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2606.13847 2026-06-15 eess.SY 新提交

Modal Analysis of Spatial Load Correlation in AI Data Center-Dominated Power Systems

AI数据中心主导电力系统中空间负荷相关的模态分析

Chandan Chaudhary, Michael Murillo, Mohammed Ben-Idris, Joydeep Mitra, Dilip Pandit, Atri Bera

AI总结 针对AI数据中心负荷的时空相关波动,提出基于动态模态分解(DMD)的模态分析方法,无需平稳性假设即可识别相关瞬态结构,并基于模态增长指标提供相关增强的早期预警。

Comments To appear in proceedings of 8th International Conference on Smart Energy Systems and Technologies, September 2-4, 2026 | Ciudad Real, Spain

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AI中文摘要

超大规模AI数据中心引起空间和时间相关的负荷波动,这些波动违反了经典独立性假设,且无法通过时间平均谱方法捕捉。这些相关性是偶发性和非平稳的,需要能够解析瞬态结构的分析。本文将动态模态分解(DMD)应用于成对母线间相关系数的时间演化,形成低维状态表示,从而无需平稳性假设即可进行模态分析。DMD特征值编码了相关状态:它们在复平面中的位置区分了持续相干、衰减瞬态和增强事件,而振荡频率映射到潜在的物理耦合机制。使用带有三个变流器接口AI数据中心负荷的IEEE 39节点实时数字仿真器(RTDS)测试平台,这些负荷由合成工作负载曲线驱动,全局DMD提供了慢热频带($f \approx 0.005$\\,Hz, $|\mu| = 0.91$)中的时间平均模态基线,捕获了93.6%的总相关能量。滑动窗口DMD公式识别了瞬态增强事件:775个窗口中有51个(6.6%)满足$|\mu_k^{(n)}| > 1$准则,这与随机工作负载巧合一致。与RTDS电压相干的交叉验证证实了这些区间内的耦合增强。所提出的模态增长指标在峰值成对相干之前提供了相关增强的早期预警信号。

英文摘要

Hyperscale AI data centers induce spatially and temporally correlated load fluctuations that violate classical independence assumptions and are not captured by time-averaged spectral methods. These correlations are episodic and non-stationary, requiring analysis that resolves transient structure. This paper applies Dynamic Mode Decomposition (DMD) to the temporal evolution of pairwise inter-bus correlation coefficients to form a low-dimensional state representation that enables modal analysis without a stationarity assumption. DMD eigenvalues encode the correlation regime: their location in the complex plane distinguishes sustained coherence, decaying transients, and intensifying events, while oscillation frequency maps to underlying physical coupling mechanisms. Using an IEEE 39-bus Real-Time Digital Simulator (RTDS) testbed with three converter-interfaced AI data center loads driven by synthetic workload profiles, global DMD provides a time-averaged modal baseline in a slow thermal band ($f \approx 0.005$\,Hz, $|\mu| = 0.91$) captures 93.6\% of total correlation energy. A sliding-window DMD formulation identifies transient intensification events: 51 of 775 windows (6.6\%) satisfy the $|\mu_k^{(n)}| > 1$ criterion, which aligns with stochastic workload coincidences. Cross-validation with RTDS voltage coherence confirms elevated coupling during these intervals. The proposed modal growth indicator provides an early-warning signal of correlation intensification prior to peak pairwise coherence.

2606.13846 2026-06-15 cs.DM 新提交

Frequencies of Patterns in Smooth Sequences Over the Alphabet $\{1,3\}$

字母表 $\{1,3\}$ 上光滑序列中模式的频率

Damien Jamet (Université de Lorraine, CNRS, LORIA, UMR 7503, F-54000 Nancy, France), Irène Marcovici (Univ Rouen Normandie, CNRS, Normandie Univ, LMRS UMR 6085, F-76000 Rouen, France), Léo Poirier (Aix-Marseille Université, CNRS, I2M UMR 7373, F-13000 Marseille, France), Thierry de la Rue (Univ Rouen Normandie, CNRS, Normandie Univ, LMRS UMR 6085, F-76000 Rouen, France)

AI总结 本文通过遍历理论框架研究奇数字母表 {1,3} 上光滑序列的统计性质,基于局部结构划分子移位并定义类型,通过分析替换结构证明所有子移位的唯一遍历性,从而得出任何有限模式在光滑序列中的渐近频率存在且依赖于类型序列,最后刻画了这些子移位的最小性。

Comments In Proceedings GASCom 2026, arXiv:2606.09910 (https://arxiv.org/abs/2606.09910)

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AI中文摘要

我们提供了一个遍历理论框架来研究奇数字母表 {1,3} 上光滑序列的统计性质。该字母表的算术性质基于光滑序列的局部结构对其子移位进行了划分,定义了这些序列的类型概念。我们描述了通过固定光滑序列逐次导数的类型序列得到的更小子移位的替换结构,由此得到所有这些子移位的唯一遍历性。一个直接推论是,在 {1,3} 上的光滑序列中,任何有限模式的渐近频率总是良好定义的,并且依赖于其类型序列。最后,我们刻画了这些子移位的最小性。

英文摘要

We provide an ergodic theory framework to study statistical properties of smooth sequences over the odd alphabet {1,3}. The arithmetic nature of this alphabet yields a partition of the subshift of smooth sequences based on their local structure, defining a notion of type for those sequences. We describe the substitutive structure of the smaller subshifts obtained by fixing the sequence of types of the successive derivatives of smooth sequences, from which we obtain the unique ergodicity of all these subshifts. A direct consequence is that the asymptotic frequency of any finite pattern in a smooth sequence over {1,3} is always well-defined and depends on its type sequence. Finally, we characterize the minimality of these subshifts.

2606.13845 2026-06-15 cs.DM 新提交

k-Convex Polyominoes by Semi-perimeter

按半周长计数的k-凸多边形

Andrew R. Conway (unaffiliated), Anthony J. Guttmann (The University of Melbourne)

AI总结 提出按半周长计数的k-凸多边形生成函数的猜想解,该解基于枚举数据分析得到。

Comments In Proceedings GASCom 2026, arXiv:2606.09910 (https://arxiv.org/abs/2606.09910)

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AI中文摘要

我们给出了按半周长计数的k-凸多边形生成函数的猜想解。该解是通过对我们生成的枚举数据进行分析得到的。

英文摘要

We give the conjectured solution for the generating function of k-convex polyominoes, enumerated by semi-perimeter. The solution was obtained from the analysis of enumeration data that we generated.

2606.13844 2026-06-15 cs.AR 新提交

Ramulator 2.1: A Composable Memory System Simulator for Modern DRAM Systems

Ramulator 2.1:用于现代DRAM系统的可组合内存系统模拟器

Haocong Luo, F. Nisa Bostancı, Ataberk Olgun, Maria Makeenkova, Ziad Malik, Ipek Akdeniz, Onur Mutlu

AI总结 Ramulator 2.1 大幅改进了模拟器,支持现代DRAM标准(HBM3/4、LPDDR5/6、GDDR7),引入基于Python的建模接口和双向代码生成框架,并提供了全面的测试与验证基础设施。

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AI中文摘要

Ramulator 2.1 是 Ramulator 2.0 的重大改进,在三个方面显著提升了模拟器:1)支持现代和新兴的 DRAM 及内存控制器特性,2)更好的可用性和可扩展性,3)更全面的测试和验证工作流。Ramulator 2.1 增加了对近期和新兴 DRAM 标准及内存控制器高级特性的支持,包括 HBM3/4、LPDDR5/6 和 GDDR7。为了提高可用性和可扩展性,Ramulator 2.1 引入了一个基于 Python 的建模和配置接口,该接口由双向代码生成框架支持,该框架 1)将底层 C++ 代码隐藏在用 Python 编写的高级 DRAM 规范之后,2)自动为模拟器的所有组件创建 Python 代理。这使得用户能够快速创建 DRAM 标准的变体并自动化设计空间探索工作流。为了提高模拟结果的可信度,Ramulator 2.1 提供了全面的测试和验证基础设施,涵盖 1)特定 DRAM 时序约束和内存控制器调度行为的细粒度验证,以及 2)使用延迟-吞吐量曲线进行系统级性能评估。为了帮助性能分析和调试,Ramulator 2.1 还包括一个易于使用且高性能的 DRAM 命令跟踪可视化工具。Ramulator 2.1 在 GitHub 上开源并正在积极开发中。

英文摘要

Ramulator 2.1 is a major overhaul of Ramulator 2.0 that substantially improves the simulator in three directions: 1) support of modern and emerging DRAM and memory-controller features, 2) better usability and extensibility of the simulator, and 3) more comprehensive tests and validation workflows. Ramulator 2.1 adds support for advanced features in recent and emerging DRAM standards and memory controllers, including HBM3/4, LPDDR5/6, and GDDR7. To improve usability and extensibility, Ramulator 2.1 introduces a Python-based modeling and configuration interface backed by a two-way code-generation framework that 1) hides low-level C++ code behind high-level DRAM specifications written in Python, and 2) automatically creates Python proxies for all components of the simulator. Doing so enables users to rapidly create variants of DRAM standards and automate design-space-exploration workflows. To improve trustworthiness in simulation results, Ramulator 2.1 provides a comprehensive testing and validation infrastructure that covers both 1) fine-grained validation of specific DRAM timing constraints and memory-controller scheduling behavior, and 2) system-level performance evaluation using latency-throughput curves. To aid performance analysis and debugging, Ramulator 2.1 also includes an easy-to-use and high-performance DRAM command trace visualizer. Ramulator 2.1 is open-source on GitHub and under active development.

