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2605.22333 2026-05-22 cs.CR

A First Measurement Study on Authentication Security in Real-World Remote MCP Servers

对现实世界远程MCP服务器认证安全性的首次测量研究

Huijun Zhou, Xiaohan Zhang, Haozhe Zhang, Haoyang Zhang, Mi Zhang, Min Yang

AI总结 本研究首次测量了现实世界远程MCP服务器的认证安全性,发现40.55%的服务器未进行认证,OAuth是主要的授权机制,但存在新的攻击面,识别出9种具体漏洞类型,并通过负责任的披露获得了9个CVE ID。

Comments 15 pages, 9 figures

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AI中文摘要

模型上下文协议(MCP)正成为连接大型语言模型(LLMs)与外部服务的常见接口。远程部署日益重要,因为代理连接到用户关联的在线服务,如社交、生产力和金融服务。在这些部署中,MCP客户端与远程服务器之间的认证边界成为安全关键,但仍未被深入研究。我们进行了首次对现实世界远程MCP服务器认证安全性的测量研究。我们识别出7,973个活跃的远程MCP服务器,发现40.55%的服务器未进行认证。在已认证的服务器中,OAuth是访问远程服务的主要授权机制,且在MCP生态系统中常见的三个特征:开放客户端环境、动态客户端注册和委托授权。这些特征使MCP部署区别于传统OAuth,并引入了新的攻击面。基于这一观察,我们推导出包含三个MCP特定类别和传统OAuth误配置的认证漏洞分类法,总计四个类别和九种具体漏洞类型。为了在大规模上评估这些漏洞,我们实现了结合被动流量检查和主动动态探测的半自动化检测框架。将其应用于119个可测试的现实OAuth启用MCP服务器,发现每个服务器至少存在一种漏洞,总共识别出325种漏洞,其中动态客户端注册漏洞影响了96.6%的测试服务器。许多这些漏洞可能导致敏感信息泄露和账户接管。通过负责任的披露,我们获得了9个CVE ID。我们的发现揭示了MCP生态系统中普遍存在的认证弱点,并强调了对加固OAuth基于的远程部署的紧迫需求。

英文摘要

The Model Context Protocol (MCP) is emerging as a common interface connecting large language models (LLMs) with external services. Remote deployments are becoming increasingly important as agents connect to user-linked online services, such as social, productivity, and financial services. In such deployments, the authentication boundary between MCP clients and remote servers becomes security-critical, yet remains underexplored. We present the first measurement study of authentication security in real-world remote MCP servers. We identify 7,973 live remote MCP servers, finding that 40.55% expose tools without authentication. Among authenticated servers, OAuth is the dominant authorization mechanism for reaching remote services, and OAuth deployments in the MCP ecosystem commonly exhibit three characteristics: open client environments, dynamic client registration, and delegated authorization. These characteristics distinguish MCP deployments from traditional OAuth and introduce new attack surfaces. Guided by this observation, we derive a taxonomy of authentication flaws comprising three MCP-specific categories and conventional OAuth misconfigurations, for a total of four categories and nine concrete flaw types. To evaluate these flaws at scale, we implement a semi-automated detection framework that combines passive traffic inspection with active dynamic probing. Applying it to 119 testable real-world OAuth-enabled MCP servers, we find that each server exhibits at least one flaw, with a total of 325 flaws identified, among which dynamic client registration flaws affect 96.6% of tested servers. Many of these flaws can lead to sensitive information leakage and account takeover. Through responsible disclosure, we obtained 9 CVE IDs. Our findings expose pervasive authentication weaknesses in the MCP ecosystem and underscore the urgent need for hardened OAuth-based remote deployments.

2605.22330 2026-05-22 hep-ph hep-ex

Symbolic Classification-Enabled LHC Limits Online BSM Global Fits

基于符号分类的LHC限制在线BSM全局拟合

Shehu AbdusSalam

AI总结 本文提出利用符号回归技术近似方法,将LHC限制在线纳入BSM全局拟合中,从而解决传统方法计算效率低下的问题,通过ATLAS约束数据构建数学表达式对pMSSM参数空间进行分类,进而实现对pMSSM的全局拟合。

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AI中文摘要

超越标准模型(BSM)物理的全局拟合通常涉及理论与实验之间的双向互动。理论模型为实验搜索提供指导,而实验结果反过来约束理论框架。这种反馈循环中的关键方面是直接将测量和排除限制“在线”纳入全局拟合中,即在参数扫描过程中。然而,将大型强子对撞机(LHC)限制纳入此类分析在计算上是不可行的,通常由于每个参数点的计算时间超过了全球拟合框架可接受的规模。在本研究中,我们展示通过利用符号回归技术推导出的近似方法,可以将LHC限制纳入“在线”全局拟合中。我们利用ATLAS对电弱ino生产搜索的约束数据,推导出一个数学表达式,能够将现象学最小超对称标准模型(pMSSM)参数空间分类为允许或排除。随后,该表达式被用于对pMSSM进行全局拟合,包括LHC Run-2限制。

英文摘要

Global fits of Beyond the Standard Model (BSM) physics often involve a two-way interplay between theory and experiment. Theoretical models provide guidance for experimental searches, while experimental results, in turn, constrain theoretical frameworks. A crucial aspect of this feedback loop is the direct inclusion of measurements and exclusion limits ``online'' global fits, i.e. during the parameter scans aspects of the global fits. However, incorporating the Large Hadron Collider (LHC) limits into such analyses has been computationally prohibitive, often due to time taken per parameter point exceeding the scales acceptable for global fit frameworks. In this study, we show that LHC limits can be incorporated ``online'' global fits by leveraging approximations derived from symbolic regression techniques. We utilize a dataset of ATLAS constraints from searches for electroweakino productions to derive a mathematical expression capable of classifying the phenomenological Minimal Supersymmetric Standard Model (pMSSM) parameter space as allowed or excluded. This is subsequently incorporated for making a global fit of the pMSSM to data, including the LHC Run-2 limits.

2605.22325 2026-05-22 cs.NI

Eliminating Premature Termination in Multihop Rendezvous for Cognitive Radio-based Emergency Response Network

消除多跳会面中的提前终止现象以实现认知无线电应急响应网络的可靠连接

Zahid Ali, Saritha Unnikrishnan, Eoghan Furey, Ian McLoughlin, Saim Ghafoor

AI总结 本文提出了一种多跳可靠双模块时钟算法(MR-DMCA),通过引入坐标辅助邻居验证机制和自主终止策略,解决多跳会面协议中因N-1终止条件导致的提前终止问题,从而确保邻居和网络拓扑的完整发现。

Comments Submitted to Results in Engineering, Elsevier

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AI中文摘要

在灾害后环境中,损坏的通信基础设施严重限制了应急响应团队之间的协调。认知无线电网络(CRNs)通过允许节点机会性访问可用频谱来实现快速部署的通信。然而,现有的多跳会面协议通常依赖于N-1终止条件,这可能导致提前终止,从而导致邻居发现不完整和无效的网络拓扑形成。本文识别了这一限制作为多跳会面协议中以前未被注意到的问题。本文提出了一种多跳可靠双模块时钟算法(MR-DMCA),该算法消除了提前终止并确保了可靠的网络形成。所提出的协议引入了坐标辅助邻居验证机制和自主终止策略,以在协议终止前保证完整的邻居和拓扑发现。尽管在MR-DMCA中实现,所提出的验证和终止方法适用于更广泛的多跳会面协议。广泛的模拟显示,在20个节点和20个信道的最坏情况可扩展场景下,高主频活动(m=2)情况下,MR-DMCA实现了100%准确的邻居和拓扑发现,同时将会面时间比基线协议减少了高达76%、37%和17%。结果表明,解决提前终止对于可靠多跳会面在认知无线电应急通信网络中至关重要。

英文摘要

In post-disaster environments, damaged communication infrastructure severely limits coordination among emergency response teams. Cognitive radio networks (CRNs) enable rapidly deployable communication by allowing nodes to opportunistically access available spectrum. However, existing multihop rendezvous protocols typically rely on N-1 termination conditions, which can lead to premature termination, resulting in incomplete neighbour discovery and invalid network topology formation. This work identifies this limitation as a previously overlooked issue in multihop rendezvous protocols. This paper proposes a Multihop Reliable Dual-Modular Clock Algorithm (MR-DMCA) that eliminates premature termination and ensures reliable network formation. The proposed protocol introduces a coordinate-assisted neighbour validation mechanism and an autonomous termination strategy that guarantees complete neighbour and topology discovery before protocol termination. Although implemented within MR-DMCA, the proposed validation and termination approach is applicable to a wider class of multihop rendezvous protocols. Extensive simulations demonstrate that, in a worst-case scalable scenario with 20 nodes and 20 channels under high primary radio activity (m=2), MR-DMCA achieves 100% accurate neighbour and topology discovery while reducing rendezvous time by up to 76%, 37%, and 17% compared with baseline protocols. The results highlight that addressing premature termination is critical for reliable multihop rendezvous in cognitive radiobased emergency communication networks.

