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2606.14390 2026-06-15 cond-mat.dis-nn stat.ML 新提交

Local Coverage Governs Memorization in Diffusion Models

局部覆盖支配扩散模型中的记忆化

Claudia Merger, Sebastian Goldt

AI总结 通过扩散模型与核密度估计的联系,发现记忆化由局部数据覆盖主导:低覆盖区域孤立样本被记忆,高覆盖区域支持插值泛化。

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AI中文摘要

扩散模型中的记忆化通常被视为模型或数据集的全局属性。然而在实践中,单个扩散模型可以同时生成记忆化和新颖的样本。哪些训练样本最有可能被记忆?在这项工作中,我们表明记忆化由\emph{局部数据覆盖}支配。利用扩散模型与核密度估计(KDE)之间的联系,我们推导出一个理论准则,根据训练数据在其邻域内的密度和训练数据集的大小来预测一个点是否被记忆。在高维极限下,这导致一个尖锐的局部转变:低覆盖区域被孤立的训练样本主导,这些样本被记忆,而密集区域支持插值和泛化。我们通过实验验证了这些预测,表明记忆化随局部稀疏性增加,并且扩散模型在同一模型内表现出记忆化和新颖样本的共存。将该框架扩展到多类设置,我们进一步表明,具有更高类内稀疏性(因此更低局部覆盖)的类别被更强烈地记忆。我们的结果提供了扩散模型中记忆化的局部视角,从数据几何角度解释了记忆化何时何地发生。

英文摘要

Memorization in diffusion models is often treated as a global property of the model or dataset. In practice, however, a single diffusion model can simultaneously generate both memorized and novel samples. Which training samples are most likely to be memorized? In this work, we show that memorization is governed by \emph{local data coverage}. Leveraging the connection between diffusion models and kernel density estimation (KDE), we derive a theoretical criterion that predicts whether a point is memorized based on the density of training data in its neighborhood and the size of the training dataset. In the high-dimensional limit, this leads to a sharp, local transition: regions of low coverage are dominated by isolated training samples, which are memorized, while dense regions support interpolation and generalization. We validate these predictions empirically, showing that memorization increases with local sparsity and that diffusion models exhibit a coexistence of memorized and novel samples within the same model. Extending this framework to multi-class settings, we further show that classes with higher intra-class sparsity (and thus lower local coverage) are more strongly memorized. Our results provide a local view of memorization in diffusion models, explaining when and where memorization occurs in terms of data geometry.

2606.14387 2026-06-15 cond-mat.mtrl-sci physics.chem-ph physics.comp-ph 新提交

The Future of Computing for Materials Science Challenges

材料科学计算面临的未来挑战

Phalgun Lolur, Richard P. Padbury, George H. Booth, Katherine Inzani, Nicole Holzmann, Thomas W. Keal, Joseph Montaya, Daniel F. Urban, Thomas Eckl, Emanuele Marsili, Wibe A. de Jong, Jonathan R. Owens, Julian van Velzen

AI总结 本文综述了材料发现中理论、计算、实验、数据驱动和量子技术的协同应用,强调可重复工作流、共享数据标准和跨范式研究文化对提升预测可靠性和加速发现的关键作用。

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27 pages with supporting info, 3 figures
AI中文摘要

材料发现日益依赖于理论、计算、实验、数据驱动方法和新兴量子技术的协调使用,然而这些工具的全部潜力只有在它们运行于反映真实系统复杂性的工作流中时才能实现。本综述总结了这些领域的当前能力、局限和机遇,借鉴了学术界、工业界和国家实验室的贡献,以确定更可靠和高效发现的科学和结构要求。经典模拟提供了设计空间上的广泛覆盖,而实验测量揭示了决定现实条件下性能的退化、异质性和动力学过程。机器学习在得到具有清晰来源和不确定性量化的精心策划数据集支持时加速探索,而量子计算在与影响工程决策的性质对齐时,为关联电子行为提供了有前景的途径。总的来说,这些见解凸显了对可重复工作流、共享数据标准、现实基准以及培养科学家跨范式工作能力的研究文化的需求。通过整合这些方法论和组织要素,社区可以朝着能够提供稳健预测、支持自信决策并缩短从概念设计到可部署材料路径的发现过程迈进。

英文摘要

Materials discovery increasingly relies on the coordinated use of theory, computation, experiment, data-driven methods, and emerging quantum technologies, yet the full potential of these tools is realised only when they operate within workflows that reflect the complexity of real systems. This perspective summarises current capabilities, limitations, and opportunities across these domains, drawing on contributions from academia, industry, and national laboratories to identify the scientific and structural requirements for more reliable and efficient discovery. Classical simulations provide broad coverage across design spaces, while experimental measurements reveal degradation, heterogeneity, and kinetic processes that determine performance under realistic conditions. Machine learning accelerates exploration when supported by well-curated datasets with clear provenance and uncertainty quantification, and quantum computing offers promising routes into correlated electronic behaviour when aligned with properties that influence engineering decisions. Collectively, these insights highlight the need for reproducible workflows, shared data standards, realistic benchmarks, and a research culture that prepares scientists to work across paradigms. By integrating these methodological and organisational elements, the community can move toward discovery processes that deliver robust predictions, support confident decision making, and shorten the path from conceptual design to deployable materials.

2606.14385 2026-06-15 hep-ph astro-ph.CO gr-qc hep-th 新提交

High-scale Mirror Standard Model Dark Matter, Dark Phase Transitions and Gravitational Waves Implications

高尺度镜像标准模型暗物质、暗相变及其引力波影响

V.K. Oikonomou

AI总结 提出暗物质由镜像标准模型构成,通过不同尺度和Yukawa耦合导致早期宇宙中的暗相变,产生可探测的引力波信号,并解释子弹星系团等观测矛盾。

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EPJC in press
AI中文摘要

我们考虑宇宙中暗物质的一种情景,其中暗物质扇区由一个暗标准模型扇区组成,该扇区仅通过引力与普通标准模型扇区相互作用。假设该暗标准模型扇区具有与普通标准模型相同的对称性,但镜像标准模型扇区的耦合常数和尺度与普通标准模型扇区不同。具体而言,假设镜像标准模型扇区的尺度远高于普通标准模型。此外,假设镜像希格斯与镜像费米子之间的Yukawa耦合与标准模型不同,我们研究了不同尺度和不同Yukawa耦合对宇宙演化的影响。我们证明,在重子宇宙的高温下会发生镜像世界相变,该相变可以是一阶或二阶的,取决于宇宙尺度和Yukawa耦合。这些暗相变发生的时间远早于真实世界的标准模型电弱相变。二阶相变的情况在现象学上非常有趣,因为它可能对未来引力波探测器探测频率范围内的随机引力波谱产生直接影响。我们还研究了这种镜像暗物质世界是否能形成原子,并表明在某些情景中,高尺度镜像暗物质可以同时包含原子和亚原子粒子成分。我们还给出了高尺度镜像暗物质总状态方程的近似,并讨论了高尺度镜像暗物质如何调和诸如子弹星系团和Abell 520星系团等相互矛盾的观测结果。

英文摘要

We consider a scenario for dark matter in the Universe, according to which the dark matter sector is comprised by a dark Standard Model sector which interacts only gravitationally with the ordinary Standard Model sector. This dark Standard Model sector is assumed to have the same symmetries as the ordinary Standard Model, with the couplings and the scale of the mirror Standard Model sector being different than the ordinary Standard Model sector. Specifically, the scale of the mirror Standard Model sector will be assumed to be quite higher compared to the ordinary Standard Model. Also the Yukawa couplings among the mirror Higgs and the mirror fermions are assumed to be different from those of the Standard Model and we examine the effects of the different scale and of the different Yukawas on the evolution of the Universe. As we show, a mirror world phase transition occurs at high temperatures of the baryonic Universe, which can be first order or second order, depending on the scale of the Universe and the Yukawa couplings. These are dark phase transitions which occur quite earlier than the real world Standard Model electroweak phase transition. The case of a second order phase transition is quite interesting phenomenologically, since it can potentially have a direct imprint on the spectrum of stochastic gravitational waves for frequencies probed by the future gravitational wave detectors. Also we examine whether this mirror dark matter world can form atoms and as we show in some scenario the high scale mirror dark matter can have both atomic and subatomic particle components. We also give an approximation of the total equation of state of high scale mirror DM and we discuss how high scale mirror DM can reconcile contradicting observations like the Bullet cluster and the Abell 520 cluster.

2606.14384 2026-06-15 math.AP 新提交

Bounds on the growth of high Sobolev norms of solutions to the fractional nonlinear Schrödinger equation on $\R^2$ and $\R^3$

在 $\R^2$ 和 $\R^3$ 上分数阶非线性薛定谔方程解的高Sobolev范数增长的界

Antonios Kapetanios, José L. Rodrigo, Vedran Sohinger

AI总结 利用倒置I-方法和更高阶修正能量方法,证明了二维和三维空间中具有三次和Hartree型非线性项的散焦分数阶非线性薛定谔方程解的高Sobolev范数的多项式增长界。

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AI中文摘要

我们证明了在二维和三维空间中,具有三次和Hartree型非线性项的散焦分数阶非线性薛定谔方程解的高Sobolev范数的多项式增长界。我们的结果基于倒置I-方法和更高阶修正能量方法。由于共振不等式的高维类比,使得我们能够控制非共振频率贡献,从而可以在高维中分析分数阶情况。

英文摘要

We prove polynomial bounds on the growth of high Sobolev norms of solutions to the defocusing fractional nonlinear Schrödinger equation with cubic and Hartree-type nonlinearities in two and three dimensions. Our result is based on the upside-down I-method and the method of higher modified energies. The analysis of the fractional case in higher dimensions is possible due to a higher-dimensional analogue of a resonance inequality, which allows us to control the nonresonant frequency contributions.

