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科学与医疗

AI for Science

科学智能、蛋白质、分子、药物、材料、气象、物理和数学 AI。

今日/当前日期收录 477 信号源:cs.LG, q-bio, physics, cond-mat, math, stat.ML

1. 其他科学智能 17 篇

2605.23086 2026-06-18 math.GT 版本更新 70%

Lifting Milnor Invariants for 3-Component Links

提升三分支链环的Milnor不变量

Christopher W. Davis, JungHwan Park

专题命中 其他科学智能 :定义链环不变量,属于数学拓扑研究。

AI总结 本文定义了三分支链环L的整数值不变量序列γ^k(L),证明其在协边和弱协边下不变,并提升了某些Milnor不变量,通过引入Kojima-Yamasaki η-不变量的三分支类比h(L)来建立该结果,应用包括当指定分支的Alexander多项式平凡时的弱协边分类,以及刻画在B^4中边界连续嵌入圆盘且补空间基本群为ℤ的纽结。

Comments 30 pages, 7 figures. Version 2: Revised to explain some connections to work of Tatsuya-Yasuhara

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AI中文摘要

我们为三分支链环L定义了一个整数值不变量序列γ^k(L)。我们证明了所得的γ-不变量在协边下不变,更一般地在弱协边下不变,并且它们提升了三分支链环的某些Milnor不变量。为了建立这一点,我们引入了一个不变量h(L),它是Kojima--Yamasaki η-不变量的三分支类比,并证明它可以恢复γ-不变量。作为应用,当指定分支具有平凡的Alexander多项式时,我们得到了一个弱协边分类,并刻画了在B^4中边界连续嵌入圆盘且其补空间基本群为ℤ的纽结。

英文摘要

We define a sequence of integer-valued invariants $γ^k(L)$ for a $3$-component link $L$. We prove that the resulting $γ$-invariants are invariant under concordance, and more generally under weak cobordism, and that they lift certain Milnor invariants of 3-component links. To establish this, we introduce an invariant $h(L)$, a $3$-component analogue of the Kojima--Yamasaki $η$-invariant, and show that it recovers the $γ$-invariants. As applications, we obtain a weak-cobordism classification when the distinguished component has trivial Alexander polynomial and characterize knots that bound continuously embedded disks in $B^4$ whose complements have fundamental group $\mathbb{Z}$.

2605.22745 2026-06-18 math.RA math.CO 版本更新 70%

Fermionic matrices and super Cayley--Hamilton algebras

费米子矩阵与超Cayley-Hamilton代数

Claudio Procesi

专题命中 其他科学智能 :费米子矩阵与超代数,属于数学物理。

AI总结 本文通过发展经典情形的分次类比,建立了玻色子和费米子矩阵n元组的第一和第二基本定理。

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AI中文摘要

我们通过发展经典情形的分次类比,建立了玻色子和费米子矩阵$n$元组的第一和第二基本定理。

英文摘要

We develop a first and second fundamental theorem for $n$--tuples of bosonic and fermionic matrices, by developing graded analogues of the classical case.

2605.22499 2026-06-18 math.AG math.CT 版本更新 70%

A condensed proof of the pro-étale and étale exodromy theorems

一个简化的证明:关于pro-étale和étale的exodromy定理

Remy van Dobben de Bruyn

专题命中 其他科学智能 :pro-étale exodromy定理证明,属于数学。

AI总结 本文通过简洁的方法证明了pro-étale和étale的exodromy定理,提出了一个新的关于Postnikov完备étalesheaves的exodromy定理,并给出了Barwick, Glasman和Haine的constructibleétaleexodromy对应关系的新证明,同时去除了对scheme的qcqs假设,扩展了sheaves的系数范围。

Comments Minor changes. 53 pages. Comments are welcome!

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AI中文摘要

Barwick, Glasman和Haine的exodromy对应关系将方案X上的可构造sheaves视为从profinite类别Gal(X)的连续函子的∞-范畴。将Gal(X)视为condensed类别后,Wolf将其扩展为pro-étalesheaves的exodromy对应关系。从condensed视角出发,本文给出了pro-étaleexodromy定理的简洁且自包含的证明。此证明被用来提取一个尚未出现在文献中的关于(Postnikov complete)étalesheaves的exodromy定理,与Lurie关于ultracategories的工作密切相关。最后,本文利用此方法给出了Barwick, Glasman和Haine的constructibleétaleexodromy对应关系的新证明。无需额外努力,本文的方法去除了对scheme的qcqs假设,并给出了sheaves在更一般∞-范畴中的版本。最后,本文进一步完善方法,当κ> |O_X(U)|对于每个affine open U⊆X时,获得一个κ-condensed陈述。

英文摘要

The exodromy correspondence of Barwick, Glasman, and Haine computes constructible sheaves of spaces on a scheme $X$ as an $\infty$-category of continuous functors from the profinite category $\operatorname{Gal}(X)$. Viewing $\operatorname{Gal}(X)$ instead as a condensed category, this was extended by Wolf to an exodromy correspondence for pro-étale sheaves. Using the condensed perspective from the outset, we give a quick and self-contained proof of the pro-étale exodromy theorem. This is used to extract an exodromy theorem for (Postnikov complete) étale sheaves that does not yet appear in the literature, which is closely related to Lurie's work on ultracategories. Finally, we use this to give a new proof of the constructible étale exodromy correspondence of Barwick, Glasman, and Haine. Without additional effort, our method removes the qcqs hypotheses on the schemes, and gives versions for sheaves with coefficients in more general $\infty$-categories. Finally, we refine the methods to obtain a $κ$-condensed statement for any uncountable cardinal $κ$ such that $κ> \lvert \mathcal O_X(U) \rvert$ for every affine open $U \subseteq X$.

2605.15031 2026-06-18 math.DG math.AP 版本更新 70%

Minimal submanifolds confined in space

空间中的极小子流形

Tobias Holck Colding, William P. Minicozzi

专题命中 其他科学智能 :极小子流形结构研究,属于数学几何。

AI总结 该研究探讨了在空间中受限的极小子流形的结构限制,证明了即使在高维情况下,这类子流形也必须满足严格的结构条件,并给出了一个最优的伯恩斯坦定理,推广了多个经典结果。

Comments Minor changes

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AI中文摘要

在R⁴中,已知存在许多极小超曲面的例子,但结构结果却很少。本文证明了任何维度的极小子流形,如果被限制在空间中,则受到严格限制。众所周知,半空间定理在R⁴中的超曲面中已经失效,其中存在许多被限制在滑动板中的例子。在R³中,猫皮的高程以对数速率增长,而在更高维度中,猫皮的高程保持有界。我们将看到,即使在高维情况下,被限制在空间中的极小子流形也必须满足严格的结构限制。我们证明了任何具有子线性增长高程的适当极小浸入必须具有欧几里得体积增长。其结果是一个最优的伯恩斯坦定理,适用于任何维度的稳定超曲面,其高程以子线性速率增长,推广了Moser、Bombieri-De Giorgi-Miranda、Trudinger、Caffarelli-Nirenberg-Spruck和Ecker-Huisken的结果。

英文摘要

Already in $\bf{R}^4$, there are many minimal hypersurfaces, yet few structural results. We show that minimal submanifolds, of any dimension and codimension, that are confined in space are very restricted. It is well-known that the half-space theorem fails already for hypersurfaces in $\bf{R}^4$, where there are many examples contained in a slab. In $\bf{R}^3$ the height of the catenoid grows at a logarithmic rate, whereas in higher dimensions the height of the catenoid remains bounded. We will see that even in high dimensions, minimal submanifolds that are confined in space must satisfy strong structural restrictions. We show that any proper minimal immersion whose height grows sublinearly must have Euclidean volume growth. A consequence is an optimal Bernstein theorem in any dimension for stable hypersurfaces with sublinearly growing height that generalizes results of Moser, Bombieri-De Giorgi-Miranda, Trudinger, Caffarelli-Nirenberg-Spruck and Ecker-Huisken. Euclidean volume growth is a powerful property and there are many other consequences.