2605.22324 2026-05-22 cs.CR

PACT: Reducing Alert Fatigue in Low-Prevalence SOC Streams with Triggered Active Learning

PACT:通过触发主动学习减少低患病率SOC流中的警报疲劳

Samuel Ndichu, Tao Ban, Seiichi Ozawa, Takeshi Takahashi, Daisuke Inoue

AI总结 本文提出PACT,一种针对触发主动学习的帕累托意识控制器,通过自适应窗口评分移位触发和混合获取规则减少低患病率SOC流中的警报疲劳,实验表明其在降低误报负担方面优于现有方法。

Comments 14 pages, 4 figures, 10 tables. Submitted to ACSAC 2026

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AI中文摘要

安全操作中心面临持续的警报疲劳问题:在低患病率流中,即使低的误报率也会产生显著的调查负担,而整体F1分数掩盖了分析师的负担。我们引入PACT,一种针对触发主动学习的帕累托意识控制器,它将已部署的冻结XGBoost-Focal筛选器与自适应窗口评分移位触发和结合阈值相对不确定性与高分采样的混合获取规则相结合。在两个公开的低患病率基准上,AIT-ADS(AIT警报数据集)和BOTSv1(SOC负责人版本1),PACT在测试的自适应方法中实现了最低的良性归一化误报(FP)负担。与冻结基线相比,PACT分别减少了43%和21%的负担,同时使用比周期性均匀随机更新少3.8倍和5.2倍的分析师查询。匹配触发消融控制触发时间,并显示获取贡献超过时间本身,但以大约10个百分点的正窗口召回率的代价。冻结阈值-only基线将FP降低得更低,但使BOTSv1召回率下降55个百分点。在评估的工作负载假设下,纯FP最小化以牺牲不可接受的召回率为代价换取更低的负担。

英文摘要

Security operations centers face persistent alert fatigue: in low-prevalence streams, even low false-positive rates generate substantial investigation load, while aggregate F1 scores obscure analyst burden. We introduce PACT, a Pareto-aware controller for triggered active learning, which wraps an already-deployed frozen XGBoost-Focal screener with an adaptive windowing score-shift trigger and a hybrid acquisition rule combining threshold-relative uncertainty with high-score sampling. On two public low-prevalence benchmarks, AIT-ADS (AIT Alert Data Set), and BOTSv1 (Boss of the SOC version 1), PACT attains the lowest benign-normalized false-positive (FP) burden among the adaptive methods tested. It reduces burden by 43% and 21%, respectively, relative to a frozen baseline, while using 3.8x and 5.2x fewer analyst queries than periodic uniform-random updating. A matched-trigger ablation controls trigger timing and shows that acquisition contributes beyond timing alone, at the cost of approximately ten percentage points of positive-window recall under free-running triggers. A frozen threshold-only baseline pushes FP lower still but collapses BOTSv1 recall by 55 percentage points. Under the evaluated workload assumptions, pure FP minimization trades unacceptable recall for that lower burden.

2605.22323 2026-05-22 astro-ph.HE astro-ph.SR

Magnetar Fireballs and Short Bursts: Curved Spacetime Lensing, QED Effects, High-Energy Spectra and Polarization, and Energy-Time Impulse Responses

磁星火球与短爆发:弯曲时空透镜效应、QED效应、高能光谱和偏振,以及能量-时间脉冲响应

Zorawar Wadiasingh, Hoa Dinh Thi, Constantinos Kalapotharakos, Kun Hu, Matthew G. Baring, Alice K. Harding, George Younes, Sebastien Guillot, Andrea Sanna, Michela Negro, Jeremy D. Schnittman, Oliver J. Roberts, Eric Burns, Chin-Ping Hu, Ersin Göğüş

AI总结 本文提出结合广义相对论光线弯曲、磁化光球中偏振传输、磁光分裂衰减和磁层真空双折射的新火球模型,以解释磁星短爆发的高能光谱、偏振特性及能量-时间脉冲响应,同时探讨其在磁星巨大耀斑脉动尾部中的应用。

Comments Comments welcome!

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AI中文摘要

磁星短爆发(SBs)是持续时间为0.01-1秒、峰值在约10-100 keV的硬X射线瞬变现象,是新型高能任务和偏振仪的主要目标。最近将SBs与SGR 1935+2154中的明亮无线电爆发关联起来,扩大了对SB物理的兴趣。我们提出了新的先进火球模型,结合广义相对论光线弯曲、磁化光球中的偏振传输、磁光分裂衰减以及磁层真空双折射。这些模型也适用于磁星巨大耀斑脉动尾部中的被困火球。我们采用与绝热火球一致的受限磁通管几何结构,并采用各向异性/偏振的涌现强度来产生光谱和偏振,以及能量-时间Stokes脉冲响应。我们预测大多数火球高度线性偏振,特别是在真空双折射重要时。存在丰富的诊断潜力:共存的直接和被透镜延迟的图像、由中子星表面遮蔽产生的间隙,以及Shapiro+Rømer延迟与时间caustics。这些效应可以印刻爆发的谱和偏振特征的自转相位依赖性。预测的特征强烈依赖于观测几何、火球配置和光子分裂假设,导致模型高能光谱形状和截止值有显著差异,以及能量依赖的偏振。这些模型可以重现已建立的双黑体SB光谱现象学,我们发现异常的2020年4月无线电关联SB从SGR 1935+2154大致符合脚点接近磁极,可能接近极视几何。我们的模型激励了SB的回声式分析,并建议高质量数据可能限制源几何、爆发地壳脚点,以及潜在的中子星质量和半径。

英文摘要

Magnetar short bursts (SBs) are hard X-ray transients of durations $0.01-1$ s peaking at $\sim 10-100$ keV, and are prime targets for new high-energy missions and polarimeters. The recent association of SBs with bright radio bursts in SGR 1935+2154 has broadened interest in SB physics. We present new advanced fireball models combining general relativistic light bending, polarized transport in magnetized photospheres, magnetic photon splitting attenuation, and magnetospheric vacuum birefringence. These models also have relevance to trapped fireballs in magnetar giant flare pulsating tails. We adopt confined flux tube geometries consistent with adiabatic fireballs, and anisotropic/polarized emergent intensities to produce spectra and polarizations, and energy-time Stokes impulse responses. We predict that most fireballs are highly linearly polarized, especially when vacuum birefringence is important. There is rich potential for diagnostics: coexisting direct and lensed delayed images, gaps by occultation of the neutron star surface, and Shapiro+Rømer delay with temporal caustics. These effects can imprint spin phase dependence of the spectral and polarization character of bursts. Predicted signatures depend strongly on viewing geometry, fireball configuration, and photon splitting assumptions, yielding large variance in model high-energy spectral shapes and cutoffs, and energy-dependent polarization. The models can reproduce established double-blackbody SB spectral phenomenology, and we find that the unusual April 2020 radio-associated SB from SGR 1935+2154 is broadly consistent with a footpoint close to the magnetic pole, and possibly near pole-on viewing geometry. Our models motivate reverberation-style analyses for SBs and suggest that high-quality data might constrain source geometry, burst crustal footpoints, and, potentially, neutron star masses and radii.

2605.22320 2026-05-22 math.AG math.CO

On the structure and generic non-Cartesianity of polynomials in product spaces

关于乘积空间中多项式的结构及其普遍非笛卡尔性质

Chun-Yen Shen, Tuyen Trung Truong, Wei-Hsuan Yu

AI总结 本文研究了复空间乘积上多项式的结构和非笛卡尔性质,证明了在固定次数下,多项式通常非笛卡尔,且通过格罗布纳基组方法可以算法判断非笛卡尔性,并将其与组合几何联系起来,得到精确的交集界和最优配置。

Comments 39 pages. Comments are welcome

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AI中文摘要

我们发展了复空间乘积上笛卡尔和非笛卡尔多项式的一般理论。我们证明,对于任何固定的次数d≥2,在广泛的维度范围内,一个(扎里斯基)通用多项式是非笛卡尔的,从而确立了笛卡尔结构的高度例外性。我们进一步引入了多项式非笛卡尔的有效充分条件。此外,我们显示,判断多项式是否(非)笛卡尔可以通过格罗布纳基组方法和希尔伯特零点定理的定量形式来算法决定。作为应用,我们将非笛卡尔条件与组合几何联系起来,得到精确的交集界,并构造了极值配置,以证明这些估计的最优性。

英文摘要

We develop a general theory of Cartesian and non-Cartesian polynomials on products of complex spaces $\mathbb{C}^{n_1} \times \cdots \times \mathbb{C}^{n_k}$. We prove that, for any fixed degree $d \ge 2$, a (Zariski) generic polynomial is non-Cartesian in a broad range of dimensions, establishing that Cartesian structure is highly exceptional. We further introduce effective sufficient criteria for a polynomial to be non-Cartesian. Moreover, we show that being (non)-Catersian can be decided algorithmically via Gröbner basis methods and quantitative forms of Hilbert's Nullstellensatz. As an application, we connect the non-Cartesian condition to incidence geometry, obtaining sharp intersection bounds and constructing extremal configurations that demonstrate the optimality of these estimates.