2606.14382 2026-06-15 stat.ME math.ST 新提交

Predictive Concordance for Parameter Optimisation and Mixture Synthesis

参数优化与混合合成的预测一致性

Tobias Adrian, Domenico Giannone, Matteo Luciani, Mike West

AI总结 基于期望误分类率(EMR)提出概率一致性度量,通过最大化EMR或其正则化变体优化参数,并应用于宏观经济政策情景预测中的混合合成。

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Comments
18 pages, 2 figures, 1 table
AI中文摘要

我们讨论了基于期望误分类率(EMR)的两个概率分布之间的一致性概率度量。重点是比较给定参考分布与参数化类别中的其他分布,并通过识别最大化EMR或其正则化变体的参数值来优化一致性。EMR是一种实用且具有决策理论意义的度量,其优化可直接解释为具有有界效用函数的贝叶斯决策分析。我们探讨了EMR的理论性质,讨论了与其他度量(包括Küllback-Leibler散度)的关系,并认识到其优化具有合成贝叶斯仿真解释,有助于理解和指定正则化惩罚。方法学的一个主要领域是混合合成,其中参数化族是给定分布的离散混合。一个详细的例子来自宏观经济政策设置中的情景预测,这是推动新方法的关键应用领域。理论发展为高效数值优化提供了基础,分析可通过直接蒙特卡洛模拟轻松实现。

英文摘要

We discuss probabilistic measures of concordance between two probability distributions based on the expected misclassification rate (EMR). The focus is on comparing a given reference distribution with other distributions in a parametrised class, and optimising concordance by identifying parameter values maximising EMR or a regularised variant. EMR is a practical and decision-theoretically meaningful measure, and its optimisation has direct interpretation as a Bayesian decision analysis with a bounded utility function. We explore theoretical properties of EMR, discuss relationships with other measures including Küllback-Leibler divergence, and recognise that its optimisation has a synthetic Bayesian emulation interpretation that aids understanding and specification of regularisation penalties. A main area of methodology is in mixture synthesis where the parametrised family is a discrete mixture of given distributions. A detailed example comes from scenario forecasting in macroeconomic policy settings, a key applied area motivating the new methodology. Theoretical developments underlie efficient numerical optimisation and analysis is easily implemented using direct Monte Carlo simulation.

2606.14381 2026-06-15 math.CO 新提交

The maximum number of edges in $C_{2k+1}^{-}$-free unbalanced signed graphs with bounded clique number

团数有界的无平衡 $C_{2k+1}^{-}$ 符号图的最大边数

Junjie Wang, Yaoping Hou

AI总结 研究团数有界且不含无平衡奇圈 $C_{2k+1}^{-}$ 的符号图的极值问题,利用稳定性定理确定了当底图不含某个色临界图 $F$ 时的最大边数。

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AI中文摘要

近年来,团数有界的图的 Turán 问题引起了广泛关注。由于图可以看作是没有负边的符号图,因此将此类 Turán 型问题的研究扩展到符号图是自然的。基于这一动机,我们研究了团数有界的无平衡 $C_{2k+1}^{-}$ 符号图的 Turán 型问题。实际上,我们通过经典的稳定性定理建立了一个一般结果。具体地,对于足够大的 $n$ 和一个色临界图 $F$,我们确定了所有 $n$ 个顶点、底图不含 $F$ 且无平衡 $C_{2k+1}^{-}$ 的符号图的最大边数。

英文摘要

Recently, the Turán problem for graphs with bounded clique number has attracted considerable attention. Since a graph can be regarded as a signed graph without negative edges, it is natural to extend the study of such Turán-type problems to signed graphs. With this motivation, we investigate the Turán-type problem for unbalanced $C_{2k+1}^{-}$-free signed graphs with bounded clique number. In fact, we establish a general result via the classical stability theorem. Specifically, for sufficiently large $n$ and a color-critical graph $F$, we determine the maximum number of edges among all $n$-vertex $C_{2k+1}^{-}$-free unbalanced signed graphs whose underlying graphs are $F$-free.

2606.14379 2026-06-15 gr-qc 新提交

Sachs-Wolfe effect as a smoking gun for cosmological gravitational wave backgrounds

Sachs-Wolfe效应作为宇宙学引力波背景的确凿证据

Giorgio Mentasti, Leon Vidal, Quentin Baghi, Carlo Contaldi

AI总结 本文研究Sachs-Wolfe效应对宇宙学引力波背景的影响,发现当背景能密度≥10^{-10}时,该效应会在引力波中留下可探测的各向异性和谱畸变,且与CMB的SW信号相关,可作为引力波背景原初性的确凿证据。

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AI中文摘要

由宇宙大尺度结构产生的Sachs-Wolfe (SW)效应会改变宇宙学背景激发的引力波(GWs)的频率。我们表明,对于$\Omega_{\rm GW}\gtrsim 10^{-10}$的背景,该效应会留下各向异性和谱畸变,这些可以通过空间干涉仪网络(如LISA+Taiji)探测到,如果不加以考虑,可能会偏置引力波背景理论模型的估计。该效应在频谱的高频端尤其增强。在原初时期激发的引力波背景中存在的SW诱导的各向异性和谱畸变将与CMB中存在的SW特征相关。因此,在大尺度上探测到引力波各向异性和CMB之间的任何互相关都是确认背景原初性的确凿证据。

英文摘要

The Sachs-Wolfe (SW) effect, arising from large-scale structures in the universe, modifies the frequencies of gravitational waves (GWs) sourced by a cosmological background. We show that for backgrounds with $\Omega_{\rm GW}\gtrsim 10^{-10}$, this effect imprints anisotropies and spectral distortions that can be detectable with a network of space-based interferometers (such as LISA + Taiji) and, if not taken into account, may bias the estimate of the theoretical model of the GW background. The effect is particularly enhanced in the high-frequency end of the spectrum. The SW-induced anisotropies and spectral distortions present in a GW background sourced at primordial times will correlate with the SW signature present in the CMB. Any detection of a cross-correlation between the GW anisotropies and the CMB at large scales is therefore a smoking gun for confirming the primordial nature of the background.

2606.14378 2026-06-15 cond-mat.mtrl-sci 新提交

Multistate Manipulation of Charge-Spin Conversion in Two-Dimensional Ferroelectric Bilayers

二维铁电双层中电荷-自旋转换的多态操控

Weiyi Pan, Xinyuan Jiang, Jaroslav Fabian

AI总结 提出在二维铁电双层中同时控制Edelstein效应和自旋霍尔效应的机制,通过层间极化构型切换实现三种不同状态的电控自旋积累,并利用第一性原理计算在PtBi2双层中验证。

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AI中文摘要

实现电荷-自旋转换(包括Edelstein效应(EE)和自旋霍尔效应(SHE))的非易失性和多态操控对于高密度自旋电子存储器至关重要。这里,我们提出了一种在二维铁电双层中同时控制EE和SHE的机制,其中层间平行和层间反平行极化构型可以共存。对称性分析表明,在层间平行态中,总极化的反转会切换EE的符号,而转变为层间反平行构型则将EE抑制为零,从而实现三种不同状态之间的电可切换电流诱导自旋积累,这可用于三进制逻辑运算。同时,SHE的大小可以通过在两类极化构型(即层间平行和层间反平行构型)之间切换来调节。利用第一性原理计算,我们在双层金属铁电体PtBi2中演示了这一机制,其中层间平行和层间反平行极化构型在能量上都是稳定的。层间平行态中的EE系数(可通过极化反转来反转)源于费米面附近电子和空穴口袋贡献的竞争。本征SHE系数源于自旋贝里曲率,该曲率可通过极化构型变化和费米能级调谐来重塑。我们的结果确立了铁电双层作为电可编程电荷-自旋转换的全能平台。

英文摘要

Achieving nonvolatile and multistate manipulation of charge-spin conversion, including the Edelstein effect (EE) and spin Hall effect (SHE), is crucial for high-density spintronic memory. Here, we propose a mechanism to simultaneously control both EE and SHE in two-dimensional ferroelectric bilayers, where interlayer-parallel and interlayer-antiparallel polarization configurations can coexist. Symmetry analysis shows that in the interlayer-parallel states, reversal of the total polarization switches the sign of the EE, whereas changing to an interlayer-antiparallel configuration suppresses the EE to zero, enabling electrically switchable current-induced spin accumulation among three distinct states, which could be used for ternary logic operations. Meanwhile, the magnitude of the SHE can be tuned by switching between two different classes of polarization configurations, namely interlayer-parallel and interlayer-antiparallel configurations. Using first-principles calculations, we demonstrate this mechanism in bilayer metallic ferroelectric PtBi2, where both interlayer-parallel and interlayer-antiparallel polarization configurations are energetically stable. The EE coefficient in interlayer-parallel states, which can be reversed by polarization switching, arises from competing electron- and hole-pocket contributions near the Fermi surface. The intrinsic SHE coefficients originate from spin Berry curvature that can be reshaped by polarization configuration variation and Fermi-level tuning. Our results establish ferroelectric bilayers as an all-in-one platform for electrically programmable charge-spin conversion.

2606.14377 2026-06-15 cs.CY 新提交

Shadows of Transparency: Signaling Transparency-Impeding Behavior Using Public Data

透明的阴影:利用公共数据揭示阻碍透明的行为

Jos Zuijderwijk, Iris Beerepoot, Thomas Martens, Eva Knies, Tanja van der Lippe, Hajo A. Reijers

AI总结 本文提出一种基于模式的方法,利用公共响应数据识别政府机构阻碍信息自由的行为,通过荷兰数据集验证了六种行为指标,并得到专家认可。

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Comments
Accepted manuscript on May 5, 2026, to the 25th IFIP International Conference on Electronic Government (EGOV 2026)
AI中文摘要

信息自由法旨在提高政府透明度,但现有评估主要关注法律合规和程序结果,忽视了组织行为。随着信息自由流程越来越多地通过数字信息系统进行,公共响应数据提供了组织如何处理请求和披露的痕迹。本文开发并评估了一种基于模式的方法,利用这些数据跨政府机构和时间揭示阻碍透明的行为。基于先前文献,我们识别出九种反复出现的阻碍透明的行为模式。利用包含15,277份荷兰信息自由档案(共139,449份文件)的数据集,我们操作化并评估了其中六种模式的可测量指标,证明它们能够跨机构和时间系统比较披露实践。对研究人员、记者和公务员的专家访谈确认了这些指标在调查优先级、比较研究和透明监督方面的可解释性和实用性。

英文摘要

Freedom of Information (FOI) laws aim to increase government transparency, yet existing assessments focus mainly on legal compliance and procedural outcomes, leaving organizational behavior underexamined. As FOI processes are increasingly mediated through digital information systems, public response data offer traces of how organizations handle requests and disclosures in practice. This paper develops and evaluates a pattern-based approach that uses such data to signal transparency-impeding behavior across government agencies and over time. Drawing on prior literature, we identify nine recurring behavioral patterns that undermine transparency. Using a dataset of 15,277 Dutch FOI dossiers comprising 139,449 documents, we operationalize and evaluate measurable indicators for six of these patterns, demonstrating that they enable systematic comparison of disclosure practices across agencies and over time. Expert interviews with researchers, journalists, and civil servants confirm the interpretability and practical usefulness of the indicators for investigative prioritization, comparative research, and transparency oversight.

