arXivDaily arXiv每日学术速递 周一至周五更新
重置
全部学科分类 2119
2606.12249 2026-06-11 astro-ph.GA 新提交

Spatially Resolved Nebular-Stellar Reddening with JWST/NIRISS

利用JWST/NIRISS的空间分辨星云-恒星红化

Peter J. Watson, Benedetta Vulcani, Tommaso Treu, Ayan Acharyya, Marc Rafelski, Anahita Alavi, Matthew Hayes, Keunho Kim, Faezeh Manesh, Claudia Scarlata

AI总结 利用JWST/NIRISS数据对1.0<z<2.4的星系进行亚kpc尺度分析,通过多区域拟合提取Hα和Hβ发射线图,发现星云与连续谱红化关系与局部星暴星系一致,并推导出微分红化与SFR和恒星质量的经验标定。

Comments 17 pages, 19 figures (including appendices), submitted to A&A

详情
AI中文摘要

准确测定星系内的尘埃消光对于推导恒星形成率(SFR)等关键物理性质至关重要。我们利用GLASS-JWST ERS计划中的JWST/NIRISS数据,研究并表征了$1.0<z<2.4$星系在亚kpc尺度上的恒星和星云红化。我们采用多区域拟合方法,提取了99个单独星系的高质量H$\alpha$和H$\beta$发射线图,其恒星质量范围为$7.0<\log_{10}(M_*/\mathrm{M}_{\odot})<10.5$。我们没有发现巴尔默减缩(H$\alpha$/H$\beta$)低于Case B复合固有极限的证据,超出观测不确定性的预期变化。我们再现了巴尔默减缩与总恒星质量的局部相关性,并在按红移分割样本时未发现可测量的差异,在$\log_{10}(M_*/\mathrm{M}_{\odot})\lesssim8.5$以下消光可忽略。类似地,星云和连续谱红化的最佳拟合关系与局部星暴星系的关系相同,即$E(B-V)_{\mathrm{SED}} = (0.46\pm0.02)E(B-V)_{\mathrm{neb}}$,共同表明在$z\lesssim2.4$范围内星系内的尘埃几何结构没有显著演化。我们推导了微分星云-恒星红化与SED导出的恒星形成率(SFR)和恒星质量之间的最佳拟合线性关系,发现两者均具有统计显著性。我们利用空间分辨测量结果,推导了分辨微分红化与SFR面密度的经验标定。这些将为更高红移(如未来Roman棱栅观测)中无法获取巴尔默线的空间分辨科学提供关键的尘埃消光校正。

英文摘要

An accurate determination of the dust attenuation within galaxies is essential to derive key physical properties such as the star formation rate (SFR). We present an analysis using the JWST/NIRISS data from the GLASS-JWST ERS programme to investigate and characterise the stellar and nebular reddening of galaxies at $1.0<z<2.4$, down to the sub-kpc scale. We use a multiregion fitting method to extract high-quality H$α$ and H$β$ emission line maps for 99 individual galaxies across a stellar mass range $7.0<\log_{10}(M_*/\mathrm{M}_{\odot})<10.5$. We find no evidence for ratios of the Balmer decrement (H$α$/H$β$) below the intrinsic limit for Case B recombination, beyond the expected variation from observational uncertainties. We reproduce the local correlation between the Balmer decrement and total stellar mass, and find no measurable difference when splitting the sample by redshift, with negligible attenuation below $\log_{10}(M_*/\mathrm{M}_{\odot})\lesssim8.5$. Similarly, the best-fit relation between the nebular and continuum reddening follows the same relation as in local starburst galaxies, $E(B-V)_{\mathrm{SED}} = (0.46\pm0.02)E(B-V)_{\mathrm{neb}}$, together indicating no significant evolution in the dust geometry within galaxies out to $z\lesssim2.4$. We derive best-fit linear relations between the differential nebular-stellar reddening and the SED-derived star formation rate (SFR) and stellar mass, finding statistically significant relations for both quantities. We use our spatially-resolved measurements to derive an empirical calibration between the resolved differential reddening, and the SFR surface density. These will enable crucial dust attenuation corrections for spatially-resolved science at higher redshifts where the Balmer lines are inaccessible, such as with future Roman grism observations.

2606.12246 2026-06-11 cs.DC cs.IR 新提交

Efficient and Robust Online Learning to Rank in Decentralized Systems

去中心化系统中高效且鲁棒的在线学习排序

Marcel Gregoriadis, Martijn de Vos, Sayan Biswas, Anne-Marie Kermarrec, Johan Pouwelse

AI总结 提出RankGuard框架,通过用户间直接交换模型更新并利用私有点击历史防御投毒攻击,首次给出去中心化在线学习排序的收敛性证明,效率最高提升62倍。

详情
AI中文摘要

在在线学习排序(OLTR)中,排序模型直接从实时用户交互中训练,但现有系统依赖可信中央服务器来收集和处理这些交互。这使得操作者可以自由引入与用户利益冲突的偏见。去中心化学习提供了一种有吸引力的替代方案,允许用户通过直接相互交换模型更新来协作训练共享排序模型,无需任何中央权威。然而,在这种设置中,恶意节点可以发送投毒模型更新,降低诚实节点的排序质量。我们引入了RankGuard,一个去中心化OLTR框架,其中用户协作训练排序模型并直接与其他节点交换模型更新。RankGuard通过仔细评估传入模型与用户自己的私有点击历史(经位置偏差校正)来防御投毒攻击。仅当传入模型比当前本地模型更好地解释用户过去交互时,才进行聚合,这使得恶意节点极难构造出能通过此测试而又不真正帮助用户的更新。我们推导了RankGuard的理论收敛保证。据我们所知,这是去中心化OLTR算法的首次形式化收敛分析。我们使用四个标准基准和三个点击模型,针对四种投毒攻击(包括一种强大的自适应攻击)评估了RankGuard。在大多数设置中,RankGuard优于所有基线,同时效率比最接近的竞争者高出62倍。

英文摘要

In Online Learning to Rank (OLTR), ranking models are trained directly from live user interactions, but existing systems rely on a trusted central server to collect and process these interactions. This leaves operators free to introduce biases that conflict with user interests. Decentralized learning offers an attractive alternative, allowing users to collaboratively train a shared ranking model by exchanging model updates directly with one another, without any central authority. In such settings, however, malicious nodes can send poisoned model updates that degrade the ranking quality of honest nodes. We introduce RankGuard, a decentralized OLTR framework in which users collaboratively train ranking models and exchange model updates directly with other nodes. RankGuard defends against poisoning attacks by carefully evaluating incoming models against the user's own private click history, corrected for position bias. An incoming model is only aggregated if it better explains the user's past interactions than the current local model, making it fundamentally hard for malicious nodes to craft updates that pass this test without also genuinely helping the user. We derive a theoretical convergence guarantee of RankGuard. To the best of our knowledge, this is the first formal convergence analysis of a decentralized OLTR algorithm. We evaluate RankGuard against four poisoning attacks, including a powerful adaptive attack, using four standard benchmarks and three click models. RankGuard outperforms all baselines in most settings while being up to 62x more efficient than its closest competitors.

2606.12244 2026-06-11 astro-ph.IM 新提交

Barycentric Corrections for HST/STIS Data

HST/STIS数据的重心校正

Joshua D. Lothringer, Joleen K. Carlberg, Sean Lockwood

AI总结 介绍新Python工具stistools.barycentric_correction,用于计算HST/STIS观测的重心时间校正,替代旧IRAF函数,利用astropy和JPL Horizons提高精度。

Comments 13 pages, 4 figures, 1 table

详情
AI中文摘要

我们描述了一个新的Python工具$\texttt{stistools.barycentric_correction}$,用于计算HST/STIS观测的重心时间校正。该工具取代了先前用于HST重心校正的已弃用的$\texttt{this http URL}$ IRAF函数。我们的新工具使用$\texttt{astropy}$进行时间格式和标准的转换,并引入了一种通过JPL Horizons计算HST位置的新方法,无需下载单独的HST轨道星历文件。在此,我们描述了新工具中使用的方法、为验证其准确性而进行的测试,并解释了为HST确定光行时精度达到毫秒级所涉及的一些复杂性。我们还总结了当前对STIS时间戳绝对精度的理解。

英文摘要

We describe $\texttt{stistools.barycentric_correction}$, a new Python utility for calculating barycentric timing corrections for HST/STIS observations. This tool replaces the deprecated $\texttt{stsdas.hst_calib.stis.odelaytime}$ IRAF function that was previously used for HST barycentric corrections. Our new utility uses $\texttt{astropy}$ for conversion between time formats and standards and introduces a new way to calculate HST's position through JPL Horizons, replacing the need to download separate HST orbital ephemeris files. Here, we describe the methods used in the new utility, the tests that were carried out to verify its accuracy, and explain some of the complexities involved in determining light travel times to accuracies down to a millisecond for HST. We also summarize the current understanding of the absolute accuracy of STIS time stamps.

