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2602.09142 2026-06-19 physics.atom-ph physics.chem-ph 版本更新

Charge Exchange Dynamics in Cold Collisions of $^{40}$CaH$^+$ and $^{39}$K

钙氢离子与钾原子在冷碰撞中的电荷交换动力学

Swapnil Patel, Dibyendu Sardar, Jyothi Saraladevi, Michał Tomza, Kenneth R. Brown

AI总结 研究了钙氢分子离子与超冷钾原子在混合离子-原子陷阱中的电荷交换碰撞,发现其速率系数显著低于兰格vin常数,通过首次原理量子化学计算揭示了电荷交换机制,表明需更全面的量子动力学处理以准确描述碰撞动力学。

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Journal ref
J. Phys. Chem. Lett. 17, 6574 (2026)
AI中文摘要

我们报告了在混合离子-原子陷阱中观测到钙单氢分子离子($^{40}$CaH$^+$)与超冷钾原子($^{39}$K)之间的电荷交换碰撞。测量的电荷交换速率系数显著低于该系统的兰格vin速率常数。我们使用首次原理量子化学计算来建模(CaH-K)$^+$复合作用在基态和激发态,并识别可能的电荷交换机制。我们的计算排除了直接非辐射电荷交换反应,而指向辐射机制,但未能定量重现测量速率,突显了需要包含振动运动和中间复合作用的全维量子动力学处理的必要性。我们的工作证明了冷混合离子-原子平台具有分子离子能够访问更丰富的化学复杂性和碰撞动力学,这些在纯原子系统中是无法实现的。

英文摘要

We report the observation of charge-exchange collisions between trapped calcium monohydride molecular ions ($^{40}$CaH$^+$) and ultracold potassium atoms ($^{39}$K) in a hybrid ion-atom trap. The measured charge-exchange rate coefficient is significantly suppressed relative to the Langevin rate constant for the system. We use $\mathit{ab\ initio}$ quantum-chemical calculations to model the (CaH-K)$^+$ complex in the ground and excited electronic states and to identify possible charge-exchange mechanisms. Our calculations rule out a direct non-radiative charge-exchange reaction and instead point to a radiative mechanism, but do not quantitatively reproduce the measured rate, highlighting the need for a full-dimensional quantum dynamics treatment that includes vibrational motion and intermediate complex formation. Our work demonstrates that cold hybrid ion-atom platforms with molecular ions enable access to richer chemical complexity and collisional dynamics inaccessible in purely atomic systems.

2602.09031 2026-06-19 physics.comp-ph cond-mat.mtrl-sci 版本更新

A complete phase-field fracture model for brittle materials subjected to thermal shocks

热冲击下脆性材料的完整相场断裂模型

Bo Zeng, John E. Dolbow

AI总结 提出一个完整的相场断裂模型,用于热力耦合问题,独立指定材料属性、强度和断裂韧性,通过玻璃淬火、陶瓷红外辐射和快速功率脉冲等实验验证,模型能统一处理不同断裂场景,优于经典方法。

Comments 34 pages, 24 figures

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AI中文摘要

受到热冲击的脆性材料会经历强烈的温度梯度,进而产生足以引起断裂的机械应力。本文提出了一个用于热力耦合问题的完整相场断裂模型,其中块体材料属性、材料强度和断裂韧性可独立指定。该模型的能力在热力断裂的广泛场景中进行了评估,从大型预存裂纹的扩展到空间均匀应力状态下的裂纹成核。特别地,我们重新审视了玻璃板的受控淬火,并展示了模型如何捕捉在不同热载荷下实验观察到的裂纹模式。还研究了受红外辐射的陶瓷盘,模型再现了带缺口试样中的直裂纹和完整试样中的分叉裂纹。最后,研究了受快速功率脉冲作用的陶瓷颗粒,模型解释了从完整到断裂颗粒的实验转变以及材料强度的重要作用。结果表明,完整的相场模型统一了热冲击下不同断裂场景的处理,超越了经典方法,能够更可靠地预测极端环境中的脆性断裂。

英文摘要

Brittle materials subjected to thermal shocks experience strong temperature gradients that in turn give rise to mechanical stresses that can be large enough to induce fracture. This work presents a complete model for phase-field fracture for coupled thermo-mechanical problems, wherein the bulk material properties, the material strength, and the fracture toughness are specified independently. The capabilities of the model are assessed across a wide span of scenarios in thermo-mechanical fracture, from the propagation of large pre-existing cracks to crack nucleation under spatially uniform states of stress. In particular, we revisit the controlled quenching of glass plates, and demonstrate how the model captures experimentally observed crack patterns across a range of thermal loads. Ceramic disks subjected to infrared radiation are also examined, with the model reproducing both straight cracks in notched specimens and branching in intact specimens. Finally, ceramic pellets subjected to rapid power pulses are examined, with the model explaining experimental transitions from intact to fractured pellets and the important role of material strength. The results demonstrate that the complete phase-field model unifies the treatment of distinct fracture scenarios under thermal shock, surpassing classical approaches and enabling more reliable prediction of brittle fracture in extreme environments.

2602.05529 2026-06-19 astro-ph.SR 版本更新

Effects of Dynamo-Generated Large-Scale Magnetic Fields on the Surface Gravity ($f$) Mode

发电机产生的大尺度磁场对表面重力($f$)模式的影响

Rajesh Mondal, Nishant K. Singh

AI总结 通过数值模拟研究太阳内部小尺度螺旋驱动产生的自洽大尺度磁场对表面重力($f$)模式的影响,发现饱和磁场增强$f$模式的频率和强度,且波数越大效应越显著。

Comments 11 pages, 5 figures. Published in ApJ Letters. Data available at Zenodo (DOI: 10.5281/zenodo.20324776)

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Journal ref
Astrophys. J. Lett. 1004, L38 (2026)
AI中文摘要

通过将太阳上层建模为计算域内存在自由表面的双层结构,我们数值研究了表面重力(或基模$f$)与磁场的相互作用。早期此类工作理想化地假设静磁场施加在光球(即自由表面)下方,以探测次表层磁场和流动在$f$模式上的特征。在本工作中,我们进行了三维(3D)数值模拟,其中光球下方的内部流体在小尺度上被螺旋驱动,从而促进$\alpha^2$发电机过程。这使我们能够研究这些自洽产生的大尺度磁场如何影响$f$模式的特性。我们发现,当磁场饱和到与流动的湍流动能接近均分时,$f$模式受到显著扰动。与无磁情况或发电机运动学阶段(磁场太弱)相比,我们注意到在饱和磁场存在下,$f$模式的频率和强度均增强,且这些效应在较大波数时更为显著。这定性地证实了早期观测和数值工作的发现,即强次表层磁场会导致$f$模式增强。

英文摘要

By modelling the upper layers of the Sun in terms of a two-layer setup where a free-surface exists within the computational domain, we numerically study the interaction between the surface gravity, or the fundamental ($f$) mode, and the magnetic fields. Earlier such works were idealized in the sense that the static magnetic fields were imposed below the photosphere, i.e., the free-surface, to detect signatures of sub-surface magnetic fields and flows on the $f$-mode. In this work, we perform three-dimensional (3D) numerical simulations where the interior fluid below the photosphere is stirred helically at small scales, thus facilitating an $α^2$-dynamo. This allows us to investigate how these self-consistently generated large-scale magnetic fields influence the properties of the $f$-mode. We find that when the magnetic fields saturate near the equipartition values with the turbulent kinetic energy of the flow, the $f$-mode is significantly perturbed. Compared to the non-magnetic case, or the kinematic phase of the dynamo when fields are too weak, we note that the frequencies and the strengths of the $f$-mode are enhanced in presence of saturated magnetic fields, with these effects being larger at larger wavenumbers. This qualitatively confirms the earlier findings from observational and numerical works which reported the $f$-mode strengthening due to strong sub-surface magnetic fields.

