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2511.10473 2026-06-08 math.OC 版本更新

Riccati-ZORO: An efficient algorithm for heuristic online optimization of internal feedback laws in robust and stochastic model predictive control

Riccati-ZORO:一种用于鲁棒和随机模型预测控制中内部反馈律在线优化的高效算法

Florian Messerer, Yunfan Gao, Jonathan Frey, Moritz Diehl

AI总结 本文提出Riccati-ZORO算法,用于管状最优控制问题,通过启发式不确定性成本设计联合优化名义轨迹和不确定性管,将计算复杂度从O(n_x^6)降至O(n_x^3)。

Comments Journal upgrade (submitted)

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AI中文摘要

本文提出Riccati-ZORO算法,用于管状最优控制问题,通过启发式不确定性成本设计联合优化名义轨迹和不确定性管,将计算复杂度从O(n_x^6)降至O(n_x^3)。

英文摘要

We present Riccati-ZORO, an algorithm for tube-based optimal control problems (OCP). Tube OCPs predict a tube of trajectories to capture predictive uncertainty. The tube induces a constraint tightening via additional backoff terms. This backoff can significantly affect the performance, and thus implicitly defines a cost of uncertainty. Optimizing the feedback law used to predict the tube can significantly reduce the backoffs, but its online computation is challenging. Riccati-ZORO jointly optimizes the nominal trajectory and uncertainty tube based on a heuristic uncertainty cost design. The algorithm alternates between two subproblems: (i) a nominal OCP with fixed backoffs, (ii) an unconstrained tube OCP, which optimizes the feedback gains for a fixed nominal trajectory. For the tube optimization, we propose a cost function informed by the proximity of the nominal trajectory to constraints, prioritizing reduction of the corresponding backoffs. These ideas are developed for ellipsoidal tubes under linear state feedback. In this case, the decomposition into the two subproblems substantially reduces the computational complexity with respect to the state dimension from $\mathcal{O}(n_x^6)$ to $\mathcal{O}(n_x^3)$, i.e., the complexity of a nominal OCP. We investigate the algorithm in numerical experiments, and provide two open-source implementations: a prototyping version in CasADi and a high-performance implementation integrated into the acados OCP solver.

2603.29803 2026-06-08 hep-ph hep-ex 版本更新

Perturbative QCD fitting of KEDR and BESIII $e^+e^-$ data for R(s) and $α_s$ determination

扰动QCD拟合KEDR和BESIII $e^+e^-$数据用于R(s)和$α_s$的确定

A. L. Kataev, K. Yu. Todyshev

AI总结 本文通过扰动QCD理论拟合KEDR和BESIII实验数据,研究R(s)比值和$α_s$的确定,探讨不同截断阶数对$α_s(M_Z)$的影响,发现高阶截断导致$α_s$值增加,归因于非完全可控的动量空间到时间空间分析延拓中的$π^2$贡献。

Comments 28 pages, 6 Tables, 2 figures; Presentation and results of the fits improved, abstract a bit modified, extra references added, conclusions unchanged; Revised upon presenting material at Quarks-2026 International Seminar, Petrozavodsk , 18-23 May 2026

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AI中文摘要

KEDR和BESIII合作组在低于charm夸克阈值的能量下收集的实验数据与质量为零的QCD表达式进行比较,该表达式用于$e^+e^- $湮灭的R比值,截断在不同扰动理论阶数。拟合显示提取的$α_s(M_Z)$值依赖于相应近似值的截断阶数。结合KEDR和BESIII数据的次领阶、次次领阶和次次次领阶拟合,截断在$J/Ψ$介子质量尺度,得到$α_s(M_Z)=0.1151_{-0.0069}^{+0.0052}$,$α_s(M_Z)=0.1190_{-0.0081}^{+0.0064}$和$α_s(M_Z)=0.1283_{-0.0075}^{+0.0028}$。拟合$α_s(M_Z)$值的增加趋势与动量空间到时间空间分析延拓中未完全可控的$π^2$贡献有关。固定扰动理论阶数展开和仔细处理分析延拓效应的应用被评论。

英文摘要

The experimental data collected by KEDR and BESIII collaborations at the energies below charm quark thresholds are compared with the massless QCD expressions for the $e^+e^-$ annihilation R-ratio truncated at different orders of perturbation theory. The fits demonstrate the dependence of the extracted $α_s(M_Z)$ values on the orders of truncation of the corresponding approximations. The next-to-leading order, next-to-next-to-leading order and next-to-next-to-next-to-leading order fits of the combined KEDR data and BESIII data , truncated at the scale of mass of $J/Ψ$ meson, give the following results $α_s(M_Z)=0.1151_{-0.0069}^{+0.0052}$, $α_s(M_Z)=0.1190_{-0.0081}^{+0.0064}$and $α_s(M_Z)=0.1283_{-0.0075}^{+0.0028}$. The increasing tendency of fitted $α_s(M_Z)$ value is associated with the effects of not totally controlled within asymptotic perturbation theory expansions kinematical $π^2$ contributions to R-ratio coefficients due to analytical continuation from the space-like to time-like energy regions. The applications of the fixed orders of perturbation theory expansions and careful treatment of the analytical continuation effects are commented.

2604.07732 2026-06-08 cs.HC cs.CY 版本更新

Twitch Third-Party Developers' Support Seeking and Provision Practices on Discord

Twitch第三方开发者在Discord上的支持请求与提供实践

Jie Cai, He Zhang, Yueyan Liu, John M. Carroll, Chun Yu

AI总结 研究探讨了Twitch第三方开发者在Discord上的支持请求与提供行为,发现其依赖Twitch平台,需在Discord和Twitch间切换,加剧平台劳动,并需通过角色衔接正式与非正式空间以提升开发者发展。

Comments Accepted by ACM CSCW 2026

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AI中文摘要

第三方开发者(TPDs)常通过在线社区寻求支持,当无法从平台获得即时响应时。Twitch作为领先的直播平台,吸引了大量TPDs,并在Discord上形成了支持社区。本研究通过混合方法(主题建模识别支持请求与提供相关主题,随后进行深入定性分析)发现:(1)TPDs在社交、技术及政策问题上的支持请求与提供高度依赖Twitch,这种依赖是一种平台劳动形式;(2)TPDs需在Discord和Twitch间切换以寻求和提供支持,加剧平台劳动;(3)TPDs的灵活角色实践反映了Discord社区的繁荣,但需要角色衔接两个平台,并将非正式支持请求转化为可能的正式支持。我们提出有效管理正式与非正式空间间支持请求与提供的意义,以改善TPDs的发展。我们还为社区支持实践和CSCW平台生态工作做出了贡献。

英文摘要

Third-party developers (TPDs) often turn to online communities for support when they can't get immediate responses from the platform. Twitch, as a leading live streaming platform, attracted many TPDs and formed an online support community on Discord. This study explores TPDs' support practices via mixed method (a topic modeling to identify topics related to support seeking and provision first and a follow-up in-depth qualitative analysis with these topics) and found that: (1) TPDs' support-seeking practices around social, technical, and policy matters are highly dependent on Twitch, and this dependence acts as a form of platform labor; (2) TPDs need to switch between Discord and Twitch regarding seeking and provision, exacerbating TPDs' platform labor; (3) TPDs' flexible role practices reflect the community's flourishing on Discord but require roles to bridge the two platforms and transfer informal support seeking to possible formal support from Twitch. We propose implications for effectively managing support seeking and provision between formal and informal spaces to improve the development of TPDs. We also contribute to community support practice and to platform ecology work in CSCW.

2512.01667 2026-06-08 stat.ME stat.CO 版本更新

Detecting Model Misspecification in Bayesian Inverse Problems via Variational Gradient Descent

通过变分梯度下降检测贝叶斯逆问题中的模型误设定

Qingyang Liu, Matthew A. Fisher, Zheyang Shen, Xuebin Zhao, Katherine Tant, Andrew Curtis, Chris. J. Oates

AI总结 提出一种通过比较标准贝叶斯后验与预测导向后验来检测模型误设定的诊断方法,并基于变分梯度下降实现高效数值算法。

Comments Several improvements to the text and fixed a typo in the statement of Theorem 2.3

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AI中文摘要

当统计模型设定正确时,贝叶斯推断是最优的;而在设定错误的情况下,贝叶斯推断可能灾难性地失败。因此,人们提出了大量后贝叶斯方法。预测导向(PrO)方法将统计模型 $P_θ$ 提升为(无限)混合模型 $\int P_θ\; \mathrm{d}Q(θ)$,并通过最小化熵正则化目标泛函来拟合该预测分布。在设定正确的情况下,期望混合分布 $Q$ 在大数据极限下集中于真实数据生成参数;而如果模型误设定,则通常不会观察到这种奇异集中。我们的贡献在于证明,通过比较标准贝叶斯后验与 PrO“后验”$Q$,可以经验性地检测模型误设定,为标准贝叶斯工作流提供一种新颖且广泛适用的诊断工具。为实现这一目标,我们提出了一种基于变分梯度下降的高效数值算法。模拟研究以及涉及地震学中贝叶斯逆问题的更详细案例研究证实,使用该框架可以自动检测模型误设定。

英文摘要

Bayesian inference is optimal when the statistical model is well-specified, while outside this setting Bayesian inference can catastrophically fail; accordingly a wealth of post-Bayesian methodologies have been proposed. Predictively oriented (PrO) approaches lift the statistical model $P_θ$ to an (infinite) mixture model $\int P_θ\; \mathrm{d}Q(θ)$ and fit this predictive distribution via minimising an entropy-regularised objective functional. In the well-specified setting one expects the mixing distribution $Q$ to concentrate around the true data-generating parameter in the large data limit, while such singular concentration will typically not be observed if the model is misspecified. Our contribution is to demonstrate that one can empirically detect model misspecification by comparing the standard Bayesian posterior to the PrO `posterior' $Q$, providing a novel and widely-applicable diagnostic tool for the standard Bayesian workflow. To operationalise this, we present an efficient numerical algorithm based on variational gradient descent. A simulation study, and a more detailed case study involving a Bayesian inverse problem in seismology, confirm that model misspecification can be automatically detected using this framework.

