arXivDaily arXiv每日学术速递 周一至周五更新
重置
2606.03633 2026-06-12 nucl-th 版本更新

Mechanical properties of the nucleon in the chiral confining model. II -- in-medium evolution of the nucleon properties

手征禁闭模型中核子的力学性质. II -- 核子性质的在介质演化

Guy Chanfray, Hubert Hansen, Bikram Keshari Pradhan

AI总结 在手征禁闭模型框架下,通过冯·劳厄稳定性条件确定介质中核子试验态,研究标量场对复合核子的响应以及禁闭和手征对称性破缺对核子质量演化的作用,并分析核子内部能量密度和压力分布的变化。

详情
Comments
22 pages, 8 figures
AI中文摘要

本文致力于在手征禁闭模型框架内研究束缚于核物质中的核子性质的演化。根据前期姊妹论文(标记为I)中建立的正式结果,通过施加冯·劳厄稳定性条件确定介质中核子试验态(局域化因子化波函数或动量投影态)。主要结果涉及复合核子对标量场的响应,以及禁闭和手征对称性破缺在介质中核子质量演化中的各自作用。该演化支配着核饱和机制所需的三体排斥力。我们还分析了介质中核子内部能量密度分布和压力分布的变化。此外,我们就束缚核子性质与中子星内部致密物质状态方程之间的映射提出了一些展望。

英文摘要

This article is devoted to the study of the evolution of the properties of nucleons bound in nuclear matter within the framework of the chiral confining model. The in-medium nucleon trial states (either localized factorized wave functions or momentum-projected states) are determined by imposing the von Laue stability condition, according to the formal results established in a preliminary companion paper (labeled as I). The main results concern the response of the composite nucleon to the scalar field, as well as the respective roles of confinement and chiral symmetry breaking in the evolution of the in-medium nucleon mass. This evolution governs the repulsive three-body forces required for the nuclear saturation mechanism. We also analyze the modification of the energy density distribution and the pressure distribution inside the in-medium nucleon. We also draw some perspectives concerning the mapping between bound nucleon properties and the equation of state of dense matter as realized in the deep interior of neutron stars.

2606.03588 2026-06-12 nucl-th 版本更新

Mechanical properties of the nucleon in the chiral confining model. I -- formal developments

手征禁闭模型中核子的力学性质 I——形式发展

Guy Chanfray, Hubert Hansen, Bikram Keshari Pradhan

AI总结 本文在手征禁闭模型框架下,通过von Laue稳定性条件确定核子试探态,形式化推导了核子内部总能量、平均压强、能量密度和压强分布的详细表达式。

详情
Comments
25 pages, 5 figures
AI中文摘要

我们在一类模型中讨论了核子的力学稳定性问题,其中大质量组分夸克受到禁闭势的作用,并与包围夸克核心的π云耦合。核子试探态(局域化因子化波函数或动量投影态)通过施加von Laue稳定性条件确定。本文主要致力于与核子内部总能量(质量)、平均压强、能量密度和压强分布详细表达式相关的形式方面。它将由一篇补充文章伴随,该文章讨论核子性质随密度的演化,与手征对称性恢复相关。

英文摘要

We discuss the issue of the mechanical stability of the nucleon within a class of models in which massive constituent quarks are subject to a confining potential and are coupled to a surrounding pion cloud enveloping the quark core. The nucleon trial states (either localized factorized wave functions or momentum-projected states) are determined by imposing the von Laue stability condition. This article is primarily devoted to the formal aspects related to the detailed expressions for the total energy (mass), the average pressure, the energy density and the pressure distribution inside the nucleon. It will be accompanied by a complementary article addressing the evolution of nucleon properties with density, associated with the restoration of chiral symmetry.

2606.02929 2026-06-12 gr-qc hep-th 版本更新

Kerr--Schild--AdS geometries in quadratic f(R) gravity: A no-go theorem

二次f(R)引力中的Kerr--Schild--AdS几何:一个不可行定理

Alikram N. Aliev

AI总结 研究二次f(R)引力中的Kerr--Schild--AdS几何,证明场方程动态强制恒定标量曲率并唯一选择Kerr--AdS解族,建立该几何类别的不可行定理。

详情
Comments
Minor revisions; 8 pages
AI中文摘要

我们在二次$f(R)$引力中研究Kerr--Schild--AdS几何,而不先验地施加恒定曲率条件$R=R_0$。对于几何上自然的Kerr--Schild--AdS子类,我们证明场方程动态强制恒定标量曲率,并唯一选择Kerr--AdS解族。因此,二次$f(R)$引力在爱因斯坦分支之外不存在Kerr--AdS黑洞解,从而为这类几何建立了一个不可行定理。

英文摘要

We investigate Kerr-Schild-AdS geometries in quadratic f(R) gravity without imposing the constant-curvature condition R=R_0 a priori. We show that the field equations dynamically enforce constant scalar curvature and uniquely select the Kerr--AdS family of solutions. Thus, quadratic f(R) gravity admits no Kerr--AdS solutions beyond the Einstein branch, establishing a no-go theorem for this class of geometries.

2606.03473 2026-06-12 cond-mat.dis-nn 版本更新

Hierarchical crack patterns: Identification of crack generations

层次裂纹模式:裂纹世代的识别

Yuri Yu. Tarasevich, Andrei S. Burmistrov, Andrei V. Eserkepov

AI总结 通过将有向无环图的拓扑排序应用于裂纹图像,提出一种鲁棒的层次裂纹世代分类方法。

详情
Comments
8 pages, 8 figures, 22 references
AI中文摘要

各种起源的层次裂纹模式在我们周围的世界中无处不在。我们将整个层次裂纹模式部分图像中的裂纹世代分类问题简化为经典的有向无环图拓扑排序。该分类方法对模式图像边界的合理偏移具有鲁棒性。

英文摘要

Identifying crack generations from microscopic images of hierarchical crack patterns is challenging due to the lack of temporal information and sensitivity to image boundaries. Existing algorithms often fragment individual cracks or lose stability when the observed fragment is shifted. We propose a method that reduces the classification problem to topological sorting of a directed acyclic graph (descendant$\to$parent), built from T-junctions and nearly collinear edges. Sequential removal of leaf vertices assigns generation numbers starting from the youngest. On 100 computer-generated networks, our method correctly classifies $\approx 70$\% of cracks at a window size of only three mean edge lengths, whereas a conventional approach that starts from primary cracks drops nearly to zero. The classification is highly stable against reasonable shifts of image boundaries but remains limited to strictly hierarchical networks.

2606.02778 2026-06-12 astro-ph.EP astro-ph.IM cs.LG 版本更新

One Transit Is All You Need: Detecting Exoplanets Through Learned Stellar Behaviour with EXOVEIL

一次凌星足矣:通过EXOVEIL学习恒星行为检测系外行星

Pratik Priyanshu

发表机构 * SRH Hochschule(SRH 高校)

AI总结 提出EXOVEIL系统,利用Transformer世界模型和自监督学习从原始光变曲线中检测单次凌星事件,在Kepler数据上实现高召回率,并零样本迁移至TESS和PLATO任务。

详情
Comments
v3: appendix gallery of confirmed-planet recoveries added; Section 6 candidate catalogue reframed as transit-like anomalies for follow-up; TLS comparison table expanded
AI中文摘要

我提出EXOVEIL,一个凌星检测系统,它学习恒星亮度应有的样子,并在现实不符时发出标记。与需要相位折叠输入的现有系统不同,EXOVEIL在原始通量时间序列上运行,可以检测仅凌星一次的行星。一个Transformer世界模型,在16,499条Kepler光变曲线上通过凌星掩蔽自监督学习训练,预测预期的恒星通量。一个带有方差加权的匹配滤波检测器从预测残差中提取凌星信号。一个学习分类器(XGBoost)将行星与假阳性区分开,在Kepler DR25上达到AUC 0.938。应用于单次凌星注入-恢复,EXOVEIL在1000 ppm深度下恢复了32%的凌星——而所有基于分类的系统由于设计原因得分为0%。对3,737颗Kepler恒星进行盲搜索,发现了179个新的凌星类信号,这些信号不在DR25 TCE目录中,包括46个单次凌星候选者。无需重新训练,应用于PLATO LOPS2场中的47颗已确认TESS行星,EXOVEIL实现了100%的恢复,展示了零样本跨任务迁移。在PLATO的25秒曝光下,检测达到100 ppm——接近地球类似物范围。我提供了共形预测在凌星检测中的首次应用(95.9%经验覆盖率),并发布了该系统,可通过pip install exoveil安装,包含预训练权重和候选目录。

英文摘要

I present EXOVEIL, a transit detection system that learns what a star's brightness should look like and flags when reality disagrees. Unlike existing systems that require phase-folded input, EXOVEIL operates on raw flux time series and can detect planets that transit only once.A Transformer world model, trained on 16,499 Kepler light curves with transit-masked self-supervised learning, predicts expected stellar flux. A matched-filter detector with variance weighting extracts transit signals from the prediction residuals. A learned classifier (XGBoost) separates planets from false positives, achieving AUC 0.938 on Kepler DR25. Applied to single-transit injection-recovery, EXOVEIL recovers 32% of transits at 1000 ppm depth a task where all classification-based systems score 0% by construction. A blind search of 3,737 Kepler stars yields 179 new transit-like signals not present in the DR25 TCE catalogue, including 46 monotransit candidates. Applied withoutretraining to 47 confirmed TESS planets in the PLATO LOPS2 field, EXOVEIL achieves 100% recovery, demonstrating zero-shot cross-mission transfer. At PLATO's 25-second cadence, detection reaches 100 ppm -- approaching the Earth-analog regime. I provide the first application of conformal prediction to transit detection (95.9% empirical coverage) and release the system as pip install exoveil with pretrained weights and a candidate catalogue.