2606.13843 2026-06-15 cs.HC 新提交

Rethinking the UI of GenUI: A Tale of Two Designs

重新思考GenUI的用户界面:两种设计的故事

Xiang `Anthony' Chen, Savvas Dimitrios Petridis, Tian Deng, Humad Bari, Ruofei Du, Yang Li

AI总结 本研究通过对比两种GenUI设计(非结构化深度优先高保真 vs. 结构化广度优先低保真),探讨如何更好地支持早期0到1设计探索,发现结构化输入和广度优先工作流有优势但存在权衡。

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AI中文摘要

GenUI是一类新兴的AI工具,利用大型模型根据用户的高层描述生成UI原型,有望为更广泛的用户群体普及UX设计探索。迄今为止,大多数GenUI设计倾向于继承对话式大型模型(如ChatGPT和Gemini)的惯例,用户主要通过非结构化提示描述设计需求,然后工具采用深度优先方法,立即深入设计并生成高保真原型。在本研究中,我们重新思考这种非结构化、深度优先、高保真的GenUI设计在多大程度上能够支持早期、从0到1的设计探索。为了探究这一问题,我们提出了一种对比设计,采用结构化输入、广度优先探索和低保真生成。随后,我们进行了一项对比研究,邀请24名UX设计师和产品经理使用现有的GenUI工具和我们的对比GenUI工具进行小型设计探索练习。研究结果揭示了参与者对两种GenUI设计的感知优势和权衡:结构化输入揭示了关键方面,但需要更多工作,提高了开始探索的门槛;广度优先工作流展示了更多可能性,但预览跨多个屏幕的UX想法仍然困难;尽管低保真有价值,但专业人士更偏好高保真,因为它符合实践,且GenAI提高了保真度期望。最后,我们总结了GenUI及类似AI驱动的创造力支持工具的设计启示。

英文摘要

GenUI is an emergent class of AI tools that use large models to generate UI mock-ups based on users' high-level descriptions, promising to democratize UX design exploration for a broader audience. Most GenUI designs to date tend to inherit the conventions of conversational large models, such as ChatGPT and Gemini, where a user describes their design needs primarily via an unstructured prompt, and the tool then takes a depth-first approach, delving into the design right away and producing a high-fidelity prototype. In this research, we rethink how well this unstructured, depth-first, and high-fidelity GenUI design can support early-stage, 0-to-1 design exploration. To probe this question, we propose a contrastive design with structured input, breadth-first exploration, and low-fidelity generation. We then conducted a comparison study with 24 UX designers and product managers who conducted mini design exploration exercises using an existing GenUI tool and our contrastive GenUI tool. Findings reveal participants' perceived benefits and trade-offs of the two GenUI designs: structured input surfaces key facets but requires more work, raising entry barriers to start exploration; breadth-first workflow reveals more possibilities, but previewing UX ideas spanning many screens remains hard; and though low fidelity has value, professionals favor high fidelity because it fits practice and GenAI heightens fidelity expectations. We conclude with design implications for GenUI and similar AI-powered creativity support tools.

2606.13841 2026-06-15 physics.plasm-ph 新提交

Ionization potential depression in degenerate plasmas and Pauli blocking of multi-electron ions

简并等离子体中的电离势降低与多电子离子的泡利阻塞

Gerd Röpke

AI总结 基于量子统计方法,研究自由电子简并条件下部分电离等离子体的组成,考虑泡利阻塞效应,提出介质中薛定谔方程近似,给出电离度和莫特效应新结果。

Comments 22 pages, 4 figures

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AI中文摘要

研究了自由电子简并的温度和密度下部分电离等离子体的组成。基于量子统计方法,讨论了泡利阻塞效应。具体研究了单电子和双电子离子。指出了推导电离势的介质中薛定谔方程的近似方法。给出了关于电离度和莫特效应的新结果。标准等离子体性质代码未考虑泡利阻塞效应,因此无法解释高密度区域(电子简并)的实验。

英文摘要

The composition of partially ionised plasmas is investigated for densities and temperatures at which the free electrons are degenerate. Based on a quantum statistical approach, the effect of Pauli blocking is addressed. Specifically, one- and two-electron ions are studied. Approximations for deriving an in-medium Schrödinger equation for the ionization potential are indicated. New results regarding the degree of ionisation and the Mott effect are presented. Standard codes for plasma properties do not take Pauli blocking effects into account and are therefore unable to explain the experiments in the high-density regime, where the electrons are degenerate.

2606.13838 2026-06-15 math.GR math.DS 新提交

Free product of bi-orderable group is bi-orderable: A simple dynamical proof

双可序群的自由积是双可序的:一个简单的动力系统证明

Juan Alonso, Cristóbal Rivas

AI总结 通过动力系统构造,给出Vinogradov定理的新证明,证明双可序群的自由积仍为双可序,并保持因子双序在自同构下的不变性。

Comments 13 pages

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AI中文摘要

我们给出了Vinogradov定理的一个新证明,该定理断言双可序群的自由积是双可序的。我们的证明依赖于一个简单的动力系统构造,该构造提供了自由积的一个双序,该双序扩展了因子上的双序。此外,如果因子的双序在某些自同构下不变,那么乘积上的双序在乘积自同构下也是不变的。

英文摘要

We give a new proof of Vinogradov's theorem asserting that free product of biorderable groups is biorderable. Our proof relies on a simple dynamical construction that provides a bi-ordering of the free product that extends the bi-orderings on the factors. Furthermore, if the bi-orders of the factors are invariant under some automorphisms, then the bi-ordering on the product turns out to be invariant under the product automorphism.

2606.13837 2026-06-15 cs.IR 新提交

Hybrid Neural Retrieval with Generative Query Refinement for Quranic Passage Retrieval

混合神经检索与生成式查询精化在古兰经段落检索中的应用

Mohamed G. Salman, Mohammad E. Moftah, Ali Hamdi

AI总结 针对古兰经段落检索中现代标准阿拉伯语与古典阿拉伯语的语义鸿沟,提出四阶段神经架构,结合稠密与稀疏检索、语义重排序、置信门控和生成式精化,提升多节检索准确率并过滤零答案查询。

Comments Accepted for presentation at the Intelligent Methods, Systems, and Applications (IMSA) 2026 conference. \c{opyright} 2026 IEEE

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AI中文摘要

古兰经段落检索(PR)由于语言复杂性和日常查询中使用的现代标准阿拉伯语(MSA)与古兰经古典阿拉伯语(CA)之间的语义差距,可能是一项具有挑战性的任务。这些因素阻碍了传统的检索方法。为了处理这些限制并改进多节检索以及过滤零答案查询,本文提出了一种四阶段神经架构,旨在提高检索准确性和上下文理解。该方法结合了使用AraColBERT稠密索引和BM25稀疏检索的混合候选检索,随后使用CAMeLBERTmix交叉编码器进行语义重排序。然后应用置信门控机制来过滤零答案查询,以及基于AraT5的精化模块用于多节聚合。该系统在扩展版的Quran QA 2022数据集上进行了评估。结果显示,与基线模型相比,性能有所提升,达到了0.7024的Recall@10和0.4947的平均平均精度(MAP@10)。虽然与高度优化的单一模型相比,系统在绝对顶级排名精度(MRR = 0.5807)上表现出轻微的权衡,但所提出的架构为多节古兰经段落检索提供了一个更全面、可靠且上下文感知的解决方案。

英文摘要

Quranic Passage Retrieval (PR) could be a challenging task due to the linguistic complexity and the semantic gap between the Modern Standard Arabic (MSA) used in daily queries and the Classical Arabic (CA) of the Holy Quran. These factors hinder conventional retrieval methods. To handle these limitations and improve multi-verse retrieval and filter the zero-answer queries, this paper proposes a four-phase neural architecture designed to enhance retrieval accuracy and contextual understanding. The methodology combines hybrid candidate retrieval using AraColBERT dense indexing and BM25 sparse retrieval, followed by semantic reranking with a CAMeLBERTmix cross-encoder. A confidence gating mechanism is then applied to filter zero-answer queries, and an AraT5-based refinement module for multi-verse aggregation. The system is evaluated on an expanded version of the Quran QA 2022 dataset. Results show improved performance compared to the baseline models, achieving a Recall@10 of 0.7024 and a Mean Average Precision (MAP@10) of 0.4947. While the system exhibits a marginal tradeoff in absolute top-rank precision (MRR = 0.5807) compared to heavily optimised single models, the proposed architecture provides a substantially more comprehensive, reliable, and context aware solution for multi-verse Quranic passage retrieval.

2606.13836 2026-06-15 math.CO 新提交

Generalized affine spaces, generalized ovoids and generalized quadrangles

广义仿射空间、广义卵形与广义四边形

Joseph Adolphe Thas

AI总结 本文研究射影空间PG(m+n-1,K)的一种特殊划分,其中K为任意交换域,并给出该类型划分的特征刻画,结果应用于广义卵形和广义四边形。

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AI中文摘要

我们考虑射影空间PG(m+n-1,K)的一个划分,其中K是任意(交换)域,该划分包含一个m-1维空间,而所有其他空间都是n-1维的。给出了这类特殊划分的特征刻画。这项研究受到平移广义四边形中一些有趣问题的启发。在本文中,我们将结果应用于广义卵形和广义四边形。最后,我们给出了一些进一步研究的思路。

英文摘要

We consider a partition of the projective space PG(m + n - 1, K), with K any (commutative) field, into one space of dimension m - 1 while all other spaces of the partition have dimension n - 1. Characterizations of particular partitions of this type are given. This research is motivated by some interesting problems on translation generalized quadrangles. In the paper we apply our results to generalized ovoids and generalized quadrangles. Finally we give some ideas for further research.