2604.06064 2026-06-08 astro-ph.EP 版本更新

Star-planet magnetic interactions in photoevaporating exoplanets: enhanced power due to atmospheric escape

系外行星光蒸发中的恒星-行星磁相互作用:由于大气逃逸增强的功率

Andrés Presa, Aline A. Vidotto, Filip Elekes

AI总结 研究通过三维辐射磁流体动力学模拟揭示了大气逃逸对恒星-行星磁耦合的影响,发现逃逸率与功率存在平方根关系,为光蒸发行星的磁耦合观测提供了新目标。

Comments 18 pages, 14 figures, 4 tables. Version accepted for publication in MNRAS, after incorporating referee's comments

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AI中文摘要

观测到近 transit 相位的恒星活动提供了恒星-行星磁相互作用(SPMI)的证据,类似于木星与其卫星之间的磁耦合。将 SPMI 信号的功率与分析理论比较可以约束系外行星磁场,但基于月球磁层类比的模型往往低估观测到的能量通量。与月球不同,许多近邻系外行星是扩展的、高度受辐射的气态巨行星,经历显著的光蒸发。然而,尚不清楚大气逃逸如何影响恒星-行星磁耦合。本文通过三维辐射磁流体动力学模拟,同时建模行星蒸发和 SPMI,在一个嵌入磁化恒星风中的热木星行星中。模拟揭示了称为阿耳法翼的磁结构的形成,这些结构将磁能输送到恒星。当行星的日侧质量损失率 $\dot{M}_d$ 低于由行星与恒星风间压力平衡定义的阈值 $\dot{M}_0$($\dot{M}_d \leq \dot{M}_0$)时,最大功率输送到恒星与阿耳法翼模型预测一致。对于更高的逃逸率,行星流出物打开额外的磁通量,SPMI 功率与 $(\dot{M}_d / \dot{M}_0)^{1/2}$ 成正比。将此标度定律应用于 HD18973 系统,发现 50 G 的行星如果 $\dot{M}_d \sim 5 \times 10^{11}$ g/s 可再现观测到的功率。尽管该信号可能仅代表总功率的一部分,其他机制可能放大能量预算。这些结果表明,处于亚阿耳法轨道的光蒸发行星是 SPMI 观测的有希望的目标。

英文摘要

Observations of periodic stellar activity near the transit phase of a close-in exoplanet provide evidence of star-planet magnetic interactions (SPMI), similar to the magnetic coupling between Jupiter and its moons. Comparing the power associated with SPMI signals to analytical theories offers a way to constrain exoplanetary magnetic fields, but models based on moon-magnetosphere analogs often underpredict observed energy fluxes. Unlike moons, many close-in exoplanets are extended, highly irradiated gas giants undergoing significant photoevaporation. However, it is not known how atmospheric escape influences the star-planet magnetic coupling. Here, we present three-dimensional radiation magneto-hydrodynamic simulations that simultaneously model planetary evaporation and SPMI in a hot Jupiter planet embedded in a magnetised stellar wind. Our simulations reveal the formation of magnetic structures known as Alfvén wings, which transport magnetic energy away from the planet. When the dayside mass-loss rate $\dot{M}_d$ of the planet lies below a threshold $\dot{M}_0$ defined by pressure balance between the planetary and stellar winds ($\dot{M}_d \leq \dot{M}_0$), the maximal power delivered to the star matches predictions from the Alfvén wing model. For higher escape rates, the planetary outflow opens additional magnetic flux, and the SPMI power increases proportionally with $(\dot{M}_d / \dot{M}_0)^{1/2}$. Applying this scaling law to the HD18973 system, we find that a $50$ G planet could reproduce the observed power if $\dot{M}_d \sim 5 \times 10^{11}$ g/s. Although this signal likely represents only a fraction of the total power, additional mechanisms could amplify the energy budget. These results show that photoevaporating exoplanets in sub-Alfvénic orbits constitute promising targets for SPMI observations.

2604.05521 2026-06-08 physics.plasm-ph cond-mat.mtrl-sci 版本更新

Development of a 3D-CNN-based Prediction Model for Migration Barriers in Plasma-Wall Interactions

基于3D-CNN的迁移障碍预测模型的开发

Seiki Saito, Keisuke Takeuchi, Hiroaki Nakamura, Yasuhiro Oda, Kazuo Hoshino, Yuki Homma, Shohei Yamoto, Yuki Uchida

AI总结 本文提出利用3D-CNN高效预测等离子体-壁相互作用中迁移障碍,通过局部三维势能分布和体素化空间坐标输入,实现快速准确的迁移障碍预测,提升分子动力学与kMC混合模拟的计算效率。

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AI中文摘要

理解等离子体面对材料如钨中氢同位素的长期输运对于磁笼聚变反应堆的稳态运行至关重要。然而,随着原子结构在持续等离子体辐照下动态变化,动态更新动能蒙特卡罗(kMC)模拟的过渡参数仍是一个严重的计算瓶颈。通常,计算这些迁移障碍需要迭代且计算成本高的Nudged Elastic Band(NEB)方法。为克服这一限制,本文提出了一种高效的替代模型,利用三维卷积神经网络(3D-CNN)预测迁移障碍,建立了实现实时分子动力学(MD)和kMC混合模拟所需的最终组件。所提出的深度学习模型采用两通道体积分输入,即局部三维势能分布和初始和最终捕获点的体素化空间坐标,直接输出迁移障碍作为标量值。在使用嵌入原子方法(EAM)势能评估的综合钨-氢配置数据集上训练,该模型表现出稳健的预测准确性,达到平均绝对误差(MAE)为0.124 eV,高决定系数为0.890。此外,利用GPU加速,推断时间减少到约2.7毫秒每障碍,比传统NEB计算快23000倍以上。这种极高的加速有效解决了过渡率评估的计算瓶颈,为等离子体-壁相互作用的大规模动态建模铺平了道路。

英文摘要

Understanding the long-term transport of hydrogen isotopes in plasma-facing materials, such as tungsten, is critical for the steady-state operation of magnetic confinement fusion reactors. However, dynamically updating the transition parameters for kinetic Monte Carlo (kMC) simulations as the atomic structure evolves under continuous plasma irradiation remains a severe computational bottleneck. Conventionally, calculating these migration barriers requires the iterative and computationally expensive Nudged Elastic Band (NEB) method. To overcome this limitation, this article presents a highly efficient surrogate model for predicting migration barriers using a three-dimensional Convolutional Neural Network (3D-CNN), establishing the final component necessary to realize on-the-fly molecular dynamics (MD) and kMC hybrid simulations. The proposed deep learning model takes a two-channel volumetric input, the local three-dimensional potential energy distribution and the voxelized spatial coordinates of the initial and final trapping sites, to directly output the migration barrier as a scalar value. Trained on a comprehensive dataset of tungsten-hydrogen configurations evaluated using the Embedded Atom Method (EAM) potential, the model demonstrated robust predictive accuracy, achieving a Mean Absolute Error (MAE) of 0.124 eV and a high coefficient of determination of 0.890. Furthermore, utilizing GPU acceleration, the inference time is reduced to approximately 2.7 milliseconds per barrier, achieving a speed-up ratio of over 23,000 compared to conventional NEB calculations. This extraordinary acceleration effectively resolves the computational barrier of transition rate evaluations, paving the way for large-scale, dynamic modeling of plasma-wall interactions.