2506.11719 2026-06-19 math.NA cs.NA physics.comp-ph 版本更新

Automatic differentiation for performing the Cauchy-Kovalevskaya procedure in Lax-Wendroff type discretizations

在Lax-Wendroff类型离散化中执行Cauchy-Kovalevskaya过程的自动微分

Arpit Babbar, Valentin Churavy, Michael Schlottke-Lakemper, Hendrik Ranocha

AI总结 本文引入自动微分(AD)执行Lax-Wendroff方法中的Cauchy-Kowalewski过程,实现任意阶数、无需雅可比矩阵且问题无关的预测步计算,数值实验验证了方法的精度和正性保持。

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Journal ref
Journal of Computational Physics, 15 October 2026, article 115101, Volume 563
AI中文摘要

Lax-Wendroff方法结合间断Galerkin/通量重构空间离散化,为求解双曲守恒律提供了一种高阶、单步、无求积的方法。本文引入自动微分(AD)来执行Lax-Wendroff方法中用于单元局部时间平均通量计算步骤(预测步)的Cauchy-Kowalewski过程。AD的应用对于任意阶数的方法都是相似的,并且在预测步中不需要正性修正。这与近似Lax-Wendroff过程形成对比,后者需要针对不同阶数的方法使用不同的有限差分公式,并且在预测步中需要对仅能在可接受状态上计算的通量进行正性修正。该方法无需雅可比矩阵且与问题无关,允许直接应用于任何物理通量函数。数值实验证明了该方法的阶数和正性保持。此外,性能比较表明,自动微分的壁钟时间始终与近似Lax-Wendroff方法相当。

英文摘要

Lax-Wendroff methods combined with discontinuous Galerkin/flux reconstruction spatial discretization provide a high-order, single-stage, quadrature-free method for solving hyperbolic conservation laws. In this work, we introduce automatic differentiation (AD) for performing the Cauchy-Kowalewski procedure used in the element-local time average flux computation step (the predictor step) of Lax-Wendroff methods. The application of AD is similar for methods of any order and does not need positivity corrections during the predictor step. This contrasts with the approximate Lax-Wendroff procedure, which requires different finite difference formulas for different orders of the method and positivity corrections in the predictor step for fluxes that can only be computed on admissible states. The method is Jacobian-free and problem-independent, allowing direct application to any physical flux function. Numerical experiments demonstrate the order and positivity preservation of the method. Additionally, performance comparisons indicate that the wall-clock time of automatic differentiation is always on par with the approximate Lax-Wendroff method.

2601.18133 2026-06-19 hep-ph 版本更新

Heavy Quarkonium Spectrum and Decay Constants from a Neural-Network-Based Holographic Model

基于神经网络的全息模型中的重夸克偶素谱和衰变常数

Yu Zhang, Xun Chen, Miguel Angel Martin Contreras

AI总结 采用多层感知机从数据中逆向构造全息对偶中的膨胀子场,同时精确拟合重夸克偶素质量和衰变常数,解决了传统解析形式无法同时描述谱和衰变常数单调抑制的难题。

Comments 24 pages, 7 figures, 2 tables

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AI中文摘要

我们提出了一种数据驱动的逆向构造方法,用于底部向上AdS/QCD描述重矢量夸克偶素中的膨胀子场。我们不采用临时解析假设,而是使用多层感知机学习\(\Phi'(z)\)作为全息坐标的光滑函数,并施加\(\Phi(0)=0\)以确保紫外一致性。通过自动微分获得的膨胀子及其导数生成全息势\(U(z)\),相关的薛定谔型方程被离散化并对角化以提取低能本征模。然后从本征值和体-边界模的近边界行为评估质量和衰变常数。在粲偶素和底偶素的PDG数据上训练,得到非二次膨胀子轮廓,解决了同时再现重夸克偶素谱和轻子衰变常数随径向激发单调抑制的长期困难。联合拟合实现了RMS偏差分别为1.26%(粲偶素)和3.32%(底偶素)。这项工作确立了神经网络重构作为全息建模的灵活工具,并为未来扩展到包含更多通道、格点约束或有限温度背景提供了基础。

英文摘要

We present a data-driven inverse construction of the dilaton field in a bottom-up AdS/QCD description of heavy vector quarkonia. Instead of adopting an \emph{ad hoc} analytic ansatz, we use a multilayer perceptron to learn \(Φ'(z)\) as a smooth function of the holographic coordinate, with \(Φ(0)=0\) imposed to ensure ultraviolet consistency. The dilaton and its derivatives obtained by automatic differentiation generate the holographic potential \(U(z)\), and the associated Schrödinger-like equation is discretized and diagonalized to extract the low-lying eigenmodes. Masses and decay constants are then evaluated from the eigenvalues and the near-boundary behavior of the bulk-to-boundary modes. Training on PDG data for charmonium and bottomonium yields a non-quadratic dilaton profile that resolves the longstanding difficulty of simultaneously reproducing both the heavy-quarkonium spectrum and the monotonic suppression of leptonic decay constants with radial excitation. The combined fit achieves RMS deviations of \(1.26\%\) (charmonium) and \(3.32\%\) (bottomonium). This work establishes neural-network reconstruction as a flexible tool for holographic modeling and provides a basis for future extensions incorporating additional channels, lattice constraints, or finite-temperature backgrounds.

2602.04115 2026-06-19 cs.GT 版本更新

Robustness of Stable Matchings When Attributes and Salience Determine Preferences

当属性和显著性决定偏好时稳定匹配的鲁棒性

Amit Ronen, S. S. Ravi, Sarit Kraus

AI总结 研究匹配市场中属性向量和显著性向量扰动下稳定匹配的鲁棒性,提出多项式时间算法验证和计算鲁棒半径,并设计近似最鲁棒匹配的搜索算法。

Comments Accepted to AAMAS 2026. This arXiv version contains the full appendix. Version 2 removes two appendix sections containing an incorrect auxiliary argument. All main results remain unchanged

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AI中文摘要

在许多匹配市场中——例如运动员招募或学术招生——一方的参与者通过另一方已知的属性向量进行评估,而另一方则应用个体的显著性向量来赋予这些属性相对重要性。由于显著性在实践中会发生变化,一个核心问题随之产生:稳定匹配对此类扰动的鲁棒性如何?我们在此背景下解决了几个基本问题。首先,我们将鲁棒性形式化为一个半径,在该半径内,稳定匹配在显著性向量的任何可容许扰动下(假设已归一化)仍能免疫于阻塞对。给定一个稳定匹配和一个半径,我们提出一个多项式时间算法来验证该匹配是否在指定半径内保持稳定。我们还给出了一个多项式时间算法来计算给定稳定匹配的最大鲁棒半径。此外,我们设计了一种随时搜索算法,利用认证的下界和上界来近似最鲁棒的稳定匹配,并通过可高效计算的界来刻画鲁棒性与成本之间的关系,这些界描述了鲁棒性与成本之间可实现的权衡。最后,我们证明,对于每个稳定匹配,保持其稳定性的显著性轮廓集是单纯形内低维多面体的乘积。这种几何结构精确刻画了每个鲁棒区域的多面体形状;其体积可以高效计算,随着维度增加可采用近似方法,从而将匹配市场中的鲁棒性分析与凸几何的经典工具联系起来。

英文摘要

In many matching markets--such as athlete recruitment or academic admissions--participants on one side are evaluated by attribute vectors known to the other side, which in turn applies individual \emph{salience vectors} to assign relative importance to these attributes. Since saliences are known to change in practice, a central question arises: how robust is a stable matching to such perturbations? We address several fundamental questions in this context. First, we formalize robustness as a radius within which a stable matching remains immune to blocking pairs under any admissible perturbation of salience vectors (which are assumed to be normalized). Given a stable matching and a radius, we present a polynomial-time algorithm to verify whether the matching is stable within the specified radius. We also give a polynomial-time algorithm for computing the maximum robustness radius of a given stable matching. Further, we design an anytime search algorithm that uses certified lower and upper bounds to approximate the most robust stable matching, and we characterize the robustness-cost relationship through efficiently computable bounds that delineate the achievable tradeoff between robustness and cost. Finally, we show that for each stable matching, the set of salience profiles that preserve its stability factors is a product of low-dimensional polytopes within the simplex. This geometric structure precisely characterizes the polyhedral shape of each robustness region; its volume can then be computed efficiently, with approximate methods available as the dimension grows, thereby linking robustness analysis in matching markets with classical tools from convex geometry.