2606.14376 2026-06-15 cs.SI 新提交

Games Mapper: Topological Data Analysis of Steam Genres

游戏映射器:Steam游戏类型的拓扑数据分析

Nicolas Grelier, Stéphane Kaufmann, Johannes Pfau

AI总结 提出基于拓扑数据分析中Mapper算法的Games Mapper工具,通过自动聚类标注方法,实现对Steam游戏类型演化结构的可视化分析,并以2015-2025年模拟游戏为例验证其有效性。

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AI中文摘要

电子游戏行业包含一个庞大且不断演变的主题和类型景观。对于在这个竞争市场中导航的工作室和发行商而言,理解特定游戏类别的结构动态和时间演变对于识别可行的切入点至关重要。在本文中,我们介绍了Games Mapper,一种基于拓扑数据分析中Mapper算法的新型分析工具。与传统的聚类技术不同,Games Mapper捕获数据集随时间(或其他指导变量)的连续拓扑关系。我们通过一种自动聚类标注方法扩展了标准算法,确保对类型演变的高度可解释和交互式可视化。为了证明我们方法的有效性,我们展示了一个关于2015年至2025年间在Steam上发布的模拟游戏的全面案例研究。Games Mapper自主地将该类型分割成连贯、持久的子类型,并捕获动态的市场变化。最终,我们为研究人员和行业人士提供了一个可扩展、可泛化的工具,以揭示复杂的市场结构并追踪Steam生态系统的演变。

英文摘要

The video game industry comprises a vast, continuously evolving landscape of themes and genres. For studios and publishers that navigate this competitive market, understanding the structural dynamics and temporal evolution of specific game categories is crucial for identifying viable entry points. In this paper, we introduce Games Mapper, a novel analytical tool based on the Mapper algorithm from topological data analysis. Unlike traditional clustering techniques, Games Mapper captures the continuous topological relationships between datasets over time (or other guiding variables). We extend the standard algorithm with an automated cluster labelling method, ensuring highly interpretable and interactive visualisations of genre evolution. To demonstrate the efficacy of our approach, we present a comprehensive case study on Simulation games released on Steam between 2015 and 2025. Games Mapper autonomously segments the genre into coherent, persistent subgenres, and captures dynamic market shifts. Ultimately, we provide a scalable, generalisable tool for researchers and industrials to unravel complex market structures and track the evolution of the Steam ecosystem.

2606.14374 2026-06-15 cond-mat.str-el 新提交

Bond-operator analytical approach for the $t$-$J$ model

$t$-$J$模型的键算符解析方法

A. V. Syromyatnikov

AI总结 提出键算符理论(BOT)解析处理$t$-$J$模型及其扩展,通过引入局域自旋和无自旋费米子空穴算符,利用$1/n$展开和常规图技术,在$n=1$时与数值结果定量吻合。

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Comments
22 pages, 12 figures
AI中文摘要

我们提出了一种键算符理论(BOT),用于解析考虑$t$-$J$模型及其具有长程跳跃项的扩展。该技术基于先前提出的电子算符表示,通过局域自旋1/2和无自旋费米子移动空穴算符,两者之间无需约束。我们在(扩展)元胞中引入自旋、空穴和电子算符的表示,该元胞包含多个格点,通过一系列玻色子和费米子算符作用于整个元胞所有量子态的希尔伯特空间。BOT利用常规图技术,以$1/n$的幂次提供物理量的正则展开,其中$n\ge1$是元胞中可容纳的最大引入准粒子(玻色子和费米子)数量。所提出的表示在任意$n>0$时重现所有算符的对易代数,并允许考虑磁有序和无序相。在BOT中由独立玻色子或费米子描述的一些基本激发,在常见方法中表现为常规准粒子的束缚态。特别地,存在双空穴束缚态(两个空穴的库珀对),在BOT中由独立玻色子描述。我们详细讨论了方晶格上最多两个空穴(极化子)的$t$-$J$模型的性质。尽管在物理上有意义的$n=1$情况下展开参数$1/n$并不小,但在考虑少数简单图后,即使在一阶$1/n$展开下,我们也与之前的数值结果取得了良好的定量一致。在一阶$1/n$下的自洽计算使我们的结果与之前关于基态能量、交错磁化强度以及磁振子、极化子和最低能量双空穴束缚态谱的数值结果非常吻合。

英文摘要

We present a bond-operator theory (BOT) for analytical consideration of the $t$-$J$ model and its extensions with longer-rage hopping terms. This technique is based on previously suggested representation of electron operators via localized spins 1/2 and spinless Fermi-operators of mobile holons which requires no constraint between them. We introduce a representation of operators of spins, holons, and electrons in (extended) unit cell containing several lattice sites via a zoo of Bose- and Fermi-operators acting in the Hilbert space of all quantum states of the whole unit cell. BOT provides a regular expansion of physical quantities in powers of $1/n$ using conventional diagrammatic technique, where $n\ge1$ is the maximum number of introduced quasiparticles (bosons and fermions) which can occupy a unit cell. The suggested representation reproduces commutation algebra of all operators at any $n>0$ and allows to consider both magnetically ordered and disordered phases. Some elementary excitations described in the BOT by separate bosons or fermions appear in common approaches as bound states of conventional quasiparticles. In particular, there are two-hole bound states (Cooper pairs of two holes) which are described within the BOT by separate bosons. We discuss in detail properties of the $t$-$J$ model on the square lattice with no more than two holes (polarons). Although the expansion parameter $1/n$ is not small in the physically meaningful case of $n=1$, we obtain a good quantitative agreement with previous numerical findings at $n=1$ even in the first order in $1/n$ after taking into account a few simple diagrams. Self-consistent calculations in the first order in $1/n$ bring our results to a very good quantitative agreement with previous numerical findings of the ground state energy, staggered magnetization, and spectra of magnons, polarons, and lowest-energy two-hole bound states.

2606.14372 2026-06-15 eess.SP 新提交

$κ$: A Geometry-Quality Metric Complementary to GDoP for Closed-Form TDoA Multilateration

$\kappa$: 一种与GDoP互补的几何质量度量,用于闭式TDoA多点定位

Abeer Nasir Chaudhry, Salman Liaquat, Muhammad Mohsin Khadim

AI总结 提出几何质量度量$\kappa$,通过闭式TDoA解算器的二次项系数表征病态条件,与GDoP互补,并推导了N维推广,验证了噪声灵敏度公式。

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AI中文摘要

几何精度因子(GDoP)表征到达时间差(TDoA)定位系统的噪声灵敏度,但并未涵盖解析多点定位解可能变得病态的所有方式。我们引入了一种互补的几何质量度量$\kappa$,即闭式TDoA解算器二次项的首项系数,并通过向量化公式推导了其$N$维推广。两个闭式代数恒等式将$\kappa$与测量模型的雅可比行列式以及二次方程的判别式联系起来,表明系统恰好存在两个不同的奇异点轨迹:分支发散和GDoP标记的雅可比/分支合并轨迹。在标准高斯ToA模型下,与克拉美-罗界相关的噪声灵敏度$\sigma_\kappa$的闭式表达式经过蒙特卡洛验证,中位相对误差为2%。在无量纲几何参数空间上的经验图谱以机器精度确认了这两个恒等式,并表明$\kappa$不良区域和GDoP不良区域在目标空间中非平凡地不相交,从而确立了这两个度量真正互补。对一个四节点操作阵列的案例研究,通过自动相关监视广播(ADS-B)配对的空中捕获数据经验估计每个传感器的到达时间(ToA)噪声,显示理论预测阈值和蒙特卡洛测量的操作阈值在部署噪声水平下对每个子系统的排序一致。它们的比值在三个二维子系统中近似恒定,作为代数$\kappa$噪声基底与下游操作阈值之间的部署特定校准常数,类似于将GDoP与圆概率误差联系起来的标准关系。

英文摘要

The Geometric Dilution of Precision (GDoP) characterizes the noise sensitivity of a Time-Difference-of-Arrival (TDoA) localization system, but does not capture every way the analytical multilateration solution can become ill-conditioned. We introduce a complementary geometry-quality metric $\kappa$, the leading coefficient of the closed-form TDoA solver's quadratic, and derive its $N$-dimensional generalization through a vectorized formulation. Two closed-form algebraic identities relate $\kappa$ to the Jacobian determinant of the measurement model and to the quadratic's discriminant, establishing that the system exhibits exactly two distinct singularity loci: branch divergence and the Jacobian/branch-merge locus flagged by GDoP. A Cramér--Rao-bound-linked closed form for the noise sensitivity $\sigma_\kappa$ under the standard Gaussian ToA model is validated against Monte Carlo to 2% median relative error. An empirical atlas over a dimensionless geometry parameter space confirms both identities at machine precision and shows that $\kappa$-bad regions and GDoP-bad regions are non-trivially disjoint in target space, establishing the two metrics as genuinely complementary. A case study on a four-node operational array, with per-sensor time of arrival (ToA) noise estimated empirically from Automatic Dependent Surveillance Broadcast (ADS-B)-paired over-the-air captures, shows that the theory-predicted threshold and a Monte-Carlo-measured operational threshold agree on the per-subsystem ordering at the deployment noise level. Their ratio is approximately constant across the three two-dimensional subsystems, serving as a deployment-specific calibration constant between the algebraic $\kappa$-noise floor and the downstream operational threshold, analogous in spirit to the standard relation linking GDoP to the circular error probable.