2604.04799 2026-06-08 math.CA 版本更新

On a $_2F_1\big(\frac{1}{4}\big)$-identity due to Gosper

关于Gosper提出的一个$_2F_1(\frac{1}{4})$恒等式

Cetin Hakimoglu-Brown

AI总结 本文提出一种基于积分的方法,用于构造特定形式的$_2F_1$级数特殊值,通过Gosper提出的恒等式评估了一个收敛速率为$(\frac{172872}{185039})^2$的$_2F_1$级数。

Comments 11 pages

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AI中文摘要

只有在极少数情况下,一个具有有理参数和有理参数的$_2F_1(z)$级数,除了与经典超几何恒等式相关的$z \in \{\pm 1, \frac{1}{2}\}$情况外,才能通过$Γ$-值的组合进行评估。本文提出了一种新的基于积分的方法,用于构造所需形式的$_2F_1$级数特殊值。我们应用这种方法,利用Gosper最初提出的、后来由Vidunas、Ebisu和Zudilin考虑的$_2F_1(\frac{1}{4})$恒等式,来评估一个收敛速率为$(\frac{172872}{185039})^2$的$_2F_1$级数。在现有研究中,如Ebisu和Zeilberger的工作,我们的新级数似乎在参数的分子/分母方面具有最大的值。

英文摘要

It is only in exceptional cases that a $_2F_1(z)$-series with rational parameters and a rational argument, apart from the cases for $z \in \{ \pm 1, \frac{1}{2} \}$ associated with classical hypergeometric identities, admits an evaluation given by a combination of $Γ$-values with rational arguments. In this paper, we present a new and integration-based approach toward the construction of special values for $_2F_1$-series of the desired form. We apply this approach using a $_2F_1\big(\frac{1}{4}\big)$-identity originally due to Gosper and later considered by Vidunas, Ebisu, and Zudilin, to evaluate a ${}_{2}F_{1}$-series of convergence rate $\big(\frac{172872}{185039}\big)^2$. With regard to extant research on so-called ``strange'' ${}_{2}F_{1}$-evaluations, as in the work of Ebisu and Zeilberger, our new series seems to have the largest numerator/denominator in its argument.

2604.04024 2026-06-08 math.CO 版本更新

A note on piercing discrete rectangles

关于刺穿离散矩形的注记

Wei Rao

AI总结 本文改进了二维情况下(p,q)问题的界限,证明当q=2且d=2时,存在一个大小为O((p log log p)^2)的子集S,使得每个矩形包含S中的点。当p=2时,S的大小可被限制为4。

Comments We improve the bounds obtained in the original manuscript

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AI中文摘要

2008年,Halman为R^d中的轴对齐长方体证明了一个离散Helly型定理。最近,Edwards和Soberón将此结果扩展到(p,q)设置中,其中p≥q≥d+1,随后Gangopadhyay、Polyanskii和本文作者将其扩展到p≥q≥2的情况。本文在q=2和d=2的情况下获得了(p,q)问题的改进界限。更具体地说,我们的主要结果指出,对于任何整数p≥2,任何P⊆R^2的集合,以及任何有限的轴对齐矩形族B,若每个矩形包含P中的点,且在任意p个矩形中存在两个交集包含P中的点,则存在一个子集S⊆P,其大小至多为O((p log log p)^2),使得每个矩形包含S中的点。此外,当p=2时,S的大小可被限制为4。

英文摘要

In 2008, Halman proved a discrete Helly-type theorem for axis-parallel boxes in $\mathbb R^d$. Very recently, this result was extended to the $(p,q)$ setting with $p \geq q \geq d+1$ by Edwards and Soberón, and subsequently to the case $p \geq q \geq 2$ by Gangopadhyay, Polyanskii, and the author of this paper. In this paper, we obtain improved bounds for the $(p,q)$ problem in the case $q=2$ and $d=2$. More precisely, our main result asserts that for any integer $p \geq 2$, any set $P \subseteq \mathbb R^2$, and any finite family $\mathcal B$ of axis-parallel rectangles in $\mathbb R^2$ such that every rectangle contains a point of $P$, if among every $p$ rectangles there exist two whose intersection contains a point of $P$, then there exists a subset $S \subseteq P$ of size at most $O\!\bigl( (p \log \log p)^2 \bigr)$ such that every rectangle contains a point of $S$. Moreover, when $p=2$, the size of $S$ can be bounded by $4$.

2604.03475 2026-06-08 math.OC 版本更新

Scheduling Electricity Production Units to Mitigate Severe Weather Impact: An Efficient Computational Implementation

调度电力生产单元以减轻恶劣天气影响:一种高效的计算实现

Yongzheng Dai, Antonio J. Conejo, Feng Qiu

AI总结 本文提出一种框架,通过预先安排发电单元的投入以适应可能发生的恶劣天气后的传输拓扑,以最小化负载削减。研究改进了物理定律的表示并开发了高效的求解算法。

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AI中文摘要

电力系统中的极端天气事件可能导致线路跳闸或输电基础设施的物理损坏,进而导致大规模负载削减。为减轻此风险,本文提出一个框架,通过战略性地提前安排发电单元(特别是慢启动单元)的投入,以适应可能发生的恶劣天气后的传输拓扑。目标是在最坏条件下最小化负载削减。本文的两个主要贡献是:首先,提供了比先前研究更准确的底层物理定律表示;其次,开发了一种高效求解算法,优于现有最先进的求解器。所提出的框架被建模为一个两阶段鲁棒优化模型。第一阶段安排发电单元以应对中断,第二阶段优化功率调度决策以在最坏的传输拓扑下最小化负载削减。为确保系统可靠性和安全性,我们整合了凸化的交流功率流约束。所得到的模型是一个三阶段混合整数非线性优化问题。为解决其计算复杂性,我们设计了一种问题特定的外近似算法,嵌入在列生成和约束生成框架中。计算结果表明,所提出的模型和求解方法可以在合理时间内为中等规模实例达到标准最优性间隙。

英文摘要

Extreme weather events in electric power systems can cause line trips or physical damage to transmission infrastructure, potentially leading to large-scale load shedding. To mitigate this risk, we propose a framework that strategically pre-positions the commitment of generation units--particularly slow-start units--to adapt to transmission topologies that may arise following such events. The objective is to minimize load shedding under worst-case conditions. This paper makes two main contributions. First, we provide a more accurate representation of the underlying physical laws than those used in prior studies. Second, we develop a highly efficient solution algorithm that outperforms state-of-the-art, off-the-shelf solvers. The proposed framework is formulated as a two-stage robust optimization model. In the first stage, generation units are scheduled in anticipation of disruptions. In the second stage, power dispatch decisions are optimized to minimize load shedding under the worst-case transmission topology. To ensure system reliability and security, we incorporate convexified AC power flow constraints. The resulting model is a tri-level mixed-integer nonlinear optimization problem. To address its computational complexity, we design a problem-specific outer approximation algorithm embedded within a column-and-constraint generation framework. Computational results show that the proposed model and solution approach can achieve solutions within a standard optimality gap in a reasonable time for moderately large instances.

2512.06697 2026-06-08 cond-mat.mtrl-sci physics.app-ph 版本更新

Learning Thermoelectric Transport from Crystal Structures via Multiscale Graph Neural Network

通过多尺度图神经网络学习热电输运特性

Yuxuan Zeng, Wei Cao, Yijing Zuo, Fang Lyu, Wenhao Xie, Tan Peng, Yue Hou, Ling Miao, Ziyu Wang, Jing Shi

AI总结 本文提出一种多尺度图神经网络模型,用于估计无机热电晶体的电子输运系数,结合第一性原理计算揭示材料输运行为的物理机制。

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AI中文摘要

图神经网络(GNNs)被设计用于从图结构数据中提取潜在模式,使其特别适合于晶体表示学习。本文提出了一种专门用于估计无机热电晶体电子输运系数的GNN模型。该模型以多尺度方式编码晶体结构和物理化学性质,涵盖全局、原子、键和角级别。该模型在基准数据集上实现了最先进的性能,具有显著的外推能力。通过将所提的GNN与第一性原理计算相结合,我们成功识别出表现出卓越电子输运性能的化合物,并从全局和原子层面进行可解释性分析,追溯其独特输运行为的起源。有趣的是,模型的决策过程自然揭示了潜在的物理模式,为计算机辅助材料设计提供了新的见解。

英文摘要

Graph neural networks (GNNs) are designed to extract latent patterns from graph-structured data, making them particularly well suited for crystal representation learning. Here, we propose a GNN model tailored for estimating electronic transport coefficients in inorganic thermoelectric crystals. The model encodes crystal structures and physicochemical properties in a multiscale manner, encompassing global, atomic, bond, and angular levels. It achieves state-of-the-art performance on benchmark datasets with remarkable extrapolative capability. By combining the proposed GNN with \textit{ab initio} calculations, we successfully identify compounds exhibiting outstanding electronic transport properties and further perform interpretability analyses from both global and atomic perspectives, tracing the origins of their distinct transport behaviors. Interestingly, the decision process of the model naturally reveals underlying physical patterns, offering new insights into computer-assisted materials design.