2605.22319 2026-05-22 cond-mat.mtrl-sci physics.app-ph

Two-dimensional alternating ferrimagnetism with strain-controlled half-metallic state and valley polarization

二维交替反铁磁性与应变调控的半金属态及谷极化

W. Z. Zhuo, Z. H. Guan, Z. L. Peng, Y. N. Pan, J. Chen, Y. Yang, M. H. Qin

AI总结 本文研究了二维交替反铁磁性,通过应变调控实现半金属态和谷极化,揭示了其在二维磁性中的新特性及应用潜力。

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AI中文摘要

交替反铁磁性的发现为探索新型量子态和开发自旋电子器件提供了新机遇,尽管零净磁化限制了传统磁方法的操控性。本文提出二维交替反铁磁性,一种相融合的交替动量依赖自旋分裂状态,具有有限的净磁化。紧束缚模型揭示,交替反铁磁性源于反铁磁体中的未补偿磁化,促进净磁化与交替自旋分裂的同时存在。第一性原理计算和蒙特卡罗模拟显示,在应变和Cr取代V2Te2O中稳定存在交替反铁磁性,表现出应变可调的净磁化、可逆的半金属性和谷极化,伴随室温以上的长程磁序。通过结合反铁磁和铁磁特性,交替反铁磁性扩展了二维磁性景观,并为高效能自旋电子应用提供了路径。

英文摘要

The discovery of altermagnetism offers new opportunities for exploring novel quantum states and developing spintronic devices for enabling momentum dependent spin splitting in compensated systems, while zero net magnetization limit its manipulability using conventional magnetic method. Here, we propose 2D alternating ferrimagnetism,a phase merging alternating momentum dependent spin splitting with a finite net magnetization. A tight binding model reveals that alternating ferrimagnetism originates from uncompensated magnetization in altermagnets, facilitating concurrent net magnetization and alternating spin splitting. First principles calculations and Monte Carlo simulations demonstrate stable alternating ferrimagnetism in strained and Cr substiting V2Te2O, which exhibit strain tunable net magnetization, reversable half metallicity and valley polarization, accompanied by long range magnetic order above room temperature. By combining altermagnetic and ferromagnetic properties, alternating ferrimagnetism expand the 2D magnetism landscape and offer pathways for energy efficient spintronic applications.

2605.22317 2026-05-22 cs.NI

Throughput and Delay Performance of Slotted Aloha in SmartBANs under Saturation Conditions

分组随机接入在饱和条件下智能体域网络的吞吐量和时延性能

Anastasios C. Politis, Constantinos S. Hilas

AI总结 本文研究了在饱和条件下,基于欧洲电信标准协会(ETSI)SmartBAN规范定义的分组随机接入协议的性能,通过构建二维离散时间马尔可夫链(DTMC)模型,评估其在饱和吞吐量和平均端到端时延方面的性能,并通过仿真验证了模型的准确性。

Comments 5 pages, 5 figures

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Journal ref
IEEE Networking Letters, vol. 6, no. 3, pp. 168-172, September 2024
AI中文摘要

本文评估了由欧洲电信标准协会(ETSI)SmartBAN规范定义的分组随机接入协议在饱和条件下的性能。为此,我们开发了一个二维离散时间马尔可夫链(DTMC)来建模该协议的操作细节,并评估其在饱和吞吐量和平均端到端时延方面的性能。通过仿真验证了所提模型的准确性,结果显示理论结果与仿真结果非常吻合。该模型可用于协议性能预测和优化目的。

英文摘要

This letter evaluates the performance of the slotted Aloha protocol defined by the European Telecommunication Standard Institute (ETSI) SmartBAN specification, under saturation conditions. For this purpose, we develop a two-dimensional Discrete Time Markov Chain (DTMC) to model the operational details of the protocol and assess its performance in terms of saturation throughput and average end-to-end delay. The accuracy of the proposed model is validated by means of simulation which reveals a very good match among theoretical and simulation results. The model can be used for protocol performance prediction and optimization purposes.

2605.22316 2026-05-22 cond-mat.dis-nn

Possible Topological Decoherence Transition in Relativistic Electron Beams Propagating through Coulomb-Disordered Media

可能的相对论电子束在库仑无序介质中传播时的拓扑退相干相变

Yury A. Budkov

AI总结 研究探讨了相对论电子束在库仑无序介质中传播时的拓扑退相干相变,通过有效二维紧凑相位场和格格斯自由场作用分析,发现临界样本厚度可能引发Berezinskii-Kosterlitz-Thouless相变,区分代数退相干与自由涡流增殖导致的指数退相干。

Comments Submitted to Physical Review Letters

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AI中文摘要

我们证明了在库仑无序介质中相对论电子束的相互相干性由一个具有对数相关函数的有效二维紧凑相位场所支配。相应的高斯自由场作用表现出与传播长度成反比的刚性。当考虑相位的紧凑性质时,系统支持相互作用如同二维库仑气体的涡旋激发。对该气体的重整化群分析表明,存在一个临界样本厚度L_c,可能引发Berezinskii-Kosterlitz-Thouless (BKT)相变,将代数退相干区域与自由涡流增殖并破坏相干性的区域分隔开。临界厚度通过基本微观参数表达,可能在液态细胞或低温样品的透射电子显微镜中被观测到。

英文摘要

We show that the mutual coherence of a relativistic electron beam in a Coulomb-disordered medium is governed by an effective two-dimensional compact phase field with a logarithmic correlation function. The corresponding Gaussian free-field action exhibits a stiffness inversely proportional to the propagation length. When the compact nature of the phase is taken into account, the system supports vortex excitations that interact as a two-dimensional Coulomb gas. Renormalization-group analysis of this gas indicates the existence of a critical sample thickness $L_c$ at which a Berezinskii--Kosterlitz--Thouless (BKT) transition may occur, separating a regime of algebraic decoherence from one where free vortices proliferate and coherence is destroyed exponentially. The critical thickness is expressed through fundamental microscopic parameters and could be observed in transmission electron microscopy of liquid cells or cryogenic samples.

2605.22315 2026-05-22 math.NA cs.NA

Schwarz Modulus Based Matrix Splittings with Minimal Polynomial Extrapolation Acceleration for linear complementarity problems arising from American option pricing

基于Schwarz模的矩阵分裂方法与最小多项式外推加速技术用于美式期权定价中出现的线性互补性问题

Martin J. Gande, Si-Wei Liao, Liu-Di Lu

AI总结 本文提出了一种基于Schwarz模的矩阵分裂方法,并利用修改后的多项式外推技术加速,以解决美式期权定价中出现的线性互补性问题,数值实验表明该方法的迭代次数比传统方法减少了近一个数量级。

Comments 8 pages, 2 figures, Proceeding paper in Domain Decomposition Methods in Science and Engineering XXIX

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AI中文摘要

美式期权定价比欧式期权复杂,因为它们可以在任何时间行使,因此需要求解线性互补性问题,而不是简单的时间步进计算欧式期权。我们介绍了一种新的基于Schwarz模的分裂方法来解决此类线性互补性问题,并进一步使用修改后的多项式外推技术加速,这是一种非线性向量序列加速技术,与线性情况下的Krylov方法密切相关。数值实验表明,我们的新求解器在迭代次数上比传统使用的模基矩阵分裂技术减少了近一个数量级。

英文摘要

Pricing American options is more complicated than pricing European options, because they can be exercised at any time, and one thus needs to solve a linear complementarity problem instead of simply doing time stepping for computing European options. We introduce a new Schwarz modulus-based splitting method for solving such linear complementarity problems, and further accelerate them using Modified Polynomial Extrapolation, a non-linear vector sequence acceleration technique, which is very much related to Krylov methods in the linear case. Numerical experiments on a model problem show that our new solver can have close to an order of magnitude lower iteration counts than the classically used modulus-based matrix splitting technique.

2605.22314 2026-05-22 math.LO

Higher-arity distality and forking triviality

更高元 arity 的 distality 与 forking triviality

Mervyn Tong

AI总结 本文回答了Goode的问题,证明在简单理论中k-triviality塌缩到(1-)triviality。特别地,每个具有量化消除的有限元 arity 关系语言的稳定理论都是trivial的。通过塌缩结果和其他关于k-triviality和k-total triviality的事实,生成了强k-distal理论的例子。塌缩结果立即表明,没有稳定理论可以严格k-distal,部分回答了Walker的问题。所有已知的非distal(强)k-distal理论都是k-ary的,使得(强)k-distality不再成为(k+1)-ary划分线;我们给出了四个不是k-ary的例子。我们还证明了distality不被取reducts所保持,同样(强)k-distality也不被保持。

Comments 17 pages

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AI中文摘要

回答Goode提出的问题,我们证明在简单理论中k-triviality塌缩到(1-)triviality。特别地,每个具有量化消除的有限元 arity 关系语言的稳定理论都是trivial的。我们利用塌缩结果和其他关于k-triviality和k-total triviality的事实,生成了(强)k-distal理论的例子。塌缩结果立即表明,没有稳定理论可以严格k-distal,部分回答了Walker的问题。所有已知的非distal(强)k-distal理论都是k-ary的,使得(强)k-distality不再成为(k+1)-ary划分线;我们给出了四个不是k-ary的例子。我们还证明了distality不被取reducts所保持,同样(强)k-distality也不被保持。

英文摘要

Answering a question of Goode, we show that $k$-triviality collapses to (1-)triviality among simple theories. In particular, every stable theory with quantifier elimination in a relational language of bounded arity is trivial. We use our collapse result, along with other facts about $k$-triviality and $k$-total triviality, to generate examples of (strongly) $k$-distal theories. The collapse result immediately implies that no stable theory can be strictly $k$-distal for some $k\geq 3$, partially answering a question of Walker. Moreover, all known examples of non-distal (strongly) $k$-distal theories are $k$-ary, rendering (strong) $k$-distality moot as a $(k+1)$-ary dividing line; we give four classes of examples that are not $k$-ary. We also show that just as distality is not preserved under taking reducts, neither is (strong) $k$-distality.