2604.04141 2026-06-18 stat.ME math.ST stat.AP stat.TH 版本更新 70%

On Data Thinning for Model Validation in Small Area Estimation

小区域估计中用于模型验证的数据稀疏化

Sho Kawano, Paul A. Parker, Zehang Richard Li

专题命中 其他科学智能 :小区域估计的模型验证方法

AI总结 提出数据稀疏化方法,将单个观测拆分为独立训练和测试集,实现小区域估计的模型验证,并分析其偏差-方差权衡,给出实用建议。

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AI中文摘要

小区域估计为样本量有限的地理和人口子组产生总体参数的估计。这些估计对政策决策至关重要,但模型的合理验证仍然是一个挑战。与传统的预测设置不同,验证数据很少可用。数据稀疏化将单个观测拆分为独立的训练和测试组件。它仅使用常规可用的区域级汇总统计量(要求其高斯性和已知抽样方差)实现样本外验证。然而,基于稀疏化的模型比较的性质尚未被正式研究。在本文中,我们发展了这些性质。我们构建了稀疏化数据均方误差的无偏估计量,并表明它与完整数据的对应量存在系统性差异;对于标准的Fay-Herriot模型,该差距具有闭式表达式,取决于候选模型的收缩行为。我们进一步表明,当训练分数接近1时,估计量方差急剧增加,产生偏差-方差权衡,且没有普遍最优的稀疏化参数。平衡这些力量的实用建议由理论指导并经经验验证。基于美国社区调查微观数据的设计模拟表明,推荐的数据稀疏化方法与信息准则和基于模拟的方法具有竞争力,并且在异质抽样设计下更稳定。

英文摘要

Small area estimation produces estimates of population parameters for geographic and demographic subgroups with limited sample sizes. Such estimates are critical for policy decisions, yet principled validation of these models remains a challenge. Unlike conventional predictive settings, validation data are rarely available. Data thinning splits a single observation into independent training and test components. It enables out-of-sample validation using only the area-level summary statistics routinely available, requiring only their Gaussianity and known sampling variances. However, the properties of thinning-based model comparison have not been formally studied. In this paper, we develop these properties. We construct an unbiased estimator of thinned-data mean squared error and show that it differs systematically from its full-data counterpart; for the standard Fay-Herriot model, the gap admits a closed-form expression that depends on the candidate model's shrinkage behavior. We further show that the estimator variance increases sharply as the training fraction approaches one, producing a bias-variance tradeoff with no universally optimal thinning parameter. Practical recommendations balancing these forces are informed by theory and verified empirically. Design-based simulations using American Community Survey microdata show that the recommended data thinning approach is competitive with information-criterion and simulation-based methods, and substantially more stable across heterogeneous sampling designs.

2601.21118 2026-06-18 math.LO 版本更新 70%

Measuring the Complexity of Countable Presburger Models

可数Presburger模型的复杂度度量

Jason Block

专题命中 其他科学智能 :研究Presburger模型的复杂度,属于数理逻辑

AI总结 通过Scott分析和度谱两种方法,研究Presburger算术模型的Scott语句复杂度和度谱可能性,并利用线性序构造Presburger群以保持序结构。

Comments Accepted to appear in ZML: Zeitschrift für Mathematische Logik und Grundlagen der Mathematik

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AI中文摘要

我们采用两种方法对Presburger模型的复杂度进行分类:Scott分析和度谱。具体地,我们研究了Presburger算术模型可能的Scott语句复杂度和可能的度谱。许多结果将通过展示如何给定一个线性序$\mathcal{L}$,构造一个Presburger群$P_\mathcal{L}$来保持$\mathcal{L}$的大部分结构而得到。

英文摘要

We take two approaches to classifying the complexity of Presburger models: Scott analysis and degree spectra. In particular, we investigate the possible Scott sentence complexities and possible degree spectra of models of Presburger arithmetic. Many of our results will be achieved by showing how given a linear order $\mathcal{L}$, we can construct a Presburger group $P_\mathcal{L}$ that maintains much of the structure of $\mathcal{L}$.

2504.03228 2026-06-18 econ.EM stat.ML 70%

Weak instrumental variables due to ignored nonlinearities in panel data: A Super Learner Control Function estimator

面板数据中因忽略非线性而弱化的工具变量:一个超级学习控制函数估计器

Monika Avila-Marquez

专题命中 其他科学智能 :提出面板数据工具变量估计器,属于计量经济学

AI总结 本文研究面板数据中因忽略非线性导致的弱工具变量问题,提出超级学习控制函数估计器以解决结构参数的识别问题。

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AI中文摘要

本文采用三角形结构面板数据模型,其中包含可加分离的个体特定效应,用于建模协变量对结果变量的因果效应,当存在不可观测的混杂因素且其中一些是时间不变的。在这种设定下,如果减少形式方程的条件均值在总体中非线性,则线性规范可能存在问题。原因在于忽略非线性可能导致弱工具(工具变量与内生协变量弱相关)由于规格错误,如通过面板数据的广义集中参数所示。为了解决这一问题,我们提出了一种由线性结构方程和非线性减少形式方程组成的面板数据三角形同时方程模型,包含可加分离的个体特定固定效应。参数关注点是内生变量的结构参数。在假设排除限制可用的情况下,通过控制函数方法获得该参数的识别。我们提供了一个称为超级学习控制函数估计器(SLCFE)的估计器。估计过程由两个主要步骤和交叉拟合组成。首先,使用超级学习估计控制函数。然后,利用估计的控制函数在结构方程中控制内生性。交叉拟合是在个体维度上进行的。该估计器是一致的且渐近正态,达到参数收敛率。我们显示SLCF估计器与插件IV估计器和朴素插件2SLS估计器不同,前者在没有交叉拟合时不一致,后者即使在交叉拟合时也不一致。

英文摘要

A triangular structural panel data model with additive separable individual-specific effects is used to model the causal effect of a covariate on an outcome variable when there are unobservable confounders with some of them time-invariant. In this setup, a linear specification for the reduced-form equation might be problematic when the conditional mean of the endogenous covariate and the instrumental variables is nonlinear in the population. The reason is that ignoring the nonlinearity could lead to weak instruments (instruments are weakly correlated with the endogenous covariate) due to misspecification as shown using a generalized concentration parameter for panel data. As a solution, we propose a triangular simultaneous equation model for panel data with additive separable individual-specific fixed effects composed of a linear structural equation with a nonlinear reduced form equation. The parameter of interest is the structural parameter of the endogenous variable. The identification of this parameter is obtained under the assumption of available exclusion restrictions and using a control function approach. We provide an estimator that we call Super Learner Control Function estimator (SLCFE). The estimation procedure is composed of two main steps and cross-fitting. First, we estimate the control function using a super learner. In the following step, we use the estimated control function to control for endogeneity in the structural equation. Cross-fitting is done across the individual dimension. The estimator is consistent and asymptotically normal achieving a parametric rate of convergence. We show that the SLCF estimator differs from both the plug-in IV estimator and a naive plug-in 2SLS estimator, with the former not being consistent without cross-fitting, and the latter not being consistent even with cross-fitting.

2603.13610 2026-06-18 math.PR 版本更新 70%

Multi-floor generalization of TASEP

TASEP的多层推广

Yuliy Baryshnikov, Alexander Stolyar

专题命中 其他科学智能 :TASEP的多层推广,属于统计物理

AI总结 研究每个站点可容纳多个粒子的TASEP推广模型,通过背压算法控制粒子移动,证明了c>1时存在非平凡相变,并给出了通量的极限行为。

Comments Revision. 24 pages, 15 figures

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AI中文摘要

我们考虑一个相互作用粒子系统,它推广了经典的全不对称简单排斥过程(TASEP),其中每个站点最多可容纳固定数量的粒子,粒子运动由{\em背压}(BP)算法(通常也称为{\em MaxWeight})控制。有$N$个站点($N$有限或无限),每个站点最多容纳$c$个粒子,$1 \le c < \infty$。新粒子以速率$\alpha\le 1$的泊松过程进入最左侧站点$1$,除非站点$1$已有$c$个粒子。粒子(如果有)以速率$\beta \le 1$的泊松过程从最右侧站点$N$移除。相邻站点间从左到右的粒子运动由BP规则控制:当站点$n$的粒子数严格多于站点$n+1$时,粒子以速率$1$的泊松过程从$n$移动到$n+1$。当$c=1$时,这就是标准的TASEP。我们的主要结果涉及有限系统平稳分布的渐近性,特别是当$N\to\infty$时通量(流)的极限。特别地,我们证明了在$c>1$的系统中会发生有趣的非平凡相变。例如,如果$c>1$且$1/2 \le \beta \le 1$,只要$\alpha \ge \alpha_c^*$,最大极限通量$1/4$就能达到,其中$\alpha_c^* < 1/2$是某个非平凡阈值。(对于标准TASEP,阈值为$1/2$。)我们还提出了关于任意参数设置下平稳分布渐近性的一般猜想。我们通过模拟说明了我们的形式结果和猜想,并指出了进一步研究的有趣方向。

英文摘要

We consider an interacting particle system, which generalizes the classical totally asymmetric simple exclusion process (TASEP), in that each site can contain up to a fixed finite number of particles, and the particle movement is governed by a {\em back-pressure} (BP) algorithm (also often called {\em MaxWeight}). There are $N$ sites (with $N$ finite or infinite), each may contain at most $c$ particles, $1 \le c < \infty$. New particles enter the system at the left-most site $1$ as a Poisson process of rate $α\le 1$, unless site $1$ has $c$ particles. Particles (if any) are removed from the right-most site $N$ as a Poisson process of rate $β\le 1$. The left-to-right movement of particles between neighboring sites is governed by the BP rule: one particle moves from site $n$ to $n+1$ at epochs of a rate $1$ Poisson process, as long as the former site has strictly more particles than the latter. When $c=1$, this is the standard TASEP. Our main results address the asymptotics of the stationary distribution of a finite system, and especially the limit of the flux (current) as $N\to\infty$. In particular, we prove that interesting non-trivial phase transitions take place in a system with $c>1$. For example, if $c>1$ and $1/2 \le β\le 1$, the maximum limiting flux $1/4$ is achieved as long as $α\ge α_c^*$, where $α_c^* < 1/2$ is some non-trivial threshold. (For the standard TASEP the threshold is $1/2$.) We also put forward a general conjecture about the stationary distribution asymptotics under an arbitrary parameter setting. We illustrate our formal results and the conjecture by simulations, and identify interesting directions for further research.