2604.02607 2026-06-08 hep-ph 版本更新

Dual Implications of Quark Mass Hierarchies to Flavor Structure

轻子质量层级对味结构的双重影响

Ying Zhang

AI总结 本文通过分析夸克质量层级揭示味结构的两个关键点:质量矩阵和CKM混合,提出一种非冗余且家族统一的夸克味结构,替代标准模型中模糊的杨-米尔斯相互作用。

Comments 11 pages, 1 figure

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AI中文摘要

为了解开味结构之谜,我们展示了夸克质量层级的两个影响:一个影响质量矩阵本身,另一个影响CKM混合。这些影响自然导致一种非冗余、有序且家族统一的夸克味结构,这为替代标准模型中模糊的杨-米尔斯相互作用提供了候选方案。

英文摘要

To solve the mystery of flavor structure, we demonstrate two implications emerging from the hierarchical masses of quarks: one for the mass matrix itself and one for the CKM mixing. These implications naturally lead to a non-redundant, ordered, and family-unified quark flavor structure, which serves as a candidate to replace the unclear Yukawa interactions of the Standard Model.

2604.02065 2026-06-08 physics.plasm-ph astro-ph.HE astro-ph.SR 版本更新

Triggering physical plasmoids in forming current sheets: conditions and diagnostics

触发形成电流片中的物理等离子体体:条件和诊断

Hubert Baty

AI总结 研究通过伪谱代码探讨触发电流片中等离子体体不稳定性条件,发现需扰动幅度超过临界值且包含不稳定波数,通过连续噪声注入验证,结果与Comisso等理论一致,解决先前矛盾。

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AI中文摘要

我们利用伪谱代码研究了在电阻磁流体动力学框架中触发形成电流片中等离子体体不稳定性条件,应用于伦琴数S≈10^5的奥萨格-坦 vortex。通过电流密度功率谱E_J(k)和涡度谱E_ω(k)评估模拟收敛性,并证明该诊断在存在物理等离子体体时仍有效。我们展示当三个条件同时满足时,物理等离子体体可在高分辨率谱模拟中被触发:扰动在最大电流密度时间附近施加,幅度超过临界阈值ε_c≈10^-5,且包含不稳定波数。通过连续噪声注入验证,结果在幅度低一个到两个数量级时相似。所得增长速率和等离子体体数量与Comisso等(2017)理论一致,解决了García Morillo & Alexakis(2025)提出的明显矛盾,并澄清了数值噪声在触发等离子体体不稳定性中的作用。

英文摘要

We investigate the conditions for triggering the plasmoid instability in a dynamically forming current sheet in the resistive magnetohydrodynamic framework, using a pseudo-spectral code applied to the Orszag-Tang vortex at Lundquist number $S \sim 10^5$. Following García Morillo \& Alexakis (2025), we use the power spectrum of the current density $E_J(k)$, complemented by the vorticity spectrum $E_ω(k)$, to assess the convergence of our simulations, and show that this diagnostic remains valid even in the presence of physical plasmoids, allowing us to unambiguously distinguish them from spurious ones. We then show that physical plasmoids can be triggered in a well-resolved spectral simulation when three conditions are simultaneously met: a perturbation applied near the time of maximum current density, with amplitude above a critical threshold $\varepsilon_c \sim 10^{-5}$ for our numerical scheme, and with spectral content containing the unstable wavenumbers. These conditions are confirmed using continuous noise injection, which yields similar results at amplitudes one to two orders of magnitude lower. The resulting growth rates and plasmoid numbers are in good agreement with the theory of \citet{Comisso2017}. These results resolve the apparent paradox raised by García Morillo \& Alexakis (2025) and also clarify the role of numerical noise in the triggering of the plasmoid instability.

2604.01717 2026-06-08 math.CO 版本更新

On expectations and variances in the hard-core model

关于硬核模型中的期望与方差

Weiyuan Zhang, Kexiang Xu

AI总结 本文研究了图中独立集数量与硬核模型中的占用分数,推导了独立数为α的n顶点图的占用分数的紧上界和下界,并验证了Davies等人提出的猜想。

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AI中文摘要

硬核模型可用于理解图中独立集的数量,在极值图论中具有重要意义。占用分数,定义为独立多项式对数导数,是硬核模型中的关键量。Davies等人(2017)为d-正则图建立了占用分数的上界,Perarnau和Perkins(2018)为给定环长的图推导了相应界。受其工作启发,本文为独立数为α的n顶点图提供了占用分数的紧上界和下界,扩展了经典独立多项式界的结果。我们还证明了Davies等人(2025)提出的相关猜想。

英文摘要

The hard-core model can be used to understand the number of independent sets in graphs in extremal graph theory. The occupancy fraction, defined as the logarithmic derivative of the independence polynomial of a graph, is a key quantity in hard-core model. Davies \textit{et al.} (2017) established an upper bound on the occupancy fraction for $d$-regular graphs, and Perarnau and Perkins (2018) derived a corresponding bound on it for graphs with given girth. Inspired by their work, we provide the tight upper and lower bounds on occupancy fraction in $n$-vertex graphs with independence number $α$, extending the classical results on bounds for independence polynomials. We also prove a relevant conjecture posed by Davies \textit{et al.} (2025) on this topic.

2604.00117 2026-06-08 gr-qc 版本更新

Distinguishing Black Holes and Neutron Stars via Optical Images Illuminated by Thick Accretion Disks

通过厚吸积盘照亮的光学图像区分黑洞和中子星

Chen-Yu Yang, Xiao-Xiong Zeng

AI总结 本文研究中子星在非辐射效高效吸积流模型下的光学图像,考虑多项式状态方程,分析多项式指数N和观测者倾角θ_o对图像形态的影响,并与Schwarzschild黑洞阴影进行比较,揭示中子星和黑洞在光学外观上的显著差异。

Comments 23 pages, 4 figures

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AI中文摘要

本文研究了中子星在非辐射效高效吸积流模型下的光学图像,考虑多项式状态方程。通过求解中子星的数值解,联合求解测地线方程和辐射传输方程。主要考察多项式指数N和观测者倾角θ_o对图像形态的影响。获得的图像也与Schwarzschild黑洞的阴影进行比较。结果显示,在假设光子轨迹终止于中子星表面的情况下,图像呈现围绕内暗区的明亮高阶结构。随着N的增加,高阶图像的大小逐渐扩大。随着θ_o的增加,中子星轮廓被来自赤道面外的辐射遮挡的程度更加明显。与相同参数配置下获得的黑洞阴影相比,中子星表现出更大的高阶图像和更延伸的遮挡内暗区,而黑洞的高阶图像更容易区分。这些结果表明中子星和黑洞在光学外观上有显著差异,从而为通过高分辨率成像区分它们提供了理论依据。

英文摘要

This paper investigates the optical images of neutron stars within the framework of the radiatively inefficient accretion flow model, taking into account a polytropic equation of state. After obtaining the numerical solutions of the neutron star, we solved numerically the geodesic equations together with the radiative transfer equation. We mainly examine the effects of the polytropic index $N$ and the observer inclination angle $θ_o$ on the image morphology. The obtained images are also compared with the shadow of a Schwarzschild black hole. It is shown that, under the assumption that photon trajectories are terminated at the neutron star surface, the image exhibits a bright higher order structure surrounding an inner dark region. As $N$ increases, the size of the higher-order image gradually expands. As $θ_o$ increases, the obscuration of the neutron star silhouette by radiation originating outside the equatorial plane becomes more pronounced. Compared with the black hole shadow obtained under the same parameter configuration, the neutron star exhibits a larger higher order image and a more extended obscured inner dark region, whereas the higher order image of the black hole is more readily distinguishable. These results indicate significant differences in the optical appearance of neutron stars and black holes, and thus provide a theoretical basis for distinguishing between them through high resolution imaging.

2511.17949 2026-06-08 physics.app-ph 版本更新

Passive acoustic logic via topology-optimized waveguides

通过拓扑优化波导实现的被动逻辑

Ali Jafari, Mohamed Mousa, Mostafa Nouh

AI总结 本文提出利用弹性结构波传播动力学实现机械逻辑,通过拓扑优化设计波导,实现波场干涉能量局部化,展示机械逻辑门的实验验证及机械加法器的可扩展应用。

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AI中文摘要

现代数字设备日益增长的能量需求促使需要替代的低功耗计算机制。当入射负载以声学或振动波形式存在时,机械信息处理能力消除了转换需求,为被动计算铺平道路。最近的研究提出了通过屈曲、双稳态和折纸启发的晶格学习和执行机械逻辑的系统。然而,由于形状变形的大时间尺度,这些概念面临操作缓慢或需要主动刺激适应材料的问题。为解决这些限制,我们提出了一种新的机械逻辑方法,利用弹性结构波传播的丰富动力学。替代传统的正向设计工具,如带图和传输光谱,我们采用多方面的拓扑优化方法,使我们能够在极大的设计空间内识别候选波导配置。通过在均匀基质中引入空洞,优化的波导能够精确操控波传播路径,触发散射波场的有利干涉,最终在对应给定逻辑函数的读出处实现能量局部化。通过实验装置验证了此类逻辑门的有效性和对非均匀加载的鲁棒性。通过将这些基本模块集成到机械加法器中,我们展示了更复杂的机械计算电路的可扩展部署,为机械信号处理和物理计算开辟了新途径。

英文摘要

Growing energy demands of modern digital devices necessitate alternative, low-power computing mechanisms. When incident loads take the form of acoustic or vibrational waves, the ability to mechanically process information eliminates the need for transduction, paving the way for passive computing. Recent studies have proposed systems that learn and execute mechanical logic through buckling, bistability, and origami-inspired lattices. However, owing to the large timescales of shape morphing, such concepts suffer from slow operation or require active stimulation of adaptive materials. To address these limitations, we present a novel approach to mechanical logic, leveraging the rich dynamics of wave propagation in elastic structures. In lieu of traditional forward-design tools, such as band diagrams and transmission spectra, we employ a multi-faceted topology optimization approach, enabling us to identify candidate waveguide configurations within an extremely large design space. By incorporating voids within an otherwise uniform substrate, the optimized waveguides are able to precisely manipulate wave propagation paths, triggering desirable interferences of the scattered wavefield that culminate in energy localization at readouts corresponding to a given logic function. An experimental setup is used to demonstrate the efficacy of such logic gates and their resilience to non-uniform loading. By implementing these building blocks into a mechanical adder, we demonstrate the scalable deployment of more sophisticated mechanical computing circuits, opening up new avenues in mechanical signal processing and physical computing.