2606.13834 2026-06-15 cs.PF cs.DC eess.SY 新提交

Solving Subgraph Extraction Problems Using $Δ$Search

使用$\Delta$Search解决子图提取问题

Rebin Silva Valan Arasu, Rajiv Gupta

AI总结 提出通用启发式框架$\Delta$Search,基于奖励-惩罚优化解决一类子图提取问题,仅需用户提供可行性约束和最优性标准,可加速精确方法,在多个图问题上匹配或超越现有启发式算法。

Comments 23 pages, 13 figures, 10 Tables

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AI中文摘要

许多NP难的图问题可以建模为具有可行性约束的最优子图提取问题。从网络设计到设施选址,从机器人学到图绘制,子图提取模式出现在不同领域。尽管有这种共性,这些问题通常用领域特定的启发式方法解决。通常,这些问题在满足连通性、平面性和可达性等结构约束的同时,平衡竞争目标,如最大化覆盖或最小化成本。在这项工作中,我们引入了$\Delta$Search,一个通用且快速的启发式框架,利用奖励-惩罚优化的见解来解决一大类子图提取问题。该框架易于使用,因为它只需要用户提供可行性约束和最优性标准来表达子图提取问题。我们还展示了如何通过积极剪枝搜索空间,用$\Delta$Search增强精确方法以提高其性能。我们在单调图问题(如最大平面子图(MPS)和最小连通支配集)、加权单调问题(如最大加权独立集和最小加权斯坦纳树)以及非单调图问题(如奖励收集顶点覆盖(PCVC)和无容量设施选址问题(UFLP))上评估了我们的框架。我们的结果表明,$\Delta$Search在MPS、UFLP和PCVC问题上以相似的运行时间匹配或超越了最先进的启发式方法。对于其余问题,$\Delta$Search在没有问题特定调整的情况下,达到了最先进算法约89%的解质量。

英文摘要

Many NP-hard graph problems can be modeled as optimal subgraph extraction problems with feasibility constraints. From Network Design to Facility Location, from Robotics to Graph Drawing, the subgraph extraction pattern emerges across diverse domains. Despite this commonality, these problems are typically solved with domain-specific heuristics. Usually, these problems balance competing objectives such as maximizing coverage or minimizing cost while satisfying structural constraints such as connectivity, planarity and reachability. In this work, we introduce $\Delta$Search, a general and fast heuristic framework that exploits the insight of Reward-Penalty optimization for solving a large class of subgraph extraction problems. The framework is easy to use as it only requires feasibility constraints and optimality criteria to be provided by the user to express the subgraph extraction problem. We also show how exact methods can be augmented with $\Delta$Search to improve their performance by aggressive pruning of the search space. We evaluate our framework on monotone graph problems such as Maximum Planar Subgraph (MPS) and Minimum Connected Dominating Set, Weighted Monotone problems such as Maximum Weighted Independent Set and Minimum Weighted Steiner Tree, and non-monotone graph problems such as Prize Collecting Vertex Cover (PCVC) and Uncapacitated Facility Location Problem (UFLP). Our results show that $\Delta$Search matches or surpasses state of the art heuristics for MPS, UFLP and PCVC problems with similar runtime. For the remaining problems, $\Delta$Search achieves approximately 89% of the solution quality of the state-of-the-art algorithms without any problem-specific tuning

2606.13833 2026-06-15 cond-mat.mtrl-sci physics.comp-ph 新提交

Machine-learned dynamics of surface polarons at reduced oxide surfaces

机器学习驱动的还原氧化物表面极化子动力学

Luca Leoni, Cesare Franchini

AI总结 利用机器学习辅助动力学模拟,研究还原性金红石TiO2(110)表面小极化子的有限温度动力学,发现表面极化子迁移率比体相低数个数量级,归因于有利跳跃路径的缺失和氧空位的束缚效应。

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AI中文摘要

可还原氧化物展现出电子、结构和化学性质的丰富相互作用,支撑着催化、光伏、电池和能源存储中的应用。这种相互作用强烈受到过量电子的影响,这些电子通常由氧空位引入,局域化为小极化子并影响电荷传输和表面化学。在表面,这些极化子在电荷局域化、迁移率和反应性中起核心作用,然而它们的有限温度动力学仍难以从第一性原理获取。从头算分子动力学通常局限于皮秒时间尺度,无法对极化子跳跃动力学进行统计上有意义的采样。为克服这一限制,我们将机器学习辅助的极化子动力学[V. Birschitzky et al., Phys. Rev. Lett. 134, 216301 (2025)]扩展到氧化还原活性氧化物表面,以缺氧金红石TiO2(110)作为范例。通过获取一系列温度下数纳秒的动力学,我们表明还原金红石TiO2(110)表面小极化子的迁移率相对于相应体材料被抑制了数个数量级,为多孔金红石TiO2中观察到的较低电子迁移率相比单晶样品提供了微观解释。这种抑制的迁移率源于有利跳跃路径的缺失:表面极化子运动主要局限于第二最顶层内的平面行间轨迹,仅发生罕见的层间跳跃事件。氧空位通过作为过量电子的吸引中心进一步重塑极化子自由能景观,使极化子分布偏向附近的Ti位点,并促进偶尔的电荷转移至最外层表面。这些结果建立了一种可迁移的机器学习策略,用于研究可还原氧化物中的极化子动力学。

英文摘要

Reducible oxides exhibit a rich interplay of electronic, structural, and chemical properties that underpins applications in catalysis, photovoltaics, batteries, and energy storage. This interplay is strongly shaped by excess electrons, often introduced by oxygen vacancies, that localize as small polarons and influence charge transport and surface chemistry. At surfaces, these polarons play a central role in charge localization, mobility, and reactivity, yet their finite-temperature dynamics remain difficult to access from first principles. Ab initio molecular dynamics is typically limited to picosecond time scales, precluding statistically meaningful sampling of polaron hopping dynamics. To overcome this limitation, we extend machine-learning-assisted polaron dynamics [V. Birschitzky et al., Phys. Rev. Lett. 134, 216301 (2025)] to redox-active oxide surfaces, using oxygen-deficient rutile TiO2(110) as a paradigmatic case. By accessing several nanoseconds of dynamics over a range of temperatures, we show that small-polaron mobility at the reduced rutile TiO2(110) surface is suppressed by several orders of magnitude relative to the corresponding bulk material, providing a microscopic interpretation of the lower electron mobilities observed in porous rutile TiO2 compared with single-crystal samples. This suppressed mobility arises from the loss of favorable hopping pathways: surface polaron motion is largely confined to planar inter-row trajectories within the second topmost layers, with only rare interlayer hopping events. Oxygen vacancies further reshape the polaron free-energy landscape by acting as attractive centers for excess electrons, biasing the polaron distribution toward nearby Ti sites and promoting occasional charge transfer to the outermost surface layer. These results establish a transferable machine-learning strategy for investigating polaron dynamics in reducible oxides.

2606.13831 2026-06-15 cond-mat.mtrl-sci 新提交

Combining Frozen Trajectory Excitation and TACAW for in silico Time-Resolved Vibrational Electron Energy Loss/Gain Spectroscopy

结合冻结轨迹激发与TACAW的硅上时间分辨振动电子能量损失/增益光谱

Wojciech Marciniak (1 and 2), Joanna Marciniak (1 and 3), José Ángel Castellanos-Reyes (1), Ján Rusz (1) ((1) Department of Physics and Astronomy, Uppsala University, Sweden (2) Institute of Physics, Poznan University of Technology, Poland (3) Institute of Molecular Physics, Polish Academy of Sciences, Poland)

AI总结 提出一种结合冻结轨迹激发(FTE)和辅助波函数时间自相关(TACAW)的计算框架,用于模拟非平衡晶格动力学的时间分辨振动电子能量损失光谱,并展示在fcc-Ni和3C-SiC中的应用。

Comments 19 pages, 13 figures

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AI中文摘要

鉴于超快(皮秒时间尺度)振动电子能量损失光谱(EELS)应很快在实验上实现,我们提出了一种能够从计算物理角度提供洞察的硅上方法。我们提出了一个结合冻结轨迹激发(FTE)与辅助波函数时间自相关(TACAW)的框架,用于研究与实验直接可比的非平衡晶格动力学的时间分辨光谱响应——(扫描)透射电子显微镜EELS,(S)TEM-EELS。在该方法中,首先使用FTE将选定的声子激发引入平衡分子动力学轨迹,然后对后续弛豫过程中的原子位置进行不同泵浦-探测延迟下的短时TACAW分析。这产生了在弛豫过程中带有声子印记的动量分辨和能量分辨电子散射信号,超越了仅有的时间分辨漫散射强度。我们在fcc-Ni和3C-SiC上演示了该方法,并讨论了在声子弛豫过程中观察到的声子模式耦合和光谱重新分布。

英文摘要

Seeing that ultrafast (picosecond timescale) vibrational electron energy loss spectroscopy (EELS) should soon be experimentally realizable, we present in silico approach capable of providing insight from the computational physics perspective. We present a framework that combines frozen trajectory excitation (FTE) with time auto-correlation of auxiliary wavefunctions (TACAW) to study the time-dependent spectral response of non-equilibrium lattice dynamics in a way comparable directly to experiment - (scanning) transmission electron microscope EELS, (S)TEM-EELS. In this approach, a selected phonon excitation is first introduced into an equilibrium molecular dynamics trajectory using FTE, after which the atomic positions during subsequent relaxations are treated with short-time TACAW analysis performed at different pump-probe delays. This yields momentum- and energy-resolved electron-scattering signals bearing a phonon imprint during the relaxation process, going beyond time-dependent diffuse-scattering intensities alone. We demonstrate the approach for fcc-Ni and 3C-SiC and discuss the observed phonon mode coupling and spectral redistribution during phonon relaxation.