2512.12850 2026-06-18 cs.AR cs.LG cs.SY eess.SY hep-ex 版本更新 70%

KANELÉ: Kolmogorov-Arnold Networks for Efficient LUT-based Evaluation

KANELÉ:基于Kolmogorov-Arnold网络的高效LUT评估

Duc Hoang, Aarush Gupta, Philip Harris

发表机构 * Massachusetts Institute of Technology(麻省理工学院)

专题命中 其他科学智能 :KAN网络在FPGA上的高效实现,属于科学计算

AI总结 提出KANELÉ框架,利用Kolmogorov-Arnold网络(KAN)的独特性质,通过量化与剪枝协同优化,首次系统实现FPGA上的高效LUT映射,相比先前方法加速高达2700倍并节省大量资源。

Comments International Symposium on Field-Programmable Gate Arrays 2026 (ISFPGA'2026)

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AI中文摘要

低延迟、资源高效的FPGA神经网络推理对于需要实时能力和低功耗的应用至关重要。基于查找表(LUT)的神经网络是一种常见解决方案,结合了强大的表示能力和高效的FPGA实现。在这项工作中,我们介绍了KANELÉ,一个利用Kolmogorov-Arnold网络(KAN)独特性质进行FPGA部署的框架。与传统的多层感知器(MLP)不同,KAN使用可学习的一维样条作为边缘激活函数,其域固定,这种结构天然适合离散化和高效的LUT映射。我们提出了第一个在FPGA上实现KAN的系统设计流程,通过量化与剪枝协同优化训练,以实现紧凑、高吞吐量和低延迟的KAN架构。我们的结果表明,与先前的KAN-on-FPGA方法相比,加速高达2700倍,并节省了数量级的资源。此外,KANELÉ在广泛使用的基准测试中匹配或超越了其他基于LUT的架构,特别是在涉及符号或物理公式的任务中,同时平衡了FPGA硬件上的资源使用。最后,我们通过将框架扩展到实时、高能效的控制系统,展示了其多功能性。

英文摘要

Low-latency, resource-efficient neural network inference on FPGAs is essential for applications demanding real-time capability and low power. Lookup table (LUT)-based neural networks are a common solution, combining strong representational power with efficient FPGA implementation. In this work, we introduce KANELÉ, a framework that exploits the unique properties of Kolmogorov-Arnold Networks (KANs) for FPGA deployment. Unlike traditional multilayer perceptrons (MLPs), KANs employ learnable one-dimensional splines with fixed domains as edge activations, a structure naturally suited to discretization and efficient LUT mapping. We present the first systematic design flow for implementing KANs on FPGAs, co-optimizing training with quantization and pruning to enable compact, high-throughput, and low-latency KAN architectures. Our results demonstrate up to a 2700x speedup and orders of magnitude resource savings compared to prior KAN-on-FPGA approaches. Moreover, KANELÉ matches or surpasses other LUT-based architectures on widely used benchmarks, particularly for tasks involving symbolic or physical formulas, while balancing resource usage across FPGA hardware. Finally, we showcase the versatility of the framework by extending it to real-time, power-efficient control systems.

2601.09462 2026-06-18 cond-mat.stat-mech 70%

Structural Comparison of Error Mitigation Methods for Ising Machines: Penalty-Spin Model versus Stacked Model

Ising机器误差缓解方法的结构比较:惩罚自旋模型与堆叠模型

Tetsuro Abe, Kanta Hino, Shu Tanaka

专题命中 其他科学智能 :比较Ising机器误差缓解方法的结构

AI总结 研究通过模拟退火比较了惩罚自旋模型与堆叠模型在二次分配问题中的性能,发现堆叠模型在保持约束满足和提升解质量方面更优,而惩罚模型在大规模并行时出现合作崩溃。

Comments 14 pages, 11 figures

Journal ref J. Phys. Soc. Jpn. 95, 074003 (2026)

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AI中文摘要

Ising机器的误差缓解方法被重新审视,不仅作为噪声抑制技术,更作为复制耦合Ising模型的结构设计问题。利用模拟退火作为硬件噪声-free的测试平台,系统比较了通过集中辅助层耦合复制的惩罚自旋(PS)模型与直接耦合相邻复制的堆叠模型。数值实验显示,铁磁耦合的堆叠模型在广泛参数范围内稳定维持约束满足并提升解质量,表现出良好的可扩展性。相比之下,PS模型在大规模并行时出现合作崩溃:PS层的多复制平均会稀释稀疏解信息,阻碍有效复制间协调。这些发现表明,复制间耦合拓扑结构对搜索鲁棒性有决定性影响,并为约束优化中的模型选择和参数调优提供了实用指导。

英文摘要

Error-mitigation methods for Ising machines are reexamined not merely as noise-suppression techniques but as a structural design problem of replica-coupled Ising models. Using simulated annealing as a hardware-noise-free testbed, we systematically compare the penalty-spin (PS) model, which couples replicas through a centralized auxiliary layer, with the stacked model, which couples adjacent replicas directly. Numerical experiments on the quadratic assignment problem reveal that the ferromagnetically coupled stacked model stably maintains constraint satisfaction and improves solution quality over a broad parameter range, exhibiting favorable scalability with both the number of replicas and problem size. In contrast, the PS model suffers from cooperation collapse at large parallelism: many-replica averaging in the PS layer washes out sparse solution information, preventing effective inter-replica coordination. These findings demonstrate that the topology of inter-replica couplings decisively influences search robustness, and provide practical guidelines for model selection and parameter tuning in constrained optimization.

2512.24275 2026-06-18 math.AG 版本更新 70%

Proper moduli spaces of orthosymplectic complexes

正交辛复形的恰当模空间

Chenjing Bu

专题命中 其他科学智能 :构造正交辛复形的恰当模空间

AI总结 本文为Bridgeland半稳定正交辛复形的模栈构造了恰当好模空间,并提出其可作为正交群和辛群主丛模空间的紧化候选。

Comments Accepted version, 10 pages

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AI中文摘要

我们在复光滑射影簇上为Bridgeland半稳定正交辛复形的模栈构造了恰当好模空间,并提出其作为正交群和辛群主丛模空间紧化的候选。我们还证明了关于有限群胚的固定点栈和映射栈的好模空间的一些结果。

英文摘要

We construct proper good moduli spaces for moduli stacks of Bridgeland semistable orthosymplectic complexes on a complex smooth projective variety, which we propose as a candidate for compactifying moduli spaces of principal bundles for the orthogonal and symplectic groups. We also prove some results on good moduli spaces of fixed point stacks and mapping stacks from finite groupoids.