2605.22313 2026-05-22 cond-mat.mtrl-sci

Photoemission intermittency via stochastic gating in rubrene nanowires coupled to plasmonic silver nanoparticles

通过随机门控在 rubrene 纳米线与等离子体银纳米颗粒耦合中观察到的光电发射间歇性

Moha Naeimi, Waqas Pervez, Frithjof Harmsen, Ingo Barke, Sylvia Speller

AI总结 研究通过随机门控在 rubrene 纳米线与等离子体银纳米颗粒耦合界面观察到光电发射间歇性现象,揭示了有机-等离子体界面中新的电荷辅助发射动态模式。

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AI中文摘要

在本工作中,我们报告了一种新的纳米尺度现象,即光电发射间歇性(开-关电子发射),表现为在准一维有机导线和银纳米颗粒界面处电子产额的随机脉冲。能量分辨测量显示,发射的电子携带混合信息,包含与纳米颗粒相关的光电电子产额增强以及由有机半导体决定的动能。间歇性导致电子光谱的动态位移,与光电电子产额相关联。我们归因于纳米界面处的光空穴积累和由于电子-空穴分离引起的电荷随机门控。这些发现将光电发射间歇性引入为一种纳米尺度现象,指示了有机-等离子体界面中新的电荷辅助发射动态模式。

英文摘要

In this work, we report a new nanoscale phenomenon observed as photoemission intermittency (On-Off electron emission), manifested as stochastic bursts in electron yield at quasi-one-dimensional organic wires and silver nanoparticles interface. Energy-resolved measurements reveal that the emitted electrons carry out hybrid information, containing photoelectron yield enhancement associated with the nanoparticles and kinetic energies determined by the organic semiconductor. The intermittency results in a dynamic shift of the electron spectra correlating with the photoelectron yield. We attribute the observed behaviour to the photo-hole accumulation and stochastic gating of charge due to electron-hole separation at the nano interface. These findings introduces the photoemission intermittency as a nanoscale phenomenon indicating a new dynamic regime of charge assisted emission at organic-plasmonic interfaces. Keywords: rubrene, nanoparticle, PEEM, exciton, charge

2605.22312 2026-05-22 math.NA cs.NA math.OC

From PDEs constrained optimization to controllability problems via time domain decomposition

从偏微分方程约束优化到可控性问题的时域分解

Pierre-Henri Cocquet, Liu-Di Lu

AI总结 本文通过时域分解方法解决偏微分方程约束优化和可控性问题,证明两者在应用时域分解后具有相同的收敛行为,并通过数值实验验证了理论结果。

Comments 10 pages, 3 figures, Proceeding paper in Domain Decomposition Methods in Science and Engineering XXIX

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AI中文摘要

本文聚焦于利用时域分解方法解决偏微分方程约束优化问题和可控性问题。在明确这两种问题之间的联系后,我们展示了将时域分解应用于这两种问题会导致相同的收敛行为。我们的数值实验也证实了这些理论发现。

英文摘要

This paper focuses on the application of time domain decomposition to solve partial differential equations constrained optimization problems and controllability problems. After clarifying the link between these two types of problems, we show that applying time domain decomposition to both problems leads to the same convergence behavior. Our numerical experiments also confirm these theoretical findings.

2605.22309 2026-05-22 astro-ph.CO gr-qc hep-ph

Signatures of Modified Gravity Below $\mathcal{O}(10)$ Mpc in a Dynamical Dark Energy Background

在动态暗能量背景中$\mathcal{O}(10)$ Mpc尺度下修改引力的特征

Yo Toda, Adrià Gómez-Valent

AI总结 研究在动态暗能量背景中,通过参数化有效引力耦合偏离牛顿常数的可能偏离,发现为了在低红移处抑制结构增长同时符合CMB约束,修改引力效应必须出现在小于$\lambda_c \sim \mathcal{O}(10)\,\mathrm{Mpc}$的尺度上,且CPL背景在标准引力下较$Λ$CDM更受青睐,但加入修改引力效应后,CPL参数略有变化。

Comments 11pages, 5 figures

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AI中文摘要

来自宇宙微波背景(CMB)、重子声学振荡和Ia型超新星的宇宙学数据表明,驱动宇宙加速膨胀的成分可能在$\sim 2.5$-$3σ$置信水平下是动态的。最佳拟合的CPL模型产生与$Λ$CDM相似的宇宙结构,但两种模型都与红移空间扭曲数据存在轻微张力。在本文中,我们使用两个红移区间(0 ≤ z < 1和1 ≤ z ≤ 3)参数化可能的有效引力耦合偏离牛顿常数的可能偏离,低于共动尺度λ_c。然后我们确定λ_c和这些偏离幅度的最佳值,假设背景为CPL形式的动态暗能量。我们发现,为了在低红移处抑制结构增长同时符合CMB约束(主要来自晚期时间ISW效应在低$\ell$和高$\ell$的透镜效应),修改引力效应必须出现在小于λ_c ~ $\mathcal{O}(10)$ Mpc的尺度上。使用Planck PR4、DESI DR2、Pantheon+(或DES-Dovekie)和红移空间扭曲数据,我们确认CPL背景在标准引力下比$Λ$CDM略受青睐;当包含修改引力效应时,这种偏好增强到中等强度水平。这种增强使CPL参数基本不变,但将它们略微进一步推向quintom区域。

英文摘要

Cosmological data from the cosmic microwave background (CMB), baryon acoustic oscillations, and Type Ia supernovae suggest that the component driving the accelerated expansion of the Universe may be dynamical at the $\sim 2.5$-$3σ$ CL. The best-fit CPL model produces a level of cosmic structure similar to that of $Λ$CDM, with both models exhibiting mild tension with redshift-space distortion data. In this {\it Letter}, we parametrize possible departures of the effective gravitational coupling from Newton's constant in the late Universe, below a comoving scale $λ_c$, using two redshift bins, $0 \leq z < 1$ and $1 \leq z \leq 3$. We then determine the optimal values of $λ_c$ and the amplitude of these deviations from General Relativity, assuming a background with dynamical dark energy in CPL form. We find that, in order to achieve the required suppression of structure growth at low redshifts while remaining consistent with CMB constraints -- primarily from the late-time ISW effect at low $\ell$ and lensing at high $\ell$ -- modified gravity effects must appear on scales smaller than $λ_c \sim \mathcal{O}(10)\,\mathrm{Mpc}$. Using Planck PR4, DESI DR2, Pantheon+ (or DES-Dovekie) and redshift-space distortions data we confirm that a CPL background with standard gravity is moderately preferred over $Λ$CDM; this preference strengthens to a mildly strong level when modified gravity effects are included. This enhancement leaves the CPL parameters largely unchanged, but shifts them slightly further into the quintom region.

2605.22308 2026-05-22 math.GT

Algebraic properties of twisted Alexander polynomial and Reidemeister torsion of torus knots

扭转Alexander多项式和扭转特征标代数性质的研究

Takayuki Morifuji, Anh T. Tran

AI总结 本文证明了扭Alexander多项式中与不可约SL_n(C)表示相关的每个系数都是SL_n(C)特征标簇上的A-值局部常函数,其中A是所有复数上的代数整数环。此外,作为Kitano和Nozaki最近结果的推广,我们显示SL_n(C)的Reidemeister扭转对于许多Seifert纤维空间是代数整数。同时,我们讨论了扭结的Reidemeister扭转的幂和,这些扭结的低维不可约表示与TQFT存在神秘关系。

Comments Accepted for publication in Topology and its Applications. Some results in Section 6 overlap with the recent preprint arXiv:2605.19460 of Terashima and Yamaguchi

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AI中文摘要

在本文中,我们证明了每个扭结的扭Alexander多项式与不可约SL_n(C)表示相关的系数都是SL_n(C)特征标簇上的A-值局部常函数,其中A是所有复数上的代数整数环。此外,作为Kitano和Nozaki最近结果的推广,我们显示SL_n(C)的Reidemeister扭转对于许多Seifert纤维空间是代数整数。同时,我们讨论了扭结的Reidemeister扭转的幂和,这些扭结的低维不可约表示提供了一种神秘的关系到TQFT。

英文摘要

In this paper we prove that every coefficient of twisted Alexander polynomials of torus knots associated with irreducible $\mathrm{SL}_n(\Bbb C)$-representations is an $\Bbb A$-valued locally constant function on the $\mathrm{SL}_n(\Bbb C)$-character variety, where $\Bbb A$ is the ring of all algebraic integers over $\Bbb C$. Moreover, as a generalization of a recent result of Kitano and Nozaki, we show that $\mathrm{SL}_n(\Bbb C)$-Reidemeister torsions are algebraic integers for many Seifert fibered spaces. Also, we discuss the power sums of Reidemeister torsions of torus knots for low-dimensional irreducible representations that provide a mysterious relation to TQFT.