2606.14371 2026-06-15 astro-ph.EP 新提交

Dust and coma radicals in C/2024 E1 (Wierzchos): evolution of the activity

C/2024 E1 (Wierzchos) 中的尘埃和彗发自由基:活动演化

Irene Mariblanca-Escalona, Pedro J. Gutiérrez, Fernando Moreno, Luisa M. Lara

AI总结 通过多历元成像和光谱研究动态新彗星C/2024 E1,测量了CN、C2、C3产率及尘埃性质,发现其处于典型与碳贫乏彗星中间分类,尘埃与气体质量比>1,定性为富尘彗星。

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Comments
13 pages, 10 figures, (accepted for publication in MNRAS)
AI中文摘要

我们展示了动态新彗星 C/2024 E1 (Wierzchos) 在近日点前阶段的多历元 R 波段成像和长缝光谱,覆盖从 4.5 au 到 2.3 au 的日心距离。检测到可见光波长范围内最显著的荧光发射。我们测量了 CN、C$_2$ 和 C$_3$ 的产率,而未识别到显著的 NH$_2$ 信号。在我们的数据集中,CN 在 3.48 au 处变得可探测,而 C$_3$ 和 C$_2$ 在 2.80 au 处变得可探测。平均比值 $\log\mathrm{C}_2/\mathrm{CN} = 0.00 \pm 0.07$ 和 $\log\mathrm{C}_3/\mathrm{CN} = -1.03 \pm 0.09$ 将彗星置于典型和碳贫乏种群之间的中间分类状态。使用蒙特卡洛尘埃尾模型约束尘埃产率、喷射速度和粒径分布,该模型再现了观测到的彗发形态。尘埃种群的特征是幂律粒径分布,指数约为 $\sim -3.5$,粒径范围从 1~$\mu$m 到 4~mm。推断的初始喷射速度范围从 $\sim$20$ m $s$^{-1}$ 到 $\sim$100$ m $s$^{-1}$。我们利用 CN 和 OH 之间的经验关系来估计水产率,并推导出日心距离 $r_{\rm{h}} \lesssim 3$ au 处的尘埃与气体质量比,在此距离水升华预计主导活动机制。尘埃与气体质量比始终高于 1,范围从 $\sim$1 到 3,具体取决于尺度长度和 CN--OH 转换因子的选择。这一结果将 C/2024 E1 定性为“富尘”彗星,其中质量损失由耐火组分而非挥发分主导。

英文摘要

We present multi-epoch R-band imaging and long-slit spectroscopy of the dynamically new comet C/2024 E1 (Wierzchos) during its pre-perihelion phase, spanning heliocentric distances from 4.5 to 2.3 au. The most prominent fluorescence emissions in the visible wavelength range are detected. We measure production rates of CN, C$_2$, and C$_3$, while no significant NH$_2$ signal is identified. In our dataset, CN became detectable at 3.48 au, and C$_3$ and C$_2$ at 2.80 au. The mean ratios $\log\mathrm{C}_2/\mathrm{CN} = 0.00 \pm 0.07$ and $\log\mathrm{C}_3/\mathrm{CN} = -1.03 \pm 0.09$ place the comet in an intermediate taxonomic regime between typical and carbon-depleted populations. Dust production rates, ejection velocities, and particle size distributions are constrained using a Monte Carlo dust tail model that reproduces the observed coma morphology. The dust population is characterized by a power-law size distribution with an exponent of $\sim -3.5$, and particle sizes ranging from 1~$\mu$m to 4~mm. The inferred initial ejection velocities span from $\sim$20$ m $s$^{-1}$ to $\sim$100$ m $s$^{-1}$. We use the empirical relation between CN and OH to estimate the water production rate and derive the dust-to-gas mass ratio for heliocentric distances $r_{\rm{h}} \lesssim 3$ au, where water sublimation is expected to dominate the activity regime. The dust-to-gas mass ratio remains consistently above unity, ranging from $\sim$1 to 3 depending on the choice of scale lengths and the CN--OH conversion factor. This result characterizes C/2024 E1 as a ``dust-rich'' comet, where the mass loss is dominated by the refractory component rather than volatiles.

2606.14370 2026-06-15 cond-mat.soft cond-mat.stat-mech 新提交

Spherical metadensity functional learning for inhomogeneous classical fluids

非均匀经典流体的球面元密度泛函学习

Stefanie M. Kampa, Matthias Schmidt, Florian Sammüller

AI总结 针对三维球面几何中截断成对相互作用的流体,开发基于神经网络的元密度泛函,通过测试粒子路径利用径向分布函数,实现非均匀结构预测与Henderson反演。

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Comments
18 pages, 11 figures
AI中文摘要

我们发展了经典密度泛函学习,以处理三维球面几何中具有截断成对粒子间相互作用的流体。具有随机排斥对势的系统的模拟数据为神经元密度泛函的监督训练提供了基础,从而通过测试粒子路径有效利用了体流体的径向分布函数结果。具体而言,我们发展了球面局部学习,以神经网络表示单体直接关联泛函,该网络捕捉空间曲率效应以及元密度泛函对热标度对势的依赖性。该框架提供了对非均匀结构及相关物理现象的有效访问,这些现象发生在流体和一般溶剂中,当它们吸附在弯曲溶质上并限制在球形和平面空腔内时。测试粒子设置有助于准确预测体流体对结构,并通过泛函线积分验证热力学测试粒子求和规则。应用元密度泛函进行Henderson反演,可以从体径向分布函数准确推断出对势。我们讨论了几何设置对二体量的影响,并通过自动微分获得了二体直接关联泛函。对于硬球流体,我们确认了元密度泛函预测与具有固定对势的标准神经密度泛函以及基本度量理论给出的解析泛函的结果一致。模拟结果进一步提供了参考,并证实了球面神经元密度泛函在广泛应用中的可靠结果。

英文摘要

We develop classical density functional learning to address fluids with truncated pairwise interparticle interactions in three-dimensional spherical geometry. Simulation data for systems with randomized repulsive pair potentials provide the basis for supervised training of a neural metadensity functional, thereby making efficient use of results for radial distribution functions in the bulk fluid via the test particle route. Specifically, we develop spherical local learning in order to represent the one-body direct correlation functional in terms of a neural network, which captures spatial curvature effects as well as the metadensity functional dependence on the thermally scaled pair potential. The framework yields efficient access to inhomogeneous structuring and related physical phenomena that occur in fluids and general solvents when adsorbed against curved solutes and confined inside of spherical and planar cavities. Test particle setups facilitate accurate prediction of the bulk fluid pair structure and verification of thermodynamic test particle sum rules via functional line integration. Applying the metadensity functional for Henderson inversion allows one to infer accurately the pair potential from the bulk radial distribution function. We address implications of the geometrical setup for two-body quantities and obtain the two-body direct correlation functional from automatic differentiation. For the hard sphere fluid, we confirm metadensity functional predictions against results from a standard neural density functional with fixed pair potential as well as to an analytic functional as given by fundamental measure theory. Simulation results provide further reference and corroborate reliable results of the spherical neural metadensity functional across a broad range of applications.

2606.14369 2026-06-15 math.NA 新提交

Local high order space-time apdaptive MLSDC

局部高阶时空自适应MLSDC

Erik Pfister, Matti Schulze, Jörg Stiller

AI总结 提出一种结合间断Galerkin谱元离散与多级谱延迟校正的时空自适应高阶方法,通过新型时间误差估计器动态平衡时空离散误差,在Burgers方程和Euler方程上实现精度保持下的计算成本显著降低。

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AI中文摘要

基于Pfister和Stiller [38]引入的半隐式多级谱延迟校正(SI-MLSDC)方法,本文提出了一种一维时空自适应高阶方法,结合了间断Galerkin谱元离散与多级谱延迟校正。所提出的方法在空间和时间上实现了真正的任意阶精度,同时动态平衡空间和时间离散误差以降低计算成本。一个关键贡献是开发了一种新的时间误差估计器,与空间中的谱误差估计器结合,为自适应细化决策提供了可靠基础。将该误差估计器与两种替代细化准则进行比较,以评估它们对精度、计算效率的影响及其在复杂问题中的适用性。该自适应方法的性能通过从Burgers方程到Euler方程的非线性守恒律进行了验证。数值结果表明,在保持所需精度的同时,运行时间大幅减少。特别是,对于Burgers方程以及具有挑战性的基准问题(如Shu-Osher激波波动基准),实现了显著的计算节省。这些结果证明了自适应SI-MLSDC方法在复杂流动问题的高效高阶时空自适应模拟中的潜力。

英文摘要

Building upon the semi-implicit multilevel spectral deferred correction (SI-MLSDC) method introduced by Pfister and Stiller [38], this work presents a 1D space-time adaptive high-order method combining discontinuous Galerkin spectral element discretizations with multilevel spectral deferred corrections. The proposed approach enables genuine arbitrary-order accuracy in space and time while dynamically balancing spatial and temporal discretization errors to reduce computational cost. A key contribution is the development of a novel temporal error estimator that in combination with a spectral error estimator in space provides a reliable basis for adaptive refinement decisions. The error estimator is compared with two alternative refinement criteria to assess their impact on accuracy, computational efficiency and their suitability for complex this http URL performance of the adaptive method is demonstrated for nonlinear conservation laws ranging from Burgers' equation to the Euler equations. Numerical results show substantial runtime reductions while maintaining the desired accuracy. In particular, significant computational savings are achieved for Burgers' equation, and challenging benchmark problems such as the Shu-Osher shock-fluctuation benchmark. These results demonstrate the potential of adaptive SI-MLSDC methods for efficient high-order space-time adaptive simulations of complex flow problems.

2606.14367 2026-06-15 math.CO 新提交

On mesh patterns of short length: Equidistribution and enumeration

短长度网格模式:等分布与枚举

Qi Fang, Shishuo Fu, Sergey Kitaev, Haijun Li, Xinyu Su, Ziyao Sun

AI总结 本文通过构造对合和双射解决两个关于长度2网格模式的分布等价猜想,将分布等价类和Wilf等价类的已知上界分别降至106和47,并确定了另外三类长度2网格模式的分布。

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Comments
18 pages,4 figures, comments are welcome
AI中文摘要

短网格模式的分类和枚举已成为该领域的两个核心方向。我们在两个方面都取得了实质性进展。我们构造了一个对合和一个双射,建立了两个长度2网格模式类的分布等价性,从而解决了一个2019年的猜想和一个近期的猜想。因此,分布等价类和Wilf等价类数量的已知上界分别降至106和47。结合已知的下界105和46(推测是精确的),这些结果使得两个分类都依赖于一个2019年猜想的分布等价问题,该问题的解决将同时解决剩余的Wilf等价情况。我们进一步猜想这个未解决的等分布也适用于对合(所有排列的一个子类)。我们还通过详细的结构分析确定了另外三类长度2网格模式的分布。我们的工作结合了双射技术和生成函数方法,为短网格模式的结构和枚举提供了新的见解。

英文摘要

The classification and enumeration of short mesh patterns have emerged as two central directions in the area. We make substantial progress on both fronts. We construct an involution and a bijection that establish distributional equivalences for two classes of length-$2$ mesh patterns, thereby resolving a conjecture from 2019 and a recent conjecture. As a consequence, the best known upper bounds for the numbers of distribution-equivalence and Wilf-equivalence classes drop to $106$ and $47$, respectively. Combined with the known lower bounds of 105 and 46, conjectured to be exact, these results leave both classifications hinging on a single distribution-equivalence question conjectured in 2019, whose resolution would at once settle the remaining Wilf-equivalence case. We further conjecture that this unresolved equidistribution also holds for involutions, a subclass of all permutations. We also determine the distributions of three additional classes of length-$2$ mesh patterns through a detailed structural analysis. Our work combines bijective techniques with generating-function methods, yielding new insights into the structure and enumeration of short mesh patterns.