2601.08716 2026-06-18 physics.atom-ph physics.app-ph 版本更新 70%

Portable Single-Beam Atomic Total-Field Magnetometer for Stand-off Magnetic Sensing

便携式单光束原子总场磁力计用于远距离磁感应

Heonsik Lee, Hyunbeen Lee, Minseok Choi, Yoontae Hwang, Deok-Young Lee

专题命中 其他科学智能 :便携式原子磁力计用于远距离磁感应

AI总结 本文报道一种手持式单光束标量铷原子磁力计,采用全光学Bell-Bloom配置和数字锁定跟踪,在无屏蔽地磁场中实现约21 pT/√Hz灵敏度,并成功检测10米距离内的电梯运动磁信号。

Comments 11 pages, 8 figures

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AI中文摘要

光泵浦原子磁力计(OPAMs)在室温下提供高灵敏度,并越来越多地被考虑用于地磁场环境中的便携式磁感应。本文报道一种手持式、单光束标量$^{87}$Rb OPAM,传感器头体积约110 mL。该器件工作在全光学Bell-Bloom配置中,使用数字锁定、色散跟踪$^{87}$Rb拉莫尔共振,通过结合内部控制硬件与商业模块的混合电子堆栈实现。单个频率调制激光束同时进行泵浦和探测,无需射频线圈。所有信号处理在单板计算机上使用Python实现,配合商用现成(COTS)数据采集模块,无需专用信号处理硬件即可立即部署。该磁力计在0.1–30 Hz闭环带内区域具有约21 pT/$\sqrt{\mathrm{Hz}}$的固有带内场灵敏度(根据锁定色散斜率估计),数字输出速率为200样本/秒。在无屏蔽地磁场部署中,我们检测到来自受控电梯运动序列的可重复瞬态磁信号,并量化了1.25 m至10 m传感器-电梯距离上的远距离可观测性。这些结果表明,紧凑型标量OPAMs可以提供适用于实际地磁场环境中可部署磁异常检测和基础设施监测的带宽和距离分辨事件灵敏度。

英文摘要

Optically pumped atomic magnetometers (OPAMs) offer high sensitivity at room temperature and are increasingly considered for portable magnetic sensing in geomagnetic-field environments. Here we report a handheld-scale, single-beam scalar $^{87}$Rb OPAM with a sensor-head volume of approximately 110~mL. The device operates in an all-optical Bell-Bloom configuration and uses digital lock-in, dispersive tracking of the $^{87}$Rb Larmor resonance, implemented with a hybrid electronics stack that combines in-house control hardware with commercial modules. A single frequency-modulated laser beam performs both pumping and probing without RF coils. All signal processing is realized in Python on a single-board computer paired with a commercial off-the-shelf (COTS) data-acquisition module, enabling immediate deployment without dedicated signal-processing hardware. The magnetometer has an intrinsic in-band field sensitivity of approximately 21~pT/$\sqrt{\mathrm{Hz}}$, estimated from the lock-in dispersion slope, over a 0.1--30~Hz closed-loop in-band region with a digital-output rate of 200~samples/s. In an unshielded Earth-field deployment, we detect repeatable transient magnetic signatures from a controlled elevator motion sequence and quantify standoff observability over sensor-elevator distances from 1.25~m to 10~m. These results show that compact scalar OPAMs can provide bandwidth and range-resolved event sensitivity suitable for field-deployable magnetic anomaly detection and infrastructure monitoring in realistic geomagnetic environments.

2412.11176 2026-06-18 math.AP 版本更新 70%

A Note on Sharpened Singular Adams-Type Inequalities

关于尖锐奇异Adams型不等式的注记

Deepak Kumar Mahanta, Tuhina Mukherjee, Abhishek Sarkar

专题命中 其他科学智能 :建立尖锐奇异Adams型不等式并应用于椭圆方程

AI总结 建立带奇异权重的尖锐Adams型不等式,证明改进的奇异集中紧致原理,并应用于含奇异指数增长的非齐次拟线性椭圆方程非平凡解的存在性。

Comments 35 pages

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AI中文摘要

我们在$\mathbb{R}^n$上建立了带奇异权重的高阶函数空间中的尖锐Adams型不等式。还证明了一个改进Lions结果的尖锐奇异集中紧致原理。该研究区分了临界和次临界尖锐奇异Adams型不等式,并证明了它们的等价性。此外,我们分析了相关界的渐近行为,并关联了临界和次临界情况的上确界。还推导了一个新的紧嵌入,这对我们的分析至关重要。此外,作为这些结果的应用,通过使用山路引理,我们研究了一类涉及具有奇异指数增长的$(p,\frac{n}{2})$-双调和算子的非齐次拟线性椭圆方程的非平凡解的存在性。

英文摘要

We establish a sharp Adams-type inequality in higher-order function spaces with singular weights on $\mathbb{R}^n$. A sharp singular concentration-compactness principle, improving Lions' result, is also proved. The study distinguishes between critical and subcritical sharp singular Adams-type inequalities and shows their equivalence. Furthermore, we analyze the asymptotic behavior of the associated bounds and relate the suprema of the critical and subcritical cases. A new compact embedding, crucial to our analysis, is also derived. Moreover, as an application of these results, by employing the mountain pass theorem, we study the existence of nontrivial solutions to a class of nonhomogeneous quasilinear elliptic equations involving the $(p,\frac{n}{2})$-biharmonic operator with singular exponential growth.

2309.16446 2026-06-18 math.NT math.AG 70%

Crystalline representations and Wach modules in the relative case II

晶态表示与相对Wach模块II

Abhinandan

专题命中 其他科学智能 :相对Wach模块与晶态表示,数论

AI总结 本文研究了广义的相对Wach模块,建立其与相对晶态表示中晶格的范畴等价,推导了相对晶态表示的纯度陈述,并提供了检查相对p-进表示晶态性的标准。

Comments Accepted for publication in Mathematische Annalen

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AI中文摘要

我们研究了相对Wach模块,扩展了我们之前在这方面的研究成果。我们的主要结果表明,相对Wach模块与相对晶态表示中的晶格之间存在范畴等价。利用这一结果,我们推导了相对晶态表示的纯度陈述,并提供了一个检查相对p-进表示晶态性的标准。此外,我们将相对Wach模块解释为具有q-连接的模,并证明对于一个晶态表示,其关联的Wach模块与Nygaard滤波器是该表示关联的过滤(φ,∂)-模的q-变形(在倒置p后)。

英文摘要

We study relative Wach modules generalising our previous works on this subject. Our main result shows a categorical equivalence between relative Wach modules and lattices inside relative crystalline representations. Using this result, we deduce a purity statement for relative crystalline representations and provide a criteria for checking crystallinity of relative $p$-adic representations. Furthermore, we interpret relative Wach modules as modules with $q$-connections, and show that for a crystalline representation, its associated Wach module together with the Nygaard filtration is the canonical $q$-deformation (after inverting $p$) of the filtered $(φ,\partial)$-module associated to the representation.

2511.19468 2026-06-18 cs.DC cs.ET cs.LG physics.space-ph 版本更新 70%

Towards a future space-based, highly scalable AI infrastructure system design

面向未来天基、高度可扩展的AI基础设施系统设计

Blaise Agüera y Arcas, Travis Beals, Maria Biggs, Jessica V. Bloom, Thomas Fischbacher, Konstantin Gromov, Urs Köster, Rishiraj Pravahan, James Manyika

发表机构 * Google(谷歌)

专题命中 其他科学智能 :天基AI基础设施系统设计,空间计算

AI总结 本文探索利用卫星集群、太阳能板、自由空间光通信和TPU芯片构建天基机器学习计算系统,并分析辐射测试、发射成本等可行性。

Comments 18 pages, 4 figures. v2: Cleaned up references. Improved rough estimates. Fixed typos. Re-ran radiation test with improved methods

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AI中文摘要

如果AI是一种基础通用技术,我们应该预期对AI计算和能源的需求将持续增长。太阳是太阳系中最大的能源来源,因此值得考虑未来的AI基础设施如何最有效地利用这种能量。本文探索了用于太空机器学习的可扩展计算系统,该系统使用配备太阳能板的卫星群、自由空间光通信的星间链路以及谷歌张量处理单元(TPU)加速芯片。为了促进高带宽、低延迟的星间通信,卫星将近距离飞行。我们通过一个半径为1公里的81颗卫星集群说明了编队飞行的基本方法,并描述了一种使用基于高精度ML模型来控制大规模星座的方法。Trillium TPU经过了辐射测试。它们在总电离剂量相当于5年任务寿命的情况下存活,没有永久性故障,并针对位翻转错误进行了表征。发射成本是整体系统成本的关键部分;学习曲线分析表明,到2030年代中期,发射到近地轨道(LEO)的成本可能达到$\lesssim$200美元/公斤。

英文摘要

If AI is a foundational general-purpose technology, we should anticipate that demand for AI compute -- and energy -- will continue to grow. The Sun is by far the largest energy source in our solar system, and thus it warrants consideration how future AI infrastructure could most efficiently tap into that power. This work explores a scalable compute system for machine learning in space, using fleets of satellites equipped with solar arrays, inter-satellite links using free-space optics, and Google tensor processing unit (TPU) accelerator chips. To facilitate high-bandwidth, low-latency inter-satellite communication, the satellites would be flown in close proximity. We illustrate the basic approach to formation flight via an 81-satellite cluster of 1 km radius, and describe an approach for using high-precision ML-based models to control large-scale constellations. Trillium TPUs are radiation tested. They survive a total ionizing dose equivalent to a 5 year mission life without permanent failures, and are characterized for bit-flip errors. Launch costs are a critical part of overall system cost; a learning curve analysis suggests launch to low-Earth orbit (LEO) may reach $\lesssim$\$200/kg by the mid-2030s.