2606.02044 2026-06-12 cs.LG physics.med-ph 版本更新

Realistic noise synthesis reduces bias and improves tissue microstructure estimation with supervised machine learning

真实噪声合成减少偏差并改善有监督机器学习的组织微结构估计

Bradley G. Karat, Maëliss Jallais, Ali R. Khan, Santiago Aja-Fernández, Jelle Veraart, Marco Palombo

AI总结 针对扩散MRI中模拟与实测信号噪声不匹配导致的协变量偏移问题,提出真实噪声合成框架,通过引入Rician期望和有效后处理噪声方差,显著降低参数估计偏差并提高精度。

详情
Comments
* Shared first author
AI中文摘要

扩散MRI能够无创探测组织微结构,但准确的参数估计受到噪声相关效应的挑战。在基于模拟数据训练的有监督机器学习框架中,模拟信号与采集信号的噪声特性差异引入了一种协变量偏移,导致训练和推理时的输入信号分布不同。我们研究了这种不匹配对微结构参数估计的影响,并提出了一种真实噪声合成(RNS)框架来缓解该问题。RNS将Rician期望和有效后处理噪声方差同时纳入模拟训练信号。Rician期望使用MPPCA估计的噪声标准差建模,而有效标准差则从预处理数据的球谐残差中导出。该方法使用cylinder-zeppelin和SANDI模型在多个SNR水平的模拟数据集以及具有重复采集的体内扩散数据上进行了评估。还评估了对噪声误估计的敏感性。训练过程中忽略幅度诱导的噪声效应会产生系统性的、依赖于SNR的参数偏差,尤其是在低SNR下。引入Rician期望显著降低了偏差,使其达到噪声感知的非线性最小二乘拟合的水平。对有效标准差进行建模进一步提高了精度。性能在很大程度上独立于回归架构,但对准确的噪声估计敏感。这些发现表明,在模拟训练数据中进行真实噪声建模可以减轻信号域的协变量偏移,并且对于无偏的监督微结构估计至关重要,特别是在与高b值或高空间分辨率相关的低SNR区域。

英文摘要

Diffusion MRI enables non-invasive probing of tissue microstructure, but accurate parameter estimation is challenged by noise-related effects. In supervised machine learning frameworks trained on simulated data, discrepancies between the noise characteristics of simulated and acquired signals introduce a form of covariate shift, whereby the input signal distribution differs between training and inference. We investigated the impact of this mismatch on microstructure parameter estimation and propose a realistic noise synthesis (RNS) framework to mitigate it. RNS incorporates both the Rician expectation and the effective post-processing noise variance into simulated training signals. The Rician expectation was modelled using a noise standard deviation estimated with MPPCA, while the effective standard deviation was derived from spherical harmonic residuals of preprocessed data. The method was evaluated using the cylinder-zeppelin and the SANDI models on simulated datasets across multiple SNR levels and on in vivo diffusion data with repeated acquisitions. Sensitivity to noise misestimation was also assessed. Ignoring magnitude-induced noise effects during training produced systematic, SNR-dependent parameter bias, particularly at low SNR. Incorporating the Rician expectation substantially reduced bias to the level of noise-aware nonlinear least-squares fitting. Modelling the effective standard deviation further improved precision. Performance was largely independent of regression architecture but sensitive to accurate noise estimation. These findings demonstrate that realistic noise modelling in simulated training data mitigates signal-domain covariate shift and is essential for unbiased supervised microstructure estimation, particularly in low-SNR regimes associated with high b-values or high spatial resolution.

2605.31544 2026-06-12 quant-ph 版本更新

More efficient Clifford+T synthesis for small-angle rotations and application to Trotterization

更高效的小角度旋转的 Clifford+T 综合及其在 Trotterization 中的应用

Marius Bothe, Christoph Sünderhauf, Michael J. Witham, Earl T. Campbell, Nick S. Blunt

AI总结 本文提出针对小角度旋转的 Clifford+T 综合方法,将 T 门成本从 O(log 1/δ) 降低到 Õ(θ²/δ),并通过准概率技术进一步降低大规模电路的总 T 成本,应用于 Trotterization 可显著减少门成本。

详情
Comments
43 pages, 12 figures
AI中文摘要

旋转门的 Clifford+T 综合是容错量子编译中的重要例程。虽然 Clifford+T 综合是可扩展的,但在实践中每次旋转需要数十个 T 门,导致许多容错算法的资源估计很高。然而,这些众所周知的结果(包括使用概率混合的结果 [Quantum 7, 1208 (2023)])与旋转角度 θ 无关,需要 O(log 1/δ) 个 T 门。我们证明,对于小角度,可以做得更好,将 T 成本降低到 Õ(θ²/δ),在最坏情况下恢复到现有的 O(log1/δ) 结果。这一点尤其重要,因为许多算法(如 Trotterization)主要由小角度旋转主导。此外,我们对准概率进行了详细的理论和数值研究,这可以进一步将大规模电路的总 T 成本降低几个数量级,而样本复杂度仅略有增加。我们还开发了一种基于 Clifford+T 回退通道的准概率混合方案。我们推导了新的依赖于 θ 的公式,可用于容错量子算法的资源估计。作为我们结果的应用,我们表明,编译到 Clifford+T 门集的 Trotterization 电路的门成本在小 Trotter 步长极限下是常数,即使对于大步长也可以降低几个数量级。鉴于这些结果,应重新审视各种应用中容错 Trotterization 的成本。我们的工作消除了广泛声称的 Clifford+T 旋转综合具有与 θ 无关的高成本的说法,并进一步开发了一种可扩展的准概率旋转综合方法。我们还期望我们的结果通过减少所需的魔法态资源,推动有用的早期容错量子计算。

英文摘要

Clifford+T synthesis of rotation gates is an important routine in fault-tolerant quantum compilation. While Clifford+T synthesis is scalable, it has a high overhead of tens of T gates per rotation in practice, translating to high resource estimates for many fault-tolerant algorithms. However, these well-known results, including those using probabilistic mixtures [Quantum 7, 1208 (2023)], are independent of the rotation angle $\theta$, requiring $O(\log 1/\delta)$ T gates. We show that it is possible to do much better for small angles, reducing the T cost to $\tilde{O}(\theta^2/\delta)$, and returning to existing $O(\log1/\delta)$ results in the worst case. This is particularly important since many algorithms, such as Trotterization, are dominated by small-angle rotations. Further, we perform a detailed theoretical and numerical study of quasi-probabilities, which can further reduce the total T cost of large circuits by orders of magnitude with only a small overhead in sample complexity. We also develop a scheme based on quasi-probability mixtures of Clifford+T fallback channels. We derive new $\theta$-dependent formulas that can be used for resource estimation of fault-tolerant quantum algorithms. As an application of our results, we show that the gate cost of Trotterization circuits compiled to a Clifford+T gate set is constant in the small Trotter step size limit, and can be reduced by orders of magnitude even for large step sizes. The cost of fault-tolerant Trotterization for a variety of applications should be re-examined in light of these results. Our work dispels the widely-stated claim that Clifford+T rotation synthesis has a high cost independent of $\theta$, and further develops a scalable quasi-probability method for rotation synthesis. We also expect our results to bring forward useful early fault-tolerant quantum computing by reducing required magic state resources.

2605.30806 2026-06-12 math-ph 版本更新

Novel energy preserving bijections between affine crystals for $U_q(\widehat{\mathfrak{sl}}_2)$ and integer partitions

关于 $U_q(\widehat{\mathfrak{sl}}_2)$ 的仿射晶体与整数分拆之间的新型保能量双射

Sota Miyazawa, Taichiro Takagi

AI总结 本文构造了仿射量子群 $U_q(\widehat{\mathfrak{sl}}_2)$ 的晶体图与整数分拆集之间的显式组合双射,并解释了自旋子构型描述。

详情
Comments
20 pages, 7 figures
AI中文摘要

设 $B(\Lambda_a) \, (a=0,1)$ 为仿射量子群 $U_q(\widehat{\mathfrak{sl}}_2)$ 的 1 级可积不可约最高权表示的晶体。我们考虑与 $B(\Lambda_0)$(对应地,$B(\Lambda_1)$)中不可约 $(2r+1)$ 维(对应地,$(2r+2)$ 维)$U_q(\mathfrak{sl}_2)$ 模相关联的 $n$ 次晶体图。在本文中,我们构造了一个显式的组合过程,提供了这些图中关于 Kashiwara 算子 $\tilde{f}_{1}$ 作用的最高权路径集合与具有 sqrank(对应地,rerank)$r$ 的整数分拆集合之间的双射,其中 sqrank 和 rerank 是最近引入的分拆统计量。作为副产品,我们还获得了 Bernard-Pasquier-Serban 在 Wess-Zumino-Witten 共形场论模型的自旋子图像中建议的自旋子构型描述的精确解释。

英文摘要

Let $B(\Lambda_a) \, (a=0,1)$ be the crystal of the level 1 integrable irreducible highest weight representation of the affine quantum group $U_q(\widehat{\mathfrak{sl}}_2)$. We consider the crystal graphs of degree $n$ associated with the irreducible $(2r+1)$-dimensional (resp. $(2r+2)$-dimensional) $U_q(\mathfrak{sl}_2)$ module in $B(\Lambda_0)$ (resp. $B(\Lambda_1)$). In this paper, we construct an explicit combinatorial procedure providing a bijection between the set of highest weight paths in these graphs with respect to the action of the Kashiwara operator $\tilde{f}_{1}$, and the set of integer partitions of $n$ with sqrank (resp. rerank) $r$, which is a recently introduced partition statistic. As a byproduct, we also obtain a precise interpretation of the motif description of spinons suggested by Bernard-Pasquier-Serban in the spinon picture for Wess-Zumino-Witten conformal field theory models.