2606.12242 2026-06-11 astro-ph.SR 新提交

Shaping the horizontal branch: The role of envelope mass in the evolution of stripped core-helium-burning stars

塑造水平分支:包层质量在剥离核心氦燃烧恒星演化中的作用

Eduardo Arancibia-Rojas, Mónica Zorotovic, Maja Vučković, Alexey Bobrick, Alex Durán-Reyes

AI总结 研究通过MESA模型分析剥离氢包层的核心氦燃烧恒星,发现残余包层质量决定水平分支位置,并确定了避免热脉冲渐近巨星分支的最大包层质量,解释了蓝钩星和膨胀剥离星的形成。

Comments Accepted for publication in A&A

详情
AI中文摘要

恒星在核心氦燃烧期间沿水平分支(HB)的位置主要由其前身星损失的质量决定。我们研究了剥离核心氦燃烧恒星的形成和性质,重点关注残余氢包层质量($M_{\mathrm{env}}$)和包层移除时机如何塑造它们的性质。我们使用MESA恒星演化代码模拟在第一红巨星分支上失去氢包层的恒星。我们探讨了剥离时机的两个极限情况,对应于氦点火的最小和最大核心质量,前身星初始质量低于$\sim$6 $M_{\odot}$,两种金属丰度($Z=0.02$和$Z=0.004$),同时系统性地改变$M_{\mathrm{env}}$。正如预期,HB上的有效温度随$M_{\mathrm{env}}$增加而降低。我们确定了避免后续通过热脉冲渐近巨星分支演化所需的最大$M_{\mathrm{env}}$,范围从低质量前身星的$\sim0.05$ $M_{\odot}$到中等质量前身星的$\sim0.30$ $M_{\odot}$。在低质量前身星中,早期包层移除会触发晚期热闪,自然解释了最热的蓝钩星。在中等质量系统中,部分包层剥离可以产生扩展的前HB构型,与在Be伴星双星中观测到的膨胀剥离星一致。我们的剥离后演化轨迹公开可用,用于双星演化和星族合成研究。

英文摘要

The location of a star along the horizontal branch (HB) during core-helium burning is primarily determined by the amount of mass lost by its progenitor. We investigate the formation and properties of stripped core-helium-burning stars, focusing on how the residual hydrogen-envelope mass ($M_{\mathrm{env}}$) and the timing of envelope removal shape their properties. We used the MESA stellar evolution code to model stars that lose their hydrogen envelopes on the first giant branch. We explored two limiting cases for the timing of stripping, corresponding to the minimum and maximum core masses for helium ignition, for progenitors with initial masses below $\sim$6 $M_{\odot}$ at two metallicities ($Z=0.02$ and $Z=0.004$), while systematically varying $M_{\mathrm{env}}$. As expected, the effective temperature along the HB decreases as $M_{\mathrm{env}}$ increases. We determined the maximum $M_{\mathrm{env}}$ required to avoid subsequent evolution through the thermally pulsing asymptotic giant branch, which ranges from $\sim0.05$ $M_{\odot}$, for low-mass progenitors to $\sim0.30$ $M_{\odot}$ for intermediate-mass progenitors. In low-mass progenitors, early envelope removal triggers a late hot flash, naturally explaining the hottest blue hook stars. In intermediate-mass systems, partial envelope stripping can produce extended pre-HB configurations consistent with puffed-up stripped stars observed in binaries with Be companions. Our post-stripping evolutionary tracks are publicly available for use in binary evolution and population synthesis studies.

2606.12241 2026-06-11 cond-mat.supr-con cond-mat.mtrl-sci cond-mat.str-el 新提交

Superconductivity in the pressure-amorphized topological insulator CrP$_4$

压力非晶化拓扑绝缘体CrP$_4$中的超导电性

Chutong Zhang, Xiangzhuo Xing, Na Zuo, Bowen Zheng, Bin Li, Jiajia Feng, Xiaolei Yi, Yan Meng, Xiaoran Zhang, Bingchao Yang, Chao Wang, Xin Chen, Yongsheng Zhang, Xiaofeng Xu, Xiaobing Liu

AI总结 本文报道了Cr基拓扑绝缘体CrP$_4$在压力下发生非晶化并出现超导电性,最高超导转变温度达4.8 K,理论计算预测了压力诱导的拓扑相变。

Comments 19 pages,6 figures, Physical Review B 113,224516(2026)

详情
AI中文摘要

超导电性、磁性和非平庸带拓扑之间的相互作用是凝聚态物理中最引人注目的前沿之一。在3d过渡金属化合物中,特别是含有强磁性Cr离子的稀有Cr基体系中,由于其非常规配对机制挑战传统认知,探索新型超导电性一直备受关注。然而,Cr基超导体仍然稀少,尤其是那些具有非平庸拓扑特性的体系,这凸显了发现新成员的迫切需求。本文报道了在压力非晶化的Cr基拓扑绝缘体CrP$_4$中观察到超导电性。在压缩过程中,CrP$_4$在约15 GPa处经历从金属态到类半导体态的异常量子相变,这是由电子结构的显著变化驱动的。在约70 GPa处,伴随着不可逆的非晶化,发生再金属化并出现超导电性。超导转变温度Tc随压力单调增加,在141.3 GPa时达到4.8 K。此外,理论计算预测在压力下存在从强拓扑绝缘体到平庸态,最终回到强拓扑态的多重拓扑相变。我们的研究不仅确立了CrP$_4$作为首个Cr基非晶超导体,而且为探索非晶材料中的超导和拓扑性质开辟了新范式。

英文摘要

The interplay among superconductivity, magnetism, and nontrivial band topology represents one of the most compelling frontiers in condensed matter physics. The exploration of novel superconductivity in 3d transition-metal compounds, particularly the rare Cr-based systems containing strongly magnetic Cr ions, has long attracted attention owing to their unconventional pairing mechanisms that challenge conventional wisdom. Yet, Cr-based superconductors remain scarce, especially those possessing nontrivial topological character, underscoring the urgent need to uncover new members. Here we report the observation of superconductivity in pressure-amorphized Cr-based topological insulator CrP$_4$. Upon compression, CrP$_4$ undergoes an anomalous quantum phase transition from a metallic to a semiconducting-like state at around 15 GPa, driven by significant changes in the electronic structure. At approximately 70 GPa, re-metallization with superconductivity occurs alongside an irreversible amorphization. The superconducting transition temperature Tc increases monotonically with pressure, reaching 4.8 K at 141.3 GPa. Furthermore, theoretical calculations predict multiple topological phase transitions from a strong topological insulator to a trivial state and finally back to a strong topological state under pressure. Our study not only establishes CrP$_4$ as the first Cr-based amorphous superconductor but also opens a new paradigm for exploring superconducting and topological properties in amorphous materials.

2606.12239 2026-06-11 cond-mat.mes-hall 新提交

Stacking switching between correlation-protected radial Rashba field and persistent spin textures in graphene encapsulated by 1T-TaS$_2$ monolayers

1T-TaS$_2$单层封装石墨烯中关联保护的径向Rashba场与持久自旋织构之间的堆叠切换

Juraj Mnich, Marko Milivojević, Martin Gmitra

AI总结 通过第一性原理、紧束缚模型和Kubo公式,发现1T-TaS2封装石墨烯的堆叠方式决定电荷-自旋/轨道转换:AA堆叠产生径向Rashba自旋织构和增强的Rashba-Edelstein效应;AA'堆叠形成持久面外自旋织构,且轨道霍尔效应比自旋霍尔效应高三个数量级。

Comments 8 pages, 4 figures

详情
AI中文摘要

我们研究了在电荷密度波相中由1T-TaS$_2$单层封装石墨烯的电子结构、自旋织构以及电荷到自旋/轨道的输运。利用第一性原理计算、紧束缚模型和Kubo形式,我们展示了封装堆叠决定了根本不同的输运机制。在非对称(AA)堆叠中,来自两个界面的邻近场相长干涉,产生累积的Rashba相位接近$\pi/2$。这种纯径向Rashba自旋模式导致了非常规的Rashba-Edelstein效应,在宽能量范围内,其强度比传统响应强35倍。相反,对称(AA')堆叠保留了水平镜面对称性,建立了稳定的、纯面外持久自旋织构。此外,计算出的轨道霍尔效应异常高效,超过自旋霍尔效应三个数量级。在邻近诱导的能隙内,轨道霍尔电导率呈现有限平台,而自旋霍尔电导率消失。我们的发现确立了石墨烯封装异质结构作为一个有前景的系统,通过选择堆叠顺序实现不同的电荷-自旋和电荷-轨道转换机制。

英文摘要

We investigate the electronic structure, spin textures, and charge to spin/orbital transport in graphene encapsulated by 1T-TaS$_{2}$ monolayers in the charge density wave phase. Using first-principles calculations, tight-binding modeling, and the Kubo formalism, we show that the encapsulation stacking dictates fundamentally distinct transport regimes. In the asymmetrical (AA) stacking, proximity fields from both interfaces constructively interfere, yielding a cumulative Rashba phase of nearly $π/2$. This pure radial Rashba spin pattern leads to the unconventional Rashba-Edelstein effect, which robustly dominates over the conventional response by a factor of 35 across a wide energy range. Conversely, the symmetrical (AA') stacking preserves a horizontal mirror symmetry, establishing a stable, purely out-of-plane persistent spin texture. Furthermore, the computed orbital Hall effect is exceptionally efficient, surpassing the spin Hall effect by three orders of magnitude. Within the proximity-induced spectral gaps, the orbital Hall conductivity exhibits a finite plateau, whereas the spin Hall conductivity vanishes. Our findings establish graphene encapsulated heterostructures as a promising system for realizing distinct charge to spin and charge to orbital interconversion regimes determined by the choice of stacking order.