2509.25521 2026-06-18 physics.data-an hep-ex 交叉投稿 70%

A Numerical Rosenblatt Method for Forced Variable Independence

一种用于强制变量独立性的数值Rosenblatt方法

Radek Vavřička, Tomáš Sýkora

专题命中 其他科学智能 :数值方法,粒子物理应用

AI总结 提出一种数值方法,将系统中一个随机变量变换为与另一随机变量统计准独立,通过粒子物理示例展示分类器与可观测量准独立的适用性。

Comments 35 pages

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AI中文摘要

提出一种新颖的数值技术,将系统中的一个随机变量变换为与系统中任何其他随机变量统计准独立。通过一个粒子物理示例展示了该方法的适用性,其中分类器被呈现为与可观测量准独立。

英文摘要

A novel numerical technique is presented to transform one random variable within a system toward statistical quasi-independence from any other random variable in the system. The method's applicability is demonstrated through a particle physics example where a classifier is rendered quasi-independent from an observable quantity.

2507.07156 2026-06-18 stat.ML cs.CG cs.LG math.AT 版本更新 70%

Unreduced Persistence Diagrams for Topological Machine Learning

未约简持久图在拓扑机器学习中的应用

Nicole Abreu, Parker B. Edwards, Francis Motta

发表机构 * Department of Mathematics and Statistics, Florida Atlantic University, Boca Raton, FL(数学与统计学系,佛罗里达国际大学, Boca Raton, FL)

专题命中 其他科学智能 :拓扑机器学习方法,非核心科学应用

AI总结 研究未约简边界矩阵生成的拓扑特征向量在机器学习中的性能,发现其与完全约简持久图性能相当甚至更优,且计算内存需求低一个数量级。

Comments Substantially expanded to include additional ML and software benchmark experiments. 11 figures, 4 tables, 20 pages (without appendix and references)

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AI中文摘要

基于持久同源性特征训练的监督机器学习流程在实验中被观察到忽略了持久图中包含的大量信息。然而,计算持久图通常是此类流程中计算最密集的步骤。为了探索这一动态,我们引入了几种从未约简边界矩阵生成拓扑特征向量的方法,并研究了它们的理论和计算性质。我们比较了基于未约简持久图向量化的流程与基于完全约简持久图向量化的流程在多种数据和任务类型上的性能。结果表明,基于未约简图构建的持久图训练的模型在某些任务上可以与基于完全约简图训练的模型表现相当,甚至更优。我们还对一个计算未约简图的算法进行了计算性能基准测试,该算法是Ripser的 heavily modified 版本。这些计算是可并行的,并且平均所需内存比计算完全持久图少一个数量级。我们的结果表明,利用未约简边界矩阵中包含信息的机器学习流程可能在计算成本和性能方面受益。

英文摘要

Supervised machine learning pipelines trained on features derived from persistent homology have been experimentally observed to ignore much of the information contained in a persistence diagram. Computing persistence diagrams is often the most computationally demanding step in such a pipeline, however. To explore this dynamic, we introduce several methods to generate topological feature vectors from unreduced boundary matrices and investigate their theoretical and computational properties. We compared the performance of pipelines trained on vectorizations of unreduced PDs to vectorizations of fully-reduced PDs across several data and task types. Our results indicate that models trained on PDs built from unreduced diagrams can perform on par and even outperform those trained on fully-reduced diagrams on some tasks. We also benchmarked the computational performance of an algorithm for computing unreduced diagrams, which was implemented as a heavily modified version of Ripser. These computations are parallelizable and required an order of magnitude less memory on average compared to computing full persistence diagrams. Our results suggest that machine learning pipelines which incorporate topology-based features may benefit in terms of computational cost and performance by utilizing information contained in unreduced boundary matrices.

2. 物理仿真 13 篇

2605.10250 2026-06-18 math-ph hep-th math.MP quant-ph 版本更新 70%

From Noncommutative Kinematics to \(U(1)_{\star}\) Gauge Theory: A Family of Spectral Triples with Localized Gauge Perturbations

从非交换动力学到 $U(1)_{\star}$ 电动力学:一族具有局部化 gauge 诱导扰动的谱三元组

Tanmoy Kumar Sarkar, Md. Rafsanjany Jim, S. Hasibul Hassan Chowdhury

专题命中 物理仿真 :构建非交换平面系统的谱三元组,关联Dirac算子。

AI总结 本文构建了非交换平面系统的谱三元组框架,通过线性Darboux规范和Stone-von Neumann定理,将光滑算子代数与有效Moyal侧Frechet *-代数关联,从而得到局部紧非单位的谱三元组,并证明有限截断谱三元组在极限下逼近最小耦合Dirac算子。

Comments 64 pages. Revised version with updated title and exposition; author order revised to reflect contributions; local compactness framework clarified; spectral multiplicity of the unperturbed Dirac operators added; localized gauge perturbations and strong resolvent convergence retained

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AI中文摘要

我们构建了一个非交换平面系统相关的谱三元组框架,该系统与非退化不可约酉对称群 $G_{\mathrm{NC}}$ 的固定中心参数 $(\hbar_0,\vartheta_0, B_0)$ 关联,其中 $\hbar_0,\vartheta_0, B_0\neq 0$ 且 $\hbar_0 - \vartheta_0 B_0\neq 0$。对于对应的两参数家族 $(r,s)$ 的单位等价具体实现,我们构建了偶谱三元组,其Dirac算子具有等谱性和紧解析子,尽管在非单位和非紧设定下。通过Moyal侧描述,线性Darboux规范和Stone-von Neumann定理将表示的光滑算子代数与有效Moyal侧Frechet *-代数在 $\vartheta_{\mathrm{eff}} =\vartheta_0/(1 -\vartheta_0 B_0/\hbar_0)$ 处关联。对于每个 $\varrho$,这产生了一个局部紧非单位的谱三元组,其基代数为involution Moyal代数 $\mathcal{A}_{\vartheta_{\mathrm{eff}},\varrho}$,参数 $(r,s)$ 为动力学呈现参数,$\varrho$ 为独立星 gauge 参数。为了引入外部 $U(1)_\star$ gauge 场,我们将线性gauge势替换为光滑截断局部化;所得的有界自伴随扰动定义了每个 $R > 0$ 的局部紧非单位谱三元组。最后,当 $R\rightarrow\infty$ 时,我们证明强解析收敛到一个自伴随极限算子,即形式最小耦合算子的闭包。因此,有限截断谱三元组在谱三元组层面逼近极限最小耦合Dirac算子,其在固定非退化 $G_{\mathrm{NC}}$ 背景下。

英文摘要

We construct locally compact non-unital spectral triples for a noncommutative planar system determined by a fixed nondegenerate irreducible unitary sector of the kinematical symmetry group \(G_{\mathrm{NC}}\). The sector is labelled by central parameters \((\hbar_0,\vartheta_0,B_0)\), with \(\hbar_0,\vartheta_0,B_0\neq0\) and \(\hbar_0-\vartheta_0B_0\neq0\). For this sector, the triples \((\mathcal S_{\hbar_0,\vartheta_0,B_0},\mathcal H, D^{r,s}_{\hbar_0,\vartheta_0,B_0})\) form an even two-parameter family indexed by \((r,s)\), and different choices of \((r,s)\) give unitarily equivalent realizations. The unperturbed Dirac operators have Landau-type spectral levels of infinite multiplicity; hence local compactness, rather than compact resolvent, is the relevant analytic condition. We then identify the represented algebra \(π(\mathcal S_{\hbar_0,\vartheta_0,B_0})\) with the effective Moyal Fréchet \(\ast\)-algebra with deformation parameter \(\vartheta_{\mathrm{eff}} =\frac{\vartheta_0}{1-\vartheta_0B_0/\hbar_0}.\) For each star-product realization parameter \(\varrho\), this yields spectral triples over the involutive Moyal algebra \(\mathcal A_{\vartheta_{\mathrm{eff}},\varrho}\). External \(U(1)_{\star_{\vartheta_{\mathrm{eff}},\varrho}}\)-gauge potentials are incorporated by localizing the affine gauge potentials with smooth cutoffs. The resulting bounded self-adjoint perturbations \(B_R^{(\varrho)}\) define Dirac operators \(D_R^{\varrho,r,s}=D^{\prime\,r,s}+B_R^{(\varrho)}.\) Finally, as \(R\to\infty\), these operators converge in the strong resolvent sense to a self-adjoint limiting operator \(D_\infty\), the closure of the formal minimally coupled operator. Thus the finite-cutoff triples rigorously approximate the limiting minimally coupled Dirac operator associated with the fixed nondegenerate \(G_{\mathrm{NC}}\)-sector.