2507.03192 2026-06-08 math.NA cs.NA 版本更新

Parallel multilevel methods for solving the Darcy--Forchheimer model based on a nearly semicoercive formulation

并行多重级方法用于基于近半协变形式的达西-福克海默模型求解

Jongho Park, S. Majid Hassanizadeh

AI总结 本文提出并行多重级方法用于求解达西-福克海默模型,通过增广拉格朗日方法将其转化为近半协变凸优化问题,并通过理论分析和数值实验验证了方法的鲁棒性和有效性。

Comments 31 pages, 3 figures

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AI中文摘要

高速流体通过多孔介质的流动通过规定流速与压力梯度之间的非线性关系,即达西-福克海默方程。本文关注于分析用于求解达西-福克海默模型的并行多重级方法。我们首先通过增广拉格朗日方法将达西-福克海默模型重新表述为一个近似半协变的凸优化问题。在此基础上,我们开发了一种并行多重级方法,也称为多重加性施瓦茨方法,在子空间校正框架下用于近似半协变凸问题,从而得到一个理论支持且计算高效的达西-福克海默模型求解器。收敛性分析建立了对增广拉格朗日参数ε的鲁棒性。为进一步提高收敛性,我们结合了回溯线搜索和全近似方案。数值结果支持了理论发现,并展示了所提方法的有效性。

英文摘要

High-velocity fluid flow through porous media is modeled by prescribing a nonlinear relationship between the flow rate and the pressure gradient, called the Darcy--Forchheimer equation. This paper is concerned with the analysis of parallel multilevel methods for solving the Darcy--Forchheimer model. We begin by reformulating the Darcy--Forchheimer model as a nearly semicoercive convex optimization problem via the augmented Lagrangian method. Building on this formulation, we develop a parallel multilevel method, also known as a multilevel additive Schwarz method, within the framework of subspace correction for nearly semicoercive convex problems, yielding a theoretically supported and computationally efficient solver for the Darcy--Forchheimer model. The convergence analysis establishes robustness with respect to the augmented Lagrangian parameter $ε$. To further enhance convergence, we incorporate a backtracking line search and a full approximation scheme. Numerical results support the theoretical findings and demonstrate the effectiveness of the proposed approach.

2603.28188 2026-06-08 math.AP 版本更新

Kohler-Jobin inequality for $p$-Laplace operator in the Gauss space

p-拉普拉斯算子在高斯空间中的科赫-乔宾不等式

Francesco Chiacchio, Vincenzo Ferone, Anna Mercaldo, Jing Wang

AI总结 研究在高斯空间中,给定泛化扭矩刚度的集合的p-拉普拉斯算子第一个狄利克雷特征值的精确下界,扩展了科赫-乔宾的经典谱不等式,并建立了一种Payne-Rayner型不等式。

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AI中文摘要

本文推导了在高斯空间中,给定泛化扭矩刚度的集合的p-拉普拉斯算子第一个狄利克雷特征值的精确下界。该结果是对科赫-乔宾经典谱不等式的一种扩展。证明基于对泛化扭矩刚度的细致分析和精确质量比较结果。此外,还建立了Payne-Rayner型不等式。

英文摘要

A sharp lower bound for the first Dirichlet eigenvalue of the $p$-laplacian in Gaussian space is derived for sets with prescribed generalized torsional rigidity. The result provides an extension of the classical spectral inequality due to Kohler-Jobin. The proof is based on a careful analysis of the generalized torsional rigidity and on a sharp mass comparison result. Furthermore, a Payne-Rayner type inequality is established.

2505.13874 2026-06-08 math.DG 版本更新

The equations of Gauss, Codazzi and Ricci of surfaces in 4-dimensional space forms

四维空间形式中曲面的高斯、卡当和里奇方程

Naoya Ando

AI总结 本文通过诱导连接研究四维空间形式中时空曲面的高斯、卡当和里奇方程,并基于此刻画与双叶外幂拉回丛相关的曲面类别。

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AI中文摘要

设N为黎曼、中性或洛伦兹4维空间形式。本文中,[7]中给出的曲面的高斯、卡当和里奇方程的表达式在曲面的双叶外幂拉回丛的复化诱导连接下自然理解。此外,基于这些表达式,我们刻画了几种与双叶外幂拉回丛的协变导数相关的曲面类别。

英文摘要

Let $N$ be a Riemannian, neutral or Lorentzian $4$-dimensional space form. In this paper, the expressions of the equations of Gauss, Codazzi and Ricci of a space-like or time-like surface in $N$ given in [7] are naturally understood in terms of the induced connection (of the complexification) of the two-fold exterior power of the pull-back bundle on the surface. Moreover, based on such expressions, we characterize several classes of surfaces related to the covariant derivatives of the twistor lifts and so on.

2603.27031 2026-06-08 hep-th cond-mat.stat-mech 版本更新

The Lee-Yang model and its generalizations through the lens of long-range deformations

李-阳模型及其通过远距变形视角的推广

Fanny Eustachon

AI总结 研究通过远距变形视角探讨李-阳模型及其推广,发现m>2时两种构造存在矛盾,而m=2的远距李-阳模型与远距伊辛模型类似。

Comments 10 pages, 3 figures; References added

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AI中文摘要

在二维情况下,非单位类共形最小模型$\mathcal{M}(2,2m+1)$最近被推测为标量场理论中具有复交互作用$iφ^{2m-1}$的重整化群固定点。我们通过分别基于最小模型及其潜在的朗道-金茨堡形式的两个远距构造的扰动研究检验了这一猜想。对于m>2,当随后将两种构造联系起来时发现不一致。相反,远距李-阳模型,即m=2的情况,被证明类似于远距伊辛模型。

英文摘要

In two dimensions, the non-unitary class of conformal minimal models, $\mathcal{M}(2,2m+1)$, has been recently conjectured to arise as renormalization-group fixed points of scalar field theories with complex $iφ^{2m-1}$ interaction, $m\in \mathbb{N}$, $m\ge2$. We test a variation of this conjecture through the perturbative study of two separate long-range constructions based on respectively the minimal model and its potential Landau-Ginzburg formalism. For $m>2$, inconsistencies are found when subsequently relating both constructions. In contrast, the long-range Lee-Yang model, the $m=2$ case, is shown to be analogue to the long-range Ising model.

2603.26352 2026-06-08 astro-ph.GA astro-ph.SR 版本更新

Population III star formation in an X-ray background: IV. On-the-fly calculation of radiation backgrounds and their impact on the intergalactic medium

III型星形成在X射线背景中的影响:IV. 用实时方法计算辐射背景及其对星际介质的影响

Jongwon Park, Massimo Ricotti

AI总结 本文通过宇宙放大模拟研究X射线源对III型星形成的影响,探讨了辐射背景对星际介质的加热和电离作用,以及其对分子氢和III型星形成的影响。

Comments 17 pages, 14 figure, accepted for publication in MNRAS

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AI中文摘要

在本文中,我们通过宇宙放大模拟研究了X射线源对III型星形成的影响,探讨了X射线对星际介质的电离和加热作用,以及其对分子氢和III型星形成的影响。我们采用了一种最小的X射线反馈模型,其中X射线仅来自III型超新星,计算了宇宙平均密度区域的全球X射线和里曼-韦纳(LW)辐射背景。这种方法在模拟过程中实时捕捉了III型星与所产生辐射背景之间的反馈循环。III型超新星产生了一个弱X射线背景(J_X,21≈10^-5)和一个中等LW背景(J_LW,21≈10^-1);后者在z≈12以下增强(J_LW,21≈10^1-10^2)随着II型星形成开始。将这些背景应用于不同平均密度区域产生净正X射线反馈,增加III型星数量密度,尤其是在低密度区域增强更显著。正反馈在实时计算X射线背景而非后处理时更为明显,证明了反馈循环的重要性。X射线背景还提高了高红移时的汤姆逊散射光学深度,而总光学深度与Planck 2018约束一致。由于我们的模型只包含III型超新星作为X射线源,因此代表了最保守的情景;当加入额外源时,预期X射线反馈会更强,这将在未来工作中探讨。