2606.14366 2026-06-15 math.FA math.CV math.OA 新提交

Regular quantum annulus unitary dilation and applications

正则量子环面酉扩张及其应用

Nitin Tomar

AI总结 本文构造了量子环面酉算子的显式双交换d元组,证明了正则量子环面酉扩张的存在性,并应用该扩张定理得到算子完全K谱集性质及相似性结果。

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28 Pages
AI中文摘要

考虑环面 $\mathbb{A}_r=\{z\in\mathbb{C}:r^{-1}<|z|<r\}$,其中 $r>1$,以及量子环面 \[ Q\mathbb{A}_r=\{T:\ T \text{ 是可逆算子且} \ \|T\|, \|T^{-1}\|\leq r\}. \] McCullough 和 Pascoe 证明了 $T\in Q\mathbb{A}_r$ 当且仅当 $\beta(T^*,T)=(r^2+r^{-2})-T^*T-(T^*T)^{-1}\ge0$。我们称可逆算子 $T$ 为量子环面酉算子,如果 $\beta(T^*,T)=0$。本文构造了一个显式的双交换 $d$ 元组量子环面酉算子,它同时扩张了 $Q\mathbb{A}_r$ 中给定的双交换 $d$ 元组算子。我们引入了正则量子环面酉扩张的概念,并证明了由我们的构造产生的扩张是正则的。作为扩张定理的一个应用,我们证明了 $\overline{\mathbb A}_r$ 是 $Q\mathbb{A}_r$ 中算子的完全 $K_t$-谱集,且 $\overline{\mathbb{A}}_r^d$ 是 $Q\mathbb{A}_r$ 中双交换 $d$ 元组算子的完全 $K_{dc}^{(d)}$-谱集,其中 \[ K_t=2\left(1+\frac{2r^2}{(r^2+1)\sqrt{r^4-1}}\right) \quad \text{和} \quad K_{dc}^{(d)}=\left[2\left(1+\frac{2r^2}{(r^2+1)\sqrt{r^4-1}}\right)\right]^d. \] 我们进一步证明了 $Q\mathbb{A}_r$ 中的每个双交换算子元组都相似于一个以 $\overline{\mathbb{A}}_r^{d}$ 为完全谱集的交换元组。此外,我们建立了最优谱常数的界,并证明当 $r\to\infty$ 时它们收敛到 $2^d$。我们还得到了 $Q\mathbb{A}_r$ 中算子和量子环面酉算子的另一种刻画,并证明了 $\overline{\mathbb{A}}_r^d$ 是 $Q\mathbb{A}_r$ 中一类交换 $d$ 元组算子的 $K$-谱集。

英文摘要

Consider the annulus $\mathbb{A}_r=\{z\in\mathbb{C}:r^{-1}<|z|<r\}$ for $r>1$ and the quantum annulus \[ Q\mathbb{A}_r=\{T:\ T \text{ is an invertible operator and} \ \|T\|, \|T^{-1}\|\leq r\}. \] McCullough and Pascoe proved that $T\in Q\mathbb{A}_r$ if and only if $\beta(T^*,T)=(r^2+r^{-2})-T^*T-(T^*T)^{-1}\ge0$. We call an invertible operator $T$ a quantum annulus unitary if $\beta(T^*,T)=0$. In this article, we construct an explicit doubly commuting $d$-tuple of quantum annulus unitaries that simultaneously extends a given doubly commuting $d$-tuple of operators in $Q\mathbb{A}_r$. We introduce the notion of a regular quantum annulus unitary dilation and show that the dilation arising from our construction is regular. As an application of the dilation theorem, we show that $\overline{\mathbb A}_r$ is a complete $K_t$-spectral set for operators in $Q\mathbb{A}_r$ and $\overline{\mathbb{A}}_r^d$ is a complete $K_{dc}^{(d)}$-spectral set for doubly commuting $d$-tuples of operators in $Q\mathbb{A}_r$, where \[ K_t=2\left(1+\frac{2r^2}{(r^2+1)\sqrt{r^4-1}}\right) \quad \text{and} \quad K_{dc}^{(d)}=\left[2\left(1+\frac{2r^2}{(r^2+1)\sqrt{r^4-1}}\right)\right]^d. \] We further prove that every doubly commuting tuple of operators in $Q\mathbb{A}_r$ is similar to a commuting tuple having $\overline{\mathbb{A}}_r^{d}$ as a complete spectral set. In addition, we establish bounds for the optimal spectral constants and show that they converge to $2^d$ as $r\to\infty$. We also obtain an alternative characterization of operators in $Q\mathbb{A}_r$ and quantum annulus unitaries, and prove that $\overline{\mathbb{A}}_r^d$ is a $K$-spectral set for a subclass of commuting $d$-tuples in $Q\mathbb{A}_r$.

2606.14365 2026-06-15 quant-ph physics.ins-det physics.optics 新提交

Certification of the genuine resolution of photon number resolving detectors

光子数分辨探测器的真正分辨能力的认证

Jef Pauwels, Towsif Taher, Roope Uola, Boris Korzh, Nicolas Brunner, Pavel Sekatski

AI总结 提出一种基于相干态探针的可扩展协议,用于认证光子数分辨探测器的真正分辨能力,并在28像素超导纳米线单光子探测器上认证了四结果分辨。

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10 + 3 pages, 3 tables, 4 figures
AI中文摘要

光子数分辨(PNR)探测器是光子量子技术的关键组件,但迄今为止,尚无实用指标来认证它们在单次测量中能真正分辨多少个光子。这里我们引入一个操作框架,用于量化PNR探测器区分不同光子数的能力,即其真正分辨能力。进而,我们开发了一种实用且可扩展的协议,基于相干态探针来认证探测器的真正分辨能力。我们将该方法应用于一个28像素光子数分辨超导纳米线单光子探测器(PNR-SNSPD),并认证了真正的四结果分辨。我们的工作强调了实现高真正分辨能力所需的探测器效率方面的关键要求。该方法为PNR探测器提供了操作基准,并填补了光子量子器件表征中的一个关键空白。

英文摘要

Photon-number-resolving (PNR) detectors are essential components of photonic quantum technologies, yet thus far, no practical metric exists to certify how many photons they can genuinely resolve in a single measurement. Here we introduce an operational framework for quantifying the capability of a PNR detector to distinguish between different numbers of photons, i.e. its genuine resolution. In turn, we develop a practical and scalable protocol for certifying the genuine resolution of a detector, which is based on coherent state probes. We apply the method to a 28-pixel photon-number-resolving superconducting nanowire single-photon detector (PNR-SNSPD) and certify genuine four-outcome resolution. Our work highlights the critical requirements in terms of detector efficiency towards achieving high genuine resolution. This approach provides an operational benchmark for PNR detectors and fills a crucial gap in the characterization of photonic quantum devices.

2606.14364 2026-06-15 astro-ph.HE 新提交

Simulating observed point-symmetric core-collapse supernova morphologies with the jittering jets explosion mechanism

模拟观测到的点对称核塌缩超新星形态与抖动喷流爆炸机制

Jessica Braudo, Amir Michaelis, Muhammad Akashi, Noam Soker

AI总结 通过三维流体动力学模拟抖动喷流爆炸机制,发射三对倾斜反向喷流,再现了单对喷流或失稳无法解释的观测形态,支持JJEM作为主要爆炸机制。

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AI中文摘要

我们进行了两次核塌缩超新星(CCSN)抖动喷流爆炸机制(JJEM)的三维流体动力学模拟,将三对倾斜反向喷流射入一个剥离包层的恒星模型核心,再现了观测到的CCSN遗迹(CCSNR)的一些形态特征,这些特征是单对喷流或单独的不稳定性无法再现的。我们在约一秒内发射了三对喷流,并追踪抛射物超过10秒直至激波突破。我们的主要发现是:(1)尽管喷流在恒星内部深处被堵塞,它们仍成功形成了显著的多极(点对称)形态。(2)喷流-恒星相互作用产生的不稳定性和涡流形成了小团块和窄纤维,其中一些形成点对称形态,类似于一些观测到的CCSNR。(3)一次模拟中能量最高的喷流在抛射物前方形成了一个大的低密度喷出物,带有拖曳的纤维,类似于天鹅座环的喷出物。(4)内部抛射物呈现两个对称轴,沿三个喷流轴中的两个:一对环和一对喷嘴,类似于点对称超新星遗迹SNR J0450.4-7050的结构。(5)三对喷流在其轴之间压缩了两个致密块。这些块表现出高度倾斜于形态轴的多普勒位移双极外流,沿喷流轴方向。倾斜的多普勒双极外流和形态轴类似于CCSNR W49B和SNR G292.0+1.8。我们的研究支持JJEM是CCSN主要爆炸机制的说法。

英文摘要

We conduct two three-dimensional hydrodynamic simulations of the jittering-jets explosion mechanism (JJEM) of core-collapse supernova (CCSN), launching three pairs of inclined opposite jets into the core of an enveloped-stripped stellar model, and reproduce some morphological features of observed CCSN remnants (CCSNRs) that a single pair of jets or instabilities alone cannot reproduce. We launch the three pairs of jets within about a second, and follow the ejecta for more than 10 seconds until after shock breakout. Our main findings are: (1) Although the jets are choked deep inside the star, they manage to form a pronounced multipolar (point-symmetric) morphology. (2) Instabilities and vortices resulting from the jet-star interaction form small clumps and narrow filaments, some of which form point-symmetric morphology, resembling some observed CCSNRs. (3) The most energetic jet of one simulation forms a large low-density blowout ahead of the ejecta, with filaments dragging behind it, resembling the blowout of the Cygnus Loop. (4) The inner ejecta presents two symmetry axes along two of the three jet axes: one of a pair of rings and one of a pair of nozzles, resembling the structure of the point-symmetric SNR J0450.4-7050. (5) The three pairs of jets compress two dense blocks between their axes. The blocks exhibit a Doppler-shift bipolar outflow highly inclined to the morphological axes along the jet axes. The inclined Doppler-bipolar outflow and morphology axis resembles the CCSNRe W49B and SNR G292.0+1.8. Our study supports the claim that the JJEM is the primary explosion mechanism of CCSNe.