2602.03649 2026-06-19 cond-mat.mtrl-sci 版本更新

Ab initio Phase Diagram of Ta2O5

Ta2O5 的从头算相图

Yan Gong, Huimin Tang, Yong Yang, Yoshiyuki Kawazoe

AI总结 通过第一性原理计算,建立了 Ta2O5 的压力-温度相图,发现零点和热声子贡献对相稳定性有显著影响,并预测了 Gamma 与 B-Ta2O5 之间的重入相变。

Comments 35 pages, 12 figures, 3 tables

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AI中文摘要

五氧化二钽 (Ta2O5) 是一种多晶型宽带隙半导体,具有优异的介电性能,广泛应用于光学和电子技术中。其丰富的结构多样性源于不同合成条件下可获得的多种多晶型,使得 Ta2O5 长期以来一直是研究热点。然而,对其多晶型在压力-温度 (P-T) 空间中的热力学稳定性和相变的统一理解仍然难以捉摸。在这里,我们利用第一性原理计算,绘制了 Ta2O5 的热力学景观,并建立了一个全面的 P-T 相图以及相稳定性层次。我们发现 Gamma-Ta2O5 和 B-Ta2O5 在广泛的 P-T 条件下主导相图:Gamma-Ta2O5 在低压下稳定,而 B-Ta2O5 在高达约 60 GPa 的压力下成为热力学有利相,超过该压力后,Y-Ta2O5 成为最稳定相。至关重要的是,零点能 (ZPE) 作为核量子效应 (NQEs) 的一个方面,在决定相对相稳定性中起着重要作用,对吉布斯自由能有显著贡献并改变了相边界。预测在约 2 GPa 附近存在 Gamma 和 B-Ta2O5 之间的重入相变,揭示了该氧化物相行为中意想不到的复杂性。更一般地,我们确定了一个特征温度 (T_0),在该温度下,自由能的零点和热声子贡献相当,并表明 T_0 约为德拜温度的三分之一。这一关系为评估 NQEs 在相稳定性中的重要性提供了一个简单、物理透明的判据,其意义超越 Ta2O5,适用于一大类复杂氧化物。

英文摘要

Tantalum pentoxide (Ta2O5) is a polymorphic wide-bandgap semiconductor with outstanding dielectric properties and widespread use in optical and electronic technologies. Its rich structural diversity, arising from multiple polymorphs accessible under different synthesis conditions, has made Ta2O5 a long-standing subject of interest. However, a unified understanding of the thermodynamic stability and phase transitions of its polymorphs across pressure-temperature (P-T) space has remained elusive. Here, using first-principles calculations, we map the thermodynamic landscape of Ta2O5 and establish a comprehensive P-T phase diagram together with a phase-stability hierarchy. We find that Gamma-Ta2O5 and B-Ta2O5 dominate the phase diagram over a broad range of P-T conditions: Gamma-Ta2O5 is stabilized at low pressures, while B-Ta2O5 becomes thermodynamically favored at higher pressures up to ~ 60 GPa, beyond which Y-Ta2O5 emerges as the most stable phase. Crucially, the zero-point energy (ZPE), one aspect of nuclear quantum effects (NQEs), plays a significant role in determining relative phase stability, contributing substantially to the Gibbs free energy and altering phase boundaries. A re-entrant phase transition between Gamma and B-Ta2O5 is predicted near ~ 2 GPa, revealing unexpected complexity in the phase behavior of this oxide. More generally, we identify a characteristic temperature (T_0), at which zero-point and thermal phonon contributions to the free energy become comparable, and show that T_0 is approximately one-third of the Debye temperature. This relationship provides a simple, physically transparent criterion for assessing the importance of NQEs in phase stability, with implications extending beyond Ta2O5 to a broad class of complex oxides.

2602.03244 2026-06-19 physics.hist-ph physics.chem-ph physics.class-ph 版本更新

Does classical thermodynamics need a third law? Securing the second law at absolute zero

热力学第三定律是一个不必要的复杂性

José-María Martín-Olalla

AI总结 本文通过重新审视能斯特-爱因斯坦争论,论证了能斯特热定理是第二定律的逻辑推论,因此第三定律作为独立公设是多余的。

Comments 3 figures, 1 table, 8800 words

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AI中文摘要

本文阐述了第二定律与第三定律之间关系的含义,并为能斯特热定理的逻辑冗余提供了全面的形式和历史论证。通过重新审视能斯特-爱因斯坦争论,考察了导致传统上将第三定律视为独立假设的潜在假设。本文认为,历史上对能斯特证明的拒绝——源于爱因斯坦坚持在绝对零度下循环在实践上不可执行——忽略了普遍的第二定律已经排除了这种循环的事实,使得独立的第三定律成为不必要的复杂性。最终,能斯特定理被证明是一个基本的自洽调节器,而非独立的物理发现。

英文摘要

This paper elaborates on the implications of the relationship between the Second and Third Laws and provides a comprehensive formal and historical justification for the logical redundancy of the Nernst heat theorem. By revisiting the Nernst-Einstein debate, the underlying hypotheses that lead to the traditional view of the Third Law as an independent postulate are examined. It is argued that the historical rejection of Nernst's proof -- motivated by Einstein's insistence on the practical non-performability of cycles at absolute zero -- overlooks the fact that a universal Second Law already precludes such cycles, rendering an independent Third Law an unnecessary complexity. Ultimately, the Nernst theorem is shown to be an essential consistency regulator rather than an independent physical discovery.

2602.02466 2026-06-19 quant-ph math-ph math.MP 版本更新

Resolving problems with the continuum limit in coherent-state path integrals

解决相干态路径积分中的连续极限问题

Oliwier Urbański

AI总结 针对玻色子热相干态路径积分中的连续极限问题,通过构造精确离散版本并比较不同排序的连续极限,证明Weyl排序适用于所有多项式哈密顿量,并利用重整化方法给出一般性证明。

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AI中文摘要

本文解决了玻色子热相干态路径积分中的连续极限问题。为此,针对哈密顿量的三种不同排序(正规序、反正规序和对称序(Weyl序))构造了路径积分的精确离散版本。随后,在谐振子上检验了它们的不同连续版本,以选择对称序作为所有多项式哈密顿量的可能正确选择。简单情况中发现的数学微妙之处为一般解提供了线索。最后,通过在虚时频域中使用重整化程序从精确离散情况推导连续路径积分,为对称序提供了普遍证明。虽然Weyl序的作用已被发现,但本文提供了其适用于每个多项式哈密顿量的缺失证明,并通过仅涉及产生和湮灭算符(不含位置和动量算符)简化了先前建立的构造。

英文摘要

The paper solves the problem of continuum limit in bosonic thermal coherent-state path integrals. For this purpose, exact discrete versions of the path integral are constructed for three different orderings of the Hamiltonian: normal, anti-normal and symmetric (Weyl order). Subsequently, their different continuum versions are checked on the harmonic oscillator, to choose the symmetric ordering as a possibly correct choice for all polynomial Hamiltonians. Spotted mathematical subtleties in the simple case serve as a clue to the general solution. Finally, a general justification for the symmetric order is provided by deriving the continuum path integral starting from the exact discrete case using a renormalization procedure in the imaginary time frequency domain. While the role of Weyl order has already been found, the paper provides the missing proof of its suitability for every polynomial Hamiltonian and simplifies the previously established construction by referring only to creation and annihilation operators (without position and momentum operators).