英文摘要

In this paper, part of a series on the effects of X-ray sources in promoting Population III (Pop III) star formation, we investigate the ionisation and heating of the intergalactic medium (IGM) and the consequent enhancement of molecular hydrogen (H$_{2}$) and Pop III formation using cosmological zoom-in simulations. We adopt a minimal X-ray feedback model in which X-rays originate solely from Pop III supernovae, and compute the global X-ray and Lyman-Werner (LW) radiation backgrounds on-the-fly during the simulation of a mean-density region of the Universe. This approach self-consistently captures the feedback loop between Pop III stars and the radiation backgrounds they produce. Pop III supernovae generate a weak X-ray background (J$_{\mathrm{X,21}} \sim 10^{-5}$) and a moderate LW background (J$_{\mathrm{LW,21}} \sim 10^{-1}$); the latter intensifies below $z \approx 12$ (J$_{\mathrm{LW,21}} \sim 10^{1}-10^{2}$) with the onset of Pop II star formation. Applying these backgrounds to regions of varying mean density produces a net positive X-ray feedback that increases the Pop III number density, with stronger enhancement in underdense regions. The positive feedback is more pronounced when the X-ray background is computed on-the-fly rather than by post-processing, demonstrating the importance of the feedback loop. The X-ray background also raises the Thomson scattering optical depth at high redshift, while the total optical depth remains consistent with Planck 2018 constraints. Because our model includes only Pop III supernovae as X-ray sources, it represents the most conservative scenario; stronger X-ray feedback is expected when additional sources are included, as will be explored in future work.

2603.26212 2026-06-08 math.NA cs.NA 版本更新

Divergence-free unfitted finite element discretisations for the Darcy problem

无拟合有限元离散化方法用于达西问题

Santiago Badia, Anne Boschman, Alberto F. Martín, Erik Nilsson, Ricardo Ruiz-Baier, Sara Zahedi

AI总结 本文提出一种基于H(div)-符合通量空间和不连续压力空间的无拟合有限元方法,实现点wise离散质量守恒,并通过L2稳定化和混合项稳定化提升鲁棒性,验证了方法的稳定性和误差估计。

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AI中文摘要

我们开发了一种基于H(div)-符合通量空间和不连续压力空间的无拟合有限元离散化方法,用于达西问题。该方法旨在保持点wise离散质量守恒,同时在存在任意小的切割单元时仍保持鲁棒性。通过结合L2稳定化和额外的混合项稳定化,增强了压力控制而不破坏局部守恒结构。我们考虑了单元级(整体)和面基的ghost-penalty实现方式。混合边界条件通过弱化在无拟合边界上的通量和压力迹来处理。我们证明了稳定性及先验误差估计,常数与切割配置无关,并在纯压力边界条件下建立了压力鲁棒的通量误差界。我们还引入了一种增广拉格朗日变体,提高了守恒约束的控制能力,并适用于高效的预处理策略。数值实验验证了理论结果,展示了最优收敛性、切割无关的条件数和质量守恒,直至求解器容忍度。

英文摘要

We develop an unfitted compatible finite element discretisation for the Darcy problem based on $H(\mathrm{div})$-conforming flux spaces and discontinuous pressure spaces. The method is designed to preserve pointwise discrete mass conservation while remaining robust in the presence of arbitrarily small cut cells arising from unfitted meshes. Robustness is achieved by combining an $L^2$-stabilisation of the flux with an additional mixed-term stabilisation that enhances pressure control without destroying the local conservation structure. We consider both cell-wise (bulk) and face-based ghost-penalty realisations of the stabilisation. Mixed boundary conditions are handled by weak imposition of both flux and pressure traces on unfitted boundaries. We prove stability and a priori error estimates with constants independent of the cut configuration, and establish pressure-robust flux error bounds in the case of pure pressure boundary conditions. We also introduce an augmented Lagrangian variant that improves control of the conservation constraint and is amenable to efficient preconditioning strategies. Numerical experiments for a range of cut configurations, boundary-condition regimes and parameter choices confirm the theoretical results, demonstrating optimal convergence, cut-independent conditioning and mass conservation up to solver tolerance.

2508.09112 2026-06-08 astro-ph.CO astro-ph.GA 版本更新

Tracing Large-Scale Structure Morphology with Multiwavelength Line Intensity Maps

通过多波段线强度图追踪大尺度结构形态

Manas Mohit Dosibhatla, Suman Majumdar, Chandra Shekhar Murmu, Samit Kumar Pal, Saswata Dasgupta, Satadru Bag, Abhirup Datta

AI总结 本文利用多波段线强度图研究大尺度结构形态,通过渗透分析探讨结构连通性,并比较其与暗物质分布的关系,揭示不同天体物理过程对信号聚类模式的影响。

Comments 30 pages, 12 figures, 1 table. Published in JCAP

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Journal ref
JCAP06(2026)014
AI中文摘要

线强度测绘(LIM)是一种新兴技术,用于探测再电离时代的大尺度结构(LSS)。该技术通过整合特定谱线发射的总通量,从多个天体中捕捉到天空中的特定区域,而无需分辨单个源。通过映射不同星系的线发射,如HI 21厘米线和CO旋转线,可以揭示线发射体如何追踪底层物质分布的偏差,以及不同天体物理现象如何影响这些信号的聚类模式。在“宇宙网”结构合并形成单一连通结构的阶段称为渗透转变。利用后再电离时代的假想HI 21厘米和CO(1-0)LIM信号,我们通过渗透分析探讨结构的连通性,并将其与底层星系分布进行比较。我们利用一种称为局部维数的形态度量,探测空洞、丝状物和板状物对星系密度和线强度图的相对贡献。CO(1-0)图表现出更高的丝状行为和更大的板状物贡献,比21厘米图更明显。我们尝试解释CO(1-0)线的这种发射可能源于偏置环境。即将来临的SKA-Mid将产生z≈3的21厘米信号的光谱测绘图,在带1中。CO图可以在SKA-Mid第二阶段产生,此时频率覆盖预计会增加到约50GHz。我们提出了SKA-Mid调查中这些线强度图受热噪声和线干扰污染时局部维数恢复的预测。

英文摘要

Line intensity mapping (LIM) is an emerging technique for probing the large-scale structure (LSS) in the post-reionisation era. This captures the integrated flux of a particular spectral line emission from multiple sources within a patch of the sky without resolving them. Mapping different galaxy line emissions, such as the HI $21$-cm and CO rotational lines via LIM, can reveal complementary information about the bias with which the line emitters trace the underlying matter distribution and how different astrophysical phenomena affect the clustering pattern of these signals. The stage at which the structures in the "cosmic web" merge to form a single connected structure is known as the percolation transition. Using mock HI $21$-cm and CO($1-0$) LIM signals in the post-reionisation universe, we explore the connectivity of structures through percolation analysis and compare it with the underlying galaxy distribution. We probe the relative contributions of voids, filaments, and sheets to the galaxy density and line intensity maps using a morphological measure known as the local dimension. The CO($1-0$) map exhibits an increased filamentary behaviour and larger contribution from sheets than the $21$-cm map. We attempt to explain such an emission of the CO($1-0$) line from biased environments. The upcoming SKA-Mid will produce tomographic intensity maps of the $21$-cm signal at $z \lesssim 3$ in Band-1. CO maps can be produced at these redshifts in phase 2 of SKA-Mid, where the frequency coverage is expected to increase up to $\sim 50$ GHz. We present forecasts for the recovery of the local dimensions of these line intensity maps contaminated by thermal noise and line interlopers in SKA-Mid surveys.

2603.25528 2026-06-08 math.CO 版本更新

On separable permutations and three other pairs in the Schröder class

关于可分离排列和Schröder类中的三个其他对

Juan B. Gil, Oscar A. Lopez, Michael D. Weiner

AI总结 本文研究了由大Schröder数计数的四个模式回避排列类别的位置统计,通过结构分解和核方法推导出多变量生成函数,证明这些类别的计数由Schröder数给出,并发现与中央二项系数和Kreweras覆盖层次序列相关的三角数组。

Comments 15 pages. Revised version with a better introduction

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AI中文摘要

我们研究了由大Schröder数计数的四个模式回避排列类别的位置统计。具体来说,我们关注模式对{2413,3142}(可分离排列)、{1324,1423}、{1423,2413}和{1324,2134}。对于每个类别,我们推导出多变量生成函数,以跟踪特定条目的相对位置。我们的方法结合了结构分解与核方法,以获得涉及Schröder数生成函数的显式公式。作为副产品,我们获得了这些类别的计数由Schröder数给出的另一种证明。我们还识别出几个已知的三角数组,这些数组源自我们的位置细化,包括与中央二项系数和Kreweras关于覆盖层次序列中出现的序列的联系。

英文摘要

We study positional statistics for four families of pattern-avoiding permutations counted by the large Schröder numbers. Specifically, we focus on the pairs of patterns $\{2413,3142\}$ (separable permutations), $\{1324,1423\}$, $\{1423,2413\}$, and $\{1324,2134\}$. For each class, we derive multivariate generating functions that track the relative positions of specific entries. Our approach combines structural decompositions with the kernel method to obtain explicit formulas involving the generating function for the Schröder numbers. As a byproduct, we obtain alternative proofs that each of these classes is enumerated by the Schröder numbers. We also identify several known triangular arrays arising from our positional refinements, including connections to the central binomial coefficients and sequences appearing in the work of Kreweras on covering hierarchies.