2605.22307 2026-05-22 math.CO

The weak $k$-metric dimension of the direct product of complete graphs

直接积完全图的弱k-度度数

Mohammad Farhan, Dorota Kuziak, Ismael G. Yero

AI总结 本文研究了两个同构完全图直接积的弱k-度度数,计算了几乎所有情况下的参数值,并在剩余情况下给出了界。

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AI中文摘要

图的弱k-度度数大致被理解为图中最小顶点集合S的基数,使得通过S中顶点到其他顶点距离差的求和可以唯一识别所有顶点。本文考虑了两个同构完全图直接积的弱k-度度数。具体而言,计算了几乎所有情况下的该参数值,并在剩余情况下提供了界。

英文摘要

The weak $k$-metric dimension of a graph is roughly understood as the cardinality of a smallest set of vertices $S$ of the graph with the property of uniquely recognizing all the vertices of the graph throughout summations of differences of distances to the vertices of $S$. The weak $k$-metric dimension of the direct product of two isomorphic complete graphs is considered in this work. Specifically, the value of such parameter is computed for almost all possibilities of these products and a bound is provided in the remaining case.

2605.22303 2026-05-22 cond-mat.supr-con

Fabrication and transfer of ultra-thin YBa$2$Cu$3$O$_{7-x}$ film on SrTiO$_3$ nanomembrane

在SrTiO3纳米膜上制备和转移超薄YBa2Cu3O7-x薄膜

J. S. Madhira, G. Potemkin, D. Grützmacher, T. Schäpers, M. Lyatti

AI总结 本研究通过高压溅射在SrTiO3/Sr1.5Ca1.5Al2O6双层上制备出高质量的超薄YBa2Cu3O7-x薄膜,并将其转移到SiO2/Si基底上,展示了其在超导纳米线单光子探测器中的应用潜力。

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AI中文摘要

自由站立的超薄高温超导薄膜的制备对于开发具有高工作温度的超导纳米线单光子探测器具有重要意义。我们成功地利用高压溅射在SrTiO3/Sr1.5Ca1.5Al2O6双层上制备出毫米级、高质量的超薄YBa2Cu3O7-x(YBCO)薄膜。通过溶解水溶性的SCAO牺牲层,将STO纳米膜与YBCO薄膜释放并转移到SiO2/Si基底上。X射线衍射证实转移至SiO2/Si基底后STO和YBCO的结晶性得以保持。转移后的YBCO薄膜上图案化的微桥表现出88.8 K的临界温度和77 K时6.8 MA/cm2的临界电流密度,显示出转移后的稳定超导传输特性。在STO纳米膜与SiO2/Si基底之间的范德华界面,热边界导热率在15-75 K范围内显著低于在体STO上生长的 epitaxial YBCO 薄膜,导致能量弛豫的改变和瞬态电阻态的稳定性增强。这些结果确立了在光学透明STO纳米膜上集成高临界温度超导器件与基于SiO2/Si的光子结构的平台。

英文摘要

The fabrication of free-standing ultra-thin films from high-temperature (high-Tc) superconductors is of great interest for the development of superconducting nanowire single-photon detectors with high operating temperatures. We successfully fabricate a millimeter-sized, high-quality, ultra-thin YBa$2$Cu$3$O$_{7-x}$ (YBCO) film on an SrTiO$_3$/Sr$_{1.5}$Ca$_{1.5}$Al$_2$O$_6$ (STO/SCAO) bilayer using high-pressure sputtering. The STO nanomembranes with the YBCO films are released by dissolving the water-soluble SCAO sacrificial layer and transferred onto the SiO2/Si substrate. X-ray diffraction confirms that STO and YBCO crystallinity is preserved following transfer onto SiO2/Si substrates. Microbridges patterned from the transferred YBCO films exhibit a critical temperature of 88.8 K and a critical current density of 6.8 MA/cm2 at 77 K, demonstrating robust superconducting transport after transfer. The thermal boundary conductance across the van der Waals interface between the STO nanomembrane with YBCO film and the SiO2/Si substrate, measured over 15-75 K, is significantly reduced compared to that of epitaxial YBCO film on bulk STO leading to modified energy relaxation and enhanced stability of transient resistive states. These results establish ultra-thin YBCO films on optically transparent STO nanomembranes as a platform for integrating high-Tc superconducting devices with SiO2/Si-based photonic structures.

2605.22302 2026-05-22 math.GR

On finite perfect two-sided skew braces

关于有限完美双侧斜格结构

Marco Damele

AI总结 本文研究了有限完美双侧斜格的结构定理,通过发展斜格的中心积理论,证明了有限完美双侧斜格可以分解为几乎平凡和平凡的斜格,从而分类了这些结构,揭示了其与完美群的关系。

Comments 29 pages

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AI中文摘要

我们证明了有限完美双侧斜格的结构定理。主要工具是这里发展的斜格的中心积理论,以外部和内部形式呈现;我们证明这两种构造是等价的。我们的主要结果指出,每一个有限完美双侧斜格 $B$ 都可以分解为 $B = B^2 \circ B^{2,\operatorname{op}}$,其中 $B^2$ 几乎平凡且具有完美加法群,而 $B^{2,\operatorname{op}}$ 是平凡的且具有完美加法群。因此,有限完美双侧斜格在中心拼接下被分类,由来自完美群的平凡和几乎平凡斜格所决定。这种分解对底层群有重要影响:对于有限双侧斜格,斜格的完美性等价于加法群或乘法群的完美性。在平凡中心情况下,中心积变为直接积,恢复了 Trappeniers 对有限简单双侧斜格的分类。我们还证明了准简单双侧斜格要么是平凡的要么是几乎平凡的。最后,我们证明这种刚性确实是双侧的,通过构造一个非双侧且既非平凡也非几乎平凡的准简单斜格。

英文摘要

We prove a structure theorem for finite perfect two-sided skew braces. The main tool is a central product theory for skew braces, developed here in both external and internal form; we show that these two constructions are equivalent. Our main result states that every finite perfect two-sided skew brace \(B\) admits the canonical decomposition $B=B^2\circ B^{2,\operatorname{op}},$ where \(B^2\) is almost trivial with perfect additive group, while \(B^{2,\operatorname{op}}\) is trivial with perfect additive group. Thus finite perfect two-sided skew braces are classified, up to central amalgamation, by trivial and almost trivial skew braces arising from perfect groups. This decomposition has strong consequences for the underlying groups: for finite two-sided skew braces, perfectness of the skew brace is equivalent to perfectness of either the additive or the multiplicative group. In the trivial-center case the central product becomes a direct product, recovering Trappeniers' classification of finite simple two-sided skew braces. We also show that quasi-simple two-sided skew braces are necessarily either trivial or almost trivial. Finally, we prove that this rigidity is genuinely two-sided by constructing a quasi-simple skew brace which is not two-sided and is neither trivial nor almost trivial.

2605.22301 2026-05-22 stat.ME

Chained Markov melding using divide and conquer sequential Monte Carlo

使用分治策略的链式马尔可夫融合

Yixuan Liu, Robert J. B. Goudie

AI总结 本文提出了一种新的多阶段采样器,用于链式马尔可夫模型,通过分治策略的序列蒙特卡洛方法,解决了现有MCMC方法在处理相邻子模型共享量时的后验推断难题。

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AI中文摘要

指定一个整合多个数据源的完整贝叶斯模型可以具有挑战性。一种自然的方法是分别指定每个个体模型并在之后进行连接。这在马尔可夫融合中采用的方法。然而,当相邻的子模型共享共同的量时,如链式马尔可夫融合,现有基于MCMC的方法的后验推断会变得具有挑战性。在本文中,我们提出了一种新的多阶段采样器,用于涉及任意数量子模型的链式马尔可夫模型。所提出的采样器采用分治策略的序列蒙特卡洛方法,以适合链式马尔可夫融合结构的树状结构模型。所得到的多阶段采样器为从复杂的联合模型中采样提供了一种灵活的替代方法,因为其对不同子模型的单独采样方案避免了直接从完整模型中采样的需求。我们通过两个例子展示了该采样器的应用。第一个是涉及11种不同类型子模型的玩具示例。第二个示例考虑了一个整合生态人口模型,结合多个数据集以估计移民和繁殖率。

英文摘要

Specifying a full Bayesian model that integrates multiple data sources can be challenging. One natural approach is to specify each individual model separately and join them afterwards. This is the approach adopted in Markov melding. However, when adjacent submodels share common quantities, as in chained Markov melding, posterior inference can be challenging for existing MCMC-based approaches. In this paper, we propose a new multi-stage sampler for chained Markov models involving an arbitrary number of submodels. The proposed sampler adopts a divide-and-conquer sequential Monte Carlo approach for the tree-structured model that fits naturally with the structure of chained Markov melding. The resulting multi-stage sampler provides a flexible alternative for sampling from complex joint models, as its separate sampling scheme for different submodels avoids the need for directly sampling from the full model. We demonstrate applications of the sampler through two examples. The first is a toy example involving 11 submodels of various types. The second example considers an ecologically integrated population model that combines multiple datasets to estimate immigration and reproduction rates.