2605.28076 2026-06-12 stat.ML math.NA nlin.CD physics.data-an 版本更新

Diagnosing the conditional-mean barrier in scientific machine-learning surrogates

条件均值障碍:从确定性回归到条件分布学习

Junfeng Chen

AI总结 本文提出条件均值障碍概念,通过残差-特征正交性和决定系数两个诊断指标识别该障碍,并证明添加潜在随机性会迫使平方损失预测器回到条件均值,从而需要分布评分损失来跨越障碍。

详情
AI中文摘要

计算科学与工程中的许多问题在粗粒化、部分观测或逆重建后变成一对多映射:一个已解析状态可能无法确定唯一的子网格强迫,一个结构描述符可能无法确定唯一的有效响应,一个低分辨率观测可能对应多个合理的高分辨率场。在这种情况下,确定性代理可能学习到一个定义明确的数学对象,但仍会遗漏应用相关的不确定性。本教程开发了一个以条件均值障碍为中心的自包含模块:平方损失预测器达到条件均值且剩余误差为不可约的偶然方差时的点。我们给出了两个定位该障碍的诊断方法:残差-特征正交性和决定系数(相对于其解释方差上限),并证明向平方损失预测器添加潜在随机性会使其坍缩回条件均值。因此,跨越障碍需要一种对分布而非点预测进行评分的损失函数。我们简要整理了常见的分布目标,包括负对数似然、矩和可观测匹配、变分目标、对抗散度和分数匹配,根据每个目标针对的条件律特征进行分类。重点在于障碍本身以及识别它的有限数据程序,而非对超越障碍的方法进行综述。基于CPU的双分支律和双尺度Lorenz-96闭合问题的演示展示了诊断如何区分确定性欠拟合与剩余分布变异性。

英文摘要

Many problems in computational science and engineering become one-to-many after coarse graining, partial observation, or inverse reconstruction: a resolved state may not determine a unique subgrid forcing, a structural descriptor may not determine a unique effective response, and a low-resolution observation may correspond to many plausible high-resolution fields. In such settings, deterministic surrogates may learn a well-defined mathematical object while still missing application-relevant uncertainty. This tutorial develops a self-contained module centered on the conditional-mean barrier: the point at which a squared-loss predictor has reached the conditional mean and the remaining error is irreducible aleatoric variance. We give two diagnostics for locating this barrier, residual-feature orthogonality and the coefficient of determination against its explained-variance ceiling, and prove that adding latent randomness to a squared-loss predictor collapses it back to the conditional mean. Crossing the barrier therefore requires a loss that scores distributions rather than point predictions. We briefly organize common distributional objectives, including negative log-likelihood, moment and observable matching, variational objectives, adversarial divergences, and score matching, by the feature of the conditional law each targets. The emphasis is the boundary itself and a finite-data procedure for recognizing it, rather than a survey of methods beyond it. CPU-based demonstrations on a two-branch law and a two-scale Lorenz-96 closure problem show how the diagnostics distinguish deterministic underfitting from residual distributional variability.

2605.27049 2026-06-12 hep-ph hep-ex hep-th 版本更新

Family-separated seesaw relations of Majorana neutrinos

马约拉纳中微子的家族分离跷跷板关系

Zhi-zhong Xing

AI总结 通过求解精确跷跷板方程,发现一种家族分离的跷跷板关系,建立了轻中微子与重马约拉纳中微子质量及混合矩阵元之间的简单联系,并预言了CP破坏效应在轻中微子振荡与重中微子衰变中的直接关联。

详情
Comments
14 pages, 2 figures. More discussions and results added
AI中文摘要

鉴于规范跷跷板机制是标准模型中微子部分最自然的扩展,我们发现了精确跷跷板方程的一个特殊但全新的解:对于第$i$家族($i = 1, 2, 3$,$α= e, μ, τ$)的轻和重马约拉纳中微子的质量和味混合矩阵元,有$m^{}_i/M^{}_i = - R^2_{αi}/U^2_{αi}$。这种家族分离的跷跷板场景使我们能够在原始跷跷板参数与活跃自由度之间建立简单关系,从而提供一些可检验的预言,例如轻中微子味振荡和重马约拉纳中微子衰变中CP破坏效应之间的直接关联。

英文摘要

Given the canonical seesaw mechanism as a most natural extension of the standard model in its neutrino sector, we find out a special but brand new solution to the exact seesaw equation: $m^{}_i/M^{}_i = - R^2_{\alpha i}/U^2_{\alpha i}$ for the masses and flavor mixing matrix elements of light and heavy Majorana neutrinos of the $i$-th family (for $i = 1, 2, 3$ and $\alpha = e, \mu, \tau$). This family-separated seesaw scenario allows us to establish simple relations between the original seesaw parameters and the active degrees of freedom, and thus offers a number of testable predictions in neutrino phenomenology.

2605.26358 2026-06-12 physics.flu-dyn cs.LG 版本更新

Deep Learning-based Algebraic Reynolds Stress Closures for RANS Simulations of Turbulent Flows

基于深度学习的代数雷诺应力闭合模型用于湍流RANS模拟

Daniel Dehtyriov, Jonathan F. MacArt, Justin Sirignano

发表机构 * Mathematical Institute, University of Oxford(牛津大学数学研究所) Aerospace and Mechanical Engineering, University of Notre Dame(诺特丹大学航空航天与机械工程系)

AI总结 提出一种物理驱动的深度学习闭合模型DARSM,通过神经网络映射流动不变量到隐式代数雷诺应力方程中的经验参数,并结合伴随方程实现端到端优化,在方形管道和周期性山丘基准测试中平均速度误差降低2-4倍。

详情
AI中文摘要

湍流在工程和科学中普遍存在,但直接模拟成本过高。雷诺平均纳维-斯托克斯(RANS)方程可节省超过十个数量级的计算量,但引入了未封闭项(封闭问题)。离线训练的机器学习(ML)闭合模型在预测模拟中会出现分布偏移,而绕过控制方程的ML方法难以从稀缺的高保真数据中泛化。我们开发了一种基于物理的深度学习RANS闭合模型——深度代数雷诺应力模型(DARSM),该模型可在小数据集上训练,并准确泛化到不同雷诺数、未见几何形状和不同流动状态。神经网络将流动不变量映射到隐式代数雷诺应力方程中的经验参数,该方程基于弱平衡假设从雷诺应力输运方程推导而来,为ML闭合施加了基于物理的结构。通过控制偏微分方程和耦合隐式闭合的端到端优化消除了分布偏移,但展开和隐式自动微分在刚性耦合求解器上均失败。我们推导了利用求解器隐式-显式结构的伴随方程,以实现高效优化。在标准方形管道和周期性山丘基准测试中,DARSM将基线RANS的平均测试速度误差降低了2-4倍(跨雷诺数、几何形状和流动状态),峰值案例级降低达12倍。在附着、各向异性主导的流动(方形管道)上训练的模型无需重新训练即可准确泛化到分离流动(周期性山丘),这是底层物理状态的改变。DARSM还优于五种已建立的ML方法:离线训练、张量基神经网络、场反演机器学习、DeepONet和物理信息神经网络。

英文摘要

Turbulence is ubiquitous in engineering and science, yet direct simulation is prohibitively expensive. The Reynolds-averaged Navier-Stokes (RANS) equations provide savings exceeding ten orders of magnitude but introduce unclosed terms (the closure problem). Offline-trained machine-learning (ML) closures suffer distribution shift in predictive simulations, while ML methods that bypass the governing equations struggle to generalise from scarce high-fidelity data. We develop a physics-derived deep learning closure model for RANS, the Deep Algebraic Reynolds Stress Model (DARSM), which can be trained on small datasets and accurately generalise across Reynolds numbers, to unseen geometries, and to different flow regimes. A neural network maps flow invariants to empirical parameters in an implicit algebraic Reynolds stress equation, derived from the Reynolds stress transport equations under the weak-equilibrium assumption, imposing physics-based structure on the ML closure. End-to-end optimisation through the governing PDEs and the coupled implicit closure eliminates distribution shift, but both unrolled and implicit automatic differentiation fail on the stiff coupled solver. We derive adjoint equations that exploit the solver's implicit-explicit structure for efficient optimisation. On canonical square-duct and periodic-hill benchmarks, DARSM reduces average test velocity error over baseline RANS by $2$-$4\times$ across Reynolds number, geometries, and flow regimes, with peak case-level reductions of $12\times$. The model trained on attached, anisotropy-dominated flows (square duct) accurately generalises without retraining to separated flows (periodic hills), a regime change in the underlying physics. DARSM also outperforms five established ML methods: offline training, tensor-basis neural networks, field-inversion machine learning, DeepONets, and physics-informed neural networks.