2606.13830 2026-06-15 cond-mat.mes-hall quant-ph 新提交

A Collective-Spin Derivation of the Uniform Magnon Hamiltonian in Cavity Magnonics

腔磁学中均匀磁振子哈密顿量的集体自旋推导

Tomas Aguiar, Marcos Cesar de Oliveira

AI总结 本文从集体自旋角度直接推导了腔磁学中的有效均匀模哈密顿量,将铁磁体视为合成大自旋原子,并得到非线性修正导致的磁振子-光子耦合的占据数依赖减弱。

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AI中文摘要

我们提出了腔磁学中使用的有效均匀模哈密顿量的直接集体自旋推导。从最近邻海森堡铁磁体与长波长磁场耦合出发,我们证明相关动力学可以限制在全对称自旋扇区,其中交换相互作用仅贡献一个常数能量偏移,铁磁体表现为长度为$Ns$的宏自旋。直接对该总自旋应用Holstein-Primakoff变换,无需先引入位点分辨的玻色子算符,即可得到通常的均匀磁振子模式及其主要非线性修正。这种集体表述明确解释了铁磁体作为合成大自旋原子的观点,并为驱动和Floquet腔磁学中使用的有效哈密顿量提供了紧凑的推导路径。作为物理结果,主要非线性修正产生了有效磁振子-光子耦合的占据数依赖减弱,为强均匀模驱动下的有限自旋饱和提供了简单标志。

英文摘要

We present a direct collective-spin derivation of the effective uniform-mode Hamiltonian used in cavity magnonics. Starting from a nearest-neighbor Heisenberg ferromagnet coupled to long-wavelength magnetic fields, we show that the relevant dynamics can be restricted to the fully symmetric spin sector, where the exchange interaction contributes only a constant energy shift and the ferromagnet behaves as a macrospin of length $Ns$. Applying the Holstein--Primakoff transformation directly to this total spin yields the usual uniform magnon mode and its leading nonlinear corrections without first introducing site-resolved bosonic operators. This collective formulation makes explicit the interpretation of the ferromagnet as a synthetic large-spin atom and provides a compact route to the effective Hamiltonians used in driven and Floquet cavity magnonics. As a physical consequence, the leading nonlinear correction produces an occupation-dependent reduction of the effective magnon--photon coupling, providing a simple signature of finite-spin saturation under strong uniform-mode driving.

2606.13828 2026-06-15 cond-mat.supr-con 新提交

Observation of intertwined charge density wave order and superconductivity in Janus monolayer

Janus单层中交织的电荷密度波序与超导的观测

Subhajit Pramanick, Shubham Patel, Sudip Chakraborty, A. Taraphder

AI总结 通过第一性原理计算,研究1T ZrSeTe Janus单层中电荷密度波(CDW)与超导的共存,发现Se替代Te削弱CDW不稳定性,而高温相中软声子模式驱动双能隙超导。

Comments 18 pages, 16 figures

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AI中文摘要

低维过渡金属硫族化合物(TMDCs)为研究电荷密度波(CDW)和超导的出现提供了理想平台。在1T $\mathrm{ZrTe_2}$ 单层中发现新兴的CDW序提出了一个重要问题:当一层 $\mathrm{Te}$ 硫族层被 $\mathrm{Se}$ 替代时,这种不稳定性是否仍然存在?在本文中,我们利用第一性原理计算研究了1T $\mathrm{ZrSeTe}$ Janus单层中的CDW(2$\times$2$\times$1)和超导不稳定性。声子谱在不可约布里渊区的 $\mathrm{M}$ 点处表现出明显的反常,这是由于增强的电子-声子相互作用以及来自带间和带内散射的电子不稳定性。由此产生的晶格畸变重构了电子结构,打开了一个小的间接带隙,将系统从半金属态驱动到半导体态。与畸变相关的能量增益明显小于 $\mathrm{ZrTe_2}$ 单层,表明用 $\mathrm{Se}$ 替代一层 $\mathrm{Te}$ 硫族层削弱了CDW不稳定性。我们进一步研究了电子关联和双轴应变的影响,两者都作为所关注不稳定性的有效调控参数。在高温未畸变相中,$\mathrm{ZrSeTe}$ 表现出声子介导的双能隙超导。它主要源于 $\mathrm{M}$ 点处的软声子模式与主要来自 $\mathrm{Zr}$ $\mathit{d}$ 和 $\mathrm{Te}$ $\mathit{p}$ 轨道并穿过费米能级的电子带之间的强耦合。自旋-轨道耦合(SOC)进一步修改了电子态并降低了超导转变温度。

英文摘要

Low-dimensional transition-metal dichalcogenides (TMDCs) provide an ideal platform for studying the emergence of charge density wave (CDW) and superconductivity. The discovery of emergent CDW order in 1T $\mathrm{ZrTe_2}$ monolayer raises an important question: does this instability persist when one $\mathrm{Te}$ chalcogen layer is substituted by $\mathrm{Se}$? In the present work, we investigate the CDW (2$\times$2$\times$1) and superconducting instability in 1T $\mathrm{ZrSeTe}$ Janus monolayer using first-principles calculations. The phonon spectrum exhibits a pronounced anomaly at the $\mathrm{M}$ point of the irreducible Brillouin zone, arising from enhanced electron-phonon interaction together with electronic instabilities originating from both interband and intraband scattering. The resulting lattice distortion reconstructs the electronic structure, opening a small indirect band gap, driving the system from a semi-metallic to a semiconducting state. The energy gain associated with the distortion is significantly smaller than that of $\mathrm{ZrTe_2}$ monolayer, indicating that the replacement of one $\mathrm{Te}$ chalcogen layer with $\mathrm{Se}$ weakens the CDW instability. We have further investigated the effects of electronic correlation and biaxial strain, both acts as effective tuning parameters for the instabilities concerened. In the high temperature undistorted phase, $\mathrm{ZrSeTe}$ exhibits phonon mediated two-gap superconductivity. It originates primarily from the robust coupling between the soft phonon mode at $\mathrm{M}$ point and the electronic bands predominantly derived from $\mathrm{Zr}$ $\mathit{d}$ and $\mathrm{Te}$ $\mathit{p}$ orbitals crossing the Fermi level. Spin-orbit coupling (SOC) further modifies the electronic states and reduces the superconducting transition temperature.

2606.13826 2026-06-15 physics.flu-dyn 新提交

Resistance tensors for aggregate particles with Stokesian dynamics

聚集粒子的阻力张量与斯托克斯动力学

J. Gissinger, G. Voth, B. Mehlig, F. Candelier

AI总结 提出一种基于斯托克斯动力学的高效方法,通过珠子组装计算刚性和柔性聚集粒子的完整阻力与迁移率张量,揭示形状对平移、旋转及与流速梯度耦合的控制作用。

Comments 32 pages, 14 Figures, Appendices

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AI中文摘要

粒子对低雷诺数流动的响应可以通过阻力或迁移率张量进行简洁预测。然而,为特定几何形状获取这些张量元素的准确值的困难阻碍了对复杂形状粒子的研究。这里我们展示如何调整斯托克斯动力学以高效计算刚性和柔性聚集粒子(包括壁面约束)的阻力与迁移率张量。我们引入了该方法的实现SHAPES,并展示了其在复杂几何形状(包括弯曲纤维、手性偶极子、相互作用的聚集粒子和活性游泳者)上的能力。聚集粒子由珠子组装表示,旨在再现刚性或柔性粒子的几何形状和运动。这种粗粒化描述保留了关键的流体动力学相互作用,同时显著降低了计算成本。该方法准确再现了已知的精确解和近似解,以及实验观测结果。计算完整阻力与迁移率张量的能力提供了关于聚集粒子形状如何控制平移、旋转以及与流体速度梯度耦合的新见解。先前的描述通常依赖于仅保留少数对称允许耦合的简化模型。虽然有用,但这种简化描述在粒子形状的微小扰动下并不总是结构稳定的。计算完整张量使得能够得出稳健的结论,并将其与形状对称性和流体动力学相互作用联系起来。特别是,该方法允许系统分析螺旋聚集粒子中出现的非杰弗里应变率耦合。因此,SHAPES为研究微流控、生物和环境流动中的刚性和柔性聚集粒子提供了一个通用框架。

英文摘要

The response of particles to low-Reynolds flow can be compactly predicted with resistance or mobility tensors. However, the difficulty of obtaining accurate values for the elements of these tensors for specific geometries has held back work on particles with complex shapes. Here we show how Stokesian dynamics can be adapted to efficiently compute the resistance and mobility tensors of rigid and flexible aggregates, including confinement by walls. We introduce SHAPES, an implementation of the method, and demonstrate its capabilities for complex geometries including curved fibres, chiral dipoles, interacting aggregates, and active swimmers. Aggregates are represented by assemblies of beads designed to reproduce the geometry and motion of rigid or flexible particles. This coarse-grained description preserves the essential hydrodynamic interactions while substantially reducing computational cost. The method accurately reproduces known exact and approximate solutions, as well as experimental observations. The ability to compute the complete resistance and mobility tensors provides new insight into how aggregate shape controls translation, rotation, and coupling to fluid-velocity gradients. Previous descriptions often relied on simplified models retaining only a few symmetry-allowed couplings. While useful, such reduced descriptions are not always structurally stable under small perturbations of particle shape. Computing the full tensors makes it possible to draw robust conclusions and relate them to shape symmetry and hydrodynamic interactions. In particular, the method allows systematic analysis of non-Jeffery couplings to the strain rate that arise for helicoidal aggregates. SHAPES therefore provides a versatile framework for studying rigid and flexible aggregates in microfluidic, biological, and environmental flows.

2606.13824 2026-06-15 quant-ph 新提交

Calibrated Helstrom geometry on the Bloch ball via Connes spectral distance

通过Connes谱距离在Bloch球上校准的Helstrom几何

Kaushlendra Kumar

AI总结 本文通过有限标量-量子比特-标量模型,证明量子比特态的等先验Helstrom迹距离几何可从Connes谱距离恢复,标量参考扇区通过恒等Dirac链接各向同性耦合到量子比特块,使完整Bloch球继承标准弦迹距离几何,标量扇区距离起校准作用。

Comments 7 pages with 2-column layout & 2 figures

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AI中文摘要

我们证明,在有限标量-量子比特-标量模型中,量子比特态的等先验Helstrom迹距离几何可从Connes谱距离恢复。两个标量参考扇区通过恒等Dirac链接各向同性耦合到量子比特块,使得完整Bloch球(包括混合态)从有限谱度量继承其标准弦迹距离几何。标量扇区距离起独特的校准作用:它们确定单个链接长度,满足勾股一致性关系,并重建中间扇区的尺度。

英文摘要

We show that the equal-prior Helstrom trace-distance geometry of qubit states is recovered from Connes spectral distance in a finite scalar-qubit-scalar model. The two scalar reference sectors couple isotropically to the qubit block through identity Dirac links, so that the full Bloch ball, including mixed states, inherits its standard chordal trace-distance geometry from the finite spectral metric. The scalar-sector distances serve a distinct calibration role: they determine the individual link lengths, satisfy a Pythagorean consistency relation, and reconstruct the middle-sector scale.