2606.12238 2026-06-11 cond-mat.mtrl-sci 新提交

Thermodynamically consistent phase field model for hydrogen-assisted cracking

热力学一致的氢致裂纹相场模型

G. F. Bouobda-Moladje, A. Ruffini, Y. Le Bouar, A. Finel

AI总结 提出一种变分框架下的相场模型,同时模拟裂纹扩展、氢在裂纹表面和晶界的偏析及界面能降低,并捕捉氢致沿晶断裂的转变。

详情
AI中文摘要

我们提出了一种能够模拟多晶材料中氢致裂纹的相场模型。在变分框架内,该模型同时描述了裂纹扩展、氢在裂纹表面和晶界上的偏析以及由此引起的界面能降低。在氢致内聚力减弱(HEDE)机制背景下,我们展示了该模型捕捉从穿晶断裂到氢致沿晶断裂转变的能力。

英文摘要

We propose a phase field model able to simulate hydrogen-assisted cracking in polycrystalline materials. Within a variational framework, the model simultaneously describes crack propagation and hydrogen segregation on crack surfaces and grain boundaries together with the associated reduction in interfacial energies. In the context of hydrogen-enhanced decohesion (HEDE) mechanisms, we demonstrate the ability of the model to capture the transition from transgranular cracking to hydrogen-assisted intergranular cracking.

2606.12237 2026-06-11 hep-th 新提交

Nonlocal Rarita-Schwinger theory

非局域 Rarita-Schwinger 理论

Fernando M. Belchior, Roberto V. Maluf

AI总结 本文构建了自旋-3/2 费米子的非局域 Rarita-Schwinger 理论,考虑两类解析形状因子,证明自由约束不变且无鬼影,并给出传播子与色散关系。

Comments 20 pages

详情
AI中文摘要

本文构建了自旋-3/2 费米子的 Rarita-Schwinger 理论的非局域扩展。考虑了两类解析形状因子:标量形状因子 $f(\Box)$ 和 Dirac 算符形状因子 $f(\slashed{\partial})$。无质量理论与协变非局域规范固定一起处理,这使得传播子可以直接用自旋-3/2 投影算子写出。在有质量理论中,我们证明对于解析形状因子,自由的 Rarita-Schwinger 约束保持不变,因此非物理的自旋-1/2 部分不会变得动力学。对于 $f(\Box)$,传播子的张量-旋量结构与局域理论相同,而极点方程被标量形状因子变形。对于 $f(\slashed{\partial})$,物理模式服从非局域 Dirac 型方程,导致修正的色散关系,对于指数形状因子可以显式写出。我们讨论了在自由层次上构造无鬼影的条件,并指出了在引入相互作用之前必须解决的自然限制。

英文摘要

In this paper, one constructs a nonlocal extension of the Rarita-Schwinger theory for spin-$3/2$ fermions. Two classes of analytic form factors are considered: scalar form factors $f(\Box)$ and Dirac-operator form factors $f(\slashed{\partial})$. The massless theory is treated together with a covariant nonlocal gauge fixing, which allows the propagator to be written directly in terms of the spin-$3/2$ projector. In the massive theory, we show that the free Rarita-Schwinger constraints remain intact for analytic form factors, so that the unphysical spin-$1/2$ sector does not become dynamical. For $f(\Box)$ the tensor-spinor structure of the propagator is the same as in the local theory, while the pole equation is deformed by the scalar form factor. For $f(\slashed{\partial})$ the physical modes obey a nonlocal Dirac-type equation, leading to modified dispersion relations that can be written explicitly for exponential form factors. We discuss the conditions under which the construction is ghost-free at the free level and identify the natural limitations that must be addressed before interactions are introduced.

2606.12235 2026-06-11 cs.AR 新提交

BenDi: An Energy-Efficient Quasi-Stochastic Systolic Architecture for Edge Bioelectronics

BenDi: 一种用于边缘生物电子学的节能准随机脉动架构

Bochen Ye, Yihan Pan, Shady Agwa, Themis Prodromakis

AI总结 提出BenDi架构,通过低电压、准随机乘法、脉动数据流和硬件感知量化,在边缘设备上高效运行CNN,相比二进制权重固定脉动架构,面积效率提升3.35倍,能效提升5倍,精度损失仅1%-3.3%。

Comments Accepted for presentation as a short paper at International Conference on Application-specific Systems, Architectures and Processors (ASAP 2026)

详情
AI中文摘要

对生物医学信号(如心电图)的连续长期监测和诊断有助于减轻对公共健康日益增长的威胁。人工智能模型(如卷积神经网络)能够对相关疾病进行准确监测和分类;然而,它们需要的计算资源超出了传统AI硬件通常所能提供的,尤其是在资源受限的边缘环境中。在这项工作中,我们提出了BenDi,一种用于边缘生物电子系统的节能准随机脉动架构。BenDi利用从电路到软件量化的多个层次的能量和功率优化,包括低供电电压、用于准随机乘法的Ben-t-Pyramid数据格式、DiP脉动数据流以及硬件感知量化,以在有限的硬件预算下在边缘设备上高精度地处理CNN。使用商业22nm技术的硬件实现结果表明,在0.5V电压和100MHz频率下,BenDi架构相比最先进的基于二进制的权重固定脉动架构,面积缩小了3.35倍,能效提高了5倍。对于生物电子边缘系统,BenDi在能效和面积效率上分别比同类架构提高了一个数量级。这种显著的改进是以在MIT-BIH和Apnea-ECG基准测试上分别损失1%至3.3%的精度为代价的,与使用32位浮点格式的传统计算相比。

英文摘要

Continuous long-term monitoring and diagnosis of biomedical signals, such as electrocardiograms (ECGs), can help mitigate an increasing threat to public health. Artificial Intelligence (AI) models, such as Convolutional Neural Networks (CNNs), provide accurate monitoring and classification for relevant diseases; however, they require more computational resources than conventional AI hardware can typically afford, especially for a resource-constrained environment on the edge. In this work, we present BenDi, an energy-efficient quasi-stochastic systolic architecture for bioelectronic systems on the edge. BenDi leverages multiple levels of energy and power optimization, ranging from circuits to software quantization, including low supply voltage, the \underline{Ben}t-Pyramid data format for quasi-stochastic multiplication, the \underline{Di}P systolic dataflow, and hardware-aware quantization, to handle CNNs with high accuracy on the edge within limited hardware budgets. The hardware implementation results, using a commercial 22nm technology, show that BenDi architecture, at 0.5 Voltage and 100 MHz, offers 3.35x smaller area and 5x higher energy efficiency, compared to state-of-the-art binary-based weight-stationary systolic architectures. Regarding Bioelectronic edge systems, BenDi achieves an order-of-magnitude improvement in energy efficiency and another order-of-magnitude improvement in area efficiency, compared to its counterparts. This significant improvement comes at the cost of 1\% to 3.3\% accuracy loss on the MIT-BIH and Apnea-ECG benchmarks, respectively, compared with conventional computing using the 32-bit floating-point format.

2606.12233 2026-06-11 physics.optics 新提交

On-chip measurement of the modal Stokes-Gell-Mann parameters for partially coherent three-mode light

部分相干三模光场的模态Stokes-Gell-Mann参数片上测量

Amin Hashemi, Abbas Shiri, Bahaa E. A. Saleh, Andrea Blanco-Redondo, Ayman F. Abouraddy

AI总结 提出并实验演示了在光子集成平台上首次直接测量部分相干三模光场的Stokes-Gell-Mann参数,通过重构3×3相干矩阵探索等熵场空间。

详情
AI中文摘要

Stokes参数是三个实数参数,完全表征由两个模式(无论是偏振模式对还是空间模式对)张成的部分相干光场,因此在光学中无处不在。由于Stokes参数是通过Pauli矩阵展开$2\ imes2$相干矩阵定义的,它们不能应用于包含三个模式的光场,这些光场由$3\ imes3$相干矩阵描述。此类光场的例子包括非傍轴场的偏振(由三个正交偏振模式张成)以及包含三个空间或时间模式的光场。理论上早已提出,高能粒子物理学中发展的$3\ imes3$ Gell-Mann矩阵可以作为$3\ imes3$光学相干矩阵的基,其8个展开系数称为Stokes-Gell-Mann (SGM)参数,但测量过程艰巨,且SGM参数至今未在光学中被直接测量。在这里,我们首次在包含六边形马赫-曾德尔干涉仪网格的光子集成平台上测量了部分相干三模光场的SGM参数。在芯片上测量SGM参数,并由此重构$3\ imes3$相干矩阵,有助于探索可以通过幺正变换相互转换的等熵场的完整空间,以及那些具有相同熵值但无法通过幺正变换相互转换的场。这些结果为在光通信、传感和信息处理等应用中利用多模部分相干光铺平了道路。

英文摘要

The Stokes parameters are three real parameters that completely characterize partially coherent optical fields spanned by two modes -- whether a pair of polarization or spatial modes -- and their use is thus ubiquitous in optics. Because the Stokes parameters are defined through an expansion of the $2\times2$ coherence matrix in terms of the Pauli matrices, they cannot be applied to optical fields comprising three modes, which are described by a $3\times3$ coherence matrix. Examples of such fields include the polarization of non-paraxial fields (spanned by three orthogonal polarization modes), and fields comprising three spatial or temporal modes. It has long been theorized that the $3\times3$ Gell-Mann matrices -- developed in high-energy particle physics -- can serve as a basis for $3\times3$ optical coherence matrices, with 8~expansion coefficients known as the Stokes-Gell-Mann (SGM) parameters, but the measurement procedure is daunting, and the SGM parameters have not been measured directly to date in optics. Here we present the first measurements of the SGM parameters for partially coherent three-mode light in a photonic integrated platform comprising a hexagonal mesh of Mach-Zehnder interferometers. Measuring the SGM parameters on chip, from which we reconstruct the $3\times3$ coherence matrix facilitates exploring the full space of iso-entropy fields that can be inter-converted into each other unitarily, and those that share the same value of entropy and yet cannot be inter-converted unitarily. These results pave the way to utilizing multimode partially coherent light in applications involving optical communications, sensing, and information processing.