2511.13643 2026-06-12 math.DS nlin.CD 版本更新

Degree-of-freedom and optimization-dynamic effects on the observability of Kuramoto-Sivashinsky systems

Kuramoto-Sivashinsky 系统可观测性的自由度和优化动力学效应

Noah B. Frank, Joshua L. Pughe-Sanford, Samuel J. Grauer

AI总结 通过将可观测性与耗散动力系统的嵌入理论联系起来,建立了变分状态估计应用于Kuramoto-Sivashinsky方程的可观测性准则,并分析了优化动力学限制,提出了结合非凸牛顿更新和伪投影步骤的鲁棒重构策略。

详情
AI中文摘要

混沌系统的模拟只有在初始条件和边界条件明确的情况下才能产生高保真轨迹。当这些条件未知但测量数据可用时,变分状态估计可以重构出与数据和支配方程一致的轨迹。一个关键未解决问题是需要多少测量才能实现准确重构,使得从稀疏数据中可观测整个系统轨迹。我们通过将可观测性与耗散动力系统的嵌入理论联系起来,建立了应用于Kuramoto-Sivashinsky方程的变分状态估计的可观测性准则。对于吸引子位于维数为$d_M$的惯性流形上的系统,我们证明$m \geq d_M$个测量确保从任意好的初始猜测出发的局部可观测性,而$m \geq 2d_M + 1$意味着基于梯度的观测器的全局可观测性,因为$M$上唯一的临界点是全局最小值。我们还分析了即使满足这些拓扑条件时仍然存在的优化动力学限制,包括流形漂移、Hessian退化、负曲率和梯度消失。为了解决这些问题,我们引入了一种鲁棒的重构策略,该策略将非凸牛顿更新与新颖的伪投影步骤相结合。Kuramoto-Sivashinsky方程的数值模拟验证了我们的分析,并展示了具有低维惯性流形的混沌系统的可观测性实际极限。

英文摘要

Simulations of chaotic systems can only produce high-fidelity trajectories if the initial and boundary conditions are well specified. When these conditions are unknown but measurements are available, variational state estimation can reconstruct a trajectory that is consistent with both the data and the governing equations. A key open question is how many measurements are required for accurate reconstruction, making the full system trajectory observable from sparse data. We establish observability criteria for variational state estimation applied to the Kuramoto-Sivashinsky equation by linking its observability to embedding theory for dissipative dynamical systems. For a system whose attractor lies on an inertial manifold of dimension $d_M$, we show that $m \geq d_M$ measurements ensures local observability from an arbitrarily good initial guess, and $m \geq 2d_M + 1$ implies global observability using a gradient-based smoother since the only critical point on $M$ is the global minimum. We also analyze optimization-dynamic limitations that persist even when these topological conditions are met, including drift off the manifold, degeneracy of the Hessian, negative curvature, and vanishing gradients. To address these issues, we introduce a robust reconstruction strategy that combines non-convex Newton updates with a novel pseudo-projection step. Numerical simulations of the Kuramoto-Sivashinsky equation validate our analysis and show practical limits of observability for chaotic systems with low-dimensional inertial manifolds.

2409.04091 2026-06-12 quant-ph physics.atom-ph 版本更新

Squeezing Enhancement in Lossy Multi-Path Atom Interferometers

有损多路径原子干涉仪中的压缩增强

Julian Günther, Jan-Niclas Kirsten-Siemß, Naceur Gaaloul, Klemens Hammerer

AI总结 本文通过引入广义输入-输出形式,研究了在包含速度选择性和散射损耗的多路径原子干涉仪中,利用自旋压缩态(特别是单轴扭曲态)提升相位灵敏度的方法,并展示了在优化布拉格分束器参数和压缩度后,即使存在实际损耗也能超越标准量子极限数分贝,同时指出了有限温度对纠缠优势的挑战。

详情
Comments
12 pages, 5 figures, added an acknowledgment of funding
AI中文摘要

本文探讨了自旋压缩态在原子干涉测量中,特别是使用布拉格衍射时,所带来的灵敏度提升。我们引入了一种广义输入-输出形式,能够准确描述包含速度选择性和散射到非期望动量态所导致损耗的现实非幺正干涉仪。该形式被应用于评估单轴扭曲自旋压缩态在提高相位灵敏度方面的性能。我们的结果表明,通过仔细优化布拉格分束器的参数并控制压缩度,尽管光脉冲操作中存在实际水平的损耗,仍有可能使干涉仪的灵敏度相对于标准量子极限提升数个分贝。然而,分析也突显了在实践中实现这些改进所面临的挑战,最显著的是有限温度对纠缠优势的影响。这些结果提示了在现实条件下优化干涉仪设置以利用量子纠缠的方法,从而推动原子干涉仪在精密测量领域的进步。

英文摘要

This paper explores the sensitivity gains afforded by spin-squeezed states in atom interferometry, in particular using Bragg diffraction. We introduce a generalised input-output formalism that accurately describes realistic, non-unitary interferometers, including losses due to velocity selectivity and scattering into undesired momentum states. This formalism is applied to evaluate the performance of one-axis twisted spin-squeezed states in improving phase sensitivity. Our results show that by carefully optimising the parameters of the Bragg beam splitters and controlling the degree of squeezing, it is possible to improve the sensitivity of the interferometer by several dB with respect to the standard quantum limit despite realistic levels of losses in light pulse operations. However, the analysis also highlights the challenges associated with achieving these improvements in practice, most notably the impact of finite temperature on the benefits of entanglement. The results suggest ways of optimising interferometric setups to exploit quantum entanglement under realistic conditions, thereby contributing to advances in precision metrology with atom interferometers.

2604.17601 2026-06-12 gr-qc hep-th 版本更新

Energy-Momentum Conservation as a Constraint to Restrict the Space of Viable Field Lagrangians: Vector Field versus Spin-Two Field

能量-动量守恒作为限制可行场拉格朗日量空间的约束:矢量场与自旋二场

Satoshi Nakajima, Antonio López-Pinto

AI总结 本文研究能量-动量守恒能否作为约束条件来限制相互作用场的拉格朗日密度形式,通过矢量场和自旋二张量场的分析,发现自旋二场情况下守恒条件唯一确定了爱因斯坦拉格朗日量。

详情
Comments
20 pages, No figure
AI中文摘要

我们研究总能量-动量守恒的要求是否可以作为对相互作用场允许的拉格朗日密度族的约束。目的不是给出广义相对论的纯场论推导,也不是从给定的引力拉格朗日量引入另一个引力能量-动量赝张量。相反,我们提出一个更一般的问题:一旦指定了确定的场能量-动量张量,守恒原理能否决定场拉格朗日量本身的形式。对于庞加莱不变的场论,我们将场对总能量-动量张量的贡献取为与场拉格朗日量关联的对称化Belinfante张量。矢量场情况表明答案通常不是肯定的。对于对称的秩二张量场,我们让物质部分保持任意,并通过物质拉格朗日量对场的变分定义其能量-动量张量。施加总能量-动量张量的守恒并仅使用场方程,则直接导出费曼一致性条件。因此,从确定的Belinfante型能量-动量张量的守恒,而不是同时使用物质运动方程和场方程,恢复了自旋二途径到广义相对论的通常一致性条件。在局域洛伦兹不变的拉格朗日密度类中,这些密度在对称场中是解析的,对一阶导数是二次的,并且不含非导数势项,该条件唯一地确定了爱因斯坦拉格朗日量,相差一个总散度。对于所得的爱因斯坦拉格朗日量,显式地得到了相应的对称化Belinfante张量,并证明它与Papapetrou能量-动量赝张量相关。

英文摘要

We investigate whether the Lagrangian density for an interacting vector field or an interacting massless spin-2 field can be determined by imposing Poincaré invariance and the conservation of energy-momentum for the entire system. We adopt the Belinfante-Rosenfeld energy-momentum tensor for systems involving either a vector field or a spin-2 field. For the vector field coupled to a system of point masses, it is not possible to determine the Lagrangian density of the vector field. On the other hand, we show that for the spin-2 field coupled to a material system such as a system of point particles, its Lagrangian density is uniquely given by the Einstein Lagrangian density. Furthermore, the Belinfante-Rosenfeld tensor for the spin-2 field becomes Papapetrou's gravitational energy-momentum pseudotensor.