2606.13822 2026-06-15 cs.CE 新提交

Price-Discovery Admissibility in Tokenized Fixed Income: Identification, Affine Characterization, and the Structure of the Token-to-Fiat Mapping

代币化固定收益中的价格发现可采纳性:识别、仿射特征及代币到法币映射的结构

Artem Alkhamov, Boris Kriuk

AI总结 研究代币化美国国债产品是否包含可恢复的底层信息,通过价格发现可采纳性标准识别出仅一个产品具有市场信息性,并给出双因子仿射特征描述。

Comments 27 pages, 5 figures, 4 tables

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AI中文摘要

代币化美国国债产品存在于两个账本上:一个链下的政府证券组合和一个声称代表它的链上包装。基本问题是链上序列是否包含关于底层资产的可恢复信息——即从代币到法币的映射是否存在,以及其结构如何。我们分三步进行。首先,在两个账本之间协调固定收益计量惯例;这些修正是有符号且联合的。其次,在协调后的序列上,我们引入一个价格发现可采纳性标准:一个基于序列依赖和异质离散度的可证伪测试,用于判断产品的序列是市场信息性的还是行政生成的。在四个具有足够历史的产品中,它恰好采纳了一个;其余的被净资产价值的计算和重新发布所主导,将其视为价差处理符合实际情况。宇宙中大部分产品不可采纳是我们的主要发现。第三,对于被采纳的映射,我们给出一个最小双因子仿射特征描述,其中基差以加法形式且与利率正交地进入,恢复了一个季度回归、一个小的正长期基差,以及一个2026年3月向平价急剧转变的制度变化。持续性被弱识别;我们通过轮廓似然将其传播到一个结果——抵押品折扣。贡献在于为链上固定收益何时可作为定量对象处理提供了测量和识别基础设施。

英文摘要

A tokenized U.S. Treasury product lives on two ledgers: an off-chain portfolio of government securities and an on-chain wrapper that claims to represent it. The foundational question is whether the on-chain series carries recoverable information about the underlying -- whether a mapping from token to fiat exists, and with what structure. We proceed in three steps. First, fixed-income measurement conventions are reconciled between the ledgers; these corrections are signed and jointly. Second, on the reconciled series we introduce a price-discovery admissibility criterion: a falsifiable test, based on serial dependence and idiosyncratic dispersion, for whether a product's series is market-informative or administratively generated. Of four products with sufficient history it admits exactly one; the rest are dominated by how net asset value is computed and republished, and treating them as spreads fits artifacts. That most of the universe is inadmissible is our principal finding. Third, for the admitted mapping we give a minimal two-factor affine characterization in which the basis enters additively and orthogonally to rates, recovering a quarterly reversion, a small positive long-run basis, and a sharp March 2026 regime change toward parity. Persistence is weakly identified; we propagate it through a profile likelihood into one consequence, a collateral haircut. The contribution is measurement and identification infrastructure for when on-chain fixed income may be treated as a quantitative object.

2606.13820 2026-06-15 hep-th 新提交

Unifying Gravities with Internal Interactions based on $SO(10)$ GUT

基于$SO(10)$大统一理论统一具有内部相互作用的引力理论

Stelios Stefas, George Zoupanos

AI总结 通过将四维时空切群扩展为$SO(2,16)$,统一了引力与内部相互作用,涵盖共形引力和模糊引力。

Comments 12 pages, no figures, contribution to the Proceedings of the International Conference "Nonlinearity, Nonlocality and Ultrametricity" on the Occasion of Branko Dragovic's 80th Birthday, Belgrade, Serbia, 26-30 May 2025

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AI中文摘要

基于两个关键要素,即成熟的引力规范理论表述以及弯曲流形的切空间不必与流形具有相同维度的观察,我们讨论了如何将所有已知的基本相互作用容纳在一个统一的框架内。通过将四维时空流形的切群扩展为$SO(2,16)$来实现统一,这一选择同时涵盖了引力部门的基础规范群和内部相互作用的$SO(10)$大统一理论。进入这一构造的引力理论是共形引力和模糊(非对易)引力,每种理论都以规范理论形式表述。

英文摘要

Building on two key ingredients, namely the well established gauge-theoretic formulation of gravity and the observation that the tangent space of a curved manifold need not have the same dimension as the manifold, we discuss how all known fundamental interactions can be accommodated within a single unified framework. The unification is realised by enlarging the tangent group of the four-dimensional spacetime manifold to $SO(2,16)$, a choice that simultaneously encompasses both the gauge group underlying the gravitational sector and the $SO(10)$ Grand Unified Theory for the internal interactions. The gravitational theories entering this construction are Conformal Gravity and Fuzzy (Noncommutative) Gravity, each formulated in gauge-theoretic terms.

2606.13819 2026-06-15 astro-ph.GA 新提交

GA-NIFS: The interplay between feedback and star formation at 3 < z < 9 probed by JWST/NIRSpec IFU

GA-NIFS: JWST/NIRSpec IFU探测的3<z<9处反馈与恒星形成之间的相互作用

L. Ulivi, M. Perna, S. Arribas, B. Rodríguez Del Pino, P. G. Pérez-González, I. Lamperti, C. Marconcini, H. Übler, F. D'Eugenio, T. Böker, A. J. Bunker, S. Carniani, S. Charlot, R. Maiolino, P. Alvarez, E. Bertola, G. Cresci, M. Curti, M. Hamed, L. R. Ivey, G. C. Jones, E. Parlanti, R. Pascalau, C. Prieto Jimenez, B. Trefoloni, G. Venturi, S. Zamora

AI总结 利用JWST/NIRSpec IFU对6个z=3-9星系进行空间分辨分析,发现AGN驱动的外流在早期宇宙中已能有效抑制大质量星系核区的恒星形成,而星暴驱动的外流则未导致明显熄灭。

Comments 23 pages, 25 figures, submitted to A&A

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AI中文摘要

星暴和AGN驱动的反馈是理解星系增长、恒星形成熄灭以及星系与其中心黑洞共同演化过程的基础。我们利用JWST/NIRSpec IFU的低分辨率($R \sim 100$)和高分辨率($R \sim 2700$)模式,对6个$3 < z < 9$的星系进行了空间分辨研究,包括星暴主导和AGN主导的系统。先前对$R \sim 2700$数据的分析揭示了所有这些星系中都存在电离外流。我们探索了外流与星族性质之间可能的联系,以评估早期宇宙中驱动星系演化的机制。结合空间分辨的星族分析与外流性质,我们发现,具有强AGN驱动电离外流的最质量星系($M_\star > 5 \times 10^{10} M_\odot$)在过去约100-300 Myr内显示出过去熄灭事件的证据,主要发生在核区($r < 3$ kpc)。相比之下,更高红移($z > 5$)且质量较小($M_\star < 10^{10} M_\odot$)的星暴星系,尽管存在强大的(星暴驱动的)外流,却似乎经历了持续增长,没有明显的熄灭迹象。具有较弱外流的大质量星系在其历史中未显示出熄灭的证据。一个巨大的AGN宿主(GS20936)显示出近期(10-30 Myr)的复苏阶段,可能由近期的一次主要并合触发。这些结果表明,(AGN驱动的)外流在早期宇宙中已经可以在塑造大质量星系的恒星形成历史中发挥关键作用。

英文摘要

The study of starburst- and AGN-driven feedback is fundamental for understanding the processes that shape galaxy growth, quench star formation, and drive the co-evolution of galaxies and their central black holes. We present a spatially resolved study of six galaxies at $3 < z < 9$, including starburst- and AGN-dominated systems, observed with JWST/NIRSpec IFU in low- ($R \sim 100$) and high-resolution ($R \sim 2700$) mode. Previous analysis of $R \sim 2700$ data revealed ionized outflows in all these galaxies. We explore possible links between outflows and stellar population properties to assess the mechanisms driving galaxy evolution at early epochs. Combining the spatially resolved stellar population analysis with the outflow properties, we find that the most massive galaxies ($M_\star > 5 \times 10^{10} M_\odot$) with strong AGN-driven ionized outflows show evidence of past quenching episodes occurring within the last $\sim 100$--$300$ Myr, mainly in the nuclear regions ($r < 3$ kpc). In contrast, higher-redshift ($z > 5$) and less massive ($M_\star < 10^{10} M_\odot$) starburst galaxies with powerful (starburst-driven) outflows appear to have experienced continuous growth, with no clear sign of quenching. Massive galaxies with weaker outflows do not show evidence of quenching in their history. One massive AGN host (GS20936) shows evidence for a recent ($10$--$30$ Myr) rejuvenation phase, likely fueled by a recent major merger. These results suggest that (AGN-driven) outflows can already play a key role in shaping the SFHs of massive galaxies at early cosmic epochs.