2602.01929 2026-06-19 math.DS stat.CO stat.ML 版本更新

Probabilistic function-on-function nonlinear autoregressive model for emulation and reliability analysis of stochastic dynamical systems

概率函数对函数非线性自回归模型用于随机动力系统的仿真与可靠性分析

Zhouzhou Song, Marcos A. Valdebenito, Styfen Schär, Stefano Marelli, Bruno Sudret, Matthias G. R. Faes

AI总结 提出F2NARX模型,从函数对函数回归角度改进NARX方法,结合PCA和高斯过程回归实现概率预测,并通过主动学习高效估计首次穿越失效概率。

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AI中文摘要

在许多工程领域,构建准确且计算高效的代理模型(或仿真器)用于预测动力系统响应至关重要,但由于外部激励和系统参数到系统响应的强非线性和高维映射,这仍然具有挑战性。本文引入了一种新颖的函数对函数非线性自回归外生输入模型(F2NARX),该模型从函数对函数回归的角度重新表述了最近提出的$\mathcal{F}$-NARX方法。所提出的框架在保持高精度的同时显著提高了预测效率。通过将主成分分析与高斯过程回归相结合,F2NARX进一步通过无迹变换以自回归方式实现动力响应的概率预测。这种概率预测能力进一步促进了首次穿越概率评估的主动学习。通过不同复杂度的案例研究证明了该方法的有效性。结果表明,F2NARX在效率上比最先进的NARX模型高出几个数量级,同时通常达到更高的精度。此外,主动学习方法能够仅使用少量训练时间历程准确估计动力系统的首次穿越失效概率。

英文摘要

Constructing accurate and computationally efficient surrogate models (or emulators) for predicting dynamical system responses is critical in many engineering domains, yet remains challenging due to the strongly nonlinear and high-dimensional mapping from external excitations and system parameters to system responses. This work introduces a novel Function-on-Function Nonlinear AutoRegressive model with eXogenous inputs (F2NARX), which reformulates the recently proposed $\mathcal{F}$-NARX method from a function-on-function regression perspective. The proposed framework substantially improves predictive efficiency while maintaining high accuracy. By combining principal component analysis with Gaussian process regression, F2NARX further enables probabilistic predictions of dynamical responses via the unscented transform in an autoregressive manner. Such probabilistic prediction capabilities further facilitate active learning for first-passage probability evaluation. The effectiveness of the method is demonstrated through case studies of varying complexity. Results show that F2NARX outperforms state-of-the-art NARX model by orders of magnitude in efficiency while achieving higher accuracy in general. Meanwhile, the active learning approach enables accurate estimation of first-passage failure probabilities for dynamical systems using only a small number of training time histories.

2507.10188 2026-06-19 math.OC 版本更新

Well-posedness of an optical flow based optimal control formulation for image registration

基于光流的最优控制公式在图像配准中的适定性

Johannes Haubner, Christian Clason

AI总结 将图像配准视为光流公式的最优控制问题,通过引入平滑最大最小函数和Orlicz空间松弛非自反Banach空间中的优化,重新建立线性双曲输运方程的存在唯一性,证明松弛问题的适定性。

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AI中文摘要

我们将图像配准视为使用光流公式的最优控制问题,即讨论一个由线性双曲输运方程控制的优化问题。要求参数化变换的向量场具有Lipschitz连续性,导致优化问题在非自反Banach空间中。我们引入涉及平滑最大最小函数和适当Orlicz空间的优化问题的松弛。为了推导松弛优化问题的适定性结果,我们重新审视并建立了线性双曲输运方程的新存在性和唯一性结果。我们进一步讨论了关于松弛参数和离散化的极限考虑。

英文摘要

We consider image registration as an optimal control problem using an optical flow formulation, i.e., we discuss an optimization problem that is governed by a linear hyperbolic transport equation. Requiring Lipschitz continuity of the vector fields that parametrize the transformation leads to an optimization problem in a non-reflexive Banach space. We introduce relaxations of the optimization problem involving smoothed maximum and minimum functions and appropriate Orlicz spaces. To derive well-posedness results for the relaxed optimization problem, we revisit and establish new existence and uniqueness results for the linear hyperbolic transport equations. We further discuss limit considerations with respect to the relaxation parameter and discretizations.

2602.00345 2026-06-19 math.AP math-ph math.MP 版本更新

Three self-similar solutions of Yang-Mills equations in high odd dimensions

高奇数维杨-米尔斯方程的三个自相似解

Piotr Bizoń, Irfan Glogić, Arthur Wasserman

AI总结 本文研究高奇数维闵可夫斯基时空中SO(d)规范群的球对称杨-米尔斯方程,证明存在恰好N个光滑自相似解,并发现对于所有奇数d≥11,N=3,其中两个解具有闭式表达式。

Comments 11 pages, 1 figure; content essentially unchanged but rearranged and expanded in places

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AI中文摘要

我们考虑$d+1$维闵可夫斯基时空中规范群为$SO(d)$的球对称杨-米尔斯方程。对于任意给定的奇数$d\geq 11$,我们证明了恰好存在$N$个光滑自相似解(模反射对称性),其中$N$是显式多项式$P_m(z)$(次数$m=(d-5)/2$)在区间$0<z<1$内零点的个数。$N$可以通过显式计算算法确定。我们对大奇数维的广泛计算表明,对于所有奇数$d\geq 11$,$N=3$。其中两个自相似解具有闭式表达式:一个先前已知,另一个似乎是新的。我们的结果指向高维杨-米尔斯方程可能的爆破情景相对简单的图景。除了纯数学兴趣外,这种自相似爆破的刚性可能也与物理相关,因为它限制了在弦理论启发的额外维设置和全息模型中出现的更高维杨-米尔斯理论中非阿贝尔规范场的可能紫外动力学。

英文摘要

We consider spherically symmetric Yang-Mills equations with gauge group $SO(d)$ in $d+1$ dimensional Minkowski spacetime. For any given odd $d\geq 11$, we establish existence and uniqueness (modulo reflection symmetry) of exactly $N$ smooth self-similar solutions, where $N$ is the number of zeros of an explicit polynomial $P_m(z)$ of degree $m=(d-5)/2$ in the interval $0<z<1$. The number $N$ can be determined algorithmically by an explicit computation. Our extensive computations for large odd dimensions suggest that $N=3$ for all odd $d\geq 11$. Two of these self-similar solutions admit closed-form expressions: one has been known previously, while the other appears to be new. Our result points toward a relatively simple landscape of possible blowup scenarios for high-dimensional Yang-Mills equations. Beyond its purely mathematical interest, this rigidity of self-similar blowup may also be relevant from a physical perspective, as it constrains the possible ultraviolet dynamics of non-abelian gauge fields in higher-dimensional Yang-Mills theories arising in string-inspired extra-dimensional setups and in holographic models.