2606.12230 2026-06-11 math.CO 新提交

Prescribed leftover chords and one-extra-edge Berge pancyclicity

预设剩余弦与单额外边的Berge泛圈性

Henry Shin

AI总结 针对奇数阶哈密顿Berge圈,证明了一个预设剩余弦定理,并由此完全解决了Bailey等人提出的单额外边问题。

Comments 8 pages, no figures

详情
AI中文摘要

我们证明了奇数阶哈密顿Berge圈的一个预设剩余弦定理。设$C$是$n=2r+1$个顶点上的哈密顿Berge圈,$\mathcal G$是一组超边,所有超边大小至少为$r$,且包含$C$的超边。如果$D\subseteq\{2,\ldots,r\}$且$|\mathcal G|\ge n+|D|$,那么可以将超边重新分配给相同循环顺序的相邻对,使得对于每个$d\in D$,一个不同的未使用超边实现循环距离$d$。因此,Bailey、Hollars、Li和Luo的单额外边问题在奇数阶情况下对所有$n=2r+1\ge7$有肯定答案,约定包括长度为$2$的Berge圈。证明结合了$\mathbb Z_{2r+1}$中的加性引理和交替匹配交换。

英文摘要

We prove a prescribed-leftover-chord theorem for Hamiltonian Berge cycles of odd order. Let $C$ be a Hamiltonian Berge cycle on $n=2r+1$ vertices, and let $\mathcal G$ be a set of hyperedges, all of size at least $r$, containing the hyperedges of $C$. If $D\subseteq\{2,\ldots,r\}$ and $|\mathcal G|\ge n+|D|$, then the hyperedges can be reassigned to the adjacent pairs of the same cyclic order so that, for each $d\in D$, a distinct unused hyperedge realizes cyclic distance $d$. Consequently, the odd-order case of the one-extra-edge question of Bailey, Hollars, Li and Luo has an affirmative answer for all $n=2r+1\ge7$, in the convention including Berge cycles of length $2$. The proof combines an additive lemma in $\mathbb Z_{2r+1}$ with an alternating matching exchange.

2606.12229 2026-06-11 math.AC math.AG math.NT 新提交

On Perfectoidizaiton of Finite Algebras over a Perfectoid Ring

完美环上有限代数的完美化

Ryo Ishizuka, Léo Navarro Chafloque

AI总结 研究完美环上有限代数的完美化的一般性质,证明判别式非零因子条件下完美化包含原代数,并给出密度准则,最后计算若干例子。

详情
AI中文摘要

我们研究了完美环上有限代数的完美化的一般性质,这有助于理解一些精确且显式的描述。例如,我们证明如果 $A=R[t]/(m(t))$ 其中 $m(t)$ 是首一的,$R$ 是完美的,且 $m(t)$ 的判别式 $d$ 是 $R$ 中满足有界挠条件的非零因子,那么 $dA_{\mathrm{pfd}}\subset A$。我们还证明了一个密度准则,将完美化的构造简化为在模 $p$ 下添加合适的 $p$ 幂根。在论文的第二部分,我们计算了几族例子中的完美化,包括Kummer型扩张和分裂有限代数。

英文摘要

We study general properties of the perfectoidization of finite algebras over a perfectoid ring, which helps to understand some precise and explicit descriptions. For example, we prove that if $A=R[t]/(m(t))$ where $m(t)$ is monic, $R$ is perfectoid and the discriminant $d$ of $m(t)$ is a non-zero divisor of $R$ satisfying a bounded torsion condition, then $dA_{\mathrm{pfd}}\subset A$. We also prove a density criterion reducing the construction of the perfectoidization to adjoining suitable $p$-power roots modulo $p$. In the second part of the paper, we compute perfectoidizations in several families of examples, including Kummer-type extensions and split finite algebras.

2606.12228 2026-06-11 cond-mat.soft math-ph math.MP 新提交

Tunable Snapping and Rigid Foldability in the Mars Origami Pattern

火星折纸图案中的可调突跳与刚性可折叠性

Menelaos Raptis, Thomas C. Hull

AI总结 研究揭示火星折纸图案因几何不兼容导致非刚性折叠,产生可重复的突跳不连续性,并通过激光刻痕实现突跳幅度的连续调节。

Comments 14 pages, 8 figures

详情
AI中文摘要

受折纸启发的超材料利用几何与弹性之间的相互作用来实现可编程的力学响应。然而,非刚性可折叠图案中突跳不稳定性的起源和可调性仍知之甚少。在这里,我们展示了火星镶嵌图案——一种由交替的方形和菱形面组成的四度顶点折纸图案——不是刚性可折叠的,因为顶点兼容性所需的折叠速度比无法在相邻单元之间一致传播。这种几何不兼容性迫使面在折叠过程中弯曲,从而在力-位移曲线中产生可重复的突跳不连续性,平均力下降约92.6±5.5%,标志着亚稳态之间的转变。在应变场模拟的指导下,对额外的对角线折痕进行激光刻痕,可以实现突跳幅度的连续调节。这些结果揭示了一种通用机制,通过该机制可以利用几何挫折来编程薄片超材料中的多稳态性。

英文摘要

Origami-inspired metamaterials exploit the interplay between geometry and elasticity to achieve programmable mechanical responses. Yet the origin and tunability of snap-through instabilities in non-rigidly foldable patterns remain poorly understood. Here we show that the Mars tessellation, a degree-4 vertex origami pattern composed of alternating square and rhombic faces, is not rigidly foldable because the folding-speed ratios required for vertex compatibility cannot be propagated consistently across neighboring units. This geometric incompatibility forces the facets to bend during folding, giving rise to a reproducible snap-through discontinuity in the force-displacement curve with a mean force drop of about 92.6 +/- 5.5 %, marking a transition between metastable states. Laser scoring of additional diagonal creases, guided by strain-field simulations, enables continuous tuning of the snap magnitude. These results reveal a general mechanism by which geometric frustration can be harnessed to program multistability in thin-sheet metamaterials.

2606.12227 2026-06-11 math.AP 新提交

Stability of the critical constant steady state of a Keller--Segel model

Keller-Segel模型临界常数稳态的稳定性

Nobuhito Miyake, Hiroshi Wakui, Tetsuya Yamada

AI总结 研究简化抛物-椭圆Keller-Segel系统在R^N(N≥3)中临界常数稳态的渐近稳定性,发现临界情况收敛速率不同于次临界情况。

详情
AI中文摘要

本文证明了简化抛物-椭圆Keller-Segel系统在$\mathbb{R}^N$($N \ge 3$)中临界常数稳态的渐近稳定性,该系统具有一族单参数常数稳态。尽管常数稳态的稳定性阈值已知,但临界情况一直未解决。我们还表明,临界情况下的收敛速率与先前研究的次临界常数稳态的速率不同。

英文摘要

In this paper, we prove the asymptotic stability of the critical constant steady state for a simplified parabolic--elliptic Keller--Segel system in $\mathbb{R}^N$ ($N \ge 3$), which admits a one-parameter family of constant steady states. Although the stability threshold for constant steady states is known, the critical case has remained open. We also show that the convergence rate in the critical case differs from the rates obtained for previously studied subcritical constant steady states.

2606.12225 2026-06-11 cs.CR 新提交

Bridging the Smart City Cybersecurity Data Gap Through AI-Driven Synthetic Dataset Generation

弥合智慧城市网络安全数据鸿沟:基于AI驱动的合成数据集生成

Stephanie Polczynski, John D. Hastings, Varghese Vaidyan, Kyle Korman

AI总结 提出AI合成数据生成框架,利用生成模型产生高保真网络安全数据集,解决真实数据稀缺问题,支持智慧城市安全工具开发与评估。

Comments 10 pages, 1 figure, 2 tables

详情
AI中文摘要

智慧城市依赖于互联的网络物理系统,这些系统集成了传感器、物联网设备、云平台以及AI驱动的服务和决策。虽然这些系统增强了城市服务,但由于其庞大的攻击面、异构的数据流和不断演变的威胁向量,也引入了复杂的网络安全挑战。为智慧城市开发和验证网络安全工具需要能够准确代表真实运行条件的高质量数据集。然而,真实世界的数据集往往不完整、包含隐私敏感数据、难以获取,或者缺乏足够的恶意活动来支持工具开发。本研究通过提出一个专门为智慧城市网络安全研究设计的基于AI的合成数据生成(SDG)框架,解决了这一关键差距。所提出的框架利用生成式人工智能模型来生成高保真的合成网络安全数据集,这些数据集复制了真实的设备行为、网络交互和网络攻击场景。合成数据集根据协议标准的一致性、与原始数据集的统计相似性以及在常见安全工具中的实用性进行评估。由此产生的合成数据生成框架和评估指标有望通过使研究人员能够更有效地建模威胁和更全面地评估防御技术,从而推进智慧城市网络安全,更好地保护关键智慧城市基础设施。

英文摘要

Smart cities rely on interconnected cyber-physical systems that integrate sensors, IoT devices, cloud platforms, and AI-driven services and decision-making. While these systems enhance city services, they also introduce complex cybersecurity challenges due to their large attack surfaces, heterogeneous data flows, and evolving threat vectors. Developing and validating cybersecurity tools for smart cities requires high-quality datasets that accurately represent real operational conditions. However, real-world datasets are often incomplete, contain privacy-sensitive data, are difficult to access, or lack sufficient malicious activity to support tool development. This research addresses this critical gap by proposing an AI-based synthetic data generation (SDG) framework designed specifically for smart city cybersecurity research. The proposed framework leverages generative artificial intelligence models to produce high-fidelity synthetic cybersecurity datasets that replicate realistic device behaviors, network interactions, and cyber-attack scenarios. The synthetic datasets are evaluated for conformity to protocol standards, statistical similarity to original datasets, and utility in common security tools. The resulting synthetic data generation framework and evaluation metrics are expected to advance smart city cybersecurity by enabling researchers to model threats more effectively and evaluate defensive techniques more comprehensively to better protect critical smart city infrastructures.

