantics with explicit internal and external qubits. Building on this semantics, QSeqSim adopts a Binary Decision Diagram (BDD)-based symbolic representation and integrates weighted model counting to compute measurement probabilities efficiently by exploiting sharing in structured and sparse BDDs. On top of this Boolean backbone, it introduces dedicated symbolic operators for state composition and state retention, thereby enabling efficient symbolic execution of sequential quantum circuits. Our experiments demonstrate that QSeqSim scales to substantial while-induced sequential circuits; in particular, in the quantum random walk benchmark we successfully simulate circuits with over 1000 qubits for more than 10 loop iterations. QSeqSim is available at https://github.com/Veri-Q/QSeqSim.

2605.14878 2026-05-15 cs.MA

Decision-Level Fusion for Robust Wearable Affect Recognition

Lokesh Singh, Athina Georgara, Jayati Deshmukh, Tan Viet Tuyen Nguyen, Sarvapali D. Ramchurn

AI总结 本文研究了如何通过可穿戴设备鲁棒地识别用户的情感状态,针对非稳态动态、传感器噪声和信号缺失等问题,提出了一种基于决策级融合的方法。该方法结合傅里叶-贝塞尔级数展开与经验小波变换,提取具有时变特性的模态特征,并通过不确定性与模态可靠性加权的决策级融合策略进行多模态整合。实验表明,该方法在WESAD数据集上表现出比特征级融合更高的鲁棒性与识别性能。

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英文摘要

Automatic recognition of affective state from wearable physiology has clear societal impact for public health, preventive care, and stress-aware interventions, but real deployments require robustness to non-stationary dynamics, artefacts, and missing sensors. We study this problem on WESAD, using baseline, stress, and amusement conditions, where common fixed-basis spectral features such as FFT bandpower and Welch PSD can oversmooth short-lived discriminative patterns. We propose a non-stationary pipeline that combines Fourier-Bessel Series Expansion (FBSE) with EWT data-driven spectral segmentation to extract mode-wise transient descriptors. For multimodal integration, we adopt decision-level aggregation over per-modality predictors and weight each modality by predictive uncertainty and modality reliability. Results on WESAD, using 15 subjects and ECG, EDA, BVP, EMG, and ACC signals across three classes, indicate that decision-level aggregation is approximately 84 percent of the time at least as good as feature-level aggregation, and approximately 48 percent of the time strictly better, suggesting improved robustness under heterogeneous and partially reliable sensing.

2605.14875 2026-05-15 hep-ph

Unified study of scalar, vector and tensor two-meson form factors in $U(3)$ resonance chiral theory

Jin Hao, Chun-Gui Duan, Zhi-Hui Guo, J. Oller, J. Ruiz de Elvira

AI总结 本文在 $U(3)$ 共振手征理论框架下,系统研究了标量、矢量和反对称张量类型的两介子形式因子。通过引入轻味伪标量介子的一圈贡献和树级共振交换,计算了守恒奇异量子数和改变奇异量子数通道下的完整微扰形式因子,并结合介子-介子最终态相互作用构建了相应的单位化形式因子。利用之前介子-介子散射研究中得到的参数,预测了各类型形式因子的数值,发现不同形式因子在不同通道中表现出显著不同的共振结构。

Comments 33 pages, 14 figures

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英文摘要

We perform a systematic study of two-meson form factors of the scalar, vector, and anti-symmetric tensor types within the framework of the $U(3)$ resonance chiral theory. The complete perturbative form factors in both the strangeness-conserving and strangeness-changing channels are calculated by incorporating one-loop light-flavor pseudoscalar meson contributions and tree-level resonance exchanges. With these newly calculated chiral results, we construct the corresponding unitarized form factors by incorporating meson-meson final-state interactions. The parameter values obtained in previous meson-meson scattering studies are then exploited to predict the corresponding form factors. Different types of form factors are found to exhibit rather distinct resonance structures across channels.