2602.00244 2026-06-19 math.NA cs.NA 版本更新

A Bayesian Approach to Feedback Control for Hyperbolic Balance Laws

双曲平衡律反馈控制的贝叶斯方法

Markus Bambach, Shaoshuai Chu, Michael Herty, Yunong Lin

AI总结 提出贝叶斯框架用于双曲平衡律的边界反馈控制,利用Lyapunov衰减估计作为似然传播反馈参数的概率分布,在线性和非线性问题中验证了方法的鲁棒性和可迁移性。

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AI中文摘要

我们提出了一个用于双曲平衡律反馈边界控制的贝叶斯框架。该方法利用Lyapunov衰减估计作为似然,在反馈参数上传播概率分布。对于线性模型,它恢复了现有的解析稳定性结果,并扩展到理论有限的非线性区域。使用一阶局部Lax-Friedrichs(LLF)离散化,我们在解耦波动系统和线性化Saint-Venant方程上验证了该方法,再现了已知的稳定性区间和混合边界耦合。然后我们处理非线性和随机问题,包括非线性Saint-Venant系统、一维和二维Burgers方程、具有随机初始数据的Burgers方程,以及带有源项的非守恒扰动,并表明推断的稳定性域相对于指标和先验是鲁棒的。最后,我们展示了向二阶半离散LLF方案和用于激光粉末床熔融功率调节的两参数反馈模型的迁移。

英文摘要

We propose a Bayesian framework for feedback boundary control of hyperbolic balance laws. The method propagates a probability distribution over feedback parameters using Lyapunov decay estimates as a likelihood. For linear models, it recovers available analytical stability results and extends to nonlinear regimes where theory is limited. Using first-order local Lax-Friedrichs (LLF) discretizations, we validate the approach on the decoupled wave system and the linearized Saint-Venant equations, reproducing known stability intervals and mixed boundary couplings. We then treat nonlinear and stochastic problems, including the nonlinear Saint-Venant system, one- and two-dimensional Burgers equations, Burgers equation with random initial data, and nonconservative perturbations with source terms, and show that the inferred stability domains are robust with respect to the indicator and the prior. Finally, we demonstrate transfer to a second-order semi-discrete LLF scheme and to a two-parameter feedback model for laser powder bed fusion with power regulation.

2601.23173 2026-06-19 stat.ME 版本更新

Robust, partially alive particle Metropolis-Hastings via the Frankenfilter

鲁棒的、部分存活的粒子Metropolis-Hastings算法:基于Frankenfilter

Chris Sherlock, Andrew Golightly, Anthony Lee

AI总结 针对隐马尔可夫模型中条件似然为零导致粒子滤波失效的问题,提出Frankenfilter,通过固定模拟次数上下限并设定成功目标,实现鲁棒且高效的似然估计,在伪边际Metropolis-Hastings中比标准粒子滤波效率提高2-3倍。

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AI中文摘要

当隐马尔可夫模型允许给定隐藏过程的观测条件似然为零时,从一个观测时间到下一个观测时间的所有粒子模拟可能产生零值。如果是这样,滤波分布无法估计,且估计的参数似然为零。存活粒子滤波器通过为每个观测间隔模拟随机数量的粒子来解决这个问题,在达到目标数量的非零条件似然后停止。对于异常观测或较差的参数值,非零结果可能极不可能发生,计算成本过高。我们引入了Frankenfilter,一种有原则的、部分存活的粒子滤波器,它在固定模拟次数上下限的同时,针对用户定义的成功量。Frankenfilter产生似然的无偏估计,适用于伪边际Metropolis-Hastings(PMMH)。我们证明,与使用标准粒子滤波器的PMMH相比,使用Frankenfilter的PMMH对异常值和错误指定的初始参数值更加鲁棒,并且通常效率至少提高2-3倍。我们还提供了选择成功量的建议。在n个精确观测的情况下,这特别简单:目标为n次成功。

英文摘要

When a hidden Markov model permits the conditional likelihood of an observation given the hidden process to be zero, all particle simulations from one observation time to the next could produce zeros. If so, the filtering distribution cannot be estimated and the estimated parameter likelihood is zero. The alive particle filter addresses this by simulating a random number of particles for each inter-observation interval, stopping after a target number of non-zero conditional likelihoods. For outlying observations or poor parameter values, a non-zero result can be extremely unlikely, and computational costs prohibitive. We introduce the Frankenfilter, a principled, partially alive particle filter that targets a user-defined amount of success whilst fixing lower and upper bounds on the number of simulations. The Frankenfilter produces unbiased estimators of the likelihood, suitable for pseudo-marginal Metropolis--Hastings (PMMH). We demonstrate that PMMH with the Frankenfilter is more robust to outliers and mis-specified initial parameter values than PMMH using standard particle filters, and is typically at least 2-3 times more efficient. We also provide advice for choosing the amount of success. In the case of n exact observations, this is particularly simple: target n successes.

2601.20690 2026-06-19 hep-lat 版本更新

Tensor renormalization group study of cold and dense QCD in the strong coupling limit

强耦合极限下冷密QCD的张量重整化群研究

Yuto Sugimoto, Shinichiro Akiyama, Yoshinobu Kuramashi

AI总结 利用张量重整化群方法研究强耦合极限下(3+1)维冷密QCD的相结构,通过手征凝聚和夸克数密度确定手征和核相变的一级相变终止点,并比较临界夸克质量。

Comments 17 pages, 9 figures, 1 table

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Journal ref
Phys. Rev. D 113, 114509 (2026)
AI中文摘要

我们使用张量重整化群方法研究了强耦合极限下具有Kogut-Susskind夸克的(3+1)维冷密QCD的相结构。通过计算手征凝聚和夸克数密度作为化学势的函数,研究了手征和核相变。对于固定的时间范围$N_\tau=8$,我们分别确定了手征凝聚和夸克数密度的临界夸克质量$m_c^{\chi}$和$m_c^{n}$,在这些临界质量处,一级相变随着热力学量间断性的消失而终止。我们发现,在相同夸克质量下,这两个量在相同化学势处表现出间断性,并且得到的临界夸克质量彼此一致。我们还将临界夸克质量的结果与从对偶形式中的蒙特卡罗模拟和平均场分析得到的结果进行了比较。我们进一步在$1024^4$格点上确认了有限夸克质量处的一级相变,该格点本质上处于零温度下的热力学极限,正如平均场分析所预期的那样。

英文摘要

We study the phase structure of the (3+1)-dimensional cold and dense QCD with the Kogut--Susskind quark in the strong coupling limit using the tensor renormalization group method. The chiral and nuclear transitions are investigated by calculating the chiral condensate and the quark number density as a function of the chemical potential. For a fixed temporal extent $N_τ=8$, we determine the critical quark masses $m_c^χ$ and $m_c^{n}$ for the chiral condensate and the quark number density, respectively, at which the first-order phase transition terminates with the vanishing discontinuity in thermodynamic quantities. We find that both quantities at the same quark mass exhibit a discontinuity at the same chemical potential, and the resulting critical quark masses are consistent with each other. We also compare our results for the critical quark masses with those obtained from the Monte Carlo simulation in the dual formulation and from the mean-field analysis. We further confirm the first-order phase transition at finite quark mass on a $1024^4$ lattice, which is essentially in the thermodynamic limit at zero temperature, as expected from the mean-field analysis.

2601.20590 2026-06-19 math.CO 版本更新

A bijection between edges of the Turán graph and irreducible elements in the dominance order lattice

Turán图的边与支配序格中不可约元素之间的双射

Nathanaël Hassler

AI总结 本文构建了部分在[1,p]内、和为n的整数分拆的支配序格中的交不可约元素与(n,p)-Turán图的边之间的双射,并利用该双射渐近计算了这些交不可约分拆上某些统计量的平均值。

Comments 10 pages, 2 figures, 1 table

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AI中文摘要

在本文中,我们构建了部分在$[1,p]$内、和为$n$的整数分拆的格(配备支配序)中的交不可约元素与$(n,p)$-Turán图的边之间的双射。利用这个双射,我们随后渐近计算了这些交不可约分拆上某些统计量的平均值。

英文摘要

In this paper we build a bijection between the meet-irreducible elements of the lattice of the compositions of $n$ with parts in $[1,p]$ equipped with the dominance order, and the edges of the $(n,p)$-Turán graph. Using this bijection, we then compute asymptotically the average value of some statistics on those meet-irreducible compositions.