2606.14363 2026-06-15 quant-ph physics.chem-ph 新提交

Quantum-Classical Hierarchical Equations of Motion

量子-经典分层运动方程

Amartya Bose

AI总结 提出量子-经典分层运动方程(QC-HEOM),通过结合经典路径系综平均与辅助量子影响泛函分层,避免热核展开,弱化温度依赖性,并适用于非简谐环境。

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8 pages, 2 figures, 1 table
AI中文摘要

我们发展了一种量子-经典分层运动方程(QC-HEOM)方法,用于模拟非马尔可夫开放量子系统。该方法将量子-经典路径积分形式中的系综平均经典路径参考与辅助量子影响泛函的分层结构相结合。通过参考轨迹的系综平均引入热涨落,分层只需表示与浴响应函数虚部相关的残余量子记忆。因此,与传统的分层运动方程不同,QC-HEOM不需要热核的Matsubara或Padé展开,且分层大小对温度的依赖性很弱。此外,由于热涨落通过参考经典轨迹提供,该框架自然扩展到简谐浴之外,并能够通过外部生成的轨迹纳入非简谐和分子环境。我们推导了该形式,并证明了其在简谐浴下的精确性。对非对称自旋-玻色子模型和七位点Fenna-Matthews-Olson复合体的应用展示了QC-HEOM的准确性。它再现了基准准绝热路径积分和分层运动方程的结果,同时需要显著更少的辅助对象,特别是在低温下。这些结果确立了QC-HEOM作为处理开放系统动力学量子-经典描述中残余量子记忆的高效框架。通过使用Wigner轨迹将热涨落与残余量子记忆分离,为处理传统HEOM方法无法触及的复杂非简谐环境提供了近似途径。

英文摘要

We develop a quantum-classical hierarchical equations of motion (QC-HEOM) approach for simulating non-Markovian open quantum systems. The method combines the ensemble-averaged classical path reference of the quantum-classical path integral formalism with a hierarchy of auxiliary quantum influence functionals. By incorporating thermal fluctuations through an ensemble average over reference trajectories, the hierarchy is required to represent only the residual quantum memory associated with the imaginary part of the bath response function. Consequently, unlike conventional hierarchical equations of motion, QC-HEOM does not require Matsubara or Padé expansions of the thermal kernel and exhibits only weak temperature dependence of the hierarchy size. Furthermore, because thermal fluctuations are supplied through reference classical trajectories, the framework naturally extends beyond harmonic baths and enables the incorporation of anharmonic and molecular environments through externally generated trajectories. We derive the formalism and demonstrate its exactness for a harmonic bath. Applications to an asymmetric spin-boson model and the seven-site Fenna--Matthews--Olson complex illustrate the accuracy of QC-HEOM. It reproduces benchmark quasi-adiabatic path integral and hierarchical equations of motion results while requiring substantially fewer auxiliary objects, particularly at low temperatures. These results establish QC-HEOM as an efficient framework for treating residual quantum memory in quantum-classical descriptions of open-system dynamics. The separation of thermal fluctuations from residual quantum memory through the use of Wigner trajectories provides an approximate route toward hierarchical treatments of complex anharmonic environments that are inaccessible to conventional HEOM approaches.

2606.14362 2026-06-15 hep-ex 新提交

Search for dark photons from Higgs boson decays in the gluon-gluon fusion channel in proton-proton collisions at $\sqrt{s}=13.6$ TeV with the ATLAS detector

在ATLAS探测器上搜索质子-质子对撞中胶子-胶子融合通道希格斯玻色子衰变产生的暗光子($\sqrt{s}=13.6$ TeV)

ATLAS Collaboration

AI总结 利用ATLAS探测器在135 fb$^{-1}$的Run 3数据中,通过光子加缺失横动量末态搜索希格斯玻色子衰变到光子与暗光子,采用新型触发器和提升决策树,未发现显著超出,给出分支比上限1.4%。

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52 pages in total, author list starting page 35, 13 figures and 6 tables, submitted to JHEP. All figures including auxiliary figures are available at this http URL
AI中文摘要

本文搜索希格斯玻色子半可见衰变到光子($\gamma$)和缺失横动量$p_T^{miss}$的末态。分析针对胶子-胶子融合产生通道优化,利用2023年部署的新型触发器,将光子横动量($p_T^{\gamma}$)阈值降至50 GeV,$p_T^{miss}$阈值降至70 GeV,并结合$p_T^{miss}$-$\gamma$系统横质量($m_T$)大于80 GeV的选择。结果解释为希格斯玻色子衰变到$\gamma$和暗光子$\gamma_d$($H \to \gamma \gamma_d$)。分析使用ATLAS在2023和2024年收集的135 fb$^{-1}$ Run 3数据。采用提升决策树识别可能影响$p_T^{miss}$计算的误重建初级顶点事件。使用数据驱动方法估计喷流和电子被误认为光子的本底,而真实光子本底来自蒙特卡罗模拟,并在含缪子的控制区中归一化到数据。对$m_T$分布进行分箱最大似然拟合,评估观测数据与标准模型期望的兼容性。未观测到显著超出标准模型预言,在95%置信水平下得到$H \to \gamma \gamma_d$分支比的观测(期望)上限为1.4%(1.2%)。结合此前Run 2搜索结果,将观测(期望)上限改进至0.9%(0.9%)。

英文摘要

This paper presents a search for semi-visible Higgs boson decays in final states with a photon ($\gamma$) and missing transverse momentum $p_T^{miss}$. The analysis is optimised for the gluon-gluon fusion production channel and exploits a novel trigger deployed in 2023, with reduced thresholds down to 50 GeV on the photon transverse momentum ($p_T^{\gamma}$) and 70 GeV on the $p_T^{miss}$, in combination with a selection on the transverse mass of the $p_T^{miss}$-$\gamma$ system ($m_T$) above 80 GeV. The results are interpreted in terms of Higgs boson decays into a $\gamma$ and a dark photon $\gamma_d$ ($H \to \gamma \gamma_d$). The analysis is performed using 135 fb$^{-1}$ of Run 3 data collected by ATLAS in 2023 and 2024. A boosted decision tree is used to identify events with misreconstructed primary vertices, which can affect the $p_T^{miss}$ calculation. Data-driven methods are employed to estimate the backgrounds from jets and electrons misidentified as photons, while the backgrounds with genuine photons are taken from Monte Carlo simulations, normalised to data in control regions with muons. A binned maximum-likelihood fit to the $m_T$ distribution is performed to evaluate the compatibility of the observed data with the Standard Model expectation. No significant excess is observed over the Standard Model prediction, and an observed (expected) upper limit on the branching ratio of $H \to \gamma \gamma_d$ of 1.4% (1.2%) is obtained at 95% confidence level. Combining this result with previous Run 2 searches improves the observed (expected) upper limit to 0.9% (0.9%).

2606.14360 2026-06-15 math.DG 新提交

Gaussian-Weighted Curvature Gaps for Self-Shrinkers

自收缩子的高斯加权曲率间隙

Fagui Li, Yuhang Zhao

AI总结 本文利用法坐标函数和加权Poincaré不等式,证明嵌入自收缩子高斯加权L²曲率积分的下界,并结合熵间隙定理得到非球面闭自收缩子的严格曲率间隙,在二维情形推广到完整嵌入自收缩子。

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11 pages, any comments are welcome!
AI中文摘要

本文证明了嵌入自收缩子的高斯加权L²曲率积分的下界。证明结合了法坐标函数与源于Ding-Xin和Brendle-Tsiamis第一特征值估计的加权Poincaré不等式。对于闭自收缩子,该估计给出了关于熵的显式下界,并与Colding-Ilmanen-Minicozzi-White的熵间隙定理一起,得到了非球面闭收缩子的严格曲率间隙。在二维情形,我们将该估计与Bernstein-Wang的分类定理和熵间隙定理结合,得到了具有多项式体积增长的完整嵌入自收缩子的相应间隙结论。

英文摘要

In this paper, we prove lower bounds for the Gaussian-weighted \(L^2\)-curvature integral of embedded self-shrinkers. The proof combines normal coordinate functions with weighted Poincaré inequalities arising from first-eigenvalue estimates of Ding--Xin and Brendle--Tsiamis. For closed self-shrinkers, the estimate gives an explicit lower bound in terms of entropy and, together with the entropy gap theorem of Colding--Ilmanen--Minicozzi--White, yields a strict curvature gap for nonspherical closed shrinkers. In dimension two, we combine this estimate with the classification theorem and entropy gap theorem of Bernstein--Wang to obtain the corresponding gap statement for complete embedded self-shrinkers with polynomial volume growth.