2605.06852 2026-06-18 cond-mat.str-el 版本更新 70%

Fluctuation-driven chiral ferromagnetism

涨落驱动的手性铁磁性

Rokas Veitas, Ahmed Khalifa, Francisco Machado, Shubhayu Chatterjee

专题命中 物理仿真 :发现量子涨落稳定手性铁磁态,适用于莫尔异质结。

AI总结 本文发现磁化不守恒耦合可导致量子涨落稳定手性铁磁态,产生轨道手性和手性条纹,并增强热霍尔效应,适用于莫尔异质结等体系。

Comments v2: 5+14 pages, 4+9 figures. v1: 5+9 pages, 4+3 figures

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AI中文摘要

量子涨落通常在铁磁材料中被抑制,因为它们允许简单的无阻挫基态,极大地限制了可观测现象的范围。在这项工作中,我们展示了自然存在的磁化不守恒耦合如何通过证明存在由量子涨落稳定的手性铁磁体,从根本上改变这一范式。更具体地说,我们展示了这些自旋-轨道相互作用如何修改经典相图;而经典分析仅预测非手性共线态,我们观察到涨落稳定的相,包括具有大轨道手性的铁磁体和手性条纹。我们阐明了这种耦合如何自发产生标量轨道手性,这与依赖于场诱导矢量手性序倾斜的传统机制形成对比。所得的手性态表现出独特的输运特征,即增强的热霍尔效应,并且与莫尔异质结构、里德伯原子阵列和具有非克拉默斯自旋的固态材料直接相关。

英文摘要

Quantum fluctuations are often suppressed in ferromagnetic materials because they admit a simple unfrustrated ground state, greatly limiting the scope of the phenomena that can be observed. In this work, we show how naturally occurring magnetization-non-conserving couplings fundamentally alter this paradigm by demonstrating the existence of a chiral ferromagnet that is stabilized by quantum fluctuations. More specifically, we show how these spin-orbit interactions modify the classical phase diagram; whereas a classical analysis predicts only achiral collinear states, we observe fluctuation-stabilized phases, including a ferromagnet with large orbital chirality and a chiral stripe. We elucidate how such couplings generate a scalar orbital chirality spontaneously, in contrast to conventional mechanisms which rely upon a field-induced canting of vector chiral order. The resultant chiral states exhibit distinct transport signatures, namely an enhanced thermal Hall effect, and are of direct relevance to moiré heterostructures, Rydberg-atom arrays, and solid-state materials featuring non-Kramers spins

2604.09194 2026-06-18 physics.plasm-ph astro-ph.GA astro-ph.SR 版本更新 70%

Pressure gradient-driven plasma flows and magnetogenesis

压力梯度驱动的等离子体流和磁场生成

Zain H. Saleem, Hamid Saleem

专题命中 物理仿真 :等离子体流和磁场生成理论,属于物理仿真

AI总结 提出自洽双流体理论,证明压力梯度同时产生等离子体流和磁场,发现总压满足拉普拉斯方程,给出解析解,应用于星系气体团和激光等离子体。

Comments 4 pages, 2 figures

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AI中文摘要

我们提出了一个自洽的双流体理论,证明压力梯度同时产生等离子体流和磁场。我们表明,离子动量平衡与质量守恒之间的兼容性对等离子体演化施加了一个先前未被认识到的约束:总压必须满足拉普拉斯方程,$\ abla^2 p = 0$。这一条件产生了一类精确解析解,其中压力驱动的流和Biermann型磁场共同出现。将该模型应用于星系气体团块揭示,在热压力下,电子和离子几乎一起运动,产生弱电流,从而产生非常小的种子磁场。离子动力学对于确定种子磁场产生时间$\ au_B$和估计离子流速也很重要。该模型进一步应用于激光产生的等离子体,以描述其短时间演化。本理论为天体物理和实验室等离子体中压力驱动的流生成和磁场生成提供了统一、自洽的描述。

英文摘要

We present a self-consistent two-fluid theory demonstrating that pressure gradients simultaneously generate plasma flows and magnetic fields. We show that compatibility between ion momentum balance and mass conservation imposes a previously unrecognized constraint on plasma evolution: the total pressure must satisfy the Laplace equation, $\nabla^2 p = 0$. This condition yields a class of exact analytical solutions in which pressure-driven flows and Biermann-type magnetic fields emerge together. Application of the model to a galactic gas clump reveals that, under thermal pressure, electrons and ions move almost together, giving rise to weak currents and consequently very small seed magnetic fields. Ion dynamics are also important for determining the seed magnetic-field generation time $τ_B$ and for estimating the ion flow velocity. The model is further applied to laser-produced plasma to describe its short-time evolution. The present theory provides a unified, self-consistent description of pressure-driven flow generation and magnetogenesis in both astrophysical and laboratory plasmas.

2604.00861 2026-06-18 math.NA cs.NA 版本更新 70%

Error Estimates for Nitsche's Method on Approximate Domains

近似域上Nitsche方法的误差估计

Mats G. Larson, Karl Larsson, Shantiram Mahata

专题命中 物理仿真 :Nitsche方法误差估计,属数值分析

AI总结 针对近似域上的椭圆问题,推导Nitsche方法的先验误差估计,量化边界位置和法向扰动引起的几何误差,并揭示不同范数下几何逼近对收敛性的影响。

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AI中文摘要

我们推导了应用于近似域上椭圆问题的Nitsche方法的先验误差估计。这种近似出现在例如非拟合有限元方法、数据驱动模拟和演化域问题中,其中计算域与物理域不完全重合。我们根据边界位置和法向扰动量化几何误差,并在标准稳定性假设下在抽象CutFEM框架中进行分析。在能量范数中,我们得到一个估计,显示出边界位置误差的$h^{-1/2}$放大。然后我们证明了一个精细的$H^1$半范数估计,消除了这种放大,得到了一个更紧的界,其中包含边界位置和法向误差的加性贡献。最后,我们基于精细的对偶论证建立了一个最优阶$L^2$误差估计,其中几何贡献作为一个单独的加性项出现,与网格尺寸$h$解耦。结果揭示了范数之间的基本区别:能量范数放大了边界位置误差,但对法向扰动不敏感;$H^1$半范数分离了位置和法向误差;$L^2$范数对法向扰动不敏感。这清晰地刻画了几何逼近如何影响基于Nitsche的有限元方法的收敛性,对非拟合离散化尤其重要。

英文摘要

We derive a priori error estimates for Nitsche's method applied to elliptic problems on approximate domains. Such approximations arise, for example, in unfitted finite element methods, data-driven simulations, and evolving domain problems, where the computational domain does not coincide exactly with the physical one. We quantify geometric errors in terms of boundary location and normal perturbations and carry out the analysis in an abstract CutFEM framework under standard stability assumptions. In the energy norm, we obtain an estimate exhibiting an $h^{-1/2}$ amplification of the boundary location error. We then prove a refined $H^1$-seminorm estimate that removes this amplification, yielding a sharper bound with additive contributions from boundary location and normal errors. Finally, we establish an optimal order $L^2$-error estimate based on a refined duality argument, where the geometry contribution appears as a separate additive term, decoupled from the mesh size $h$. The results reveal a fundamental distinction between the norms: the energy norm amplifies boundary location errors while remaining insensitive to normal perturbations, the $H^1$-seminorm separates location and normal errors, and the $L^2$-norm is insensitive to normal perturbations. This provides a clear characterization of how geometric approximation affects convergence in Nitsche-based finite element methods, with particular relevance for unfitted discretizations.

2603.27714 2026-06-18 math.NA cs.NA math.DG 版本更新 70%

Releasing the pressure: High-order surface flow discretizations via discrete Helmholtz-Hodge decompositions

释放压力:通过离散Helmholtz-Hodge分解的高阶曲面流离散化

Tim Brüers, Christoph Lehrenfeld, Tim van Beeck, Max Wardetzky

专题命中 物理仿真 :曲面流离散Helmholtz-Hodge分解,属数值方法

AI总结 提出一种针对任意拓扑三角曲面上H(div)协调Brezzi-Douglas-Marini有限元的离散Helmholtz-Hodge分解,将无散BDM子空间分解为连续流函数空间的旋转梯度与有限维调和场空间,消除压力和鞍点结构,确保精确切向性、逐点无散性和压力鲁棒性。

Comments 28 pages, 7 figures, 2 table

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AI中文摘要

我们提出了一种针对任意拓扑三角曲面上H(div)协调Brezzi-Douglas-Marini (BDM)有限元的离散Helmholtz-Hodge分解。无散BDM子空间被L2正交地分解为连续流函数空间的旋转梯度与一个有限维离散调和场空间,其维数等于曲面的第一Betti数。因此,在此子空间上离散的任何不可压缩流都可以用标量流函数和有限个调和系数作为唯一未知量重新表述。这消除了压力和鞍点结构,同时确保了精确切向性、逐点无散性和压力鲁棒性。我们提出了一种随机算法来构造调和基,并讨论了实现方面的问题,包括杂交、调和未知量的高效处理以及压力重构。针对三叶结和多连通雕塑曲面上的非定常曲面Navier-Stokes方程的数值实验展示了该方法,并说明了调和速度分量的物理作用。

英文摘要

We present a discrete Helmholtz--Hodge decomposition for H(div)-conforming Brezzi--Douglas--Marini (BDM) finite elements on triangulated surfaces of arbitrary topology. The divergence-free BDM subspace is split L2-orthogonally into rotated gradients of a continuous streamfunction space and a finite-dimensional space of discrete harmonic fields whose dimension equals the first Betti number of the surface. Consequently, any incompressible flow discretized on this subspace can be reformulated with a scalar streamfunction and finitely many harmonic coefficients as the only unknowns. This eliminates the pressure and the saddle-point structure while ensuring exact tangentiality, pointwise divergence-freeness, and pressure-robustness. We present a randomized algorithm for constructing the harmonic basis and discuss implementation aspects including hybridization, efficient treatment of the harmonic unknowns, and pressure reconstruction. Numerical experiments for unsteady surface Navier--Stokes equations on a trefoil knot and a multiply-connected sculpture surface demonstrate the method and illustrate the physical role of the harmonic velocity component.