2605.14873 2026-05-15 physics.plasm-ph physics.acc-ph

Few-Attosecond electron pulse trains with tunable periods produced by two counter-propagating lasers

Qi Huang, Qing Jia, Zhongxuan Wang, Jian Zheng

AI总结 该研究提出并验证了一种利用两束反向传播激光产生具有可调周期的飞秒电子脉冲列的紧凑方案,解决了传统调制方法在亚飞秒脉冲下焦长急剧缩短的问题。通过特定的参量共振条件,电子束可被稳定调制为高度周期性的飞秒脉冲列,并实现快速能量增益。实验模拟表明,该方法可生成约1阿秒的电子脉冲,显著延长了焦长,为超快物质动态探测提供了新的技术途径。

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英文摘要

Attosecond electron pulses enable real-time probing of ultrafast matter dynamics, yet conventional modulation schemes suffer from drastically shortened longitudinal focal lengths when targeting sub-attosecond durations. To address this bottleneck, we propose and demonstrate a compact scheme utilizing two counter-propagating lasers that reveals a previously unidentified stable modulation regime. Contrary to established models of ponderomotive forces and stochastic acceleration in dual-laser fields, we show that a specific parametric resonance condition permits the electron beam to be stably modulated into highly periodic attosecond trains with rapid energy gain. Using a sub-relativistic electron beam, simulations confirm the generation of ~1 as pulses with a Lorentz factor up to 15 and a relative energy spread below 0.02%, extending the focal length by three orders of magnitude compared with conventional approaches. This work identifies the critical transition from ordered modulation to stochastic acceleration, offering a viable route to overcoming the focal-length barrier in attosecond electron-pulse applications.

2605.14870 2026-05-15 gr-qc math-ph math.MP

On the catastrophe time of fluids under the action of a gravitational field

D. Astesiano, G. Ortenzi, M. L. Ruggiero

AI总结 本文研究了在引力场作用下流体的灾变时间问题,重点分析了球对称引力场中类似伯格斯方程的动力学行为。通过引入拉格朗日映射的不可逆性作为灾变判据,作者在牛顿框架下推导了径向运动的灾变时间,并发现其展开式由无量纲参数 $α$ 控制,而非局部引力加速度,从而在强引力条件下仍具有有效性。研究进一步将分析扩展至施瓦茨希尔德时空中的径向测地线运动。

Comments 18 pages, 2 figures

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英文摘要

Motivated by the central role of the Zel'dovich approximation in the description of cosmic structure formation through gravitational collapse, we investigate Burgers-type dynamics in a spherically symmetric gravitational field. In the Newtonian setting, we derive perturbatively the catastrophe time for radial motion by imposing the loss of invertibility of the Lagrangian map. We show that the perturbative expansion is controlled by the dimensionless parameter $ α=μ/{r_0^3 v_0(r_0)'^2}, $ rather than by the local gravitational acceleration alone. Hence, the expansion remain valid even when gravity is strong. We then extend the analysis to radial geodesic motion in Schwarzschild spacetime.

2605.14869 2026-05-15 astro-ph.HE

Self-confinement of ultra-high-energy nuclei in cosmic filaments: implications for the UHECR spectrum and composition

Alessandro Cermenati, Roberto Aloisio, Carmelo Evoli

AI总结 本文研究了超高能宇宙线(UHECR)在宇宙丝状结构中的自限制机制,探讨其对UHECR能谱和成分的影响。通过引入非共振流不稳定性模型,作者扩展了自限制理论以处理混合核素成分,并构建了一个包含逃逸、光离解和次级粒子生成的有效漏箱模型。研究发现,自生成的磁湍流可有效抑制低于EV尺度的逃逸粒子通量,有助于解释UHECR能谱拐折处的成分特征,并对宇宙中性粒子和伽马射线背景提供了新的约束。