2606.14359 2026-06-15 astro-ph.SR 新提交

Gravity-mode main-sequence pulsators in the open clusters NGC 3532 and NGC 2516: Instability strip, near-core rotation, and internal structure

疏散星团 NGC 3532 和 NGC 2516 中的重力模式主序脉动星:不稳定带、近核心自转与内部结构

Gang Li, Chenyu He, Joey S. G. Mombarg, Dario J. Fritzewski, Conny Aerts

AI总结 利用 TESS 测光数据,在约 3 亿年老的疏散星团 NGC 3532 中探测重力模式脉动,测量近核心自转速率,并结合 NGC 2516 揭示自转-质量关系,发现 1.6 太阳质量处自转速率出现平台,暗示不同自转减速机制。

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Main text: 15 pages, 12 figures, and 2 tables. Appendices: 11 pages, 14 figures, and 8 tables. Accepted for publication in A&A. Due to the character limit, the abstract in the arXiv version is shorter than the abstract in the main text
AI中文摘要

背景。研究星团中的脉动星为恒星物理学开辟了新窗口。疏散星团中的重力模式(g-mode)脉动星使我们能够测量它们的近核心自转速率,并结合星团年龄和质量约束,检验约 1.5 太阳质量以上恒星中的角动量输运。目标。我们旨在探测年轻疏散星团 NGC 3532(约 300 Myr)成员星中的 g 模式脉动,并测量其近核心自转速率和内部性质。方法。我们使用 TESS 测光数据提取 NGC 3532 成员星的光变曲线。观测到的 g 模式周期间距使我们能够测量近核心自转速率和渐近周期间距 Pi0。我们还对 NGC 3532 和 NGC 2516 的颜色-星等图进行了等时线拟合,以精化星团年龄并获得恒星质量。结果。我们将年轻 γ Doradus 成员星的观测不稳定区域约束在蓝端约 7760 K 到红端约 7070 K,同时也观测到一些更热的 g 模式脉动星。近核心自转速率显示出与 NGC 2516 相似的自转-质量关系:低于 1.6 太阳质量时,自转速率随质量增加而增加,而高于 1.6 太阳质量时,NGC 3532 恒星的自转速率达到约 2.8 d^-1 的平台。这一质量可能标志着不同自转减速机制之间的阈值。现有的考虑角动量输运的演化模型表明,这些 g 模式脉动星诞生时的自转速度超过临界值的 55%。我们假设球对称、角动量守恒和刚性内部自转的简化模型表明,要么需要依赖于质量的初始自转速率,要么在 1.6 太阳质量以上仍有微小的角动量损失。最后,我们的 Pi0 测量揭示了一些脉动星与理论预测之间的差异,正如在更年轻的星团 NGC 2516 中也发现的那样。

英文摘要

Context. Studying pulsating stars in clusters opens a new window onto stellar physics. Gravity-mode (g-mode) pulsators in open clusters allow us to measure their near-core rotation rates and, together with cluster age and mass constraints, test angular momentum transport in stars above about 1.5 solar masses. Aims. We aim to detect g-mode pulsations in member stars of the young open cluster NGC 3532, about 300 Myr old, and to measure their near-core rotation rates and internal properties. Methods. We used TESS photometry to extract light curves of NGC 3532 members. The observed g-mode period spacings allow us to measure near-core rotation rates and the asymptotic period spacing, Pi0. We also fitted isochrones to the colour-magnitude diagrams of NGC 3532 and NGC 2516 to refine the cluster ages and obtain stellar masses. Results. We constrain the observed instability region of young gamma Doradus members from a blue edge at about 7760 K to a red edge at about 7070 K, while some hotter g-mode pulsators are also seen. The near-core rotation rates show a rotation-mass relation similar to that in NGC 2516: below 1.6 solar masses, the rotation rate increases with mass, whereas above 1.6 solar masses the NGC 3532 stars reach a plateau at about 2.8 d^-1. This mass may mark a threshold between different rotational spin-down mechanisms. Existing evolutionary models with angular momentum transport imply that these g-mode pulsators were born rotating above 55 percent of the critical value. Our simplified models, assuming spherical symmetry, angular momentum conservation, and rigid internal rotation, suggest that either mass-dependent initial rotation rates are required, or that minor angular momentum loss still operates above 1.6 solar masses. Finally, our Pi0 measurements reveal a discrepancy with theoretical predictions for some pulsators, as also found in the younger cluster NGC 2516.

2606.14358 2026-06-15 cs.CY 新提交

Observing Teachers' Instrumental Pedagogical Orchestration in Synchronous Online Learning: A Multimodal Grid Based on Videoconferencing Traces

观察同步在线学习中教师的工具性教学编排:基于视频会议轨迹的多模态网格

Intissar Bamou, Christine Michel (Techné [Poitiers]), Hassina El Kechai (Techné [Poitiers], LIUM)

AI总结 提出一种基于视频会议轨迹的多模态观察网格,用于分析同步在线教学中教师的工具性教学编排,识别沟通手势、姿势、眼神和数字工具管理中的可观察指标。

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AI中文摘要

同步在线教学环境对教学活动的分析提出了特定挑战,因为教学通过视频会议平台进行,且交互是多模态的。虽然教学编排在面对面课程和教学设计层面已得到广泛研究,但在视频会议环境中的教学分析仍未被充分探索,且在方法论上缺乏足够的工具支持。本文提出了一种多模态观察网格,旨在分析教师在同步在线课堂中的工具化教学编排。基于教学编排、多模态和教师专业手势的理论,该网格识别了与沟通手势、姿势、眼神和数字工具管理相关的一组可观察指标。这些指标根据其可观察性和分析相关性进行结构化和优先级排序,并针对视频会议课堂中可分析数据的约束进行了操作化。所提出的网格旨在为分析工具化教学编排提供一个可重复的方法论框架,以便未来进行实证验证。

英文摘要

Synchronous online teaching environments pose specific challenges for the analysis of pedagogical activity as teaching takes place via videoconferencing platforms and interactions are multimodal. While pedagogical orchestration has been extensively studied in the context of face-to-face courses and at the level of instructional design, the analysis of teaching in videoconferencing environments remains under-explored and insufficiently instrumented in terms of methodology. This article proposes a multimodal observation grid designed to analyze the instrumentalised pedagogical orchestration of teachers during synchronous online classes. Based on theories of pedagogical orchestration, multimodality and professional gestures of teachers, this grid identifies a set of observable indicators related to communicational gestures, posture, gaze and the management of digital tools. These indicators are structured and ranked in order of priority according to their observability and analytical relevance. They are operationalised to consider the constraints associated with data that can be analysed in videoconference class contexts. The proposed grid aims to provide a reproducible methodological framework for the analysis of instrumental pedagogical orchestration, with a view to future empirical validation.

2606.14352 2026-06-15 cond-mat.quant-gas quant-ph 新提交

Modeling light-matter coupled systems with neural quantum states

用神经量子态建模光-物质耦合系统

Noe Salmeron, Marin Bukov, Markus Schmitt

AI总结 针对短程和长程相互作用共存的冷原子多体系统,提出基于神经量子态的方法,通过设计处理混合希尔伯特空间的神经网络架构,在里德伯原子-光子耦合模型中实现高效计算,并发现与平均场理论在基态相边界上的定量偏差。

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Comments
15 pages, 8 figures, The data associated with this manuscript version is available under DOI: https://doi.org/10.5281/zenodo.20630702
AI中文摘要

冷原子操控的最新进展使得研究相邻原子间短程相互作用与光子介导的长程相互作用共存的多体系统成为可能。这种相互作用的组合使得超越平均场方法的理论方法具有挑战性。在这项工作中,我们开发了一种基于神经量子态的方法来数值研究这些系统。我们引入了一种神经网络架构,能够处理强相互作用自旋-光子系统中具有大局部玻色子维度的混合希尔伯特空间。我们在一个与光子模式耦合的二维里德伯原子晶格模型上对该方法进行了基准测试。在大自旋-光子耦合区域中发现的超辐射基态使我们能够证明该方法在高光子占据情况下的效率。此外,捕捉自旋-自旋和自旋-光子相关性的能力使我们观察到基态相边界相对于平均场理论的定量偏差。该方法可扩展到具有类似混合希尔伯特空间结构的其他系统,如自旋-声子系统,并为研究其基态性质提供了一个可扩展的框架。

英文摘要

Recent advances in cold atom manipulation enable the study of many-body systems where short-range interactions between neighboring atoms coexist with long-range interactions mediated by photons. Such a combination of interactions makes a theoretical approach challenging beyond mean-field methods. In this work, we develop a neural quantum state based approach to study these systems numerically. We introduce a neural-network architecture capable of handling hybrid Hilbert spaces with large local bosonic dimensions in strongly interacting spin-photon systems. We benchmark this approach on a model of a two-dimensional lattice of Rydberg atoms coupled to a photon mode. The superradiant ground states found in the large spin-photon coupling regime allow us to demonstrate the efficiency of the method in the presence of high photon occupation. Furthermore, the ability to capture spin-spin and spin-photon correlations leads us to observe quantitative deviations in the ground state phase boundaries with respect to mean-field theory. The method extends to other systems with a similar hybrid Hilbert space structure, such as spin-phonon systems, and provides a scalable framework for investigating their ground state properties.

2606.14349 2026-06-15 hep-lat hep-ph hep-th 新提交

Finite-volume effects on smeared spectral densities

有限体积效应对涂抹谱密度的影响

Francesca A. Bresciani, Mattia Bruno, Maxwell T. Hansen

AI总结 本文推导了周期性立方体积中涂抹矢量-矢量谱密度的主导有限体积效应的普适表达式,基于两种方法并证明指数抑制,有助于控制外推。

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Comments
19 pages, 8 figures
AI中文摘要

使用两种不同的方法,我们推导了在边长为 $L$ 的周期性立方空间体积中涂抹矢量-矢量谱密度(与涂抹的强子 $R$ 比成正比)的主导有限体积效应的普适表达式。首先,基于先前关于欧几里得两点函数有限体积效应的工作,我们表明对于某类涂抹核,$L$ 依赖关系是指数抑制的,并且主导效应可以普适地用 $\pi$ 介子形状因子表示。然后,从关联器谱分解的 Lellouch-Lüscher-Meyer 表达式出发,推导出相同的表示。这些结果可能有助于控制涂抹谱密度的 $L \to \infty$ 外推,特别是通过定义一个标度区域,在该区域中有限体积效应由大 $L$ 展开中的主导项支配,从而可以可靠地估计。为了说明这一点,我们还基于各种核和粒子相互作用模型给出了数值估计。尽管专注于矢量通道,我们的推导定义了一个适用于其他情况的通用框架。

英文摘要

Using two distinct approaches, we derive a universal expression for the leading finite-volume effects of the smeared vector-vector spectral density (proportional to the smeared hadronic $R$-ratio) in a periodic cubic spatial volume of side length $L$. First, building on the results of previous work for finite-volume effects on Euclidean two-point functions, we show that the $L$ dependence is exponentially suppressed for a certain class of smearing kernels, and that the leading effects can be expressed universally in terms of the pion form factor. The same representation is then derived starting from the Lellouch-Lüscher-Meyer expression for the spectral decomposition of the correlator. The results may prove useful for controlling the $L \to \infty$ extrapolation of smeared spectral densities, in particular by defining a scaling regime in which the finite-volume effects are dominated by the leading terms in a large $L$ expansion and thus can be reliably estimated. To illustrate this point, we also present numerical estimates based on various kernels and models of particle interactions. Despite focusing on the vector channel, our derivation defines a general framework applicable to other cases as well.