2605.18148 2026-06-12 cond-mat.str-el 版本更新

Taming the 3D Wilson-Fisher Fixed Point via Nonlocal Effective Action

通过非局部有效作用量镇压三维Wilson-Fisher固定点

Hyeon Jung Kim, Seung-Jong Yoo, Jinmo Bok, Lemuel John Sese, Semin Park, Ki-Seok Kim

AI总结 本文提出一种基于非局部有效作用量假设的新型重整化群框架,通过Hubbard-Stratonovich变换将四次相互作用分解为基本场ϕ和辅助场φ,从而镇压三维相对论ϕ⁴理论中的强耦合动力学,结果验证了非局部自由度解冻能有效消除传统局部假设的系统截断误差,解决了Wilson-Fisher universality类的静态标度和热力学流。

详情
Comments
Completely rewritten and fine-tuned
AI中文摘要

我们提出一种基于非局部有效作用量假设的新重整化群(RG)框架,以镇压三维相对论ϕ⁴理论中的强耦合动力学。通过实施Hubbard-Stratonovich变换,我们将四次相互作用分解为基本场ϕ和辅助场φ∼ϕ²的系统。与冻结中间标度维度不同,我们有效作用量的非局部性允许两个指数Δ_ϕ和Δ_φ作为完全独立、无约束的动态变量。这种非局部传播框架在RG流中起关键作用:在一阶近似下评估场自能,在非零二阶骨架近似下计算顶点波动,底层Ward-like结构恒等式驱动多阶波动在“高斯”极限附近精确的交叉抵消。求解由此产生的闭合双变量主方程,得到一个稳健的非平凡物理固定点,Δ_ϕ*≈0.9814和Δ_φ*≈0.4148。这些动态指数给出运动学异常维度η_ϕ≈0.0372,能量算符维度Δ_{ϕ²}≈1.4148,并通过质量变形得到热关联长度指数ν≈0.6308,与高精度量子蒙特卡洛(QMC)和共形 Bootstrap 验证结果有极好的定量一致。我们的结果严格证实,解冻非局部自由度能有效消除传统局部假设的系统截断误差,同时解决Wilson-Fisher universality类的静态标度和热力学流。

英文摘要

We present a Renormalization Group (RG) framework based on a nonlocal effective action ansatz to analyze the strong coupling dynamics of the three-dimensional relativistic $\phi^{4}$ theory. By implementing a Hubbard-Stratonovich transformation, we decouple the quartic interaction into the primary field $\phi$ and an auxiliary field $\varphi \sim \phi^2$, allowing both exponents $\Delta_{\phi}$ and $\Delta_{\varphi}$ to act as independent, unconstrained variables rather than fixed scaling dimensions. Within this nonlocal propagator framework, both the field self-energies and vertex corrections are evaluated at the one-loop order. The resulting one-loop logarithmic derivatives determine the renormalization group flows of the couplings and the scaling exponents. For $d = 3$ and $\epsilon = 0.5$, the self-consistent equations yield a physical fixed point at $\Delta_{\phi} \approx 0.81479$ and $\Delta_{\phi^2} \approx 1.37042$. These exponents result in a kinematic anomalous dimension $\eta_{\phi} \approx 0.37042$, an energy operator dimension $\Delta_{\phi^2} \approx 1.37042$, and a thermal correlation length exponent $\nu \approx 0.61366$. For $\epsilon\approx-0.28996$, the self-consistent equations yield another fixed point at $\Delta_{\phi}\approx0.87284$, $\Delta_{\varphi}\approx-0.53564$, and $\Delta_{\phi^2}\approx1.25432$, corresponding to $\eta_{\phi}\approx0.25432$ and $\nu\approx0.57284$. Although these leading-order results show deviations from high-precision Quantum Monte Carlo (QMC) and conformal bootstrap benchmarks, they characterize the baseline scaling behavior of the Wilson-Fisher universality class.

2508.08402 2026-06-12 hep-ph 版本更新

Sweeping the pion chimney for axion-like particles with KOTO

用KOTO扫描轴子类粒子的π子烟囱

Reuven Balkin, Stefania Gori, Dean J. Robinson, Christiane Scherb

AI总结 通过将KOTO数据重新解释为搜索K_L→2π^0a→6γ,研究如何获得对轴子类粒子在难探测质量范围内的新限制,并探讨KOTO6γ数据对更广范围轴子质量的探测能力。

详情
Comments
12 pages, 10 figures, updated to published version
AI中文摘要

我们证明,通过将KOTO数据重新解释为搜索K_L→2π^0a→6γ,可以获得对轴子类粒子(ALPs)在中性π子附近难以探测的质量范围内的新限制。我们还探讨了KOTO6γ数据对K_L→2π^0a的探测能力,以更广泛范围的ALP质量为研究对象,并纳入延迟衰变。

英文摘要

We demonstrate that novel limits on prompt axion-like particles (ALPs) in the hard-to-probe mass range near the neutral pion - the so-called pion chimney - may be obtained from recasting $K_L \to 3\pi^0 \to 6\gamma$ data taken by the J-PARC KOTO experiment, to search for $K_L \to 2\pi^0a \to 6\gamma$. We also explore the power of KOTO $6\gamma$ data to probe $K_L \to 2\pi^0a$ for a broader range of ALP masses, incorporating displaced decays.

2511.18168 2026-06-12 cond-mat.mtrl-sci cond-mat.str-el 版本更新

Trigonal Distortion Driven Ground States in VX3 (X = Br and I)

三重对称扭曲驱动的VX3(X=Br和I)基态

Chamini S. Pathiraja, Deniz Wong, Christian Schulz, Yi-De Chuang, Yu-Cheng Shao, Byron Freelon

AI总结 研究通过高分辨共振非弹性X射线散射(RIXS)结合配体场多重态计算,揭示了VX3(X=Br和I)的基态电子结构,确定了三重扭曲参数和 Racah 参数,并展示了从Br到I的共价性增加,为设计基于钒卤化物的二维磁性和自旋电子材料提供了重要见解。

详情
Comments
14 pages, 9 figures
AI中文摘要

过渡金属卤化物VX3(X=Br和I)因其层依赖磁性和可调电子态,成为二维自旋电子和量子应用的有希望候选者。然而,对其基态电子结构的实验研究仍有限。本文通过高分辨率共振非弹性X射线散射(RIXS)结合配体场多重态计算,对VX3进行了全面研究。RIXS光谱揭示了明显的dd和电荷转移激发,允许精确确定电子结构参数,包括晶场分裂、三重扭曲和Racah参数。确定的参数显示出明显变化,表明从Br到I的共价性增加。三重扭曲参数ΔD3d在VBr3中为-0.096 eV,在VI3中为0.07 eV,表明两种化合物的符号相反,与实验RIXS数据一致。聚类模型计算得到高自旋V3+(S=1)配置,VBr3的基态为e'2g,VI3的基态为e'1ga11g,分别与三重伸长和压缩一致。本研究提供了VX3低能电子结构的最完整实验确定,为基于钒卤化物的二维磁性和自旋电子材料设计提供了有价值的见解。

英文摘要

Transition-metal halides V$X_3$ ($X$ = Br and I) have emerged as promising candidates for two dimensional spintronic and quantum applications due to their layer-dependent magnetism and tunable electronic states. However, experimental insights into their ground state electronic structures remain limited. Here, we present a comprehensive investigation of V$X_3$ using high resolution resonant inelastic x-ray scattering (RIXS) combined with ligand field multiplet calculations. The RIXS spectra reveal distinct $dd$ and charge-transfer excitations, allowing precise determination of electronic structure parameters, including the crystal field splitting, trigonal distortion, and Racah parameters. The determined parameters showed clear variation, indicating an increase in covalency from Br to I. The trigonal distortion parameters $\Delta_{D_{3d}}$ were determined to be -0.096 eV in VBr$_3$ and 0.07 eV in VI$_3$, indicating a sign opposition between the two compounds, reflecting good agreement with experimental RIXS data. Cluster model calculations yield a high-spin V$^{3+}$ $(S = 1)$ configuration, with an $e'^2_g$ ground state in VBr$_3$ and an $e'^1_ga^1_{1g}$ ground state in VI$_3$, consistent with trigonal elongation and compression, respectively. Our findings provide the most complete experimental determination of the low energy electronic structure in V$X_3$, offering valuable insights for designing 2D magnetic and spintronic materials based on vanadium halides.

2602.09102 2026-06-12 astro-ph.HE gr-qc 版本更新

Polarization Signatures of Inspiraling Hotspots around Kerr Black Holes

Kerr黑洞周围 inspiraling热点的偏振特征

Pablo Ruales, Delilah E. A. Gates, Alejandro Cárdenas-Avendaño

AI总结 本文提出了一种模拟Kerr时空内等纬度inspiraling热点偏振发射的通用框架,通过参数化四速度剖面,展示了inspiral运动产生的独特观测特征:偏振Stokes Q-U循环模式的预cession和unwinding演变,与稳定轨道上的闭合Q-U环形成鲜明对比。

详情
Comments
v3: Fixed typo in Eq.II.10
AI中文摘要

偏振干涉测量是一种用于探测黑洞吸积物理和背景时空的强大工具。目前解释Sgr A*观测到的多波段耀斑的模型通常假设热点沿测地线、开普勒轨道运动。然而在许多情况下,热点可能遵循inspiraling轨迹,最终向黑洞 plunge。本文提出了一种通用框架,利用参数化四速度剖面模拟Kerr时空内等纬度inspiraling热点的偏振发射。该参数化定义了一个连续的流体族,从Cunningham盘模型(固定半径轨道在最内稳定圆轨道外, plunge运动在最内稳定圆轨道内)到纯径向运动,从而扩展了标准假设。在该框架下,我们展示了inspiral运动产生独特的观测特征:Q-U循环模式的预cession和unwinding演变,与固定半径稳定轨道上的闭合Q-U环形成鲜明对比。然后我们探讨了这些特征的形态如何依赖于黑洞自旋、观测者倾角和磁场配置。所提出的模型可用于当前和未来线性偏振干涉测量观测,提供了一种新的途径来探测物质向内螺旋运动的物理和relativistic速度的plunging等离子体。

英文摘要

Polarimetric interferometry is a powerful tool for probing both black hole accretion physics and the background spacetime. Current models aimed at explaining the observed multiwavelength flares in Sgr A* often assume hotspots moving on geodesic, Keplerian orbits. In many scenarios, though, a hotspot may instead follow an inspiraling trajectory, potentially transitioning into a plunge toward the black hole. In this work, we present a general framework to simulate the polarized emission from generic equatorial inspiraling hotspots in Kerr spacetime using a parametric four-velocity profile. This parametrization defines a continuous family of flows, ranging from Cunningham's disk model (fixed radius orbits outside the innermost stable circular orbit and plunging motion within the innermost stable circular orbit) to purely radial motion, thereby extending the standard assumptions. Within this framework, we show that inspiral motion produces a distinctive observational signature: a precessing, unwinding evolution of the polarimetric Stokes Q-U looping pattern, in sharp contrast with the closed Q-U loops associated with stable orbits at a fixed radius. We then explore how the morphology of these signatures depends on black hole spin, observer inclination, and magnetic-field configuration. The presented model can be applied to current and near-future interferometric observations of linear polarization, offering a new avenue to probe the physics of matter spiraling inward and the relativistic velocities of plunging plasma.