Comments 13 pages (11 main text + 2 appendix), 7 figures

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英文摘要

The spectrum and composition of ultra-high-energy cosmic rays (UHECRs) suggest that the population dominating above the ankle releases particles with an unusual hard spectrum at low rigidity, below the EV scale. In self-confinement scenarios, such an apparent hardening arises from transport: escaping UHECRs generate magnetic turbulence that delays their own release from the magnetized environments surrounding their sources. We extend the self-confinement scenario based on the non-resonant streaming instability to a mixed nuclear composition. We describe the confinement region with an effective leaky-box model including escape, photodisintegration, and secondary production. We then compare the resulting spectrum and composition with Auger measurements and compute the associated cosmogenic neutrino and gamma-ray emission. We find that self-generated turbulence can suppress the escaping flux below the EV scale for source luminosities and magnetic-field coherence lengths compatible with UHECR sources hosted in galaxy clusters and propagating through cosmic filaments. During confinement, heavy nuclei efficiently photodisintegrate, producing secondary protons that contribute below the ankle and help account for the observed composition. The predicted neutrino flux remains compatible with current limits, while the diffuse gamma-ray background provides a potentially strong constraint on the most extreme configurations.

2605.14864 2026-05-15 math.RT

Spherical Twists for Gorenstein Orders and $G$-Hilb

Marina Godinho

AI总结 本文研究了Gorenstein环的导出自同构,通过球形函子的扭转变换进行构造。作者给出了在特定条件下,限制标量函子的导出扭变成为Gorenstein环的导出自同构,并证明了相应的对偶扭变是环B的Nakayama函子的移位。利用这些结果和局部到整体的技术,文章构造了斜群代数和G-Hilbert方案的新导出自同构,并应用于具体例子中。

Comments 29 pages, 1 figure, comments welcome

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英文摘要

This paper constructs derived autoequivalences of Gorenstein orders as twists around spherical functors. More precisely, given a Gorenstein order $A$ and a quotient $p \colon A \to B$, then we specify natural conditions on $B$ under which the twist around the corresponding derived restriction of scalars functor is a derived autoequivalence of $A$. In the process, we show that the associated cotwist is a shift of the Nakayama functor of $B$. These results, together with local-to-global technology, are then used construct new derived autoequivalences for skew group algebras and $G$-Hilbert schemes, and we apply this theory to explicit examples.

2605.14863 2026-05-15 cs.DC

Embedded Made Easy -- Rethinking Embedded + Cloud Software Development (WIP)

Anthony Arnold, Mark Marron

AI总结 本文探讨了在边缘/嵌入式系统中开发和部署应用程序所面临的复杂挑战,包括软件栈异构性、调试困难以及语言和运行时的不一致性。为此,作者提出了一种统一的语言和运行时系统,旨在实现从边缘设备到云端的无缝扩展,使开发者能够在单一环境中开发、测试并部署应用。该方法还支持集成的诊断与调试工具,便于记录和回放分布式事件,从而简化分布式系统的分析与调试。

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英文摘要

The process of engineering and deploying applications in the edge/embedded space is massively complicated by the non-homogeneous nature of the software stack and the complexity of diagnostics & debugging. Often different languages and runtimes are used for different components of the system forcing designers to, irrevocably, make decisions about what components run on the periphery and what components run in the cloud. Further complications arise when handling and diagnosing failures in the system. Multiple stacks and, often, limited support for debugging complicate the already difficult task of analyzing distributed applications. This paper presents a work-in-progress vision for a unified language and runtime system that allows applications to scale seamlessly across the edge and cloud. Using a single language and runtime, applications can be developed and tested in a single environment, and then deployed to any component of the system -- from resource limited controllers to large cloud servers. Further, we outline how this retargetable stack can provide integrated diagnostics and debugging tools that allow developers to record and replay distributed events locally for analysis and debugging.