2601.19443 2026-06-19 math.GR 版本更新

On the maximal subgroups of almost simple and primitive perfect groups

关于几乎单群和本原完全群的最大子群

Patricia Medina Capilla, Luca Sabatini

AI总结 本文证明有限几乎单群的最大子群的导出列第10项是完全群,并推广到完全群的无核最大子群,且常数10是最优的。

Comments 18 pages, presentation improved, to appear in Math. Proc. Cambridge Philos. Soc

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AI中文摘要

我们证明,如果$G$是有限几乎单群且$H$是$G$的最大子群,那么$H$的导出列的第10项是完全群。如果$G$是完全群且$H$是无核的,同样成立。常数$10$是最优的。

英文摘要

We prove that, if $G$ is a finite almost simple group and $H$ is a maximal subgroup of $G$, then the $10$th term of the derived series of $H$ is perfect. The same is true if $G$ is perfect and $H$ is core-free. The constant $10$ is best possible.

2601.18882 2026-06-19 hep-ph hep-th nucl-th 版本更新

Next-to-next-to-leading power corrections to unpolarized Semi-Inclusive Deep Inelastic Scattering

非极化半单举深度非弹性散射的次次领头幂次修正

Ian Balitsky, Alexei Prokudin

AI总结 本文利用快度因子化形式,推导了非极化半单举深度非弹性散射(SIDIS)中次次领头幂次(NNLP)修正的解析表达式,包括非极化分布与碎裂函数以及Boer-Mulders函数与Collins碎裂函数的卷积,并与实验数据进行了比较。

Comments 30 pages, 15 figures, JHEP published version

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AI中文摘要

半单举深度非弹性散射(SIDIS)是通过横向动量依赖的部分子分布和碎裂函数探索核子三维结构的关键工具。虽然SIDIS截面的领头幂次贡献已得到充分研究,但次领头幂次(NLP,$1/Q$阶)和次次领头幂次(NNLP,$1/Q^2$阶)对强子张量的修正直到最近才开始被系统研究。这些修正对于现代高精度数据的可靠唯象学和解释至关重要。在作者近期的工作中,利用快度因子化形式推导了Drell-Yan过程的NNLP修正。本文将此方法推广到SIDIS,并得到了非极化结构函数的解析表达式。我们推导的NNLP修正包括非极化分布$f_1$与非极化碎裂函数$D_1$的卷积,以及Boer-Mulders函数$h_1^\perp$与Collins碎裂函数$H_1^\perp$的卷积。我们将结果与先前公式进行了比较,提供了数值研究,将预测与HERMES和COMPASS测量进行了对比,并给出了未来在Jefferson Lab和电子-离子对撞机上实验的预测。

英文摘要

Semi-Inclusive Deep Inelastic Scattering (SIDIS) is a key tool for exploring the three-dimensional structure of the nucleon through Transverse Momentum Dependent parton distributions and fragmentation functions. While leading-power contributions to the SIDIS cross-section are well established, next-to-leading (NLP) of order $1/Q$ and next-to-next-to-leading power (NNLP) corrections of order $1/Q^2$ to the hadronic tensor have only recently begun to be systematically investigated. These corrections are essential for the reliable phenomenology and interpretation of modern high-precision data. In recent papers by one of the authors, NNLP corrections to Drell-Yan process were derived using rapidity factorization formalism. In the present work we extend this approach to SIDIS and obtain analytic expressions for the unpolarized structure functions. We derive NNLP corrections that include convolutions of unpolarized distributions, $f_1$, with unpolarized fragmentation functions, $D_1$, and Boer-Mulders functions, $h_1^\perp$, with Collins fragmentation functions, $H_1^\perp$. We compare our results with previous formulations, provide numerical studies, confront our predictions with HERMES and COMPASS measurements, and present predictions for future experiments at Jefferson Lab and the Electron-Ion Collider.

2601.18600 2026-06-19 cond-mat.mtrl-sci cond-mat.mes-hall 版本更新

On-surface dehydrogenative lateral homo-coupling and aromatization of n-octane on Pt(111)

正辛烷在Pt(111)上的表面脱氢横向自偶联与芳构化

D. Arribas, E. Tosi, V. Villalobos-Vilda, B. Cirera, I. Palacio, A. Sáez-Coronado, P. Lacovig, A. Baraldi, L. Bignardi, S. Lizzit, C. Sanchez-Sanchez, A. Gutiérrez, J. A. Martín-Gago, M. Garnica, J. I. Martínez, P. L. de Andres, P. Merino

AI总结 利用扫描隧道显微镜和第一性原理计算,研究了正辛烷在Pt(111)表面热诱导芳构化及分子间脱氢偶联反应,揭示了环芳构化和拉链式C-C键形成机制。

Comments 24 pages, 1 scheme, 3 figures

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AI中文摘要

脂肪烃(如正构烷烃)是碳原子的天然丰富来源。特别令人感兴趣的是从脂肪族反应物形成环状和芳香族产物。结合扫描隧道显微镜和从头算计算,我们研究了线性正辛烷分子在催化Pt(111)表面上的热诱导芳构化以及它们在600 K以上温度下的分子间自偶联反应。单个正辛烷分子的环芳构化需要线性吸附物在脱氢前弯曲,并形成分子内C-C键,产生吸附的苯环。此外,Pt(111)表面通过引发化学吸附的正辛烷分子脱氢甲基末端之间C-C键的形成,然后以拉链式方式沿碳骨架传播,催化了自偶联反应。我们的发现为生成芳香族产物和稳定的表面多环物种的多相催化过程提供了分子层面的见解。

英文摘要

Aliphatic hydrocarbons, such as normal alkanes, constitute a naturally abundant source of carbon atoms. Of special interest is the formation of cyclic and aromatic products from aliphatic reactants. Combining scanning tunneling microscopy and ab initio calculations, we investigate the thermal induced aromatization of linear n octane molecules on the catalytic Pt(111) surface and the reactions of intermolecular homocoupling between them at temperatures above 600 K. The cycloaromatization of individual n octane molecules requires bending the linear adsorbates prior to their dehydrogenation and the formation of an intramolecular C-C bond, yielding adsorbed benzene rings. In addition, the Pt(111) surface catalyzes a homocoupling reaction by initiating the formation of a C-C bond between the dehydrogenated methyl ends of the chemisorbed n octane molecules and then propagating along the carbon backbone in a zipper like fashion. Our findings provide molecular level insight into the heterogeneous catalytic processes underlying the generation of aromatic products and stable on surface polycyclic species.

2601.18147 2026-06-19 hep-ph 版本更新

Radiative generation of chiral vector operators in $b\to s ν\barν$ transition

辐射生成 $b\to s \nu\bar{\nu}$ 转换中的手性矢量算符

Xin-Shuai Yan, Wen-Feng Liu, Qin Chang, Ya-Dong Yang

AI总结 研究 $b\to s \nu\bar{\nu}$ 转换中手性矢量算符的辐射生成,提出两种极简模型,并发现增强某一衰变通道通常会抑制另一通道,但标量丰富模型中脱耦味结构可使两者相长干涉。

Comments 27 pages, 9 figures, and 18 tables

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AI中文摘要

最近 Belle II 对 $B^+ \to K^+ \nu \bar{\nu}$ 的证据,结合受抑制的分支比 $R \equiv \mathcal{B}(B^0 \to K^{*0} \nu \bar{\nu}) / \mathcal{B}(B^+ \to K^+ \nu \bar{\nu})$,要求新的物理贡献于左右手矢量算符。我们系统地对一阶修正完成进行了拓扑分类,辐射生成两者而不依赖树级媒介,并构建了两种极简基准场景:标量丰富模型和费米子丰富模型。在特定基准质量方案和四种不同味结构下评估这些框架,发现一种通用反相关性,增强某一衰变通道通常会抑制另一通道。标量丰富模型中脱耦味结构是一个例外,使两者相长干涉,使 $R$ 减少 4.22%,同时满足所有互补味约束。在统一耦合假设下,标量丰富模型在带电模式中产生精确抵消,突显了味结构与环生成 Wilson 系数之间非平凡的相互作用。

英文摘要

The recent Belle II evidence for $B^+ \to K^+ ν\barν$, combined with a suppressed branching fraction ratio $R \equiv \mathcal{B}(B^0 \to K^{*0} ν\barν) / \mathcal{B}(B^+ \to K^+ ν\barν)$, necessitates new physics contributing to both left- and right-handed vector operators. We perform a systematic topological classification of one-loop completions that radiatively generate both operators without tree-level mediation, and construct two minimal benchmark scenarios: a scalar-rich model and a fermion-rich model. Evaluating these frameworks under specific benchmark mass schemes and four distinct flavor structures, we find a generic anti-correlation where enhancing one decay channel typically suppresses the other. A notable exception is a decoupled flavor configuration within the scalar-rich model, which yields simultaneous constructive interference, reducing $R$ by $4.22\%$ while satisfying all complementary flavor bounds. Under a universal coupling assumption, the scalar-rich model yields exact cancellation in the charged mode, highlighting the non-trivial interplay between flavor structure and loop-generated Wilson coefficients.