2512.17561 2026-06-08 physics.app-ph 版本更新

Guided progressive reconstructive imaging: a new quantization-based framework for low-dose, high-throughput and real-time analytical ptychography

引导式渐进重建成像:一种基于量化的新框架,用于低剂量、高通量和实时分析ptychography

Hoelen L. Lalandec Robert, Arno Annys, Tamazouzt Chennit, Jo Verbeeck

AI总结 本文提出一种基于量化的新型框架,用于低剂量、高通量和实时分析ptychography,通过快速处理和预计算的核限制函数库,提高重建效率和灵活性。

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AI中文摘要

通过利用最近的探测器技术发展,使能够获取具有纳秒级时间分辨率的检测事件流,建立了一种新的ptychographic工作流程。这种方法学框架被称为引导式渐进重建成像,通过基本推导对获取的强度进行量化描述。已建立的直接相位检索解决方案,如Wigner分布去卷积方法,可以适应对接收计数的连续处理,无需密集的数据表示。因此,结果以逐步改进的估计形式获得,同时通过足够高的处理速度提供即时用户反馈,超越了采集带宽。这种快速测量得益于预计算的核限制函数库的累积使用,按触发探测器像素函数累积计数贡献。因此,重建提供了与直接相位检索方法相同的优势,特别是高剂量效率和没有复杂收敛动态,比当前替代方法的视场限制要少很多。其实施也显著更简单和灵活。总体而言,这项工作是当前技术的重大进步,使重复性和低剂量实验具有高可访问性,并适用于基于电子的成像、X射线衍射和光学显微镜。

英文摘要

By profiting from recent developments in detector technologies, making it possible to access a stream of detection events with few-ns time resolutions, a new ptychographic workflow is established. This methodological framework, referred to as guided progressive reconstructive imaging, relies on a quantization-based description of the acquired intensity, through an elementary derivation. Established direct phase retrieval solutions, such as the Wigner distribution deconvolution approach, can then be adapted to a continuous treatment of received counts, with no need for a dense data representation. Consequently, the result is obtained in the form of a progressively improving estimate, while providing immediate user feedback thanks to a processing speed high enough to surpass the acquisition bandwidth. This fast measurement is enabled by the cumulative usage of a pre-calculated library of kernel-limited functions, accumulating count-wise contributions as a function of the triggered detector pixel. Hence, the reconstruction offers the same advantages of direct phase retrieval methods, in particular a high dose-efficiency and the absence of complex convergence dynamics, with much less stringent restrictions on the field of view than is typical in current alternatives. Its implementation is also significantly more straightforward and flexible. Overall, this work constitutes a major evolution in the state-of-the-art, facilitating repeatable and low-dose experiments with high accessibility, and being applicable to electron-based imaging, X-ray diffraction and optical microscopy.

2603.24290 2026-06-08 quant-ph 版本更新

Emergence of the Partial Trace from Classical Probability Theory

从经典概率理论中涌现的部分追踪

Andrés Macho Ortiz, Francisco Javier Fraile Peláez, José Capmany

AI总结 本文基于经典概率理论,通过要求Born规则与概率质量函数的边缘化一致,推导出量子力学中部分追踪操作的起源,揭示其作为概率结构自然结果的本质。

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AI中文摘要

部分追踪通常在量子力学中被介绍为一种代数操作,用于定义复合系统的缩减状态。然而,这种操作的概率起源在文献中被系统性地忽视。本文展示,通过要求Born规则与概率质量函数的经典边缘化一致,部分追踪自然地从这种一致性要求中涌现。从经典边缘化规则出发,我们要求子系统的缩减密度算子必须重现由全局状态导出的本地测量统计。我们证明,这一要求直接导致标准的部分追踪表达式。从这一视角看,缩减密度算子并非一种任性的代数构造,而是量子力学概率结构的自然结果。

英文摘要

The partial trace is commonly introduced in quantum mechanics as an algebraic operation used to define reduced states of composite systems. However, the probabilistic origin of this operation goes systematically unnoticed in the literature. Here, we show that the partial trace emerges naturally from the requirement of consistency between the Born rule for measurement probabilities and the classical marginalization of probability mass functions. Starting from the classical marginalization rule relating joint and marginal probability distributions, we impose that the reduced density operator of a subsystem must reproduce the local measurement statistics derived from the global state. We show that this requirement directly leads to the standard expression of the partial trace. From this perspective, the reduced density operator appears not as an ad hoc algebraic construction, but as a natural consequence of the probabilistic structure of quantum mechanics.

2603.23697 2026-06-08 math.AG 版本更新

Log purity, torsors on root stacks and log Nori fundamental group

log纯度,根堆栈上的torsors与log Nori基本群

Sara Mehidi

AI总结 本文基于log纯度定理,推广至Kummer log flat拓扑下的torsors,并通过根堆栈解释,将其与tame代数堆的properness准则联系,最终构造log Nori基本群方案以分类torsors并进行比较。

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AI中文摘要

我们把Fujiwara-Kato-Mochizuki的log纯度定理推广到由Kummer log flat拓扑下有限平坦线性可约群方案产生的torsors。然后通过根堆栈给出纯度定理的堆栈解释,将其与Bresciani-Vistoli对 tame代数堆的properness准则联系起来。最后,我们构造了一个log regular log scheme的log Nori基本群方案,以分类此类torsors,并将其与经典Nori基本群和tame基本群进行比较。

英文摘要

We generalize the logarithmic purity theorem of Fujiwara-Kato-Mochizuki to torsors which arise in the Kummer log flat topology under finite flat linearly reductive group schemes. We then give a stack-theoretic interpretation of our purity theorem via root stacks, relating it to the valuative criterion of properness for tame algebraic stacks of Bresciani-Vistoli. Finally, we construct a logarithmic Nori fundamental group scheme of a log regular log scheme classifying such torsors, and compare it with the classical Nori fundamental group and the tame fundamental group.

2603.23606 2026-06-08 astro-ph.GA astro-ph.CO 版本更新

A hydrodynamical CLONE of the Virgo cluster: II. Confronting observed and synthetic galaxy population twins in a dense environment

一个Virgo团的流体动力学CLONE:II. 在密集环境中对比观测和合成星系种群双胞胎

Jenny G. Sorce, Sean L. McGee, Yohan Dubois, Jérémy Blaizot, Alexander Knebe, Gustavo Yepes

AI总结 本文研究了在密集环境中,合成星系种群如何再现观测到的星系形成和淬熄趋势,探讨了不同质量星系的星形成密度、特定星形成率、金属licity和淬熄分数等关系。

Comments Accepted for publication in A&A, 13 pages+appendixes, 8 figures in the core text + 4 figures in the appendixes, synthetic and observational data used for comparisons in Fig.4 (left panel) updated, conclusion unchanged

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AI中文摘要

星系团为研究密集环境中星系演化提供了有力实验室。在此背景下,受约束的局部和嵌套环境(CLONE)项目提供了一个针对Virgo团的缩放入流体动力学模拟,包括活动星系核和超新星反馈,其分辨率降至350 pc,旨在模仿Virgo的观测特性。先前研究表明,该复制品与Virgo共享相同的历史、质量和光度分布,包括中心M87。本研究检查了几种观测关系,这些关系延伸到比以前合成种群研究更低的恒星质量:恒星形成密度、(特定)恒星形成率、金属licity和星系淬熄分数作为恒星质量和团簇中心距离的函数。尽管金属licity略低且淬熄分数足够高,模拟的星系即使在不进行平均或考虑观测不确定性的情况下也能再现关键观测趋势,除了投影效应的考虑:在固定恒星质量下,团簇星系的恒星形成率低于场星系;大多数星系被淬熄,除了中间质量或孤立星系;低质量星系被高度淬熄,因此暗示金属licity的急剧下降,低金属licity并不意味着年轻;淬熄发生在最 massive 和最小质量星系中比中间质量星系更早,至少直到它们进入团簇;淬熄星系经历了暗物质剥离;气体耗尽驱动淬熄,尤其是在低质量星系和远离团簇中心的星系中。总体而言,合成种群共同再现了多个观测趋势,使其成为探索从水母星系到团簇核心气体动力学过程的有价值工具。