2512.20608 2026-06-18 cond-mat.str-el quant-ph 版本更新 70%

Rényi-like entanglement probe of the chiral central charge

手性中心荷的类Rényi纠缠探针

Julian Gass, Michael Levin

专题命中 物理仿真 :手性中心荷纠缠探针,属量子多体物理

AI总结 提出一种通过特定几何构型中约化密度矩阵的幂来探测二维能隙量子多体系统手性中心荷的纠缠探针,并给出非相互作用费米子和弦网模型基态的解析表达式。

Comments 15 pages, 6 figures

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AI中文摘要

我们提出一种用于有能隙的二维量子多体系统的基态纠缠探针,该探针涉及在特定几何构型中对约化密度矩阵取幂。该量记为$\omega_{\alpha,\beta}$,由两个正实数$\alpha, \beta$参数化,可视为模交换子(另一种从体波函数计算手性中心荷的纠缠探针)的“类Rényi”推广。我们得到了非相互作用费米子哈密顿量的有能隙基态以及弦网模型基态的$\omega_{\alpha,\beta}$解析表达式。在这两种情况下,我们发现$\omega_{\alpha,\beta}$取一个与手性中心荷相关的普适值。对于整数$\alpha$和$\beta$,我们的量$\omega_{\alpha,\beta}$可以表示为作用于适当副本系统上的置换算符的期望值,这为在数值模拟以及可能的实验中测量$\omega_{\alpha,\beta}$提供了自然途径。

英文摘要

We propose a ground state entanglement probe for gapped, two-dimensional quantum many-body systems that involves taking powers of reduced density matrices in a particular geometric configuration. This quantity, which we denote by $ω_{α,β}$, is parameterized by two positive real numbers $α, β$, and can be seen as a ``Rényi-like" generalization of the modular commutator -- another entanglement probe proposed as a way to compute the chiral central charge from a bulk wave function. We obtain analytic expressions for $ω_{α,β}$ for gapped ground states of non-interacting fermion Hamiltonians as well as ground states of string-net models. In both cases, we find that $ω_{α,β}$ takes a universal value related to the chiral central charge. For integer values of $α$ and $β$, our quantity $ω_{α,β}$ can be expressed as an expectation value of permutation operators acting on an appropriate replica system, providing a natural route to measuring $ω_{α,β}$ in numerical simulations and potentially, experiments.

2602.02245 2026-06-18 quant-ph physics.comp-ph 版本更新 70%

Sampling two-dimensional isometric tensor network states

采样二维等距张量网络态

Alec Dektor, Eugene Dumitrescu, Chao Yang

专题命中 物理仿真 :提出采样二维等距张量网络态的算法,用于量子系统概率分布。

AI总结 提出两种采样二维等距张量网络态的新算法,分别实现独立采样和贪心搜索高概率构型,数值实验验证了其在不同纠缠和系统规模下的有效性。

Comments 26 pages, 5 figures

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AI中文摘要

采样量子系统的基础概率分布是一项重要的计算任务,例如用于量子优势实验和量子蒙特卡洛算法。张量网络是高效表示具有有限纠缠的大规模量子系统状态的重要工具。一维张量网络的采样算法已经成熟,并应用于多种一维张量网络方法中。本文针对二维等距张量网络态(isoTNS)提出了两种新的采样算法,推广了现有的一维张量网络采样算法。我们提出的第一个算法执行独立采样,并生成单个构型及其关联概率。第二个算法采用贪心搜索策略来识别$K$个高概率构型及其对应概率。数值结果展示了这些算法在不同纠缠和系统规模的量子态上的有效性。

英文摘要

Sampling a quantum system's underlying probability distributions is an important computational task, e.g., for quantum advantage experiments and quantum Monte Carlo algorithms. Tensor networks are an invaluable tool for efficiently representing states of large quantum systems with limited entanglement. Algorithms for sampling one-dimensional (1D) tensor networks are well-established and utilized in several 1D tensor network methods. In this paper we introduce two novel sampling algorithms for two-dimensional (2D) isometric tensor network states (isoTNS) that generalize existing 1D tensor networks sampling algorithms. Our first proposed algorithm performs independent sampling and yields a single configuration together with its associated probability. The second algorithm employs a greedy search strategy to identify $K$ high-probability configurations and their corresponding probabilities. Numerical results demonstrate the effectiveness of these algorithms across quantum states with varying entanglement and system size.

2601.13028 2026-06-18 math-ph math.MP 版本更新 70%

Generalized MICZ-Kepler systems on three-dimensional sphere and hyperboloid

三维球面和双曲面上广义的MICZ-Kepler系统

Levon Mardoyan, Armen Nersessian

专题命中 物理仿真 :研究三维球面和双曲面上广义MICZ-Kepler系统

AI总结 提出三维球面和双曲面上广义MICZ-Kepler系统的类似物,构造其能谱和归一化波函数,发现系统是极小超可积的。

Comments 11 pages, revised version

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AI中文摘要

我们提出了三维球面和双曲面上广义MICZ-Kepler系统的类似物。我们构造了它们的能谱和归一化波函数,发现它们依赖于两个量子数,这表明这些系统是极小超可积的。

英文摘要

We propose analogs of the generalized MICZ-Kepler system on the three-dimensional sphere and the two-sheet hyperboloid. We construct their energy spectra and normalized wave functions and find that they depend on two quantum numbers, which suggests that the systems are minimally superintegrable.

2502.17736 2026-06-18 math.DS math-ph math.MP 版本更新 70%

Dynamical spectrum of power-free integers in quadratic number fields and beyond

二次域及更广范围内无幂整数的动力学谱

Michael Baake, Daniel Luz, Tanja Schindler

专题命中 物理仿真 :无幂整数动力学谱,动力系统

AI总结 从谱角度研究无幂整数及相关格点集诱导的动力系统,利用Halmos–von Neumann定理计算纯点动力学谱并给出显式群结构,同时通过Fourier–Bohr系数得到闭式本征函数。

Comments 31 pages, revised and improved version, with one important change in Section 4

Journal ref Discr. Cont. Dynam. Syst. A 49 (2026) 403--431 and 54 (2016) 545--545 (Corrigendum)

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AI中文摘要

无幂整数及相关格点子集产生了有趣的动力系统。本文从谱角度,在Halmos–von Neumann定理的框架下重新审视它们。关于自然补丁频率测度(也称为Mirsky测度),这些系统中的许多具有纯点动力学谱,但具有平凡的拓扑点谱。我们以加法符号显式计算了谱,并推导了它们的群结构,既针对$\RR^d$中的一大类$\cB$-自由格点系统,也针对二次域中的无幂整数。此外,在所有情况下,本征函数都可以通过通用元素及其平移的Fourier–Bohr系数以闭式给出,这些元素构成一个全Mirsky测度的子集。基于Kolmogorov强大数定律的简单论证,我们展示了Fourier–Bohr系数如何也为唯一最大熵测度提供本征函数,并且我们得到了两种测度的相位一致性。

英文摘要

Power-free integers and related lattice subsets give rise to interesting dynamical systems. They are revisited from a spectral perspective, in the setting of the Halmos--von Neumann theorem. With respect to the natural patch frequency measure, also known as the Mirsky measure, many of these systems have pure-point dynamical spectrum, but trivial topological point spectrum. We calculate the spectra explicitly, in additive notation, and derive their group structure, both for a large class of $\cB$-free lattice systems in $\RR^d$ and for power-free integers in quadratic number fields. Further, in all cases, the eigenfunctions can be given in closed form, via the Fourier--Bohr coefficients of generic elements and their translates, which form a subset of full Mirsky measure. Based on a simple argument via Kolmogorov's strong law of large numbers, we show how the Fourier--Bohr coefficients also provide the eigenfunctions for the unique measure of maximal entropy, and that we get phase consistency for both measures.