2606.12224 2026-06-11 cond-mat.mes-hall cond-mat.dis-nn 新提交

Enhanced localization length in a disordered one-dimensional band via cavity coupling to delocalized states

通过腔耦合到离域态增强无序一维能带中的局域长度

Francesco Mattiotti, Guido Pupillo, Jérôme Dubail, David Hagenmüller

AI总结 研究无序一维能带中局域态通过腔模耦合到离域带,发现光-物质耦合增强局域长度,在超强耦合下可达数个晶格尺度,并在量子霍尔系统中实现微米级有效离域行为。

Comments 9 pages, 4 figures

详情
AI中文摘要

我们研究了无序系统中腔耦合电子态的局域性质,受近期量子霍尔系统中腔介导跳跃的提议启发。首先引入一个最小双带模型,其中无序一维能带中的局域态通过均匀腔模耦合到离域态的激发带。结合微扰论与转移矩阵方法,我们表明局域态之间的腔辅助跳跃随距离指数衰减,这意味着即使在微扰区域之外,本征态仍然保持局域化。然而,相应的局域长度随光-物质耦合强度增加,并且在单电子超强耦合区域可扩展到多个晶格位点。然后,我们在参考文献[1,2]发展的框架内研究无序朗道带与腔模的耦合。我们发现边缘态之间的有效腔介导耦合也随距离指数衰减,但局域长度在实验现实参数下可达到微米尺度。通过分析逆参与比,我们表明这种增强耦合主要由上朗道带中最扩展的态介导。我们的结果证明,虽然无序量子霍尔系统中腔诱导跳跃仍然是指数局域的,但相关的局域长度可以变得足够大,使得相应态在介观长度尺度上表现出有效的离域行为。

英文摘要

We investigate the localization properties of cavity-coupled electronic states in disordered systems, motivated by recent proposals of cavity-mediated hopping in quantum Hall systems. We first introduce a minimal two-band model in which localized states in a disordered one-dimensional band are coupled, through a homogeneous cavity mode, to an excited band of delocalized states. Combining perturbation theory with a transfer-matrix approach, we show that cavity-assisted hopping between localized states decays exponentially with distance, implying that the eigenstates remain localized even beyond the perturbative regime. Nevertheless, the corresponding localization length increases with the light-matter coupling strength and can extend over several lattice sites in the single-electron ultrastrong-coupling regime. We then study a disordered Landau band coupled to a cavity mode within the framework developed in Refs.[1,2]. We find that the effective cavity-mediated coupling between edge states also decays exponentially with distance, but with a localization length that can reach micrometer scales for experimentally realistic parameters. By analyzing the inverse participation ratio, we show that this enhanced coupling is predominantly mediated by the most extended states of the upper Landau band. Our results demonstrate that, while cavity-induced hopping in disordered quantum Hall systems remains exponentially localized, the associated localization length can become sufficiently large for the corresponding states to exhibit effectively delocalized behavior on mesoscopic length scales.

2606.12223 2026-06-11 eess.SP 新提交

Characterization of Speech Imagery in Scalp EEG and Comparison with Motor Imagery

头皮脑电中言语想象的特性及其与运动想象的比较

Bob Van Dyck, Liuyin Yang, Qiang Sun, Ang Li, Marc M. Van Hulle

AI总结 本研究通过头皮脑电分析言语想象的时空特征,并与手指运动想象对比,发现言语想象呈现更弱、更分散的α波增强,分类准确率较低,表明其主导模式不同于运动想象,更接近非发音任务相关活动。

详情
AI中文摘要

言语想象作为一种内源且本质语言性的脑机接口范式,在通信领域具有吸引力。然而,尽管兴趣日益增长,其主导的头皮脑电时空特征仍未得到充分表征。在此,我们探究了言语想象在头皮脑电中的表现,并将其与手指运动想象进行比较。利用一个包含言语想象、手指运动想象和无任务试次的受试者内数据集(所有试次采用相同的实验结构),我们分析了跨通道和时间的频带功率动态。手指运动想象在感觉运动区域显示出预期的对侧mu/alpha和低beta去同步化,而言语想象则显示出更弱、更分散的alpha主导增强。在归一化到各自条件自身的试后期后,言语相关的alpha增加在提示开始后仅发生适度变化,表明言语与无任务差异的大部分在指令期间已经存在。区分想象与无任务的分类器对言语想象的平均平衡准确率为0.563 ± 0.072,对运动想象为0.718 ± 0.127,运动想象对alpha/beta的依赖性比言语想象更强。总之,这些结果提供了言语想象在头皮脑电中更清晰的群体级特征,并表明其主导时空模式不同于手指运动想象,且更符合大量非发音任务相关贡献,而非清晰的发音运动类似物。

英文摘要

SSpeech imagery is attractive as a brain-computer interface paradigm for communication because it is endogenous and intrinsically linguistic. Yet despite growing interest, its dominant scalp-EEG spatiotemporal characteristics remain poorly characterized. Here, we asked how speech imagery appears in scalp EEG and compared it against finger motor imagery. Using a within-subject dataset containing speech imagery, finger motor imagery, and no-task trials recorded under the same trial structure, we analyzed band-power dynamics across channels and time. Finger motor imagery showed the expected contralateral mu/alpha and low-beta desynchronization over sensorimotor areas, whereas speech imagery showed a weaker, more distributed alpha-dominant increase. After normalization to each condition's own post-trial interval, the speech-related alpha increase changed only modestly after cue onset, indicating that much of the speech-versus-no-task difference was already present during the instruction period. A classifier discriminating imagery from no-task reached mean balanced accuracies of 0.563 $\pm$ 0.072 for speech imagery and 0.718 $\pm$ 0.127 for motor imagery, with a stronger alpha/beta dependence for motor imagery than for speech imagery. Together, these results provide a clearer group-level characterization of speech imagery in scalp EEG and indicate that its dominant spatiotemporal pattern differs from that of finger motor imagery and is more consistent with substantial non-articulatory task-related contributions than with a clear articulatory-motor analogue.

2606.12222 2026-06-11 cond-mat.str-el cond-mat.mtrl-sci cond-mat.supr-con 新提交

Structural responses incipient to pressure-driven antiferromagnetic quantum critical point of van der Waals heavy-fermion metal CeSiI

范德华重费米子金属CeSiI中压力驱动反铁磁量子临界点前的结构响应

Hanming Ma, Tong Shi, Wenhao Li, Qingxin Dong, Xiaoli Ma, Shaoheng Ruan, Zhongjin Wu, Pengtao Yang, Zhaoming Tian, Jianping Sun, Yoshiya Uwatoko, Xiaohui Yu, Hechang Lei, Bosen Wang, Jinguang Cheng

AI总结 通过高压单晶X射线衍射,发现CeSiI在室温下于压力驱动反铁磁量子临界点附近出现晶格参数的突变和各向异性响应,为理解其低温量子临界行为提供了新视角。

Comments 19 pages, 5 figures

详情
AI中文摘要

CeSiI是一种范德华重费米子金属,最近发现在Pc=6 GPa的压力诱导反铁磁量子临界点(QCP)附近表现出非常规超导电性。本文报道了在室温下高达8.3 GPa压力下对CeSiI进行的全面单晶X射线衍射研究,揭示了压力驱动QCP之前的微妙结构响应。我们发现,在所研究的压力范围内,晶胞体积随压缩平滑减小,没有出现任何结构相变。有趣的是,我们在Pc=6 GPa附近观察到晶格参数突然且同时的各向异性响应,即a轴收缩而c轴突然伸长,但晶胞体积随压力平滑变化。结构精修进一步表明,这些晶格异常主要源于Ce-Ce和Ce-Si键长的变化,以及Pc附近CeSiI单层内蜂窝状Si层的扁平化。我们的发现建立了一个有趣的联系,将低温下QCP的压力驱动电子跃迁与室温下的初始结构响应联系起来,从而为CeSiI的压力-温度相图提供了新的见解。

英文摘要

CeSiI is a van der Waals heavy-fermion metal recently found to exhibit unconventional superconductivity near a pressure-induced antiferromagnetic quantum critical point (QCP) at Pc =6 GPa. Here, we report a comprehensive single-crystal X-ray diffraction study of CeSiI under high pressures up to 8.3 GPa at room temperature, revealing subtle structural responses that precede pressure-driven QCP. We find that the unit-cell volume decreases smoothly upon compression without showing any structural phase transition in the investigated pressure range. Intriguingly, we observe abrupt and concurrent anisotropic responses of the lattice parameters around Pc =6 GPa, i.e., the a-axis contracts while the c-axis enlongated suddenly, with the unit-cell volume smoothily varies with pressure. Structural refinements further show that these lattice anomalies primarily originate from changes of Ce-Ce and Ce-Si bond lengths, as well as a flattening of the inner honeycomb Si layer within the CeSiI monolayer around Pc. Our findings establish an interesting case linking pressure-driven electronic transition of QCP at low temperatures to incipient structural responses at room temperature, thereby providing fresh insight into the pressure-temperature phase diagram of CeSiI.