2510.12136 2026-06-12 hep-lat 版本更新

Nevanlinna-Pick interpolation from uncertain data

从不确定数据进行Nevanlinna-Pick插值

Sarah Fields, Norman Christ

AI总结 本文提出了一种基于Nevanlinna-Pick插值的新方法,用于解决格点QCD中多粒子产生过程的计算问题,并探讨了该方法在计算包涵重粒子衰变中的应用。

详情
Comments
42 pages, 10 figures, updated to match PRD version
AI中文摘要

计算涉及许多粒子产生过程的inclusive过程对格点QCD来说是一个挑战,因为格点QCD是一种欧几里得空间方法,与实时多粒子产生过程相差甚远。Bergamaschi等人提出了一种基于Nevanlinna-Pick插值的新方法来解决这个问题。本文扩展了该方法,探讨了格点QCD计算中统计和系统误差通过该插值过程的传播。通过研究一个简化多粒子谱函数的例子,重点探讨了这些方法在计算包涵重粒子衰变中的潜在应用。

英文摘要

The calculation of inclusive processes that involve the production of many particles is a challenge for lattice QCD, a Euclidean-space method that is far removed from real-time, multiparticle production. A new approach to this problem based on Nevanlinna-Pick interpolation has been proposed by Bergamaschi et al. Here we extend their method by exploring the propagation of the statistical and systematic errors that accompany a lattice QCD calculation through this interpolation process. A simplified example of a multiparticle spectral function is studied with a focus on the possible applications of these methods to the calculation of inclusive heavy-particle decays.

2605.17049 2026-06-12 physics.optics 版本更新

Biting fly vision and zebra stripes

飞虫视觉与斑马条纹

Krispin M. Dettlaff

AI总结 本文研究斑马条纹对吸血蝇类昆虫的防御机制,通过光学模型揭示条纹与昆虫复眼采样作用产生的伪空间频率,支持条纹在防咬蝇中的作用。

详情
Comments
41 pages, 11 figures
AI中文摘要

斑马条纹的功能自达尔文和沃尔科特以来一直存在争议。越来越多的比较和实验证据支持条纹主要作为防御视觉导向的吸血蝇类(如马蝇、采血蝇和蚊子)的机制。提出的保护机制包括偏极化破坏、轮廓破碎和基于运动的错觉,这些错觉出现在昆虫视觉系统的里赫尔德特运动检测器中。本文聚焦于一种互补的纯光学机制:当周期性条纹刺激被昆虫复眼的周期性小眼晶状体晶格采样时产生的莫尔干涉。我们开发了一个线性、移不变的傅里叶模型,参数化自已发表的光数据,应用于观察到的斑马条纹图像。模型预测在接近距离1-5米的范围内,条纹图案与小眼采样作用产生伪空间频率,这些频率在物理刺激中不存在,并且落在最相关的宿主固定和着陆控制的空间频率窗口内。后视网膜运动检测器阶段显示,这些伪频率转化为伪局部运动向量,与实验证实的马蝇和采血蝇无法在条纹表面干净着陆一致。因此,我们的结果支持斑马条纹的咬蝇假说。

英文摘要

The function of the zebra's striped coat has been debated since Darwin and Wallace. A growing body of comparative and experimental evidence supports the hypothesis that the stripes act primarily as a defence against visually orienting biting Diptera - in particular tabanids (horse flies), glossinids (tsetse flies) and culicids (mosquitoes). The mechanisms proposed for this protection range from polarotactic disruption and silhouette break-up to motion-based illusions arising in the Reichardt-type motion detectors of the insect visual system. In this work we focus on a complementary, purely optical mechanism: the Moiré interference that arises when a periodic striped stimulus is sampled by the periodic ommatidial lattice of an insect compound eye. We develop a linear, shift-invariant Fourier model of the diptera compound eye, parameterised from published optical data on diurnal Culicidae, and apply it to images of zebra coats observed at biologically relevant viewing. The model predicts that, in a band of approach distances of approximately 1-5 m, the interaction of the stripe pattern with ommatidial sampling generates parasitic spatial frequencies that are absent from the physical stimulus and that fall within the spatial-frequency window most relevant to host fixation and landing control. A post-retinal motion-detector stage demonstrates that these parasitic frequencies translate into spurious local motion vectors, consistent with the empirical observation that tabanid and glossinid flies fail to land cleanly on striped surfaces. Our results are therefore consistent with the biting-fly hypothesis of zebra striping.

2602.12077 2026-06-12 gr-qc astro-ph.CO hep-ph hep-th 版本更新

Cosmographic Connection Between Cosmological And Planck Scales: The Barrow-Tsallis Entropy

宇宙学与普朗克尺度之间的类比关系:巴罗-塔斯里斯熵

Yu. L. Bolotin, V.V. Yanovsky, D. A. Yerokhin

AI总结 研究通过巴罗-塔斯里斯熵探讨宇宙学和普朗克尺度参数间的联系,揭示量子泡沫微观结构与非广延效应宏观参数的关联,并评估分数导数在描述宇宙晚期演化中的可行性。

详情
Comments
12 pages, 4 figures. Submitted to JCAP for consideration
AI中文摘要

量子引力的一个基本挑战是理解宇宙视界微观自由度如何塑造宇宙的演化。一种可能的解决方法是基于巴罗-塔斯里斯熵。这种熵考虑了量子引力效应和任何长程相互作用固有的非扩展效应。我们开发了一种通用方法来寻找宇宙学模型的参数,发现了描述量子泡沫微观结构的参数与与宏观非扩展效应相关的参数之间的关系。我们还使用这种方法来评估分数导数在描述宇宙晚期演化中的可行性。所得到的关系是精确的。因此,模型参数之间的不确定性仅取决于当前宇宙学参数值的不确定性。

英文摘要

One of the fundamental challenges of quantum gravity is to understand how the microscopic degrees of freedom of the cosmological horizon shape the evolution of the Universe. One possible approach to this problem is based on the Barrow--Tsallis entropy. This entropy accounts for both quantum gravitational effects and the nonextensive effects inherent in any long-range interaction. By employing an inverse cosmographic reconstruction of the model parameters, we derive a relation between the Barrow parameter, which encodes the microscopic deformation of the horizon geometry, and the Tsallis parameter, which characterizes macroscopic nonextensivity. Within the IR--UV correspondence, this relation determines the scaling of the microscopic length uncertainty in terms of the current cosmographic parameters and demonstrates how long-range nonextensive effects alter the standard Karolyhazy-type scaling. We also used our method for finding the parameters of cosmological models to evaluate the feasibility of using fractional derivatives to describe the late evolution of the Universe. The resulting relationships are exact. Therefore, the uncertainty in the relationship between the model parameters depends only on the current uncertainty in the values of the cosmographic parameters.

2605.15233 2026-06-12 quant-ph cs.ET 版本更新

Measuring Control-Plane Openness in Near-Term Quantum Computing: A Rubric, Its Validation, and an Application to Thirteen Vendor Stacks

近期量子计算中的控制平面开放性:对供应商堆栈和现场影响的调查

Rylan Malarchick

AI总结 本文调查了13家商业供应商的超导、离子阱、中性原子和光子模态的开放性,分析了控制平面的开放性对可重复性、硬件感知研究和跨供应商基准测试的影响。

详情
Comments
11 pages, 1 table, 1 figure. Accompanying machine-readable catalog available at this https URL
AI中文摘要

商业量子计算中对脉冲级和控制电子接口的公共访问已出现分裂。最大的超导云平台在此层关闭了访问,IBM于2025年2月从所有生产QPUs中移除了脉冲级控制;中端超导供应商和更开放的中性原子平台则朝相反方向发展。我们调查了13家商业供应商,根据六个开放性轴对每个供应商进行评分,这些轴被称为控制平面:位于门级电路规范和物理控制电子之间的层。该目录作为单独的机器可读制品发布,遵循CC-BY-4.0许可(DOI:https://doi.org/10.5281/zenodo.20163276)。分裂情况按行记录,对可重复性、硬件感知研究和跨供应商基准测试有影响。我们不提出架构或参考实现;我们描述了随着访问景观变化,该领域所失去的内容,以及在此层实现最低开放访问需要怎样的样子。

英文摘要

Public access to pulse-level and control-electronics interfaces in commercial quantum computing has bifurcated. This paper proposes a six-axis rubric for measuring control-plane openness, the layer between gate-level circuit specification and physical control electronics, defined operationally so that the same evidence produces the same grade across vendors. The rubric is validated three ways: a blinded re-grading pass, thirty-nine days after the evidence cutoff, that tests whether the cited evidence and the level definitions alone reproduce the recorded grades; a boundary-case methodology that fixes where each level begins and ends; and a published grading protocol that lets others reproduce and contest any cell. We establish that the rubric measures change rather than describing a snapshot by comparing the catalog against the documented control plane before the February 2025 removal of pulse-level access from IBM hardware, and reporting the cells that moved. The rubric is applied to thirteen commercial vendors across superconducting, trapped-ion, neutral-atom, and photonic modalities as of May 1, 2026, as its first application, and one of the three harms the rubric is designed to detect is demonstrated through a reproduction-access audit of five pre-2025 IBM Qiskit Pulse experiments against the access available on current hardware, carried through to a client-side structural port of the audit's selected target to Rigetti Quil-T. The catalog ships as a separate machine-readable artifact under CC-BY-4.0 with per-cell source URLs ( this https URL ). The catalog readings will change as vendor policies shift; the rubric is the contribution that survives them.