2506.08764 2026-06-18 cs.LG 版本更新 70%

On the Stability of the Jacobian Matrix in Deep Neural Networks

深度神经网络中雅可比矩阵的稳定性

Benjamin Dadoun, Soufiane Hayou, Hanan Salam, Mohamed El Amine Seddik, Pierre Youssef

专题命中 物理仿真 :利用随机矩阵理论研究神经网络雅可比矩阵稳定性,属于物理仿真。

AI总结 本文利用随机矩阵理论,建立了深度神经网络中雅可比矩阵谱稳定性的通用定理,适用于稀疏和非独立同分布权重,扩展了初始化方案的理论基础。

Comments 21 pages, 28 figures; the main theorem was wrong (again) and is now corrected

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AI中文摘要

深度神经网络随着深度增加容易出现梯度爆炸或消失,这一现象与输入-输出雅可比矩阵的谱行为密切相关。先前的工作确定了确保雅可比稳定性的关键初始化方案,但这些分析通常局限于具有独立同分布权重的全连接网络。在这项工作中,我们显著超越了这些限制:我们建立了一个适用于深度神经网络的通用稳定性定理,该定理能够处理稀疏性(例如由剪枝引入的)以及非独立同分布、弱相关权重(例如由训练引起的)。我们的结果依赖于随机矩阵理论的最新进展,并为更广泛类别的网络模型提供了谱稳定性的严格保证。这扩展了具有结构化和依赖随机性的现代神经网络中初始化方案的理论基础。

英文摘要

Deep neural networks are known to suffer from exploding or vanishing gradients as depth increases, a phenomenon closely tied to the spectral behavior of the input-output Jacobian. Prior work has identified critical initialization schemes that ensure Jacobian stability, but these analyses are typically restricted to fully connected networks with i.i.d. weights. In this work, we go significantly beyond these limitations: we establish a general stability theorem for deep neural networks that accommodates sparsity (such as that introduced by pruning) and non-i.i.d., weakly correlated weights (e.g. induced by training). Our results rely on recent advances in random matrix theory, and provide rigorous guarantees for spectral stability in a much broader class of network models. This extends the theoretical foundation for initialization schemes in modern neural networks with structured and dependent randomness.

2510.14805 2026-06-18 math.NA cs.NA math.OC 版本更新 70%

An Augmented Lagrangian Method-Based Framework in the Adjoint Space for Sparse Reconstruction of Acoustic Sources

基于增广拉格朗日方法的伴随空间框架用于声源稀疏重建

Nirui Tan, Hongpeng Sun

专题命中 物理仿真 :提出声源稀疏重建的增广拉格朗日框架,属于数值计算。

AI总结 提出一种半光滑牛顿增广拉格朗日框架,在测量(伴随)空间进行更新,通过Fenchel-Rockafellar对偶恢复声源,显著加速计算并降低成本。

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AI中文摘要

我们提出了一种基于半光滑牛顿的增广拉格朗日框架,用于逆声散射问题中稀疏源的重建。我们的半光滑牛顿更新不是在未知源空间中进行,而是在测量(伴随)空间中进行,当测量数量远小于离散源维度时,这种方法尤其高效。然后通过Fenchel-Rockafellar对偶恢复源。我们的方法大幅加速了计算并降低了成本。二维和三维数值实验证明了所提方法的高效性。

英文摘要

We propose a semismooth Newton-based augmented Lagrangian framework for reconstructing sparse sources in inverse acoustic scattering problems. Rather than working in the unknown source space, our semismooth Newton updates operate in the measurement (adjoint) space, which is especially efficient when the number of measurements is much smaller than the discretized source dimension. The source is then recovered via Fenchel-Rockafellar duality. Our approach substantially accelerates computation and reduces costs. Numerical experiments in two and three dimensions demonstrate the high efficiency of the proposed method.

2505.22471 2026-06-18 math.PR 版本更新 70%

Phase transitions for contact processes on sparse random graphs via metastability and local limits

稀疏随机图上接触过程的相变:基于亚稳态和局部极限

Benedikt Jahnel, Lukas Lüchtrath, Christian Mönch

专题命中 物理仿真 :研究稀疏随机图上接触过程的相变

AI总结 通过亚稳态密度和局部收敛技术,研究稀疏有限图上接触过程的快慢灭绝渐近区域,给出临界阈值与局部极限中存活/灭绝阈值一致的条件,并证明稀疏图上快灭绝可能发生在拉伸指数时间尺度。

Comments v2: revised version; to appear in Bernoulli

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AI中文摘要

我们提出了一种新的视角,研究局部收敛的稀疏有限图序列上接触过程的快慢灭绝渐近区域。我们通过亚稳态密度的存在来刻画相边界,这使得相变的研究特别适合局部收敛技术。我们利用这种方法推导了临界阈值与局部极限中存活/灭绝阈值一致的一般条件。我们进一步论证,在稀疏图中,分离快灭绝和慢灭绝的正确时间尺度通常是指数尺度,通过展示在稀疏无标度空间网络中快灭绝可能发生在拉伸指数时间尺度上。结合Nam、Nguyen和Sly (Trans.\ Am.\ Math.\ Soc.\ 375, 2022)的结果,我们的方法可用于推断稀疏配置模型中的快/慢阈值与极限Galton-Watson树上的存活/灭绝阈值一致。

英文摘要

We propose a new perspective on the asymptotic regimes of fast and slow extinction in the contact process on locally converging sequences of sparse finite graphs. We characterise the phase boundary by the existence of a metastable density, which makes the study of the phase transition particularly amenable to local-convergence techniques. We use this approach to derive general conditions for the coincidence of the critical threshold with the survival/extinction threshold in the local limit. We further argue that the correct time scale to separate fast extinction from slow extinction in sparse graphs is, in general, the exponential scale, by showing that fast extinction may occur on stretched exponential time scales in sparse scale-free spatial networks. Together with {the results of} Nam, Nguyen and Sly (Trans.\ Am.\ Math.\ Soc.\ 375, 2022), our methods can be applied to deduce that the fast/slow threshold in sparse configuration models coincides with the survival/extinction threshold on the limiting Galton-Watson tree.

2505.11260 2026-06-18 math.PR math-ph math.MP 版本更新 70%

Metastability for the Curie-Weiss-Potts model with unbounded random interactions

具有无界随机相互作用的Curie-Weiss-Potts模型的亚稳态

Johan L. A. Dubbeldam, Vicente Lenz Burnier, Elena Pulvirenti, Martin Slowik

专题命中 物理仿真 :研究Curie-Weiss-Potts模型亚稳态行为

AI总结 研究无序Curie-Weiss-Potts模型在Glauber动力学下的亚稳态行为,通过势理论方法和测度集中技术,比较了该模型与无随机版本在亚稳态跃迁时间上的比值,并推导了该比值的渐近尾部和矩。

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AI中文摘要

我们分析了无序Curie-Weiss-Potts(DCWP)模型在Glauber动力学下的亚稳态行为。该模型是平均场$q$-自旋Potts模型(CWP)的随机无序版本,其中自旋之间的相互作用系数为一般独立随机变量。这些随机变量具有固定的均值(为简单起见取为$1$)和定义良好的累积生成函数,且其分布不依赖于粒子数。系统以离散时间马尔可夫链的形式演化,采用单自旋翻转的Metropolis动力学,在有限逆温度$\beta$下进行。我们比较了当$N \to \infty$时CWP和DCWP模型的亚稳态行为。首先,我们建立了CWP模型的亚稳态,并利用这一结果证明了DCWP模型(以高概率)的亚稳态。然后,我们确定了DCWP模型亚稳态跃迁时间与CWP模型相应时间的比值。具体地,我们推导了该比值的渐近尾部行为和矩。我们的证明结合了亚稳态的势理论方法和测度集中技术,后者针对我们的特定情境进行了调整。

英文摘要

We analyse the metastable behaviour of the disordered Curie--Weiss--Potts (DCWP) model subject to a Glauber dynamics. The model is a randomly disordered version of the mean-field $q$-spin Potts model (CWP), where the interaction coefficients between spins are general independent random variables. These random variables are chosen to have fixed mean (for simplicity taken to be $1$) and well defined cumulant generating function, with a fixed distribution not depending on the number of particles. The system evolves as a discrete-time Markov chain with single spin flip Metropolis dynamics at finite inverse temperature $β$. We provide a comparison of the metastable behaviour of the CWP and DCWP models, when $N \to \infty$. First, we establish the metastability of the CWP model and, using this result, prove metastability for the DCWP model (with high probability). We then determine the ratio between the metastable transition time for the DCWP model and the corresponding time for the CWP model. Specifically, we derive the asymptotic tail behavior and moments of this ratio. Our proof combines the potential-theoretic approach to metastability with concentration of measure techniques, the latter adapted to our specific context.