2606.12221 2026-06-11 cond-mat.mtrl-sci 新提交

Quantum dynamic simulation of triplet formation in an effective model of Y6 (BTP-4F)

Y6 (BTP-4F) 有效模型中三重态形成的量子动力学模拟

Isabel Creed, Lucy J. F. Hart, Pranay Venkatesh, Tom Ward, Jarvist Moore Frost

AI总结 构建Y6二聚体五态模型,用分层运动方程方法求解非绝热动力学,发现三重态主要通过瞬态激发的分子间电荷转移单重态到三重态Frenkel激子路径生成,聚集直接实现快速高产量系间窜越。

Comments 11 pages, 6 figures; 22 page SI, 29 figures

详情
AI中文摘要

我们构建了Y6 (BTP-4F) 二聚体中光激发的五态模型,然后使用分层运动方程(HEOM)方法求解非绝热动力学。我们发现三重态主要通过瞬态激发的\textit{分子间}电荷转移单重态到三重态Frenkel激子路径布居;该路径对单体不可用。对单粒子跃迁密度矩阵的分析表明,电荷转移态在空间上不同于Frenkel激子态,表明该跃迁的大自旋-轨道耦合是由于其被伴随的轨道特性变化所允许。因此,Y6中的聚集直接实现了快速且高产率的系间窜越。我们对模型二聚体进行硒化处理,显著增强了自旋-轨道耦合,从而加速了这种电荷转移介导的路径。展望未来对更大聚集体的模拟,我们表明,尽管Marcus理论在定性上给出了正确的动力学,但由于其忽略了量子回复,长时间产率是不正确的。相反,我们展示了最近发展的记忆核投影方法\cite{Gestsson2025-ez}可以直接从HEOM方程产生半经典速率,从而得到定量正确的动力学和产率。

英文摘要

We construct a five-state model for photoexcitation in Y6 (BTP-4F) dimers, and then solve the non-adiabtic dynamics using the Hierarchical Equations of Motion (HEOM) method. We find that triplets are populated mainly via a transiently excited \textit{intermolecular} charge-transfer singlet to triplet Frenkel exciton route; this route is not available to the monomer. Analysis of one-particle transition density matrices suggests that the charge-transfer states are spatially distinct to the Frenkel exciton states, indicating that the large spin-orbit-coupling for this transition is due to it being permitted by an associated change in orbital character. Aggregation in Y6 therefore directly enables fast and high-yield intersystem crossing. We selenise our model dimers, significantly enhancing spin-orbit-coupling, which then accelerates this charge-transfer mediated route. Looking forwards to simulations on larger aggregates, we show that, though Marcus theory gives qualitatively correct dynamics, the long-time yields are incorrect due to it missing quantum recurrences. Instead, we show that the recently developed memory-kernel projector\cite{Gestsson2025-ez} method can produce semi-classical rates directly from the HEOM equations which lead to quantitatively correct dynamics and yields.

2606.12220 2026-06-11 math.NT math.AG 新提交

Modular variants of p-adic fundamental sequence

p进基本序列的模变体

Heng Du, Qingyuan Jiang, Yucheng Liu

AI总结 将扩展上半平面中的任何Farey三角形与p进Hodge理论中Colmez-Fontaine基本引理的变体相关联,原始引理对应基本Farey三角形。

Comments 11 pages, 1 figure. arXiv:2404.04551v1 has been split into two papers; this is the first part. All comments are welcome!

详情
AI中文摘要

在本文中,我们将扩展上半平面中的任何Farey三角形与$p$进Hodge理论中Colmez--Fontaine基本引理的变体联系起来。特别地,他们的原始基本引理对应于基本Farey三角形$(\frac{1}{0},\frac{1}{1},\frac{0}{1})$。

英文摘要

In this article, we relate any Farey triangle in the extended upper half-plane to a variant of Colmez--Fontaine's fundamental lemma in $p$-adic Hodge theory. In particular, their original fundamental lemma corresponds to the fundamental Farey triangle $(\frac{1}{0},\frac{1}{1},\frac{0}{1})$.

2606.12219 2026-06-11 q-bio.GN q-bio.MN 新提交

m6A-FORM: A Foundation Model for Decoding N6-methyladenosine Biology

m6A-FORM:解码N6-甲基腺苷生物学的基础模型

Tinghe Zhang, Sumin Jo, Shou-Jiang Gao, Yufei Huang

AI总结 提出基于Transformer的基础模型m6A-FORM,利用MeRIP-seq峰作为先验,预训练后微调实现m6A位点预测,性能优于现有方法,并支持调控因子结合位点预测和组织保守位点分析。

详情
AI中文摘要

N6-甲基腺苷(m6A)是真核生物mRNA中最丰富的内部修饰。然而,现有大多数预测器采用以腺苷为中心的公式,计算效率低且易产生假阳性。本文提出m6A-FORM,一种基于Transformer的RNA甲基化基础模型,使用MeRIP-seq峰作为甲基化富集先验,并在来自143个人类MeRIP-seq研究的约2200万个峰衍生序列上预训练。使用来自m6A-Atlas v2.0和GLORI的高置信度单核苷酸m6A注释微调后,m6A-FORM-sites实现了最先进的m6A位点预测性能,PR-AUC为0.635,ROC-AUC为0.988,PR-AUC比现有方法至少提高0.14,同时推理速度显著加快。任务特定适配进一步支持19个m6A相关调控因子的结合位点预测,以及识别与mRNA降解相关的YTHDF2结合m6A位点。将m6A-FORM应用于来自24个人类组织的67个数据集,识别出19,631个组织保守位点,这些位点具有独特的定位、聚类、甲基化、表达、RBP相互作用和衰变相关特征。

英文摘要

N6-methyladenosine (m6A) is the most abundant internal modification in eukaryotic mRNA. However, most existing predictors use adenosine-centered formulations that are computationally inefficient and prone to false positives. Here we present m6A-FORM, a transformer-based foundation model for RNA methylation that uses MeRIP-seq peaks as methylation-enriched priors and is pretrained on approximately 22 million peak-derived sequences from 143 human MeRIP-seq studies. After fine-tuning with high-confidence single-nucleotide m6A annotations from m6A-Atlas v2.0 and GLORI, m6A-FORM-sites achieves state-of-the-art m6A site prediction performance, with a PR-AUC of 0.635 and ROC-AUC of 0.988, improving PR-AUC by at least 0.14 over existing methods while enabling substantially faster inference. Task-specific adaptation further supports prediction of binding sites for 19 m6A-associated regulators and identification of YTHDF2-bound m6A sites associated with mRNA degradation. Applying m6A-FORM across 67 datasets from 24 human tissues identifies 19,631 tissue-conserved sites with distinct localization, clustering, methylation, expression, RBP-interaction, and decay-associated signatures.

2606.12216 2026-06-11 quant-ph 新提交

Time-Frequency Grid States for Reconstruction and Correction of Channel-Induced Distortion in Entangled Photons

纠缠光子中信道诱导失真的重建与校正的时频网格态

Siang-Yun Liu, Bo-Ren Huang, Zhi-Xuan Zen, Yen-Hung Chen, Pin-Ju Tsai

AI总结 提出使用时频网格态作为内在频域参考,通过高斯过程回归学习校正映射,无需先验失真模型,将时频网格态坐标偏差降低约11倍,并将独立测试态的保真度从76.2%提升至90.0%。

Comments 12 pages, 10 figures

详情
AI中文摘要

时频量子态的表征需要可靠地重建其时频分布。然而,不完美的传输或测量信道会扭曲重建的联合光谱强度(JSI),尤其是在底层扰动机制未知的情况下。本文实验演示了一个重建与校正框架,该框架使用时频网格态作为内在频域参考。通过分析网格点的位移,采用高斯过程回归模型重建非线性坐标变形的校正映射,无需假设失真的先验物理模型。学习到的映射将时频网格态的残余坐标偏差降低了约11倍,并且当应用于独立的频率纠缠测试态时,将高斯形状保真度从76.2%提高到90.0%。这些结果确立了时频网格态作为诊断和校正时频量子系统中失真的实用计量资源,为抗失真量子通信和高维量子信息处理提供了途径。

英文摘要

Characterization of time-frequency (TF) quantum states requires reliable reconstruction of their TF distributions. However, imperfect transmission or measurement channels can distort reconstructed joint spectral intensities (JSIs), especially when the underlying perturbation mechanism is unknown. Here, we experimentally demonstrate a reconstruction and correction framework that uses a TF grid state as an intrinsic frequency-domain reference. By analyzing the displacement of the grid points, a Gaussian process regression model is employed to reconstruct a correction mapping for the nonlinear coordinate deformation without assuming a prior physical model of the distortion. The learned mapping reduces the residual coordinate deviation of the TF grid state by approximately a factor of 11 and, when applied to an independent frequency-entangled test state, improves the Gaussian-shape fidelity from 76.2\% to 90.0\%. These results establish TF grid states as practical metrological resources for diagnosing and correcting distortions in TF quantum systems, providing a pathway toward distortion-resilient quantum communication and high-dimensional quantum information processing.