2606.14345 2026-06-15 math.CO 新提交

Inherited arcs in André planes of even order

偶阶André平面中的继承弧

S.G. Barwick, Alice M.W. Hui, Wen-Ai Jackson

AI总结 本文通过André替换过程,从Desarguesian平面中的圆锥曲线构造偶阶André平面中的卵形线,并证明某些圆锥曲线在替换过程中不继承为弧。

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AI中文摘要

阶为$q^t$的André平面可以通过替换André网从Desarguesian平面$PG(2,q^t)$构造。本文构造了偶阶$q$和素数$t$的André平面中的卵形线,这些卵形线是从Desarguesian平面$PG(2,q^t)$的圆锥曲线继承而来的。此外,还证明了某些圆锥曲线在André替换过程中不继承为弧。

英文摘要

André planes of order $q^t$ can be constructed from the Desarguesian plane $PG(2,q^t)$ using a process that involves replacing André nets. This article constructs ovals in André planes of order $q^t$, $q$ even and $t$ prime that are inherited from conics of the Desarguesian plane $PG(2,q^t)$. Further, it is shown that certain conics do not inherit to arcs under the process of André replacement.

2606.14343 2026-06-15 physics.optics 新提交

Chirally-sensitive optical rectification by isotropic chiral media

各向同性手性介质的手性敏感光整流效应

Raju Adhikary, Luca Assogna, Ambaresh Sahoo, Matteo Venturi, Andrea De Marcellis, Massimiliano Aschi, Antonio Mecozzi, Jens Biegert, Davide Tedeschi, Carino Ferrante, Andrea Marini

AI总结 提出基于光整流效应的新型手性传感方法,在填充药液的微腔中产生手性敏感的纳伏电压,实现纳升体积的手性检测。

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AI中文摘要

手性光学传感对于深入了解手性分子的电子、振动和转动自由度至关重要,并且是纳米医学和药物发现平台的基石。当前评估手性药物对映体失衡的手性传感技术对毫升体积敏感,但耗时且无法集成在芯片上,从而成为药物发现和纳米医学的主要瓶颈。在这里,我们提出一种基于光整流效应的新型手性光学传感方法,该方法使用填充纳升体积药液的光子微腔。我们从理论上证明,在强脉冲激光激发下,这种非线性效应在电控微腔边界产生手性敏感的纳伏电压脉冲,其符号仅取决于药物的对映体失衡。我们的结果揭示了光整流作为创新性芯片实验室器件稳健平台的潜力,能够实现纳升灵敏度的手性传感。

英文摘要

Chiroptical sensing is central to gain fundamental insight into electronic, vibrational and rotational degrees of freedom of chiral molecules, and is a cornerstone for nanomedicine and drug discovery platforms. Current chiral sensing technologies to assess the enantiomeric imbalance of chiral pharmaceutical compounds are sensitive to ml volumes but are time-consuming and cannot be integrated on a chip, thus creating a major bottleneck for drug discovery and nanomedicine. Here, we propose a novel chiroptical sensing approach based on optical rectification in a photonic micro-cavity filled by a drug solution with nl volume. We theoretically demonstrate that, upon optical excitation by intense pulsed laser light, such a nonlinear effect produces a chirally-sensitive nV voltage burst at the electrically-gated micro-cavity boundaries, with sign depending solely on the drug enantiomeric imbalance. Our results shed light on the potential of optical rectification as a robust platform for innovative lab-on-a-chip devices enabling chiral sensing with nl sensitivity.

2606.14342 2026-06-15 physics.flu-dyn 新提交

Flow behind the Imperial Front Wing: comparison of results from volumetric PTV experiment and Nektar++ simulations

帝国前翼后方流动:体PTV实验与Nektar++模拟结果的比较

Isabella Fumarola, Alexandra I. Liosi, Parv Khurana, Adam Meziane, Isaac Balbolia, Sherwin J. Spencer, Jonathan F. Morrison

AI总结 通过体PTV实验与高保真LES模拟对比,验证了Shake-The-Box算法在赛车空气动力学中的适用性,并发现了前翼尾流中一个此前未报道的关键涡结构。

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Comments
Submitted to Measurement Science and Technology
AI中文摘要

由于计算能力和直接数值模拟(DNS)及混合大涡模拟(LES)等方法的进步,高保真模拟正被越来越多地采用。这些方法对于高雷诺数下复杂几何体周围的非定常流动尤其有价值,但仍需仔细的实验验证。平面和立体粒子图像测速(PIV)广泛用于测量,但受限于测量平面选择及其捕捉涡旋形状和轨迹的能力。这激发了人们对体测量技术的兴趣,而该技术在工业环境中历来难以实施。粒子跟踪测速(PTV)在测量大体积流动方面的最新进展使其适用于验证复杂几何体的数值模拟。本研究将体PTV测量与高保真LES进行比较,以评估其在工业流动中的能力和局限性。目的是使用Shake-The-Box算法为赛车空气动力学建立一个基准PTV数据集。实验在帝国理工学院配备滚动道路(用于地面效应模拟)的10x5风洞中进行,能够测试高达50%比例的F1模型。在开源帝国前翼(IFW)下游,Re=74896条件下进行了体PTV测量。结果与平面PIV研究和使用Nektar++中谱h/p元素的隐式LES模拟进行了比较。这项工作解决了文献中关于IFW尾流的开放问题。在尾流拓扑中观察到良好的定量一致性。识别出一个此前未报道的涡旋,它在阻止其他主导结构合并方面起着关键作用。这些结果证明了PTV和STB在工业应用中的适用性,同时为IFW提供了基准数据集。

英文摘要

High-fidelity simulations are increasingly adopted, due to advances in computational power and methods such as Direct Numerical Simulation (DNS) and hybrid Large-Eddy Simulation (LES). These approaches are particularly valuable for unsteady flows around complex geometries at high Reynolds numbers; however they still require careful experimental validation. Planar and stereo Particle Image Velocimetry (PIV) are widely used for measurements but limited by measurement-plane selection and their ability to capture vortices shapes and trajectories. This motivates the growing interest in volumetric techniques, historically difficult to implement in industrial settings. Recent advances in Particle Tracking Velocimetry (PTV) for measuring flows over large volumes make this approach suitable for validating numerical simulations of complex this http URL study compares volumetric PTV measurements against high-fidelity LES to assess the capabilities and limitations for industrial flows. The aim is to establish a benchmark PTV dataset for motorsport aerodynamics using the Shake-The-Box algorithm. The experiment was carried out in the 10x5 wind tunnel at Imperial College London equipped with a rolling road for ground effect simulation and capable of testing up to 50% scale F1 model. Volumetric PTV measurements were performed downstream of the open-source Imperial Front Wing (IFW) at Re=74896. Results are compared with planar PIV studies and implicit LES simulation using spectral h/p elements in Nektar++. This work addresses open questions in the literature concerning the wake of the IFW. Good quantitative agreement is observed in the wake topology. A previously unreported vortex is identified which has the key role of preventing the merging of other dominant structures. These results demonstrate the suitability of PTV and STB for industrial applications while providing a benchmark dataset for the IFW.

2606.14341 2026-06-15 astro-ph.HE 新提交

Multiwavelength Analysis of the Einstein Probe X-ray Transient EP240305a

爱因斯坦探针X射线暂现源EP240305a的多波段分析

Ruican Ma, Ye Li, Lian Tao, Tao An, Ailing Wang, Arne Rau, Roberto Soria, Huaqing Cheng, Jing Wang, Hua Feng, Yuanqi Liu, Seán Brennan, Jingran Xu, Dave Buckley, Philip Charles, YuPeng Chen, Francesco Coti Zelati, Sebastien Guillot, Long Ji, Chengkui Li, Jinzhong Liu, Yuan Liu, Pierre Maggi, Itumeleng Monageng, Yanan Wang, Yanjun Xu, Guobao Zhang, Qingchang Zhao, Diego Altamirano, Peter Jonker, Nanda Rea, Xiaofeng Wang, Xuefeng Wu, Weimin Yuan, Shuangnan Zhang

AI总结 报告EP240305a的多波段观测,发现其X射线、光学、近红外和射电波段特征不同,射电波段显示自吸收到光学薄的长期谱演化,暗示离散喷流,排除长时标暂现源和短时标恒星耀发,类似伽马射线暗的伽马暴暂现源。

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Comments
11 pages, 6 figures, 4 tables. Accepted for publication in MNRAS
AI中文摘要

我们报告了EP240305a的多波段观测结果,这是一个由爱因斯坦探针于2024年3月5日探测到的未编录X射线暂现源。该源在X射线、光学、近红外和射电波段展现出不同的特征。软X射线观测显示两次显著的耀发,持续约100-250秒,随后在几天内快速衰减,光学和近红外数据揭示了一个微弱的候选对应体。相比之下,射电观测在两个月内揭示了从自吸收到光学薄状态的长期谱演化,暗示了离散的喷流抛射。我们将EP240305a与已知的X射线暂现源类别进行比较,发现它不太可能与长时标暂现源(如喷流潮汐瓦解事件或X射线双星)相关。其特性也不支持短时标恒星耀发起源。尽管缺乏光学光谱无法确定红移,但该源表现出与伽马射线暗的伽马暴样暂现源相似的性质,这些暂现源可能与离轴观测的相对论性喷流或受阻喷流有关。EP240305a的发现,连同爱因斯坦探针探测到的其他未编录暂现源,突显了高灵敏度X射线巡天望远镜和快速响应多波段后随观测在探索非典型天文暂现源性质方面的科学潜力。

英文摘要

We report multiwavelength observations of EP240305a, an uncatalogued X-ray transient detected by the Einstein Probe on March 5, 2024. The source exhibits distinct characteristics across the X-ray, optical, near-infrared, and radio bands. The soft X-ray observations show two significant flares lasting ~100-250 s, accompanied by rapid flux decay in a few days, and the optical and near-infrared data reveal a faint, candidate counterpart. In contrast, the radio observations expose a long-term spectral evolution from a self-absorbed to an optically thin state within two months, implying discrete jet ejection. We compare EP240305a with known classes of X-ray transients and find that it is unlikely to be associated with long-timescale transients such as jetted tidal disruption events or X-ray binaries. Its properties also disfavor a short-timescale stellar flare origin. Although the absence of optical spectroscopy prevents a redshift determination, the source exhibits properties similar to those of gamma-ray-dark gamma-ray burst-like transients, which may be associated with relativistic jets viewed off-axis or with choked jets. The discovery of EP240305a, along with other uncataloged transients detected by the Einstein Probe, underscores the scientific potential of highly sensitive X-ray survey telescopes and rapid-response multiwavelength follow-up observations in exploring the nature of atypical astronomical transients.