2508.07816 2026-06-19 math.GR 版本更新

Finiteness properties of Subgroups of Houghton Groups of full Hirsch length

完全Hirsch长度的Houghton群子群的有限性性质

Charles Garnet Cox, Peter Kropholler, Armando Martino

AI总结 研究Houghton群中具有完全Hirsch长度的子群的有限性性质,证明当n≥3时,所有存在满同态到Z^{n-1}的大子群属于F_{n-1}型而非FP_n型,并引入广义置换圈积来描述这些子群。

Comments 37 pages; version accepted by Groups, Geometry, and Dynamics. v3 makes minor changes to the exposition, v2 incorporates the helpful suggestions of the referee

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AI中文摘要

在1980年代,K.S. Brown证明了Houghton群$H_n$属于$\operatorname{F}_{n-1}$型而非$\operatorname{FP}_n$型。我们证明,当$n\ge3$时,同样的结论对所有满足存在满同态$G\twoheadrightarrow\mathbb{Z}^{n-1}$的“大”子群$G\subseteq H_n$成立。我们的研究自然引向广义置换圈积,其中圈积的基是有限群的直积,这些有限群在同构类型上允许在不同轨道间变化。这种广义圈积自然出现在Houghton群的大子群中,并由广义Jordan--Wielandt定理所容纳。

英文摘要

In the 1980's K.S. Brown proved that the Houghton group $H_n$ is of type $\operatorname{F}_{n-1}$ but not $\operatorname{FP}_n$. We show that, provided $n\ge3$, the same conclusion holds for all subgroups $G$ of $H_n$ that are 'large' in the sense that there is an epimorphism $G\twoheadrightarrow\mathbb{Z}^{n-1}$. Our research leads naturally to the study of generalised permutational wreath products in which the base of the wreath product is a direct product of finite groups which are allowed to vary in isomorphism type from one orbit to another. Such generalised wreath products arise naturally amongst the large subgroups of Houghton groups and are accommodated by a generalised Jordan--Wielandt theorem.

2601.17464 2026-06-19 eess.SY cs.SY 版本更新

Robust Output Regulation of Uncertain Linear Time-Varying Systems

不确定线性时变系统的鲁棒输出调节

Jinmeng Zha, Zhen Zhang

AI总结 针对线性时变系统的鲁棒输出调节问题,提出轨迹匹配系统浸入框架,揭示参数不确定性的根本影响,建立有限线性参数化的精确代数边界,并设计近似鲁棒控制器以实现任意小的有界跟踪误差。

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AI中文摘要

线性时变系统的鲁棒输出调节几十年来一直是一个开放问题。为了解决这个问题,我们提出了轨迹匹配系统浸入框架,通过将调节方程重新表述为更具洞察力的形式。这一视角表明,找到内模等价于通过构造一个无外力系统来再现给定受迫系统的稳态输出轨迹。这揭示了参数不确定性的根本影响,给出了鲁棒调节的精确代数边界,称为有限线性参数化。由此,我们进一步证明时变系统中的不确定性容易激发无限维函数族,使得有限维调节器无法实现精确鲁棒调节。因此,我们建立了一个全面的近似鲁棒设计,它产生一个可以任意小的有界跟踪误差,并避免显式求解调节方程。此外,当不确定性以某些特定方式影响系统时,它可以确保精确调节。总体而言,这些结果为构建基于内模的设计提供了一个通用的、可执行的框架,并简化了鲁棒控制的实现过程。

英文摘要

Robust output regulation for linear time-varying systems has remained an open problem for decades. By augmenting the classical immersion viewpoint, we propose the trajectory-matching system immersion framework. It reformulates the regulator equation as a forced system, and demonstrates that finding an internal model is equivalent to reproducing the non-decaying output trajectories of this forced system by constructing an unforced one. This perspective yields an exact algebraic boundary for finite-dimensional internal models, termed finite linear parameterization. It further reveals a distinctive obstruction in time-varying systems: even highly structured, finite-dimensional affine parametric uncertainties can generate infinite-dimensional families of non-decaying error-zeroing signals, thereby precluding exact robust regulation via linear finite-dimensional internal models in general. Hence, we develop a comprehensive approximate robust design, which yields a bounded tracking error that can be arbitrarily small, and avoids explicitly solving the regulator equation. Additionally, it recovers exact regulation when the uncertainty influences the system in some specified ways. Overall, these results clarify the intrinsic limitation of exact finite-dimensional robust regulation for uncertain LTV systems, and provide a general, executable framework for constructing an internal model-based design.

2601.17137 2026-06-19 cond-mat.mtrl-sci 版本更新

On-the-Fly Machine-Learned Force Fields for High-Fidelity Polymer Glass Transition Simulations

用于高保真聚合物玻璃化转变模拟的即时机器学习力场

Ashutosh Srivastava, Sakshi Agarwal, Shivank Shukla, Harikrishna Sahu, Rampi Ramprasad

AI总结 提出混合AIMD与即时机器学习力场构建的方法,实现量子力学精度下聚合物玻璃化转变温度的预测,计算成本降低约六个数量级。

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AI中文摘要

长期以来,以第一性原理精度预测聚合物玻璃化转变温度(Tg)一直遥不可及,因为在宽温度范围内以可接受的速率冷却包含数千个原子的系统超出了从头算分子动力学(AIMD)的计算极限。这里,我们采用一种混合方案,将AIMD与加速的即时(OTF)机器学习力场(MLFF)构建相结合,使得以近经典计算成本实现量子力学精度的Tg预测成为可能。构建MLFF的OTF协议自适应地触发第一性原理计算,仅当新遇到的构型超出当前模型的置信域时,从而仅需每个聚合物1000个AIMD采样构型即可构建鲁棒、无参数的MLFF。然后利用这些MLFF对包含数千个原子的非晶超胞进行长时间冷却模拟。该方法应用于涵盖芳香族、脂肪族、杂原子和支链化学的十二种聚合物,预测结果与实验高度一致,同时相对于AIMD将计算成本降低了约六个数量级。这项工作为预测性聚合物建模建立了新范式,表明OTF-MLFF为以近量子力学保真度模拟复杂无序材料的热物理行为提供了一条可推广、准确且可扩展的途径。

英文摘要

Predicting polymer glass transition temperatures (Tg) with first-principles fidelity has long remained out of reach, as cooling multi-thousand-atom systems over a broad temperature range at acceptable rates exceeds the computational limits of ab initio molecular dynamics (AIMD). Here we employ a hybrid scheme that merges AIMD with accelerated on-the-fly (OTF) machine-learned force-field (MLFF) construction, enabling Tg prediction at quantum-mechanical accuracy with near-classical computational cost. The OTF protocol to construct MLFFs adaptively triggers first-principles calculations only when newly encountered configurations lie outside the current model's domain of confidence, allowing robust, parameter-free MLFFs to be built from merely 1000 AIMD-sampled configurations per polymer. These MLFFs are then utilized to perform long-time cooling simulations on amorphous supercells containing several thousand atoms. Applied across twelve polymers spanning aromatic, aliphatic, heteroatomic, and branched chemistries, the method yields predictions in excellent accord with experiment while reducing computational cost by approximately six orders of magnitude relative to AIMD. This work establishes a new paradigm for predictive polymer modeling, demonstrating that OTF-MLFFs provide a generalizable, accurate, and scalable route to simulating the thermophysical behavior of complex disordered materials at near quantum-mechanical fidelity.