2606.13816 2026-06-15 astro-ph.IM 新提交

Design and Commissioning of an Iodine Cell for the ESPRESSO Spectrograph

用于ESPRESSO光谱仪的碘室设计与调试

Gillian Nave, R. Paul Butler

AI总结 为ESPRESSO光谱仪设计、建造并调试了碘吸收室,结合碘室与超稳定光谱仪技术,旨在将长期多普勒径向速度不确定度降至10 cm/s以下。

Comments 18 pages, 13 Figures, 3 Tables. To be published in The Astronomical Journal

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AI中文摘要

高分辨率阶梯光谱仪仍然是精密多普勒径向速度(RV)项目的支柱,探测了50 pc内几乎所有已知系外行星。精密多普勒RV光谱仪传统上分为两类。标准非稳定阶梯光谱仪通过碘吸收室观测目标。碘光谱嵌入目标光谱中,提供波长尺度和光谱仪点扩散函数(PSF)的记录。超稳定光谱仪放置在真空箱内,温度稳定在0.001°C级别,并由两根扰频光纤馈入。一根光纤携带目标,另一根携带校准源(ThAr、法布里-珀罗、激光梳)。两种技术都已发现数百颗行星,并在目前可用的最高分辨率阶梯光谱仪上产生亚米/秒的不确定性。两种技术各有优缺点,可以结合使用,目标是将长期多普勒RV不确定度降至10 cm/s以下。我们为欧洲南方天文台(ESO)的ESPRESSO光谱仪设计、建造、校准并调试了一个碘室。该室的设计和建造于2022年完成。2023年初,该室在美国国家标准与技术研究院(NIST)原子光谱实验室进行了校准,并于2023年5月进行了调试。调试运行仅限于VLT-UT2的黄昏和黎明时分。观测了五颗主序矮星,光谱类型从G到早期K,每颗星观测4至6个夜晚,总计十个夜晚。

英文摘要

High resolution echelle spectrographs remain the backbone of precision Doppler radial velocity (RV) programs, detecting almost all known exoplanets within 50 pc. Precision Doppler RV spectrographs have traditionally fallen into two camps. Standard unstabilized echelles observe targets through an iodine absorption cell. The iodine spectrum is embedded on the target spectrum, and provides a wavelength scale and a record of the spectrometer point-spread-function (PSF). Super-stabilized spectrometers are placed inside a vacuum tank, temperature stabilized at the level of 0.001 deg C, and fed by two scrambled fibers. One fiber carries the target, the other the calibration source (ThAr, Fabry-Pérot, laser-comb). Both techniques have found hundreds of planets and produce sub m/s uncertainties on the highest resolution echelles currently available. Both techniques have advantages and disadvantages and can be combined with the goal of reducing the long-term Doppler RV uncertainty to the sub 10 cm/s level. We have designed, built, calibrated, and commissioned an iodine cell for the European Southern Observatory's (ESO) ESPRESSO spectrograph. The design and construction of the cell was carried out in 2022. The cell was calibrated at the National Institute of Standards Technology (NIST) Atomic Spectroscopy laboratory in early 2023 and was commissioned in May 2023. The commissioning run was limited to evening and morning twilight on VLT-UT2. Five main sequence dwarf stars ranging in spectral type from G to early K were observed between 4 and 6 nights spanning a total of ten nights.

2606.13814 2026-06-15 cs.IR 新提交

TASR: Training-Free Adaptive Stopping for Iterative Retrieval

TASR:无需训练的迭代检索自适应停止规则

Adrian Kieback, Uyiosa Philip Amadasun, Aman Chadha, Aaron Elkins

AI总结 提出TASR,一种无需训练的迭代检索停止规则,通过重复答案检测和逻辑回归边际阈值减少冗余检索,在多种配置下保持高F1值并降低调用次数。

Comments 9 pages, 5 figures. Accepted at Agent4IR Workshop, KDD 2026

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AI中文摘要

迭代检索增强生成代理通常在模型收敛于答案后继续检索,导致不必要的调用,既不改变预测也不改变支持证据。现有方法从标注轨迹中学习停止策略,将决策与需要为每个新模型或任务重新训练的训练组件绑定。我们提出TASR(无需训练的自适应停止规则),这是一个单行谓词,当模型重复上一轮的归一化答案且等渗校准的逻辑回归边际超过0.25时触发。不学习分类器或价值头;阈值在我们评估的所有24种(模型、检索器、语料库)配置中固定。在3模型×2数据集的干扰项网格上,TASR以62.6%的调用次数保留了固定k=5的94.8%宏F1,并超过固定k=3的F1值+3.42。该模式在九个开放域BM25单元(2.98次调用时F1为55.01,而固定k=3在3.00次调用时为54.33)以及从干扰项分割锁定校准后,在两个检索器家族的九个密集检索单元上成立,且两个扩展中均无显著回归。该规则从381个候选停止规则的穷举枚举中选出;没有任何替代规则在任何评估配置上帕累托支配它。信号质量分析表明,RLHF调优模型上的口头1-5置信度崩溃(96.5%的值为5,熵0.182纳特),而逻辑回归边际实现了44倍更好的类条件分离,将设计建立在可测量的模型病理上。TASR是一个可审计、无需训练的帕累托基线,可用于比较学习型停止控制器。代码已公开。

英文摘要

Iterative retrieval-augmented generation agents commonly overspend by continuing to retrieve after the model has converged on an answer, incurring calls that change neither the prediction nor the supporting evidence. Existing remedies learn a stopping policy from labeled trajectories, tying the decision to a trained component that requires retraining for each new model or task. We propose TASR (Training-Free Adaptive Stopping Rule), a one-line predicate that fires when the model repeats its previous-round normalized answer and the isotonically calibrated logit margin exceeds 0.25. No classifier or value head is learned; the threshold is fixed across all twenty-four (model, retriever, corpus) configurations we evaluate. On a 3-model x 2-dataset distractor grid, TASR retains 94.8% of fixed-k=5's macro F1 at 62.6% of its calls and exceeds fixed-k=3 by +3.42 F1. The pattern holds on nine open-domain BM25 cells (55.01 F1 at 2.98 calls vs. 54.33 at 3.00 for fixed-k=3) and, with calibration locked from the distractor split, on nine dense-retrieval cells across two retriever families, with zero significant regressions in either extension. The rule was selected from an exhaustive enumeration of 381 candidate stopping rules; no alternative Pareto-dominates it on any evaluated configuration. A signal-quality analysis shows that verbalized 1-5 confidence collapses on RLHF-tuned models (96.5% of values equal 5, entropy 0.182 nats), while the logit margin achieves 44x better class-conditional separation, grounding the design in a measurable model pathology. TASR is an auditable, training-free Pareto baseline against which learned stopping controllers can be compared. Code is publicly available.

2606.13813 2026-06-15 math.AT cs.DM math.CO math.RT 新提交

Computing stable homology representations of graph configuration spaces

计算图配置空间的稳定同调表示

Eric Ramos, Claudia He Yun

AI总结 本文利用计算机代数计算了若干图族(完全图、完全二部图、皇冠图、完全三部图)的k=2配置空间的稳定同调表示,并给出了k=3时完全图的稳定重数。

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AI中文摘要

图的配置空间随着参数化的粒子数量增加,其复杂度通常呈阶乘增长。然而,对于具有相容对称群作用的嵌套图族 $G_\ullet$,Ramos 和 White 证明,对于固定的 $k$,$G_\ullet$ 的第 $k$ 个配置空间的有理同调具有重数稳定性。在本文中,我们推导了稳定范围,并使用计算机代数确定了 $k=2$ 时 $G_\ullet$ 为若干图族(包括完全图、$2n$ 个顶点上的完全二部图、$2n$ 个顶点上的皇冠图以及 $2n+1$ 个顶点上的完全三部图)的同调上的稳定表示。我们还确定了 $k=3$ 且 $G_\ullet$ 为完全图时某些不可约分量的稳定重数。

英文摘要

Configuration spaces of graphs frequently grow factorially in complexity with the number of particles they parametrize. However, for suitable families of nested graphs $G_\bullet$ with compatible symmetric group actions, Ramos and White prove that, for fixed $k$, the rational homology of the $k$\textsuperscript{th} configuration spaces of $G_\bullet$ has multiplicity stability. In the current work, we derive the stable range and use computer algebra to determine the stable representations on homology for $k=2$ and $G_\bullet$ several families of graphs, including the complete graphs, the complete bipartite graphs on $2n$ vertices, the crown graphs on $2n$ vertices, and the complete tripartite graphs on $2n+1$ vertices. We determine the stable multiplicities for certain irreducible components in the case $k=3$ and $G_\bullet$ the complete graphs.

2606.13812 2026-06-15 q-fin.CP q-fin.GN 新提交

CFOs Meet LLMs

CFO 与 LLM 相遇

John R. Graham, Campbell R. Harvey, Manish Jha

AI总结 本研究利用大语言模型扮演特定公司CFO,基于杜克-美联储CFO调查数据预测经济乐观情绪,发现LLM能有效复现个体人类反应,为金融研究和政策提供可扩展的高频预期数据。

Comments 21 pages, 4 tables, 1 figure

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AI中文摘要

商业情绪是一个备受关注的经济信号,但测量它既缓慢又昂贵:调查仅覆盖数百家公司,定期进行,且需要时间汇编。我们表明,大语言模型有潜力解决这些缺陷。我们提示LLM扮演特定公司在特定日期的CFO,并关注2002-2025年杜克-美联储CFO调查中的经济乐观问题。我们发现LLM再现了个体人类反应:预测的乐观分数显著预测了CFO的实际答案,且在公司与年-季度固定效应以及控制最近一次先前反应后依然成立。预测准确性随着提供的信息量增加而提高,因为受访者历史和企业特征都改善了拟合,且这种关系在季度汇总下仍然存在。通过适当的条件设置,LLM可能能够充当可信的高管数字孪生,为金融研究和政策提供可扩展的高频预期数据。

英文摘要

Business sentiment is a closely watched economic signal, but measuring it is slow and costly: surveys reach only a few hundred firms, arrive periodically, and take time to compile. We show that large language models hold the potential to address these shortcomings. We prompt an LLM to role-play as the CFO of a specific company at a specific date and focus on the economic-optimism question on the Duke-Federal Reserve CFO Survey over 2002-2025. We find that the LLM reproduces individual human responses: the predicted optimism score significantly forecasts the CFO's actual answer, surviving firm and year-quarter fixed effects and a control for the most recent prior response. Predictive accuracy increases with the amount of information supplied, as both respondent history and firm characteristics improve fit, and the relationship persists under quarterly aggregation. With appropriate conditioning, LLMs may be able to serve as credible digital twins of executives, offering scalable, high-frequency expectations data for financial research and policy.