2606.12214 2026-06-11 cs.HC cs.GR 新提交

Identifying cybersickness causes in virtual reality games using symbolic machine learning algorithms

使用符号机器学习算法识别虚拟现实游戏中的晕动症原因

Thiago Porcino, Erick Oliveira Rodrigues, Flavia Bernardini, Daniela Trevisan, Esteban Clua

AI总结 提出用符号机器学习算法对VR游戏中晕动症原因进行排序,通过两个游戏和37个有效样本的实验,发现旋转和加速度在飞行游戏中更易引发晕动症,且VR经验不足者更易不适。

详情
Journal ref
Entertainment Computing 2022
AI中文摘要

虚拟现实(VR)和头戴式显示器在教育、军事、娱乐和健康等各个领域越来越受欢迎。尽管此类技术提供了高度的沉浸感,但它们也可能引发不适症状。这种状况被称为晕动症(CS),在最近的虚拟现实出版物中相当常见。本文提出了一种新颖的实验分析,使用符号机器学习来对VR游戏中CS的潜在原因进行排序。我们估计CS的原因并根据其影响使用经典机器学习进行排序。实验使用了两个虚拟现实游戏和6个实验协议,以及来自88名志愿者的37个有效样本。我们的结果表明,与赛车游戏相比,在飞行游戏中旋转和加速度更频繁地引发晕动症。我们还可以观察到,VR经验较少的受试者更容易感到不适。以往经验在赛车游戏中扮演更重要的角色,因为该游戏在控制器方面给用户更多自由,更多的位移选择以及更多用户控制的加速度。此外,根据短期或长期VR暴露,引发不适的不同原因会出现。我们针对这两种场景(短期和长期暴露体验)提出了缓解CS的策略,并比较了两种突出场景(赛车和飞行)。

英文摘要

Virtual reality (VR) and head-mounted displays are constantly gaining popularity in various fields such as education, military, entertainment, and health. Although such technologies provide a high sense of immersion, they can also trigger symptoms of discomfort. This condition is called cybersickness (CS) and is quite popular in recent virtual reality publications. This work proposes a novel experimental analysis using symbolic machine learning to rank potential causes of CS in VR games. We estimate CS causes and rank them according to their impact using classical machine learning. Experiments are performed using two virtual reality games and 6 experimental protocols along with 37 valid samples from a total of 88 volunteers. Our results show that rotation and acceleration triggered cybersickness more frequently in a flight game in contrast to a race game. We could also observe that subjects that are less experienced with VR are more prone to feel discomfort. Former experience plays a more important role on the race game, as this game provides more liberty to the user in terms of controllers, more displacement alternatives and a more user-controlled acceleration. Furthermore, different causes that trigger discomfort arise based on short or long term VR exposures. We suggest strategies for mitigating CS for these two scenarios: short and long term exposure experiences and compare the two highlighted scenarios (race and flight).

2606.12212 2026-06-11 cs.SE cs.CR 新提交

Mind your key: An Empirical Study of LLM API Credential Leakage in iOS Apps

注意你的密钥:iOS应用中LLM API凭证泄露的实证研究

Pinran Gao, Lingxiang Wang, Ying Zhang, Fan Yang

AI总结 本研究首次系统调查iOS应用中LLM API密钥泄露问题,通过动态分析框架LLMKeyLens检测444个应用,发现282个存在可被利用的凭证泄露,并识别出三种泄露模式,三个月后仅28%完成修复。

Comments 12 pages, 4 figures, 4 tables

详情
AI中文摘要

大型语言模型(LLM)快速集成到移动应用中引入了一类新的凭证安全风险:泄露的凭证允许未经授权访问LLM推理服务,给开发者造成经济损失。先前关于凭证泄露的工作主要集中在Android应用上;迄今为止,尚无实证研究系统调查iOS应用中的LLM API密钥泄露。我们首次对集成LLM的应用中的API密钥泄露进行了深入的实证研究。我们构建了一个包含444个iOS应用的高质量数据集,这些应用通过标准化流程从1092个候选应用中筛选出来,并开发了LLMKeyLens,一个动态分析框架,通过流量拦截、特定于提供商的密钥提取和主动有效性确认来检测LLM API密钥泄露,无需源代码访问或二进制解密。我们的分析显示,282个应用在网络流量中暴露了可利用的LLM API凭证,涉及至少十个提供商。我们识别出三种泄露模式:基于JWT的令牌泄露(48%)、未经身份验证的后端代理访问(33%)和明文API密钥传输(19%)。为评估修复情况,我们在负责任披露三个月后重新分析了相同的282个易受攻击的应用;只有28%修复了报告漏洞,而72%仍然可利用,问题持续源于未经身份验证的后端和损坏的JWT实现。我们的发现表明,LLM API密钥泄露在iOS生态系统中既普遍又持久,暴露出开发者实践与安全集成原则之间的系统性差距,并表明安全的LLM集成不仅需要开发者意识,还需要提供商明确的安全指导和平台级强制执行。

英文摘要

The rapid integration of large language models (LLMs) into mobile applications has introduced a new class of credential security risk: leaked credentials that grant unauthorized access to LLM inference services, causing financial damage to developers. Prior work on credential leakage has focused primarily on Android apps; to date, no empirical study has systematically investigated LLM API key leakage in iOS applications. We present the first in-depth empirical study of API key leakage in LLM-integrated apps. We construct a high-quality dataset of 444 iOS applications, filtered from 1092 candidates through a standardized process, and develop LLMKeyLens, a dynamic analysis framework that detects LLM API key leakage via traffic interception, provider-specific key extraction, and active validity confirmation, requiring neither source code access nor binary decryption. Our analysis reveals that 282 applications expose exploitable LLM API credentials in network traffic, spanning at least ten providers. We identify three leakage patterns: JWT-based token leakage (48%), unauthenticated backend proxy access (33%), and plaintext API key transmission (19%). To assess remediation, we re-analyzed the same 282 vulnerable applications three months after responsible disclosure; only 28% had remediated the reported vulnerability, while 72% remained exploitable, with persistent issues stemming from unauthenticated backends and broken JWT implementations. Our findings show that LLM API key leakage is both prevalent and persistent in the iOS ecosystem, exposing a systemic gap between developer practice and secure integration principles, and suggest that secure LLM integration requires not only developer awareness but also explicit security guidance from providers and platform-level enforcement.

2606.12209 2026-06-11 q-bio.QM 新提交

Interpretable enzyme function prediction via sparse autoencoder features of ESMC across the microbial protein universe

通过ESMC稀疏自编码器特征实现可解释的酶功能预测:跨越微生物蛋白质宇宙

Yue Hu, Wanyu Cheng, Junqing Wang, Yingchao Liu

AI总结 利用ESMC-6B蛋白质语言模型的稀疏自编码器特征,无需任务特定训练即可准确预测酶功能,在微生物酶基准上实现78.9% top-1准确率,并发现16.9万个暗酶候选。

Comments 17 pages, 5 figures, 3 tables

详情
AI中文摘要

微生物基因组和宏基因组包含数百万功能未知的酶,即酶暗物质。虽然深度学习改进了蛋白质功能预测,但大多数方法是基于序列或结构相似性的黑箱,限制了新型催化活性的发现。ESMC-6B蛋白质语言模型及其稀疏自编码器(具有16,384维可解释生物学概念码本,每个概念由GPT-5注释)创造了新的机会:直接将这些特征用作酶功能的语义签名。在这里,我们展示了ESMC-SAE特征能够实现准确且可解释的酶委员会(EC)编号预测,无需任务特定训练或GPU密集型计算。在包含4,868个微生物SwissProt酶(涵盖161个EC3子类)的平衡基准上,ESMC-SAE二元特征达到78.9%的top-1和88.5%的top-5准确率,比3-mer基线(57.3%)高37.6%。在模拟发现新型酶类的留一EC3子类评估中,SAE特征在47.7%的情况下恢复了EC1超类(随机为14.3%,3.3倍),而序列方法为26.6%。判别性特征对应于机制上可解释的概念:水解酶的催化三联体几何结构、氧化还原酶的NAD(P)H结合Rossmann折叠、转移酶的磷酸结合P环。我们还调查了包含770万个簇的ESM Atlas,并在所有主要微生物门中识别出169,859个暗酶样候选。我们的结果为微生物暗物质中的酶功能发现建立了一个范式:设计上可解释,无需GPU集群即可扩展,适用于ESM Atlas中的数十亿蛋白质。

英文摘要

Microbial genomes and metagenomes contain millions of proteins whose enzymatic functions remain unknown, the enzyme dark matter. While deep learning has improved protein function prediction, most methods are black boxes relying on sequence or structural similarity, limiting discovery of novel catalytic activities. The ESMC-6B protein language model and its sparse autoencoder with a 16,384-dimensional codebook of interpretable biological concepts, each annotated by GPT-5, creates a new opportunity: using these features directly as semantic signatures for enzyme function. Here, we show that ESMC-SAE features enable accurate and interpretable enzyme commission (EC) number prediction without task-specific training or GPU-intensive computation. On a balanced benchmark of 4,868 microbial SwissProt enzymes across 161 EC3 subclasses, ESMC-SAE binary features achieve 78.9% top-1 and 88.5% top-5 accuracy, 37.6% higher than 3-mer baselines (57.3%). In leave-one-EC3-class-out evaluation simulating discovery of novel enzyme classes, SAE features recover the EC1 superclass in 47.7% of cases (3.3x random, 14.3%), versus 26.6% for sequence methods. Discriminative features correspond to mechanistically interpretable concepts: catalytic triad geometry for hydrolases, NAD(P)H-binding Rossmann folds for oxidoreductases, phosphate-binding P-loops for transferases. We also survey the ESM Atlas of 7.7 million clusters and identify 169,859 dark enzyme-like candidates across all major microbial phyla. Our results establish a paradigm for enzyme function discovery in microbial dark matter: interpretable by design, scalable without GPU clusters, and applicable to the billions of proteins in the ESM Atlas.