2605.22299 2026-05-22 math.DS nlin.CD

Data-Driven Reduced Modeling of Delayed Dynamical Systems via Spectral Submanifolds

通过谱子流形实现延迟动力系统的数据驱动降维建模

Giacomo Abbasciano, Gergely Buza, George Haller

AI总结 本文提出了一种基于谱子流形理论的数据驱动方法,用于减少非线性延迟系统的模型复杂度,通过比较基于方程和数据驱动的SSM降维方法,展示了该方法在处理延迟微分方程时的有效性,并应用于多个非线性延迟系统,得到无延迟的ODE模型。

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AI中文摘要

我们展示了最近将谱子流形(SSM)理论扩展到延迟微分方程(DDEs)中的方法,使能够对非线性延迟系统进行数据驱动的模型降维。首先,使用一个具有单个离散延迟的标量DDE,比较基于方程和数据驱动的SSM降维方法,以说明后者的重要性。然后,我们使用相同的算法对多个非线性延迟系统获得纯数据驱动的SSM降维无延迟ODE模型。我们的方法不需要关于底层DDE形式或其包含的延迟数量和幅度的信息。我们的SSM降维低维模型即使在混沌动力学下仍具有预测性。我们还展示了参数SSM降维在具有分布和离散延迟的系统中捕捉分岔的应用。最后,我们将延迟SSM降维的理论基础扩展到具有周期性延迟的非自治系统,并将这些结果应用于具有反馈延迟和量化误差的控制系统的实验数据。

英文摘要

We show how the recent extension of spectral submanifold (SSM) theory to delay differential equations (DDEs) enables data-driven model reduction of nonlinear delay systems. First, using a scalar DDE with a single discrete delay, we compare equation-based and data-driven SSM reductions, to illustrate the need for the latter. We then use the same algorithm to obtain purely data-driven, SSM-reduced, delay-free ODE models for several nonlinear delayed systems. Our approach requires no information about the form of the underlying DDE, or about the number and magnitude of the delays it contains. Our SSM-reduced, low-dimensional models remain predictive even for chaotic dynamics. We also illustrate the use of parametric SSM-reduction to capture bifurcations in systems with both distributed and discrete delays. Finally we extend the theoretical underpinning of delayed SSM-reductions to non-autonomous systems with periodic delays, and apply these results to experimental data from a control system with feedback delay and quantization.

2605.22298 2026-05-22 physics.optics

Mid-infrared temporal ghost imaging via two-photon structured encoding

中红外时间鬼成像通过双光子结构编码

Ziyu He, Kun Huang, Huijie Ma, Wen Zhang, Jianan Fang, Heping Zeng

AI总结 本文提出了一种基于非退化双光子吸收的宽带中红外时间鬼成像系统,实现了超快信号重建,提高了检测灵敏度和压缩感知能力,适用于分子光谱学、高精度红外测距和高速自由空间通信。

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Journal ref
Photonics Research 14, 1919 (2026)
AI中文摘要

时间鬼成像(TGI)能够超越电子带宽限制实现超快信号重建。通过非线性频率转换将这一概念扩展到中红外(MIR)领域,为高保真度时间检测提供了新机会,但受限于严格的相匹配条件、有限的光谱覆盖和复杂的光学对准。本文提出并演示了一种基于非退化双光子吸收的宽带中红外TGI系统。一个时间编码的近红外泵将结构化调制直接施加到中红外信号上,通过硅探测器实现的同时调制和检测,无需外部非线性晶体。重建的时间波形超过探测器带宽40倍以上,检测灵敏度达到0.05 pJ/pulse,支持80%更少的测量压缩感知,并在2.5-3.8 μm范围内实现宽频带操作。这种紧凑、无对准、室温系统为快速和灵敏的中红外时域分析提供了实用途径,对时间分辨分子光谱学、高精度红外测距和高速自由空间通信具有巨大应用前景。

英文摘要

Temporal ghost imaging (TGI) enables ultrafast signal reconstruction beyond electronic bandwidth limits. Extending this concept to the mid-infrared (MIR) regime through nonlinear frequency conversion offers new opportunities for high-fidelity temporal detection, but remains constrained by stringent phase-matching condition, limited spectral coverage, and intricate optical alignment. Here, we propose and demonstrate a broadband MIR TGI system based on non-degenerate two-photon absorption. A temporally encoded near-infrared pump transfers structured modulation onto a MIR signal directly at a silicon detector, which facilitates concurrent modulation and detection without external nonlinear crystals. The reconstructed temporal waveforms exceed the detector bandwidth by more than fortyfold, achieve a detection sensitivity of 0.05 pJ/pulse, allow compressed sensing with 80\% fewer measurements, and support broadband operation across 2.5-3.8 $μ$m. This compact, alignment-free, and room-temperature system establishes a practical route for fast and sensitive MIR time-domain analysis, holding great promise for applications in time-resolved molecular spectroscopy, high-precision infrared ranging, and high-speed free-space communication.

2605.22296 2026-05-22 astro-ph.EP

Probing close-in satellites of Trans-Neptunian Objects through thermal and direct size measurements

通过热和直接尺寸测量探测近距卫星:穿越海王星天体

J. M. Gómez-Limón, R. Leiva, J. L. Ortiz, P. Santos-Sanz, M. Kretlow, Y. Kilic, J. L. Rizos, A. Álvarez-Candal, T. G. Müller

AI总结 本文通过热和直接尺寸测量研究穿越海王星天体的近距卫星,利用掩星推导的尺寸和热发射数据,验证了四个已知双星系统的卫星存在,并发现三个新的双星系统,提供了可能卫星的尺寸估计。

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AI中文摘要

背景:穿越海王星天体是遥远的天体,保留着关于太阳系起源和演化的宝贵信息。许多这些天体构成双星系统。研究双星系统有助于进一步 characterize 这个原始群体,并对确定质量密度至关重要,这是关键但难以捉摸的物理属性。然而,卫星检测可能具有挑战性。目标:本研究旨在约束一组十个穿越海王星天体周围的近距卫星的存在,包括四个已知双星系统用于方法验证。方法:我们开发了一种不依赖主次分离的方法。我们利用掩星推导的尺寸和“TNOs are Cool”哈伯空间望远镜关键项目中的热发射数据。我们对双星系统建模,以解释无法用单个天体的掩星推导尺寸复现的热过剩。结果:我们对验证目标(208996) Achlys、(229762) G!kún{

英文摘要

Context: Trans-Neptunian objects are distant bodies that retain valuable information about the origin and evolution of the Solar System. Many of these objects constitute binary systems. Studying binaries allows us to further characterise this primitive population and is critical for determining mass densities, a key but elusive physical property. Nevertheless, satellite detection can be challenging. Aims: This study aims to constrain the presence of close-in satellites around a selection of ten trans-Neptunian objects, including four known binary systems used for methodology validation. Methods: We developed a methodology independent of primary-secondary separation. We exploit the combination of occultation-derived sizes and thermal emission data from the "TNOs are Cool" Herschel Space Observatory key project. We model the thermal emission from a binary system to explain the thermal excess that cannot be reproduced by a single body of the occultation-derived size. Results: We obtain satisfactory constraints for the validation targets (208996) Achlys, (229762) G!kún{"hòmdímà, (38628) Huya and (174567) Varda. We find that (84522) 2002 TC302, (119951) 2002 KX14, and (307261) Máni are likely binary systems, which was previously unknown. We report size estimates for their putative satellites. For (84922) 2003 VS2, (28978) Ixion, and (470316) 2007 OC10 we find that no sizable satellite is needed to reconcile thermal and occultation data.