2606.13810 2026-06-15 quant-ph cond-mat.stat-mech hep-th 新提交

Universal Crossovers of Stabilizer Entropy Beyond Criticality

稳定子熵在临界点之外的普适交叉行为

Reyhaneh Khasseh, E. A. Ramirez Trino, M. A. Rajabpour

AI总结 通过精确有限尺寸公式,揭示有限范围自旋链中稳定子熵从临界到非临界行为的普适交叉,并展示体积律、密度尖点及边界贡献等标度结构。

Comments 55 pages, 12 figures

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AI中文摘要

稳定子Rényi熵已成为量子多体系统中非稳定性的探针,但与纠缠熵相比,其在临界点之外的标度结构仍知之甚少。最近的场论方法表明,稳定子熵包含普适临界数据和边界敏感项,这引发了这些结构如何扩展到有质量和交叉区域的问题。我们针对Rényi指数为1/2的一类广泛有限范围自旋链解决了这一问题。我们推导了完整周期链和无限链有限区间的精确有限尺寸公式,使从临界到非临界行为的普适交叉在解析上易于处理。在周期几何中,熵在远离临界点时服从体积律,并表现出由系统尺寸和关联长度竞争控制的普适有限尺寸交叉。我们还表明,大尺度SRE密度在场调谐临界线上出现尖点,而XX端点由与饱和点相关的不同标度区域控制。在子区域几何中,区间熵将体临界行为与由有限区域切割无限链的方式产生的边界贡献分开。从临界到有质量行为的交叉则编码在边界常数和由关联长度控制的普适函数中。通过精确的稳定子熵对应关系,标度理论扩展到内部XY约化、有限范围自旋链和Cluster-Ising代表。我们的结果为超越孤立共形点的稳定子熵的涌现QFT描述提供了精确的晶格基准。

英文摘要

Stabilizer Rényi entropy has emerged as a probe of nonstabilizerness in quantum many-body systems, but its scaling structure beyond critical points remains poorly understood compared with entanglement entropy. Recent field-theory approaches indicate that stabilizer entropy contains universal critical data and boundary-sensitive terms, raising the question of how these structures extend into massive and crossover regimes. We address this problem for a broad class of finite-range spin chains at Rényi index one-half. We derive exact finite-size formulas for both full periodic chains and finite intervals of the infinite chain, making the universal crossover from critical to noncritical behavior analytically accessible. In periodic geometry, the entropy obeys a volume law away from criticality and exhibits a universal finite-size crossover controlled by the competition between system size and correlation length. We also show that the large-scale SRE density develops a cusp across the field-tuned critical line, while the XX endpoint is governed by a distinct scaling regime associated with the saturation point. In the subsystem geometry, the interval entropy separates bulk critical behavior from boundary contributions generated by the way the finite region cuts the infinite chain. The crossover from critical to massive behavior is then encoded in boundary constants and universal functions controlled by the correlation length. Through exact stabilizer-entropy correspondences, the scaling theory extends to internal XY reductions, Finite-range spin chains, and Cluster--Ising representatives. Our results provide an exact lattice benchmark for the emerging QFT description of stabilizer entropy beyond isolated conformal points.

2606.13807 2026-06-15 math.NA 新提交

A WKB-related time-stepping scheme for differential equations describing oscillatory systems

描述振荡系统的微分方程的WKB相关时间步进方案

Juliane Rosemeier, Rupert Klein

AI总结 提出一种基于多模态WKB近似的变量变换时间步进方案,消除或高阶化主导振荡,应用于van der Pol振荡器,数值验证了参数适应性和计算成本有界性。

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AI中文摘要

在本研究中,我们提出了一种新颖的时间步进方案,用于描述具有良好分离尺度的振荡系统的多尺度微分方程,其中尺度分离由小参数$\epsilon$控制。该时间步进方法与多模态WKB近似相关,并依赖于本文推导的变量变换。分析表明,在变换后的公式中,主导振荡被消除或仅出现在更高的渐近阶数中。该方法应用于常微分方程,包括著名的van der Pol振荡器。我们通过数值方法研究了所提方法在不同参数区域(特别是$\epsilon$递减时)的精度,并研究了随着$\epsilon$减小,数值方案的参数必须如何调整。在呈现的数值测试中,随着$\epsilon$减小,计算成本保持有界。

英文摘要

In this study, we present a novel time-stepping scheme for multiscale differential equations describing oscillatory systems with well-separated scales, where the scale separation is controlled by a small parameter $\epsilon$. The time-stepping method is related to a multi-modal WKB approximation and relies on a transformation of variables derived in this work. The analysis reveals that, in the transformed formulation, the leading-order oscillations are either eliminated or appear only at higher asymptotic order. The method is applied to ordinary differential equations, including the well-known van der Pol oscillator. We investigate the accuracy of the proposed method numerically for different parameter regimes, in particular for decreasing values of $\epsilon$, and study how the parameters of the numerical scheme must be adapted as $\epsilon$ is reduced. In the presented numerical tests, the computational cost remains bounded as $\epsilon$ is decreased.

2606.13806 2026-06-15 astro-ph.HE astro-ph.IM 新提交

Observational Biases and Improved Modelling of Off-axis Relativistic Jets

观测偏差与离轴相对论性喷流的改进建模

A. J. Cooper, A. P. Scott, L. Rhodes, F. Carotenuto, A. K. Hughes, J. H. Matthews, K. Savard, F. J. Cowie, E. L. Elley, C. Lilje, R. Fender

AI总结 通过两个X射线双星案例,研究相对论性多普勒增亮导致的观测偏差,并展示将后退喷流非探测纳入运动学建模可显著提高参数估计精度,恢复喷流静止系辐射。

Comments Accepted for publication, comments welcome before final submission

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AI中文摘要

相对论性多普勒增亮显著影响天体物理喷流的观测辐射,导致观测偏差。本文利用两个X射线双星案例研究相对论性增亮带来的观测偏差和建模机会。通过MAXI J1535-571的单侧喷流抛射物,我们证明将后退喷流抛射物的非探测纳入运动学建模可以显著改善参数估计,将后验不确定性降低超过40%。对于MAXI J1820+070的双极喷流,我们恢复了接近和后退喷流成分的固有喷流静止系辐射,表明它们遵循共同的幂律演化。利用该静止系辐射轮廓作为基础模型,我们表明当前的观测策略强烈偏向于避免探测具有高初始洛伦兹因子(>5)的抛射物以及广泛参数空间区域内的后退喷流成分。这些结果强调了观测策略选择的重要性,特别是早期和晚期观测,以及在相对论性喷流建模中利用非探测。更一般地,通过量化观测偏差并利用后退喷流的非探测最大化建模能力,可用于增强对未来的引力波/光学触发的离轴、河外喷流瞬变事件的解释。

英文摘要

Relativistic Doppler boosting significantly affects the observed emission of astrophysical jets resulting in observational biases. In this work we investigate the observational biases and modelling opportunities which arise due to relativistic boosting using two X-ray binary case studies. Using the one-sided jet ejecta from MAXI J1535-571, we demonstrate that incorporating non-detections of the receding jet ejecta into kinematic modelling can significantly improve parameter estimation, reducing posterior uncertainties by over 40%. For the bipolar jets of MAXI J1820+070, we recover the intrinsic jet rest-frame emission of both approaching and receding jet components, demonstrating that they follow a common powerlaw evolution. Using this rest-frame emission profile as a base model, we show that current observational strategies strongly bias against detecting ejecta with high initial Lorentz factors >5 and receding ejecta components across a broad region of parameter space. These results highlight the importance of observational strategy selection, particularly early-time and late-time observations, and leveraging non-detections in the modelling of relativistic jets. More generally, quantifying observational biases and maximising modelling capabilities by incorporating the non-detection of receding jets can be employed to enhance interpretation of future gravitational-wave/optically-triggered observations of off-axis, extragalactic jetted transients.

2606.13805 2026-06-15 cond-mat.mes-hall 新提交

Enhancement of spin current in Fe$_{85}$Co$_{15}$/Ni$_{80}$Fe$_{20}$ bilayers via interlayer ferromagnetic coupling

通过层间铁磁耦合增强Fe$_{85}$Co$_{15}$/Ni$_{80}$Fe$_{20}$双层膜中的自旋电流

A. A. Pérez Martínez, D. Velázquez Rodríguez, D. Goijman, T. Torres, M. H. Aguirre, J. Gómez, A. Butera, E. De Biasi, J. Milano

AI总结 研究通过改变FeCo/NiFe双层膜中层间磁耦合强度来调控自旋波行为,发现通过优化层间交换常数可最大化坡莫合金层磁化进动面积,从而增强注入自旋电流。

Comments 11 pages, 14 figures

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AI中文摘要

我们详细研究了Fe$_{85}$Co$_{15}$/Ni$_{80}$Fe$_{20}$双层膜中层间磁耦合强度如何改变该系统的自旋波行为。通过磁控溅射在MgO[100]衬底上生长了一系列Fe$_{85}$Co$_{15}$/Ni$_{80}$Fe$_{20}$双层膜。使用振动样品磁强计和磁光克尔效应对样品进行磁性表征。面内磁滞回线显示出源于磁晶各向异性的立方磁各向异性,易轴和难轴分别沿Fe-Co的[100]和[110]晶向。通过铁磁共振测量分析了共振场的面内角度依赖性,并沿难轴确定了多个频率下的共振场。利用Landau-Lifshitz-Gilbert磁化运动方程框架下的双层模型,计算了磁化进动分量,以及进动面积对Fe-Co层厚度和铁磁层间耦合的依赖性。我们观察到在特定交换常数下,坡莫合金层磁化进动产生的椭圆面积达到最大值,表明该效应可用于最大化注入自旋电流,而注入自旋电流可通过改变双层系统中的层间交换常数、材料的饱和磁化强度或激发频率来调控。

英文摘要

We present a detailed study on how the strength of the interlayer magnetic coupling on Fe$_{85}$Co$_{15}$/Ni$_{80}$Fe$_{20}$ bilayers modifies the spin wave behavior of this system. A series of Fe$_{85}$Co$_{15}$/Ni$_{80}$Fe$_{20}$ bilayers deposited on MgO[100] substrates were grown by magnetron sputtering. Magnetic characterization of the samples was performed using a vibrating sample magnetometer and magneto-optical Kerr effect. The in-plane hysteresis loops reveal a cubic magnetic anisotropy of magnetocrystalline origin, with easy and hard axis along the [100] and [110] Fe-Co crystallographic directions, respectively. Ferromagnetic resonance measurements were performed to analyze the in-plane angular dependence of the resonance field, and also the resonance field at several frequencies was determined along the hard axis. By using a bilayer model in the frame of the Landau-Lifshitz-Gilbert magnetization equation of motion, the magnetization precession components were calculated, as well as the dependence of precession area on the Fe-Co layer thickness and the ferromagnetic interlayer coupling. We observe a maximum in the area of the ellipsoid generated by the magnetization precession of the permalloy layer at a certain exchange constant, showing that this effect could be used to maximize the injected spin currents, which could be tuned by changing the interlayer exchange constant in bilayer systems, the saturation magnetization of the materials, or the excitation frequency.