2606.12208 2026-06-11 cond-mat.quant-gas 新提交

Weakly interacting Bose gases in the canonical ensemble

正则系综中的弱相互作用玻色气体

Jonata S. Soares, Axel Pelster, Arnaldo Gammal

AI总结 基于无相互作用玻色气体的正则描述,研究弱两体相互作用对热力学和统计性质的微扰修正,得到正则配分函数的递归公式,并应用于盒陷阱中接触相互作用的稀薄玻色气体。

详情
AI中文摘要

基于无相互作用玻色气体的正则描述,我们研究了弱两体相互作用如何微扰地改变热力学和统计性质。到一阶为止,我们得到了正则配分函数的递归公式,该公式由与巨正则描述相同的费曼图组成,但具有不同的费曼规则。对正则配分函数的这个递归公式进行重求和,可以分别通过其累积量来表征基态占据数的统计特性。我们通过分析盒陷阱中具有接触相互作用的稀薄玻色气体来展示该方法的适用性。为此,我们使用了狄利克雷边界条件,考虑到它们与当前原子气体实验的相关性,在这些实验中,盒陷阱例如通过数字微镜器件实现。

英文摘要

Based on the canonical description of a non-interacting Bose gas, we work out how both thermodynamic and statistical properties change perturbatively with respect to weak two-particle interactions. Up to first order, we obtain a recursion formula for the canonical partition function, which consists of the same Feynman diagrams as the grand-canonical description but with different Feynman rules. Resumming this recursion formula for the canonical partition function allows one to characterize the statistics of the ground-state occupancy by its respective cumulants. We demonstrate the applicability of this approach by analyzing a dilute Bose gas with contact interaction in a box trap. To this end, we used Dirichlet boundary conditions in view of their relevance for current experiments with atomic gases, where the box trap is implemented, for instance, with digital mirror devices.

2606.12206 2026-06-11 math.AT 新提交

Stable homology of complex braid groups

复辫群的稳定同调

Andrea Bianchi, Filippo Callegaro, Luigi Caputi, Paolo Salvatore

AI总结 通过计算quillenization,确定了所有无限族复辫群的稳定同调,并证明了Fuchs在70年代声称的D型Artin群稳定同调的识别。

Comments 16 pages, comments welcome!

详情
AI中文摘要

我们计算了固定$e\ge2$且$n$递增时,类型$B(e,e,n)$和$B(2e,e,n)$的复辫群的稳定同调。这解释了所有无限族复辫群的稳定同调。我们通过显式计算其稳定分类空间的quillenization来实现这一点。特别地,我们提供了对Fuchs在70年代声称的D型Artin群稳定同调识别的证明。

英文摘要

We compute the stable homology of complex braid groups of types $B(e,e,n)$ and $B(2e,e,n)$ for fixed $e\ge2$ and increasing $n$. This accounts for the stable homology of all infinite families of complex braid groups. We achieve this by explicitly computing a quillenization of their stable classifying spaces. In particular, we provide a proof of an identification of the stable homology of Artin groups of type $D$ claimed by Fuchs in the '70s.

2606.12205 2026-06-11 astro-ph.HE gr-qc 新提交

Evidence for additional structure in the effective spin distribution hints at multiple formation pathways in GWTC-5.0

有效自旋分布中额外结构的证据暗示GWTC-5.0中存在多种形成途径

Sofia Alvarez-Lopez, Jack Heinzel, Salvatore Vitale

AI总结 通过分析GWTC-5.0数据,发现有效自旋分布中存在超出高斯主体的额外结构,并初步证据表明该结构具有质量依赖的正负不对称性,暗示多种形成途径。

Comments Letter: 5 pages, 4 figures. Supplementary Material: 4 pages, 2 figures

详情
AI中文摘要

LIGO-Virgo-KAGRA探测到的双黑洞的有效旋进自旋($\chi_\mathrm{eff}$)分布可以揭示其形成途径。我们使用两种模型(一种灵活,一种完全参数化)联合描述$\chi_\mathrm{eff}$和主质量,分析了GWTC-5.0数据集。我们澄清了先前报道的$\chi_\mathrm{eff}$分布的偏斜应理解为在中心位于小$\chi_\mathrm{eff}$的非偏斜高斯主体之外的额外结构。这种额外结构延伸到更大的$|\chi_\mathrm{eff}|$,这一结果先前使用GWTC-4.0数据报道过。我们从数据中测量了高斯主体外$\chi_\mathrm{eff}$分布的不对称性。通过参数化和灵活分析,我们发现了初步证据表明,在高斯主体外,正$\chi_\mathrm{eff}$相对于负$\chi_\mathrm{eff}$存在质量依赖的过剩。仅在$m_1 \in [46,65]\\,M_\odot$时,数据要求在高斯主体外存在负$\chi_\mathrm{eff}$成分,优势比为$23:1$。如果高斯主体外的$\chi_\mathrm{eff}$是由层级并合产生的——正如之前所提出的——那么这些并合中的一部分可能产生于能够生成正$\chi_\mathrm{eff}$双星过剩的环境中,例如活动星系核的盘。

英文摘要

The distribution of the effective inspiral spin ($χ_\mathrm{eff}$) of the binary black holes detected by LIGO-Virgo-KAGRA can shed light on their formation pathways. We analyze the GWTC-5.0 dataset with two models-one flexible, one fully parametric-that jointly describe $χ_\mathrm{eff}$ and primary mass. We clarify that the previously-reported skewness in the $χ_\mathrm{eff}$ distribution is better understood as additional structure beyond a non-skewed Gaussian bulk centered at small $χ_\mathrm{eff}$. This additional structure extends to larger $|χ_\mathrm{eff}|$, a result previously reported using GWTC-4.0 data. We measure the asymmetry of the distribution of $χ_\mathrm{eff}$ outside the Gaussian bulk from the data. With both the parametric and the flexible analyses, we find tentative evidence for a mass-dependent excess of positive $χ_\mathrm{eff}$ over negative ones outside the Gaussian bulk. Only at $m_1 \in [46,65]\,M_\odot$ do the data require a negative $χ_\mathrm{eff}$ component outside the Gaussian bulk, with $23\text{:}1$ odds. If $χ_\mathrm{eff}$ outside the Gaussian bulk are produced by hierarchical mergers-as it has been suggested-then a fraction of those mergers may be produced in environments that can generate a surplus of binaries with positive $χ_\mathrm{eff}$, such as the disks of active galactic nuclei.

2606.12204 2026-06-11 cond-mat.str-el 新提交

Kinetic kagome magnetism: from self-trapping RVB polarons to semiclassical correlations

动力学kagome磁性:从自陷RVB极化子到半经典关联

Yufei Pei, Shuai A. Chen, Claudio Castelnovo, Roderich Moessner

AI总结 研究kagome晶格上单空穴反Nagaoka问题,发现自陷RVB极化子及随自旋极化演变为√3×√3反铁磁关联。

Comments 15 pages, 18 figures

详情
AI中文摘要

为了更深入地理解空穴动力学在高度受挫掺杂Mott绝缘体磁性决定中的作用,我们考虑kagome晶格上的单空穴反Nagaoka问题,使用磁化强度作为调节参数。在接近完全极化时,掺杂的空穴通过结合反转自旋形成一种单重态键图案(我们称之为共振价键(RVB)极化子)而离域。这些RVB极化子可能具有极小的有效带宽,因此表现出自陷。通过调节自旋极化,我们追踪这些态向非极化区域的演化,在那里我们观察到$\sqrt{3}\times\sqrt{3}$反铁磁关联的出现,类似于kagome晶格上的经典Potts和Heisenberg模型。这些结果提供了一个框架,用于理解短尺度上的RVB物理如何演变为长尺度上的常规磁关联。

英文摘要

To gain deeper insight into the role of hole kinetics in determining magnetism in highly frustrated doped Mott insulators, we consider the single-hole counter-Nagaoka problem on the kagome lattice, using magnetization as a tuning parameter. Near full polarization, a doped hole delocalizes upon binding reversed spins in a pattern of singlet bonds which we term resonating-valence-bond (RVB) polaron. These RVB polarons can have extremely small effective bandwidths, and hence exhibit self-trapping. By tuning the spin polarization, we track the evolution of these states toward the unpolarized sector, where we observe the emergence of $\sqrt{3}\times\sqrt{3}$ antiferromagnetic correlation reminiscent of the classical Potts and Heisenberg models on the kagome lattice. These results provide a framework to understand how RVB physics at short scales evolves into conventional magnetic correlations at long scales.

2606.12202 2026-06-11 math.MG 新提交

Sparse metric spaces and sparse ends

稀疏度量空间与稀疏端

William Geller, Michal Misiurewicz

AI总结 研究在无穷远处稀疏的度量空间,定义并探讨稀疏性的拟等距不变量,引入稀疏空间的端概念,并给出多种背景下的例子。

详情
AI中文摘要

我们研究在某种意义下在无穷远处稀疏的度量空间。我们定义并探讨了一种稀疏性的度量,它是拟等距不变量,并引入了稀疏空间的端概念,该概念在拟等距下也是不变的。我们研究了在不同背景下出现的一些例子。

英文摘要

We study metric spaces that in some sense thin out at infinity. We define and investigate a measure of sparsity that is a quasi-isometry invariant, and introduce an analogue of topological ends for sparse spaces that is also invariant under quasi-isometries. We study some 51F30examples arising in various contexts.