2605.13983 2026-06-12 astro-ph.IM astro-ph.HE hep-ph 版本更新

Rapid and robust simulation-based inference for kilonovae

快速且鲁棒的基于模拟的推断用于千新现象

Stephanie M. Brown, Mattia Bulla, Hiranya V. Peiris, Nikhil Sarin, Daniel Mortlock, Stephen Thorp, Gurjeet Jagwani, Stephan Rosswog, Samaya Nissanke

AI总结 本文提出基于模拟的推断框架,用于快速且鲁棒地推断千新现象参数,相比MCMC方法,该框架在模拟器不确定性及似然误指定情况下表现更优。

详情
Comments
27 pages, 12 figures, 5 tables
AI中文摘要

随着下一代电磁波和引力波观测站开始投入使用,快速分析千新现象数据的方法在天文学中变得越来越重要。传统的贝叶斯参数估计使用马尔可夫链蒙特卡罗(MCMC)方法耗时且依赖显式似然近似,当建模不确定性显著时会失效。我们开发了一种基于模拟的推断(SBI)框架,用于千新现象参数估计,利用密度估计似然自由推断。该框架使用经过约1300次辐射转移模拟训练的高斯过程模拟器。我们证明SBI为使用模拟器或近似似然的推断提供了快速替代MCMC的方法,且在模拟器不确定性和似然误指定情况下表现更稳健。在模拟数据上,SBI方法准确恢复了注入参数并产生与数据一致的后验预测光变曲线,但MCMC后验恢复受到似然误指定系统偏差的影响。在分析AT2017gfo时,SBI和MCMC方法产生相似的光变曲线预测,但后验分布不同,部分MCMC后验在先验边界堆积。MCMC的似然未能捕捉到模拟器不确定性的非高斯、相关结构,但SBI直接从正向模拟中学习后验,这些模拟包含完整的预测分布。一旦训练完成,SBI框架可在几秒内生成约2×10^4个后验样本。

英文摘要

With the next generation of both electromagnetic and gravitational wave observatories beginning to come online, rapid analysis methods for kilonova data are becoming increasingly important in astronomy. Traditional Bayesian parameter estimation using Markov chain Monte Carlo (MCMC) is time-consuming and relies on explicit likelihood approximations that can break down when modeling uncertainties are significant. We develop a simulation-based inference (SBI) framework for kilonova parameter estimation using density-estimation likelihood-free inference. The framework uses a Gaussian process emulator trained on $\sim 1300$ POSSIS simulations. We demonstrate that SBI provides a rapid alternative to MCMC that is robust to likelihood misspecification. The standard Gaussian likelihood approximation fails to capture the non-Gaussian, correlated structure of emulator uncertainty; SBI learns this structure directly from forward simulations. Simulation studies show that the SBI method accurately recovers injected parameters, while the MCMC suffers from systematic bias caused by likelihood misspecification. This problem persists when analyzing AT2017gfo, where a subset of the MCMC posteriors pile up at prior boundaries and the SBI posteriors do not. The SBI framework infers a total ejecta mass of $\sim 0.087 M_{\odot}$ dominated by lanthanide-poor ejecta and excludes toroidal and peanut ejecta geometries at the 99th percentile for both components. The SBI framework generates $\sim 2 \times 10^{4}$ posterior samples in seconds.

2605.13766 2026-06-12 cs.CE math.NA physics.comp-ph 版本更新

Elastica++: A high-performance, multiphysics framework for large interacting assemblies of Cosserat rods

Elastica++:一种高性能的多物理场框架,用于大规模相互作用的柯西-罗德结构

Tejaswin Parthasarathy, Seung Hyun Kim, Songyuan Cui, Mattia Gazzola

AI总结 本文提出Elastica++,一种高性能多物理场框架,用于模拟大规模相互作用的柯西-罗德结构,通过高效内核和共享内存并行计算,实现大规模模拟,并支持多物理场工作流。

详情
AI中文摘要

柔软、细长的结构在自然和工程系统中普遍存在,具有从仿生材料到软机器人广泛的应用潜力。然而,缺乏能够同时保持高保真连续杆力学、扩展到大规模相互作用集合,并在多种生物物理环境中保持灵活性的计算工具。本文介绍了Elastica++,一种开源的高性能量化柯西-罗德模型,用于大规模细长体动力学模拟。Elastica++结合了面向性能的内核和共享内存并行计算,以复杂离散化域和物理相互作用下仍能维持超千兆浮点运算吞吐量。该框架进一步可以与外部数值求解器互操作,支持高效的多物理场工作流。通过覆盖被动巢状元材料、集体主动物质动力学、鞭毛地毯、软磁性微机器人和群游游泳者等案例研究,展示了其鲁棒性和广泛适用性。Elastica++因此为研究相互作用弹性细长结构中涌现行为的高吞吐量研究提供了缺失的基础。

英文摘要

Soft, slender structures are ubiquitous in natural and engineered systems, with broad application potential from biomimetic materials to soft robotics. However, there is a notable lack of computational tools that simultaneously preserve high-fidelity continuum rod mechanics, scale to large interacting ensembles, and remain flexible across diverse biophysical settings. Here we introduce Elastica++, an open-source, high-performance implementation of the Cosserat-rod model for large-scale simulations of slender-body dynamics. Elastica++ combines performance-oriented kernels with shared-memory parallelism to sustain teraflop-scale throughput despite complex discretization domains and physical interactions. The framework further interoperates with external numerical solvers, supporting efficient multiphysics workflows. We demonstrate robustness and breadth through case studies spanning passive nest-like metamaterials, collective active-matter dynamics, cilia carpets, soft magnetic microrobots, and schooling swimmers. Elastica++ thus provides a missing foundation for high-throughput studies of emergent behavior in interacting assemblies of elastic slender structures.

2605.13463 2026-06-12 nlin.SI math-ph math.DS 版本更新

On the Darboux-Halphen system: Jacobi vs Lie

关于达布-哈勒芬系统:雅可比与李

A.V. Tsiganov

AI总结 本文讨论达布-哈勒芬系统的两种构造方法,对比雅可比和李的构造方式,分析其积分性与单值表示的差异。

详情
Comments
16 pages, LaTeX with AMS fonts
AI中文摘要

本文讨论达布-哈勒芬系统的两种构造方法。在雅可比构造中,我们从多值函数开始,这些函数被固定为第一个积分。在李构造中,我们使用简单代数的单值表示,这种表示在李的术语中是非可积的。

英文摘要

Two constructions of the Darboux-Halphen system are discussed. In the Jacobi construction we start with transcendental functions which are fixed as the first integrals. In the Lie construction we use a single-valued representation of the simple Lie algebra $sl(2,\mathbb R)$ which is non-integrable in Lie's terminology.

2605.12907 2026-06-12 cond-mat.str-el 版本更新

Grassmann tensor networks

Grassmann张量网络

Jian-Gang Kong, Jia-Ji Zhu, Z. Y. Xie

AI总结 本文介绍Grassmann张量网络方法,从基础操作到典型算法的Grassmann化,验证了其在粒子物理和凝聚态物理中的应用。

详情
Comments
75 pages, 10 figures
AI中文摘要

发展非微扰方法以揭示强关联费米子系统中的奇异性质仍然是理论物理中最关键的任务之一。具有Grassmann代数的张量网络方法为费米子多体系统在相干态路径积分表示中提供了强大的数值工具。尽管其在凝聚态和粒子物理领域有巨大潜力,但Grassmann张量网络方法在实际模拟中仍被低估。本文提供了一个详尽且自包含的Grassmann张量网络方法介绍,从Grassmann张量操作的基础到典型张量网络算法的Grassmann化。此外,所得到的Grassmann张量网络方法在粒子物理和凝聚态物理中的几个有趣模型中得到了验证。

英文摘要

Developing non-perturbative methods to reveal exotic properties of strongly correlated fermionic systems remains one of the most essential tasks of theoretical physics. Tensor network methods with Grassmann algebra offer powerful numerical tools for fermionic many-body systems in the coherent-state path-integral representation. Despite their vast potential for both condensed-matter and particle-physics communities, Grassmann tensor network methods are somewhat underexploited in practical simulations. In this work, we provide a detailed, self-contained introduction to Grassmann tensor network methods, from the basics of the Grassmann tensor operations to the Grassmannization of typical tensor network algorithms. Furthermore, the resulting Grassmann tensor network methods are validated in several interesting models in both particle physics and condensed matter physics.