2606.13804 2026-06-15 cs.SE 新提交

An Empirical Study of Gemini 3 for Detecting Natural Language Test Smells in Manual Test Cases

Gemini 3 检测手动测试用例中自然语言测试异味的实证研究

Keila Lucas, Rohit Gheyi, Márcio Ribeiro, Fabio Palomba, Luana Martins, Elvys Soares

AI总结 研究使用 Gemini-3-Pro-Preview 通过整体测试用例分析策略检测手动测试用例中的七种测试异味,相比小型语言模型性能更优,并发现平均每步近一个异味。

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AI中文摘要

手动测试中,测试人员遵循自然语言指令验证系统行为,对于发现自动化难以捕捉的问题仍然至关重要。然而,手动测试用例通常包含测试异味,如歧义、冗余或缺失检查等质量问题,降低了可靠性、可维护性和可重复性。现有检测方法主要依赖人工设计的规则,难以在异构测试套件中泛化和扩展。在先前工作中,我们通过评估 GEMMA-3-4B、LLAMA-3.2-3B 和 PHI-4-14B 在来自 143 个真实世界 Ubuntu 测试用例的测试步骤上的表现(涵盖七种异味类型),评估了使用小型语言模型(SLM)检测测试异味的可行性。PHI-4-14B 取得了最佳性能。本文中,我们研究当时可用的当代大型语言模型(GEMINI-3-PRO-PREVIEW)是否能够通过基于提示的完整测试用例分析策略,识别自然语言手动测试用例中的测试异味。与单独分析各个测试步骤的方法不同,我们的方法评估完整的测试用例,使模型能够考虑测试步骤之间的关系和依赖。我们在 100 个 Ubuntu 测试用例上评估该方法,涵盖七种测试异味类型,并将其性能与之前评估的 SLM(包括 GEMMA-3-4B、LLAMA-3.2-3B 和 PHI-4-14B)进行比较。结果表明,GEMINI-3-PRO-PREVIEW 优于 SLM,同时生成可操作的解释,帮助从业者修改手动测试用例以提高清晰度和一致性。我们还发现测试异味在实践中普遍存在,平均每步检测到近一个异味,突显了对手动测试工件进行可扩展和自动化质量支持的需求。

英文摘要

Manual testing, in which testers follow natural language instructions to validate system behavior, remains essential for uncovering issues that are difficult to capture with automation. However, manual test cases often contain test smells, quality issues such as ambiguity, redundancy, or missing checks that reduce reliability, maintainability, and reproducibility. Existing detection approaches largely depend on manually engineered rules and thus struggle to generalize and scale across heterogeneous test suites. In our previous work, we assessed the feasibility of using Small Language Models (SLMs) for test smell detection by evaluating GEMMA-3-4B, LLAMA-3.2-3B, and PHI-4-14B on test steps from 143 real-world Ubuntu test cases, covering seven smell types. PHI-4-14B achieved the best performance. In this article, we investigate whether a contemporary Large Language Model (GEMINI-3-PRO-PREVIEW) available at the time of the study can identify test smells in natural language manual test cases using a prompt-based, whole-test-case analysis strategy. Unlike approaches that analyze individual test steps in isolation, our approach evaluates complete test cases, enabling the model to consider relationships and dependencies among test steps. We evaluate the approach on 100 Ubuntu test cases covering seven test smell types and compare its performance against previously evaluated SLMs, including GEMMA-3-4B, LLAMA-3.2-3B, and PHI-4-14B. Our results show that GEMINI-3-PRO-PREVIEW outperforms the SLMs, while producing actionable explanations that can help practitioners revise manual test cases for greater clarity and consistency. We also find that test smells are pervasive in practice, with nearly one detected test smell per step on average, highlighting the need for scalable and automated quality support for manual testing artifacts.

2606.13800 2026-06-15 astro-ph.HE astro-ph.GA 新提交

Resolving the temporal evolution of M87 jet with $\lesssim0.1$-arcsec Chandra observations

利用 $\lesssim0.1$ 角秒的 Chandra 观测解析 M87 喷流的时间演化

Camille Poitras (1), Gerrit Schellenberger (2), Ralph Kraft (2), Paul Nulsen (2 and 3), Marie-Lou Gendron-Marsolais (1), Eileen Meyer (4) ((1) Département de physique, de génie physique et d'optique, Université Laval, Québec, QC, Canada, (2) Center for Astrophysics | Harvard & Smithsonian, Cambridge, MA, USA (3) ICRAR, University of Western Australia, Crawley, WA, Australia (4) Department of Physics, University of Maryland Baltimore County, Baltimore, MD, USA)

AI总结 利用 13 年 Chandra/HRC-I 数据,通过点扩散函数反卷积实现亚角秒级 X 射线分辨,揭示了 M87 喷流中 HST-1 的双成分结构及下游结的复杂形态,并发现 X 射线整体流量下降高达 84%,符合同步辐射冷却模型。

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AI中文摘要

我们利用 13 年的 Chandra/HRC-I 数据对 M87 喷流进行了研究,通过点扩散函数反卷积实现了对其千秒差距尺度结构和时间演化的前所未有的亚角秒级 X 射线分辨。反卷积图像揭示了喷流内先前被模糊的结构,包括 HST-1 中的两个成分以及下游结的复杂形态。流量测量显示,喷流整体的 X 射线辐射下降高达 84%,这与同步辐射冷却一致。对衰减的建模得出 HST-1 的最小磁场强度约为 324-1006 $\mu$G,结 A 约为 41-115 $\mu$G。与 ALMA、JWST 和 HST 的多波段比较表明,主要的 X 射线结构与低能下观测到的喷流宽度和结位置紧密匹配,而 X 射线辐射通常向上游偏移。自行测量显示,喷流特征表现出准静止和超光速视运动,HST-1 的速度高达 4.8 $c$,并且还表明未分辨的成分混合会显著偏差推断的速度。这些结果证明了高分辨率 Chandra X 射线成像在长时间基线内解析相对论性喷流演化子结构以及探测塑造其动力学的粒子加速和能量耗散过程的独特能力。

英文摘要

We present a 13-year Chandra/HRC-I study of the M87 jet, using point-spread-function deconvolution to achieve unprecedented sub-arcsecond X-ray resolution of its kiloparsec-scale structure and temporal evolution. The deconvolved images reveal previously blended structures within the jet, including two components in HST-1 and complex morphology in downstream knots. Flux measurements reveal a global decrease in X-ray emission across the jet of up to 84 %, consistent with synchrotron cooling. Modeling the fading yields minimum magnetic field strengths of ~324-1006 $\mu$G for HST-1 and ~41-115 $\mu$G for knot A. Consistent with synchrotron cooling, multi-wavelength comparisons with ALMA, JWST, and HST show that the principal X-ray structures closely match the jet width and knot locations observed at lower energies, while the X-ray emission is generally shifted upstream. Proper motion measurements show that jet features exhibit both quasi-stationary and superluminal apparent motions, reaching up to 4.8 $c$ for HST-1, and also demonstrate that unresolved component blending can substantially bias inferred velocities. These results demonstrate the unique capability of high-resolution Chandra X-ray imaging over long temporal baselines to resolve the evolving substructure of relativistic jets and to probe the particle acceleration and energy dissipation processes that shape their dynamics.

2606.13798 2026-06-15 cs.CR 新提交

Smart Blockchain-Based Access Control for the Internet of Things

基于智能区块链的物联网访问控制

Mahdi Manavi, Yunpeng Zhang, Guoning Chen

AI总结 针对物联网大规模部署中访问控制的安全与延迟权衡问题,提出一种风险自适应的Hyperledger Fabric增强层,结合离线LSTM风险预言机与链上确定性检查,通过分级背书策略在不修改排序服务的前提下提升高风险请求验证强度,同时保持低延迟。

Comments 6 pages, 3 figures. Accepted to the 35th International Conference on Computer Communications and Networks (ICCCN 2026)

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AI中文摘要

在大型物联网(IoT)部署中保护访问控制需要能够适应风险同时为良性流量保持低延迟的机制。许可区块链(如Hyperledger Fabric)通过智能合约提供可审计性,但静态背书策略对所有请求施加相同的验证深度,无论其安全态势如何。我们提出了一种针对Hyperledger Fabric的风险自适应增强层,该层将基于LSTM的链下风险预言机与链上确定性检查相结合。预言机将每个请求分配到一个等级(低、中、高),并签发一个绑定到客户端身份和目标键/版本的签名证明。背书节点在链码中验证该证明,并执行基于等级的条件SBE策略,而无需修改排序服务或共识。在Fabric测试平台上的实验表明,基于等级的条件背书加强了对高风险请求的验证,同时为良性工作负载保持了较低的确认延迟。

英文摘要

Securing access control in large-scale Internet of Things (IoT) deployments requires mechanisms that adapt to risk while preserving low latency for benign traffic. Permissioned blockchains such as Hyperledger Fabric offer auditability through smart contracts, but static endorsement policies impose the same validation depth on all requests, regardless of security posture. We propose a risk-adaptive enforcement layer for Hyperledger Fabric that couples an off-chain LSTM-based risk oracle with deterministic on-chain checks. The oracle assigns each request to a tier (Low, Moderate, High) and issues a signed attestation bound to the client identity and target key/version. Endorsing peers verify the attestation in chaincode and enforce tier-conditioned SBE policies without modifying the ordering service or consensus. Experiments on a Fabric testbed show that tier-conditioned endorsement strengthens validation for higher-risk requests while retaining low confirmation latency for benign workloads.