英文摘要

Galaxy clusters offer powerful laboratories for studying galaxy evolution in dense environments. In this context, the Constrained LOcal and Nesting Environment (CLONE) project provides a zoom-in hydrodynamical simulation of the Virgo cluster, including active galactic nucleus and supernova feedback, with a resolution down to 350~pc, designed to mirror Virgo's observed properties. Previous work showed that this replica and Virgo share the same history, mass, and luminosity distributions including the central M87. This study examines several observational relations extending to lower stellar masses than previous synthetic-population studies: star formation density, (specific) star formation rate, metallicity, and quenched fraction of galaxies as a function of stellar mass and cluster-centric distance. Despite the slightly low metallicity and the sufficiently high quenched fraction, simulated galaxies reproduce key observational trends even without averaging or accounting for observational uncertainties, aside from the consideration of projection effects: At fixed stellar mass, cluster galaxies form fewer stars than field counterparts; Most galaxies are quenched, except for intermediate-mass or isolated galaxies; Low-mass galaxies are highly quenched, thus implying a sharp metallicity drop, and low metallicity does not imply youth; Quenching occurs earlier for the most massive and the smallest galaxies than for those of intermediate mass, at least until they enter the cluster; Quenched galaxies have undergone dark matter stripping; Gas depletion drives quenching, especially in low-mass galaxies and the farther from the cluster center they are. Overall, the synthetic population jointly reproduces multiple observational trends, making it a valuable tool to probe processes from jellyfish galaxies to cluster-core gas dynamics.[Abridged]

2603.23538 2026-06-08 physics.optics 版本更新

Magneto-optic perturbation theory for near-complete violation of Kirchhoff's law of thermal emission at low magnetic fields

低磁场下近完全违反Kirchhoff热发射定律的磁光扰动理论

Daniel Cui, Aaswath P. Raman

AI总结 本文提出一种磁光扰动理论,用于分析低磁场下光子系统对Kirchhoff热发射定律的违反,通过设计III-V超材料实现了0.1T下的非 reciprocity发射对比度达0.8。

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AI中文摘要

磁光光子系统可通过破坏洛伦兹互易性来违反Kirchhoff热发射定律。我们开发了一种色散扰动理论,推导出在施加磁场下等离子体半导体中磁光共振频率偏移的解析表达式。该表达式表明偏移由模式的光学自旋密度与磁光材料的重叠决定。我们利用该表达式设计了一种III-V超材料,在仅0.1T下实现了0.8的非 reciprocity发射对比度,并证明该理论可以解释不同光子结构之间磁感应灵敏度数量级差异。

英文摘要

Magneto-optic photonic systems can violate Kirchhoff's law of thermal emission by breaking Lorentz reciprocity. We develop a dispersive perturbation theory yielding an analytical expression for magneto-optical resonance frequency shifts in plasmonic semiconductors under applied magnetic fields. This expression shows the shift is governed by the overlap of the mode's optical spin density with the magneto-optical material. We use this expression to design a III-V metasurface that achieves nonreciprocal emissivity contrast of 0.8 at only 0.1 T, and demonstrate that the theory can explain order-of magnitude differences in magnetic field sensitivity between different photonic structures.

2603.15202 2026-06-08 cs.DC cs.OS 版本更新

Simple is Better: Multiplication May Be All You Need for LLM Request Scheduling

简单即最佳:乘法可能就是LLM请求调度所需的一切

Dingyan Zhang, Jinbo Han, Kaixi Zhang, Xingda Wei, Sijie Shen, Chenguang Fang, Wenyuan Yu, Jingren Zhou, Rong Chen

AI总结 本文提出通过简单乘法结合KVCache和负载均衡指标,实现LLM请求调度的双重目标,无需超参数调优,实验显示在真实工作负载中显著提升性能。

Comments To appear in the Proceedings of 20th USENIX Symposium on Operating Systems Design and Implementation (OSDI'26)

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AI中文摘要

高质量LLM请求调度需要同时满足两个关键目标:确保路由实例具备KVCache以加速请求执行,以及确保工作负载在实例间平衡。实现这两个目标具有挑战性,因为追求其中一个可能损害另一个。当前方法使用各种组合器(如线性组合)计算调度分数,结合两个目标的指标。这些方法复杂:要么需要大量工作负载特定的超参数调优,要么需要模型-硬件感知的模拟器开发,但可能仍会导致性能不佳。本文表明,使用两个精心选择的指标的简单乘积(如KVCache-aware和负载均衡-aware)作为调度分数(LMETRIC)可以同时实现两个目标,无需任何超参数调优。关键思想是,简单乘积的分数以类似于线性组合的方式考虑两个目标,但原始超参数在比较过程中抵消,因此无需调优以找到最佳参数。这两个指标基于我们对LLM特性分析的选择。我们的广泛实验表明,这种简单方法可将TTFT减少92%和39%,TPOT减少24%和51%,相比vLLM-v1和生产调度器。我们还推导了乘法可能失效的数学条件,并发现这些条件在实践中极为罕见,可以提前检测并缓解。LMETRIC已在生产环境中部署,金丝雀发布证实其有效性。

英文摘要

High-quality LLM request scheduling requires meeting two key objectives: ensuring the routed instance has KVCache to accelerate request execution, and ensuring that the workload is balanced across instances. Achieving both objectives is challenging because pursuing one may compromise the other. Current approaches use various combinators (e.g., linear combinations) to compute a scheduling score that combines indicators for the two objectives. These approaches are complex: they either require significant workload-specific hyperparameter tuning or model-hardware-aware simulator development, yet could still lead to suboptimal performance. In this paper, we show that using a simple multiplication of two carefully chosen indicators: one KVCache-aware (new prefill tokens if routed to an instance) and one load-balancing-aware (current batch size of the instance), as the scheduling score (LMETRIC) can achieve both objectives simultaneously without any hyperparameter tuning. The key idea is that the simply multiplied score considers both objectives in a manner similar to a linear combination, but the original hyperparameters cancel out during comparison, so no tuning is needed to find the best parameters. The two indicators are chosen based on our analysis of LLM characteristics. Our extensive experiments show that this simple approach can reduce TTFT by 92% and 39%, and TPOT by 24% and 51%, compared to vLLM-v1 and an in-production scheduler on real-world workloads covering chatbots and coding agents. We also derive the mathematical conditions under which multiplication may fail, and find that such conditions are extremely rare in practice and can be detected (and mitigated) beforehand. LMETRIC has been deployed in production and canary release confirms its effectiveness

2510.08213 2026-06-08 physics.flu-dyn 版本更新

Generalised actuator disk theory: wake development with turbulent entrainment

广义叶轮机盘理论:含湍流混入的尾涡发展

Majid Bastankhah, Peter E. Hydon, Carl Shapiro, Dennice F. Gayme, Charles Meneveau

AI总结 本文提出一种广义叶轮机盘理论,结合流管和尾涡控制体积,可预测任意距离处的涡流变化,改进高负载盘的推力和功率系数预测。

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AI中文摘要

经典叶轮机盘理论,发展超过一个世纪,提供涡轮机性能的理想化描述。它将涡轮机视为无限薄的渗透盘,并在包含盘的流管上应用控制方程。该理论的局限性在于其假设盘下游为理想流动,限制了其在湍流和混合过程主导尾涡发展之前较短下游距离的应用。经典理论还导致高负载涡轮机的推力和功率系数的非物理预测。相比之下,湍流轴对称尾涡是广泛研究的典型自由剪切流,其进展和应用到风力涡轮机主要局限于远尾涡动力学。本文引入基于混合流管和尾涡控制体积的广义叶轮机盘理论,无缝整合经典叶轮机盘分析与尾涡湍流建模,在任意距离从涡轮机处进行。所得模型,尽管仍理想化,可用于预测速度、压力和横截面流量面积随位置变化的函数,无论是涡轮机盘上游还是下游。此外,通过在尾涡发展中考虑湍流混入,它为高负载盘提供了更真实的推力和功率系数预测。

英文摘要

Classical actuator disk theory, developed more than a century ago, provides an idealised description of turbine rotor performance. It treats a rotor as an infinitesimally-thin permeable disk and applies the governing flow equations over a streamtube encompassing the disk. A well-known limitation of the theory is its assumption of ideal flow downstream of the disk, which restricts its applicability to short downwind distances before turbulence and mixing processes governing the wake evolution take hold. The classical theory also leads to unphysical predictions of thrust and power coefficients for highly-loaded rotors. Turbulent axisymmetric wakes, by contrast, represent an extensively-studied canonical free shear flow with much of the progress and its applications to wind turbines limited to the far-wake dynamics. In this work, we introduce a generalised actuator disk theory based on a hybrid stream-tube and wake control volume, that seamlessly integrates classical actuator disk analysis with wake turbulence modelling at arbitrary distances from the rotor. The resulting model, while still idealised, can be used to predict variations in velocity, pressure, and cross-sectional flow area as function of position, both upstream and downstream of the rotor disk. Furthermore, by accounting for turbulent entrainment in the wake development, it provides more realistic predictions of thrust and power coefficients for highly-loaded disks.