2605.22295 2026-05-22 math.CA math.PR

Discrepancy of determinantal point processes on compact, connected two-point homogeneous spaces

确定性点过程在紧连通二点齐性空间上的偏差

Carlos Beltrán, Ujué Etayo, Giacomo Gigante, Pedro R. López-Gómez, Ryan W. Matzke

AI总结 本文研究了在紧连通二点齐性空间(即球面和射影空间)上生成的确定性点过程的L^∞偏差,通过集中不等式和度量球内点数的方差估计,推导出一般性的偏差上界。对于谐振集合,证明N个点的偏差以高概率为O((N^{1-1/D})^{1/2}log N),其中D为流形的实维数。对于射影空间上的射影集合,得到更紧的界O((N^{1-1/D}log N)^{1/2})。这些结果将之前已知的球面上确定性点过程的偏差估计扩展到所有紧连通二点齐性空间。

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AI中文摘要

我们研究了在所有紧连通二点齐性空间(即球面和射影空间)上生成的确定性点过程的L^∞偏差。利用集中不等式和度量球内点数的方差估计,我们推导出关于齐性确定性点过程偏差的一般上界。在谐振集合的特例中,我们证明N个点的偏差以高概率为O((N^{1-1/D})^{1/2}log N),其中D表示流形的实维数。对于射影空间上的射影集合,我们得到更紧的界O((N^{1-1/D}log N)^{1/2})。这些结果将之前已知的球面上确定性点过程的偏差估计扩展到所有紧连通二点齐性空间。

英文摘要

We study the $L^{\infty}$ discrepancy of point sets generated by determinantal point processes on all compact, connected two-point homogeneous spaces, namely spheres and projective spaces. Using concentration inequalities and variance estimates for the number of points in metric balls, we derive general upper bounds for the discrepancy of homogeneous determinantal point processes. In the particular case of the harmonic ensemble, we show that the discrepancy of $N$ points is $O((N^{1-1/D})^{1/2}\log N)$ with high probability, where $D$ denotes the real dimension of the manifold. For the projective ensemble on $\mathbb{CP}^d$, we obtain the sharper bound $O((N^{1-1/D}\log N)^{1/2})$. These results extend previously known discrepancy estimates for determinantal point processes on the sphere to all compact, connected two-point homogeneous spaces.

2605.22293 2026-05-22 quant-ph

Modular Variables and the Limits of Phase Detectability in Open Quantum Systems

模变量与开放量子系统中相检知的极限

S. V. Mousavi

AI总结 本文研究了模变量在开放量子系统中相检知的极限,通过分析高斯波包叠加在均匀引力场中的时间演化,探讨了模算符的局部期望值以及环境诱导相关性对相位敏感性的影响。

Comments Accepted for publication in Physica Scripta

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AI中文摘要

模变量作为一种量子非局域性的显著例子,特别是在空间上良好分离的波包叠加中,其中组件之间的相对相位无法通过常规局部测量访问。在本工作中,我们研究了在均匀引力场影响下,高斯波包叠加的Hermitian模算符的时间演化。我们考虑了由Schrödinger方程支配的幺正动力学和在高温极限下由Caldeira-Leggett主方程描述的开放系统动力学。采用Bohmian量子力学解释,我们计算了这些模算符的局部期望值沿单个粒子轨迹。我们的分析表明,引力加速度诱导了一个随时间变化的模信号,即模可观测值的期望值,仍然对分离波包之间的相对相位敏感。相比之下,标准局部量如概率密度和概率电流,尽管被引力修改,但在空间重叠可忽略的范围内对相对相位不敏感。对于耦合到共享环境的一对粒子,我们发现环境诱导的相关性可以修改一个粒子观察到的局部模期望值,产生明显的环境影响特征。然而,在考虑的范围内,通过环境生成的纠缠将相位敏感性传递到远处粒子的模信号仍然是可忽略的。我们进一步证明,传统的相干性和纠缠性度量在非重叠范围内并不捕捉相对相位信息。

英文摘要

Modular variables serve as a striking example of quantum nonlocality, particularly in superpositions of wave packets that are spatially well separated, where the relative phase between components cannot be accessed through conventional local measurements. In this work, we explore the time evolution of Hermitian modular operators for Gaussian wave-packet superpositions under the influence of a uniform gravitational field. We consider both unitary dynamics governed by the Schrödinger equation and open-system dynamics described by the Caldeira-Leggett master equation in the high-temperature limit. Adopting the Bohmian interpretation of quantum mechanics, we compute local expectation values of these modular operators along individual particle trajectories. Our analysis shows that gravitational acceleration induces a time-varying modular signal, the expectation value of the modular observable, that remains sensitive to the relative phase between the separated wave packets. In contrast, standard local quantities such as the probability density and probability current, while modified by gravity, become insensitive to the relative phase in the regime of negligible spatial overlap. For a pair of particles coupled to a shared environment, we find that environment-induced correlations can modify the local modular expectation value observed for one particle, yielding a clear signature of environmental influence. However, the transfer of phase sensitivity via environment-generated entanglement to the modular signal of the distant particle remains negligible within the regime considered. We further demonstrate that conventional measures of coherence and entanglement do not capture the relative phase information in this non-overlapping regime.

2605.22292 2026-05-22 cond-mat.str-el cond-mat.mtrl-sci

Equilibrium Stabilization of a Hidden Phase Like Metallic State in 1T-TaS2

1T-TaS2中隐藏相类金属态的平衡稳定

Turgut Yilmaz, Anil Rajapitamahuni, Suji Park, Houk Jang, Asish K. Kundu, Elio Vescovo

AI总结 研究通过角分辨光电子能谱学揭示了1T-TaS2中在室温下稳定存在的金属相态,其具有有限费米能级谱权重和星形大卫带折叠特征的杂化间隙,为调控层状材料中的竞争电子态提供了平台。

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AI中文摘要

位于平衡基态之外的电子相态为研究相关材料中的竞争配置提供了途径。在1T-TaS2中,超快激发访问到一种与相干绝缘基态不同的金属隐藏相。本文利用角分辨光电子能谱学显示,在剥离的中间厚度1T-TaS2薄片中,等效的电子配置被稳定,其在室温下持续存在并在不同的电子转变序列中演变。这种平衡隐藏相态宿主具有有限费米能级谱权重的金属带,同时保留与星形大卫带折叠相关的特征杂化间隙。这些结果为调控层状材料中的竞争电子态提供了平台,对量子科学和相变技术均有影响。

英文摘要

Electronic phases that lie outside the equilibrium ground state offer a route to explore competing configurations in correlated materials. In 1T-TaS2, ultrafast excitation accesses a metallic hidden phase that is distinct from the commensurate insulating ground state. Here we use angle-resolved photoemission spectroscopy to show that an equivalent electronic configuration is stabilized in exfoliated intermediate-thickness 1T-TaS2 flakes, where it persists up to room temperature before evolving through a different sequence of electronic transitions. This equilibrium hidden-phase-like state hosts a metallic band with finite Fermi-level spectral weight while retaining the characteristic hybridization gaps associated with the star-of-David band folding. These results establish a platform for controlling competing electronic states in layered materials, with implications for both quantum science and phase change technologies.

2605.22289 2026-05-22 math.CO

$(r,s)$-sets from Desarguesian ovoids

$(r,s)$-sets from Desarguesian ovoids

Francesco Pavese

AI总结 本文研究了射影空间PG(n,q)中的(n,n-2)-集和(n-2,n-3)-集,证明了某些平凡上界在特定条件下几乎是最优的,并构造了一个大小为(q^6-1)/(q-1)的(3,2)-集。

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AI中文摘要

An $(r, s)$-${ extit set}$ in ${ m PG}(n, q)$ is a set of points, say $\mathcal X$, such that each $s$-dimensional projective subspace contains at most $r$ points of $\mathcal X$. We investigate $(n, n-2)$-sets and $(n-2, n-3)$-sets in ${ m PG}(n, q)$, $n \le 6$. We show that the trivial upper bounds on $(n, n-2)$-sets in ${ m PG}(n, q)$, $4 \le n \le 6$, $(4, 3)$-sets in ${ m PG}(6, q)$ and $(3, 2)$-sets in ${ m PG}(5, q)$ are essentially sharp. A $(3, 2)$-set in ${ m PG}(13, q)$ of size $ rac{q^6-1}{q-1}$ is also constructed.

英文摘要

An $(r, s)$-${\textit set}$ in ${\rm PG}(n, q)$ is a set of points, say $\mathcal X$, such that each $s$-dimensional projective subspace contains at most $r$ points of $\mathcal X$. We investigate $(n, n-2)$-sets and $(n-2, n-3)$-sets in ${\rm PG}(n, q)$, $n \le 6$. We show that the trivial upper bounds on $(n, n-2)$-sets in ${\rm PG}(n, q)$, $4 \le n \le 6$, $(4, 3)$-sets in ${\rm PG}(6, q)$ and $(3, 2)$-sets in ${\rm PG}(5, q)$ are essentially sharp. A $(3, 2)$-set in ${\rm PG}(13, q)$ of size $\frac{q^6-1}{q-1}$ is also constructed.