2605.14862 2026-05-15 math.GR

Commutative decomposition of infinite symmetric groups and transformation monoids

Luna Elliott, Alex Levine

AI总结 本文研究了无限对称群及其变换半群的交换子群(或子半群)分解宽度问题。作者改进了之前关于无限对称群对称子群宽度的上界结果,证明其交换子群宽度至多为9,并将下界提升至4。同时,作者还研究了对称群的半群类比对象,发现它们的交换子半群宽度均为3,并进一步证明无限对称逆半群的交换逆子半群宽度总是无限的。

Comments 12 pages

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英文摘要

The commutative subgroup width of a group $G$ is the smallest $k$ such that there are abelian subgroups $A_0,A_1,\ldots,A_{k-1}\leq G$ with $G=A_0A_1\cdots A_{k-1}$. Commutative (inverse) submonoid width is defined analogously. In 2002, Abért showed, rather surprisingly, that the commutative subgroup width of the symmetric group on an infinite set is always finite. It was later shown by Seress that it is always bounded above by $14$. We answer a question of Seress and show that in fact the commutative subgroup width of $\operatorname{Sym}(\mathbb{N})$ is at most $9$. We improve the best known lower bound to $4$. We also study standard monoid analogues of the symmetric group; showing that the commutative submonoid widths of the full transformation monoid $\mathbb{N}^\mathbb{N}$, the partial transformation monoid $P_\mathbb{N}$ and the symmetric inverse monoid $I_\mathbb{N}$ are exactly $3$. We conclude by showing that the commutative inverse submonoid width of any infinite symmetric inverse monoid is always infinite.

2605.14861 2026-05-15 cond-mat.stat-mech hep-ph nlin.AO physics.comp-ph

Lévy-like flights and fractal geometry of finite point sets

Konstantinos Chalas, F. K. Diakonos, A. S. Kapoyannis

AI总结 本文研究了类似Lévy的飞行和截断Lévy飞行,分析了步长概率分布为 $r^{-1+ν}$ 时生成点集的分形几何特性,探讨了不同ν值对分形结构的影响。通过构建固定数量点集的集合,研究者开发了能够精确控制关联维数的模拟方法,并展示了在小规模数据集上实现所需分形特性的可能性。研究还表明,正ν分布除靠近上限尺度区域外,其分形行为可延伸至极小尺度,研究成果可用于重离子碰撞实验中寻找QCD临界端点相关的临界涨落模拟。

Comments 35 pages, 16 figures

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英文摘要

We study Lévy-like and truncated Lévy-like flights with step probability distribution of the form $r^{-1+ν}$ for negative, positive, and zero $ν$, focusing on the appearance of fractal geometry characteristics in the generated point sets. Forming ensembles of such point sets with fixed multiplicity, we develop simulation techniques leading to the desired value of correlation dimension in a vast continuous interval of scales. In particular, we demonstrate the possibility to produce ensembles of data sets with a low number of points with the needed properties. Furthermore, we show that the positive $ν$ distributions, apart from a region near the upper scale limit, show fractal behaviour that extends to infinitesimally low scales. As an example, we apply our findings to producing simulations relevant to the search for critical fluctuations, related to QCD critical endpoint, in heavy-ion collision experiments.

2605.14858 2026-05-15 quant-ph

Efficient ultrafast homodyne detection of quantum light

Young-Do Yoon, Chan Roh, Geunhee Gwak, Young-Sik Ra

AI总结 本文研究了高效超快同源探测量子光的方法,针对超快连续变量量子态在实际探测中面临效率低下的问题,提出了一种利用探测信号时间相关性的优化方法。通过优化时间权重以提取象限信息,显著提升了信噪比和探测效率,并通过求解广义瑞利商问题确定了最优权重,有效增强了实验中观测到的压缩和反压缩水平,突显了信号处理优化在量子测量中的重要性。

详情
英文摘要

Ultrafast continuous-variable quantum states offer new opportunities for advanced quantum technologies, but efficient homodyne detection of these states remains challenging. Here, we present a method for efficient ultrafast homodyne detection by exploiting temporal correlations in detector signals. By optimizing the temporal weight used to extract quadrature outcomes, we achieve a substantial increase in the signal-to-noise ratio of ultrafast homodyne detection, thereby improving the detection efficiency. We analyze the autocorrelations of shot noise and electronic noise and determine the optimal weight by solving a generalized Rayleigh quotient problem. The optimal weight enhances the squeezing and anti-squeezing levels observed experimentally. These results highlight the importance of optimized signal processing for efficient quantum measurements.