2605.12542 2026-06-12 astro-ph.IM astro-ph.EP cs.LG 版本更新

Earth Science Foundation Models: From Perception to Reasoning and Discovery

地球科学基础模型:从感知到推理与发现

Xiangyu Zhao, Bo Liu, Yuehan Zhang, Zelin Song, Wanghan Xu, Feng Liu, Fengxiang Wang, Ben Fei, Fenghua Ling, Wangxu Wei, Wenlong Zhang, Xiao-Ming Wu

发表机构 * Department of Data Science and Artificial Intelligence, The Hong Kong Polytechnic University(数据科学与人工智能系,香港理工大学) Shanghai Artificial Intelligence Laboratory(上海人工智能实验室)

AI总结 本文综述了地球科学基础模型,探讨了其从感知到多模态推理及科学发现的能力演进,并总结了其在大气、水圈、岩石圈等领域的广泛应用。

详情
AI中文摘要

大规模基础模型(FMs)正在通过整合异构多模态数据,如多平台影像、格网再分析数据、多样的地球物理和地球化学观测以及领域特定文本,来推动地球科学的发展。本文通过两个互补维度对地球科学基础模型(地球FMs)进行统一综述:深度,即追踪模型能力从感知到多模态推理和代理科学工作流的演变;广度,即总结其在大气、水圈、岩石圈、生物圈、人类圈和冰圈以及耦合地球系统过程中的扩展应用。利用这一框架,我们回顾了代表性多模态地球基础模型,并编译了超过200个数据集和基准,涵盖多样化的地球科学任务和模态。我们进一步讨论了多模态数据异构性、科学可靠性和持续更新、可扩展性和可持续性以及从基础模型到代理和具身地球智能的转变,并展望了更集成、可信和可操作的AI地球科学家的未来方向。总体而言,本文为理解地球基础模型的发展提供了结构化的路线图,从能力和应用广度两个方面进行综述。

英文摘要

Large foundation models (FMs) are transforming Earth science by integrating heterogeneous multimodal data, such as multi-platform imagery, gridded reanalysis data, diverse geophysical and geochemical observations, and domain-specific text, to support tasks ranging from basic perception to advanced scientific discovery. This paper provides a unified review of Earth science foundation models (Earth FMs) through two complementary dimensions: depth, which traces the evolution of model capabilities from perception to multimodal reasoning and agentic scientific workflows, and breadth, which summarizes their expanding applications across the atmosphere, hydrosphere, lithosphere, biosphere, anthroposphere, and cryosphere, as well as coupled Earth system processes. Using this framework, we review representative multimodal Earth foundation models and compile more than 200 datasets and benchmarks spanning diverse Earth science tasks and modalities. We further discuss key challenges in multimodal data heterogeneity, scientific reliability and continual updating, scalability and sustainability, and the transition from foundation models to agentic and embodied Earth intelligence, and outline future directions toward more integrated, trustworthy, and actionable AI Earth scientists. Overall, this paper offers a structured roadmap for understanding the development of Earth foundation models from both capability depth and application breadth.

2605.08341 2026-06-12 quant-ph 版本更新

Quantum metrology via partial quantum error correction

通过部分量子纠错的量子计量学

Yinan Chen, Zongyuan Wang, Sisi Zhou

AI总结 提出仅需部分量子纠错即可抑制局域噪声并保持探针态超标准量子极限传感性能的方法,通过将探针态编码为量子码能量不同态的叠加,并采用自适应权重递增策略维持超SQL性能。

详情
Comments
Added discussion of mixed X/Z noise; fixed typos; improved clarity throughout
AI中文摘要

我们引入了一种纠错量子计量学方法,其中仅需部分量子纠错(QEC)即可抑制局域噪声并保持探针态的超标准量子极限(super-SQL)传感性能。这与现有QEC辅助传感方案(Phys. Rev. Lett. 112, 080801 (2014) 和 Phys. Rev. Lett. 112, 150802 (2014))形成对比,后者将探针态编码到量子码的逻辑子空间中,纠错涉及对码的所有校验子进行测量。在这里,我们将探针态编码为底层量子码中能量不同态的叠加。对于我们的探针态,使用校验子子集进行纠错足以抑制相位印记前后的噪声。我们分析了噪声抑制中的权衡。对于平行于我们权重为$l$的相位印记器的噪声,我们实现了$p^\delta$的抑制,其中$p$是噪声强度,$\delta = \lfloor (l+1)/2 \rfloor$。我们提出了一种自适应印记器权重递增策略,以在系统扩展时维持超SQL性能。在我们的所有示例中,校验子和相位印记器均选择为局域算子,避免了非局域连接。

英文摘要

We introduce a method for error-corrected quantum metrology where only partial quantum error correction (QEC) is needed to suppress local noise and maintain the probe states' super-standard-quantum-limit (super-SQL) sensing performance. This stands in contrast to the existing QEC-assisted sensing schemes in Phys. Rev. Lett. 112, 080801 (2014) and Phys. Rev. Lett. 112, 150802 (2014), where a probe state is encoded into the logical subspace of a quantum code and error correction involves measurements on all checks of the code. Here, we encode the probe states into superpositions of energetically different states of the underlying quantum code. For our probe states, error correction using a subset of checks is enough to suppress noise both before and after phase imprinting. We analyze the tradeoff in noise suppression. For noise parallel to our phase imprinter of weight $l$, we achieve a suppression of $p^\delta$ where $p$ is the noise strength and $\delta = \lfloor (l+1)/2 \rfloor$. We propose an adaptive imprinter weight increasing strategy to maintain super-SQL performance as we scale up the system. In all our examples, checks and phase imprinters are chosen to be local operators avoiding non-local connectivity.

2605.06162 2026-06-12 astro-ph.HE 版本更新

Vacuum polarization and cyclotron resonance effects on radiative transfer and plasma deceleration in subcritical X-ray pulsars

亚临界X射线脉冲星中的真空极化和回旋共振效应对辐射传输和等离子体减速的影响

I. D. Markozov, A. Y. Potekhin, A. D. Kaminker, A. A. Mushtukov

AI总结 通过自洽辐射流体动力学模拟,研究强磁场中吸积通道的极化辐射传输,发现真空极化主导等离子体双折射,增强回旋谱特征和辐射减速,且回旋特征能量与吸积光度正相关。

详情
Comments
20 pages, 14 figures, 1 table, submitted to MNRAS. The submitted version (v2) is substantially amended, partly due to the feedback on v1
AI中文摘要

我们利用自洽的辐射流体动力学模拟,研究了强磁场中吸积通道内从亚临界X射线脉冲星发出的辐射的谱和极化。模拟了热点上方通道中两种正常模式的极化辐射传输,考虑了强磁化等离子体中的共振康普顿散射和真空极化效应。我们表明,亚临界状态下吸积物质的减速主要由共振散射控制。我们的模拟提供了等离子体流的速度剖面,并证明真空极化主导等离子体双折射,增强了回旋谱特征和等离子体的辐射减速。我们还发现,回旋特征的能量随吸积光度增加而增加,表明存在正相关,这与先前的观测结果和理论解释一致。

英文摘要

We investigate the spectrum and polarization of radiation emerging from a subcritical X-ray pulsar using self-consistent radiation-hydrodynamic simulations of an accretion channel in a strong magnetic field. The polarized radiative transfer in the channel above the hot spot is simulated for the two normal modes, taking into account resonant Compton scattering in a strongly magnetized plasma and the effects of vacuum polarization. We show that the deceleration of the accreting matter in the subcritical regime is mainly governed by resonant scattering. Our simulations provide the velocity profiles of the plasma flow and demonstrate that vacuum polarization dominates over plasma birefringence, enhancing both the cyclotron spectral feature and the radiative deceleration of the plasma. We also find that the energy of the cyclotron feature increases with accretion luminosity, indicating a positive correlation consistent with previous observational results and theoretical interpretation.

2605.05317 2026-06-12 hep-th gr-qc 版本更新

Inflation and topology from the no-boundary state

无边界态下的暴胀与拓扑

Victor Godet

AI总结 通过将空间拓扑从3-球面改为3-环面,并利用GL(3)自守形式求和SL(3,Z)几何族,解决了无边界波函数指数偏好小宇宙的问题,得到偏好大暴胀宇宙的波函数,并计算环面模涨落对CMB功率谱的修正。

详情
Comments
15 pages, 2 figures; v2: added discussion of topology selection on the Lorentzian contour, minor fixes
AI中文摘要

3-球面上慢滚暴胀的无边界波函数指数偏好小宇宙,与观测严重不符。我们证明,通过将空间拓扑改为3-环面可以解决这个问题。利用GL(3)自守形式理论对SL(3,Z)几何族求和,产生的波函数偏好一个具有${\cal N} \gtrsim 250$ e-折的大暴胀宇宙。我们还计算了环面模涨落对CMB功率谱的修正。

英文摘要

The no-boundary wavefunction for slow-roll inflation on the 3-sphere exponentially favors a small universe, in sharp disagreement with observations. We show that this problem is resolved by changing the spatial topology to the 3-torus. The sum over the ${\rm SL}(3,\mathbb{Z})$ family of geometries, computed using the theory of automorphic forms for ${\rm GL}(3)$, produces a wavefunction favoring a large inflating universe with ${\cal N} \gtrsim 250$ e-folds. We also compute corrections to the CMB power spectrum induced by torus moduli fluctuations.