2605.22288 2026-05-22 cs.IT eess.SP math.IT

Multi-Cell 6DMA: Cooperative Interference Management and Antenna Rotation Optimization

多小区6DMA:协作干扰管理和天线旋转优化

Qijun Jiang, Xiaodan Shao, Rui Zhang

AI总结 本文研究了一种多小区六维可移动天线(6DMA)网络,旨在通过协作干扰管理提升下行链路通信性能。通过联合优化短时下行预编码和长时6DMA旋转,提出了一种平均加权总速率最大化问题,以解决多小区系统中的天线旋转设计和传输预编码固有的耦合问题。

Comments 14 pages, 12 figures; submitted to IEEE for possible publication

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AI中文摘要

本文研究了一种多小区六维可移动天线(6DMA)网络,旨在通过协作干扰管理提升下行链路通信性能。每个基站(BS)配备多个6DMA表面,6DMA旋转影响小区内用户所需信号增强和对邻小区的干扰泄漏,这使得天线旋转设计和传输预编码在BS之间固有耦合。为了解决这个问题,我们通过联合优化短时下行预编码和长时6DMA旋转,提出了一种多小区系统的平均加权总速率最大化问题,以在实际天线几何约束下进行优化。为解决由此产生的非凸问题,我们提出了一种基于邻近BS之间干扰功率约束(IPC)协调的分布式双时间尺度设计,在此之下,每个BS根据即时信道状态信息(CSI)进行本地短时预编码优化,并根据统计CSI进行长时6DMA旋转更新,同时限制了BS间的信息交换。特别地,开发了一种基于两阶段一维网格搜索和随机最大匹配的边缘-wise IPC协调机制,以实现可扩展的分布式实现。还提供了一个集中式的离线基准用于性能比较。数值结果表明,所提出的分布式设计在不同干扰条件下能够实现接近集中式基准的性能,同时随着网络规模的增加,保持了良好的可扩展性。

英文摘要

In this paper, we investigate a multi-cell six-dimensional movable antenna (6DMA) network for enhancing downlink communication performance under inter-cell interference (ICI). Each base station (BS) is equipped with multiple 6DMA surfaces, and the 6DMA rotations affect both the desired-signal enhancement for in-cell users and the interference leakage toward neighboring cells, which makes the antenna-rotation design and transmit precoding intrinsically coupled across BSs. To address this issue, we formulate an average weighted sum-rate maximization problem for the multi-cell system by jointly optimizing the short-term downlink precoders and long-term 6DMA rotations under practical antenna geometric constraints. To tackle the resulting nonconvex problem, we propose a distributed two-timescale design based on inter-cell interference power constraint (IPC) coordination among neighboring BSs, under which each BS performs local short-term precoder optimization based on instantaneous channel state information (CSI) and long-term 6DMA rotation update according to statistical CSI with limited inter-BS information exchange. In particular, an edge-wise IPC coordination mechanism based on two-stage one-dimensional grid search and random maximal matching is developed to enable scalable distributed implementation. A centralized offline benchmark is also provided for performance comparison. Numerical results show that the proposed distributed design achieves performance close to the centralized benchmark under different interference conditions, while maintaining favorable scalability as the network size increases.

2605.22284 2026-05-22 stat.CO cs.GR

moveEZ: An R Package for Animated Biplots

moveEZ:用于动画双图的R包

Raeesa Ganey, Johané Nienkemper-Swanepoel

AI总结 该研究提出了一种用于构建动画PCA双图的R包moveEZ,通过动画展示多变量结构在有序分类变量层次上的演变,支持高维数据集及分组结构,并可与gganimate集成生成高质量动画。

Comments R package

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AI中文摘要

moveEZ(发音为move easy)R包提供了构建动画PCA双图的工具,这些动画能够揭示多变量结构如何在有序分类变量的层次上演变。该包作为biplotEZ的扩展,提供了三种递增的方法学复杂度的动画框架:固定变量框架,其中变量向量保持不变,仅样本位置被动画化;以及两个动态框架,其中在每个层次中样本位置和变量向量都会被重新计算并动画化。动态框架支持Procrustes对齐和反射以确保不同层次之间的视觉连续性,并且适用于高维数据集,包括分组结构。该包可与gganimate集成以生成适用于出版和演示的高质量动画,并通过单个参数支持动画和静态分面显示。尽管最初是为跟踪非洲气候指标的偏移量而设计,但moveEZ是领域无关的,适用于任何在有序分类变量层次上重复记录多变量测量的场合,包括经济、生态和生物领域。

英文摘要

The moveEZ (pronounced move easy) R package provides tools for constructing animated PCA biplots that reveal how multivariate structure evolves across the ordered levels of a categorical variable. Built as an extension to the biplotEZ package, moveEZ offers three animation frameworks of increasing methodological complexity: a fixed variable frame, in which variable vectors remain constant and only sample positions are animated; and two dynamic frames, in which both sample positions and variable vectors are recomputed and animated at each level. The dynamic frames support Procrustes alignment and reflection to ensure visual continuity across levels, and are compatible with high-dimensional datasets including grouped structures. The package integrates with gganimate to produce high-quality animations suitable for publications and presentations, and supports both animated and static faceted displays via a single argument. Although originally motivated by tracking shifts in African climate indicators, moveEZ is domain-agnostic and applicable wherever multivariate measurements are recorded repeatedly across an ordered categorical variable, including economic, ecological, and biological settings.

2605.22282 2026-05-22 cond-mat.mtrl-sci cond-mat.mes-hall

Enrichment of rhombohedral stacking by mechanical exfoliation of graphite

通过机械剥离富集菱形堆叠

Krisztián Márity, Konrád Kandrai, Gergely Dobrik, Zsolt E. Horváth, Kristóf Németh Dániel, György Kálvin, Levente Tapasztó, Péter Nemes-Incze

AI总结 本研究通过机械剥离方法富集石墨中的菱形堆叠结构,发现通过简单的刀片辅助剥离步骤可进一步增强该效果,从而为研究相关和拓扑电子相提供了新的途径。

详情
AI中文摘要

菱形(ABC)石墨支持一个表面局域化的平坦带,支持相关的和拓扑的电子相,但其实验研究受限于自然石墨中ABC堆叠的稀缺性,这主要由伯纳尔(AB)堆叠主导。这里我们显示,常规的机械剥离步骤本身会增加石墨片的菱形含量,并且一个简单的刀片辅助剥离步骤,引入额外的剪切,进一步放大了这一效果。使用大区域拉曼2D带斜率映射,我们测量了在原始源晶体中ABC含量占面积分数为3%,在常规剥离后为16%,在刀片辅助剥离后为26%。对于薄片(<20层),每个片的面积分数达到75%在分布的上尾。追踪剥离前后的单个片显示,皱纹在AB-ABC域壁中起种籽作用,单轴应变可以移动这些壁。因此,刀片辅助机械剥离去除了制备富含ABC石墨样品以研究菱形石墨中相关和拓扑相的一个瓶颈。

英文摘要

Rhombohedral (ABC) graphite hosts a surface-localized flat band that supports correlated and topological electronic phases, but its experimental study is limited by the scarcity of ABC stacking in natural graphite, which is dominated by Bernal (AB) stacking. Here we show that the routine mechanical exfoliation step itself enriches the rhombohedral content of graphite flakes, and that a simple blade-assisted exfoliation step, which introduces additional shear, amplifies the effect further. Using large-area Raman 2D-band skewness mapping we measure ABC content at area fractions of 3\% in the pristine source crystal, 16\% after conventional exfoliation, and 26\% after blade-assisted exfoliation for thick flakes. In thin flakes ($<20$ layers) the per-flake area fraction reaches 75\% in the upper tail of the distribution. Tracking individual flakes before and after blade-assisted exfoliation shows that wrinkles seed AB-ABC domain walls, and uniaxial strain can move these walls. Blade-assisted mechanical exfoliation therefore removes one of the bottlenecks to the preparation of ABC-rich graphite samples for studies of correlated and topological phases in rhombohedral graphite.

2605.22281 2026-05-22 math.NA cs.NA

Randomized Flexible LSQR and LSMR with applications to inverse problems

随机灵活的LSQR和LSMR及其在反问题中的应用

Alberto Bucci, Silvia Gazzola, Leonardo Robol

AI总结 本文提出了一种随机化的灵活LSQR和LSMR算法,用于解决大规模反问题,通过引入随机化技术提高计算效率并保持重建质量。

详情
AI中文摘要

LSQR和LSMR是基于Golub-Kahan双对角化算法的迭代方法,广泛用于大规模线性最小二乘问题。FLSQR和FLSMR分别是LSQR和LSMR的灵活变体,基于灵活的Golub-Kahan(Arnoldi-like)因子化算法,自然允许修改解近似子空间和/或处理不精确的矩阵向量乘法与系数矩阵的转置,从而能够将先验信息纳入计算解中。本文的目标是介绍sFLSQR和sFLSMR,即FLSQR和FLSMR的sketched变体,其中随机化特别有效,因为它允许恢复解近似中的短递归。特别地,本文探讨了在大规模反问题中的应用,展示了新的随机求解器在缓解计算瓶颈的同时保持重建质量的能力。提供了sFLSQR和sFLSMR的理论分析,并通过数值实验验证了其性能。

英文摘要

LSQR and LSMR are iterative methods, based on the Golub-Kahan bidiagonalization algorithm, widely used for large-scale linear least squares problems. FLSQR and FLSMR are flexible variants of LSQR and LSMR, respectively, based on a flexible Golub-Kahan (Arnoldi-like) factorization algorithm, which naturally allow modifications of the solution approximation subspace and/or handling inexact matrix-vector multiplications with the (transpose of the) coefficient matrix, thereby enabling to enforce prior information into the computed solution. The goal of this paper is to introduce sFLSQR and sFLSMR, i.e., sketched variants of FLSQR and FLSMR, respectively, where randomization becomes particularly effective, as it allows to recover short recurrences for the solution approximation. In particular, this paper explores applications to large-scale inverse problems, showing the ability of the new randomized solvers to alleviate computational bottlenecks while preserving reconstruction quality. A theoretical analysis of sFLSQR and sFLSMR is provided, and their performance is validated through numerical experiments.