2601.00069 2026-06-19 hep-th gr-qc 版本更新

Diagnosing Critical Behavior in AdS Einstein-Maxwell-Scalar Theory via Holographic Entanglement Measures

通过全息纠缠度量诊断AdS爱因斯坦-麦克斯韦-标量理论中的临界行为

Zhe Yang, GuangZai Ye, Jian-Pin Wu, Peng Liu

AI总结 在爱因斯坦-麦克斯韦-标量理论中,通过全息纠缠熵、互信息、纠缠楔截面和蝴蝶速度等混合态纠缠度量,诊断相变临界行为,发现临界指数均为1。

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AI中文摘要

我们研究了爱因斯坦-麦克斯韦-标量(EMS)理论中的全息混合态纠缠度量。计算了几个量,包括全息纠缠熵(HEE)、互信息(MI)、纠缠楔截面(EWCS)和蝴蝶速度($v_B$)。我们的发现表明,这些度量可以有效诊断相变。值得注意的是,作为混合态纠缠度量的EWCS和MI表现出与HEE相反的行为。此外,我们研究了动态量子信息度量——蝴蝶速度,并观察到其行为与静态量子信息度量不同。我们分析了蝴蝶速度,发现其非单调行为源于其表达式中两个贡献之间的竞争,解析结构表明这可能与不同的物理解释相关。此外,我们检查了全息纠缠度量的标度行为,发现所有临界指数都等于$1$,是标量场的两倍。我们还探讨了EWCS和MI之间的不等式,注意到在相变过程中MI的增长率始终超过EWCS。这些特征预计在热力学相变中具有普适性,并且随着远离临界点,不等式变得更加显著。

英文摘要

We investigate the holographic mixed-state entanglement measures in the Einstein-Maxwell-Scalar (EMS) theory. Several quantities are computed, including the holographic entanglement entropy (HEE), mutual information (MI), entanglement wedge cross-section (EWCS), and butterfly velocity ($v_B$). Our findings demonstrate that these measures can effectively diagnose phase transitions. Notably, EWCS and MI, as mixed-state entanglement measures, exhibit behavior opposite to that of the HEE. Additionally, we study the butterfly velocity, a dynamic quantum information measure, and observe that it behaves differently from the static quantum information measures. We analyze the butterfly velocity and find that its non-monotonic behavior arises from the competition between two contributions in its expression, which the analytic structure suggests may be correlated with distinct physical interpretations. Moreover, we examine the scaling behavior of the holographic entanglement measures and find that all the critical exponents are equal to $1$, which is twice that of the scalar field. We also explore the inequality between EWCS and MI, noting that the growth rate of MI consistently exceeds that of EWCS during phase transitions. These features are expected to be universal across thermodynamic phase transitions, with the inequalities becoming more significant as one moves away from the critical point.

2601.16744 2026-06-19 math.NA cs.NA 版本更新

On the analysis of spectral deferred corrections for differential-algebraic equations of index one

关于指标1微分代数方程的谱延迟校正分析

Matthias Bolten, Lisa Wimmer

AI总结 提出一种可并行的新谱延迟校正方法求解半显式指标1微分代数方程,通过仅对微分方程进行数值积分并利用代数约束隐式处理,实现高精度求解,与龙格-库塔方法竞争。

Comments 40 pages, 13 figures

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AI中文摘要

本文提出了一种新的谱延迟校正(SDC)方法,用于求解半显式微分代数方程(DAEs),并具有并行化能力。新方案将数值积分限制在微分方程上。在Y. Xia等人(2007)的工作中,表明每次校正将解的阶数提高一阶。我们证明这同样适用于新的SDC方案。该方法的推导结合了SDC方法和E. Hairer与G. Wanner(1996)在ε-嵌入方法中提出的无需数值积分即可强制执行代数约束的思想。将代数方程作为系统的隐式条件,可以高效地求解高精度的半显式DAEs。将所提出的方案与其他DAE方法进行了比较。我们证明,所提出的SDC方案在精度上与用于DAEs的龙格-库塔方法具有竞争力,并且其并行版本相对于相应的顺序SDC变体非常高效。

英文摘要

In this paper, we present a new spectral deferred corrections (SDC) method to solve semi-explicit differential-algebraic equations (DAEs) with the ability to be parallelized. The new scheme restricts numerical integration to differential equations. In Y. Xia et al. (2007), it was shown that each correction elevates the order of the solution by one. We show that this carries over to the new SDC scheme. The derivation of the method combines the approach of SDC and the idea to enforce the algebraic constraints without numerical integration as shown in the $\varepsilon$-embedding method by E. Hairer and G. Wanner (1996). Keeping the algebraic equations as an implicit condition of the system allows an efficient solve of semi-explicit DAEs with high-accuracy. The proposed scheme is compared with other DAE methods. We demonstrate that the proposed SDC scheme is competitive with Runge-Kutta methods for DAEs in terms of accuracy and its parallelized versions are very efficient compared to their associated sequential SDC variants.

2512.19780 2026-06-19 hep-th 版本更新

Higher-Point Correlators in N=4 SYM: Ten-Dimensional Null Polygons

N=4 SYM中的高关联函数:十维零多边形

Till Bargheer, Albert Bekov, Carlos Bercini, Frank Coronado

AI总结 通过扭量方法直接计算平面N=4超杨-米尔斯理论中多边形关联函数的圈积分,得到任意外点数的两圈积分表达式,并验证了与可积性计算的一致性。

Comments 42 pages + data files; v2: fixed equation, added figure, minor rewording; v3: references added, typos fixed, new twistor appendix, published version

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Journal ref
J. High Energ. Phys. 2026, 176 (2026)
AI中文摘要

我们考虑了平面N=4超杨-米尔斯理论中“八边形”大荷四点点关联函数的高点推广。这些n点多边形关联函数定义为具有任意R荷的保护标量算子n点点关联函数生成函数的十维零极限,并推测对偶于理论库仑支上W玻色子的大质量散射振幅。我们提出了一种基于扭量的多边形圈积分的直接计算方法,并确定了任意数量外算子的两圈积分。结果表示为共形积分的线性组合,系数是时空距离和算子极化的有理函数。我们与一圈可积性计算精确匹配,并研究了五边形函数的近零质量极限。

英文摘要

We consider higher-point generalizations of the "octagon" large-charge four-point function in planar N=4 super Yang-Mills theory. These n-point polygon correlators are defined as ten-dimensional null limits of generating functions of n-point correlators of protected scalar operators with arbitrary R-charge, and are conjecturally dual to massive scattering amplitudes of W-bosons on the Coulomb branch of the theory. We present a twistor-based direct computation of the polygon loop integrands, and determine the two-loop integrands for any number of external operators. The result is expressed as a linear combination of conformal integrals, with coefficients that are rational functions of the spacetime distances and operator polarizations. We obtain an exact match with a one-loop integrability computation, and study the near-massless limit of the pentagon function.

2508.20053 2026-06-19 econ.TH 版本更新

Misperception and informativeness in statistical discrimination

统计歧视中的误解与信息量

Matteo Escudé, Paula Onuchic, Ludvig Sinander, Quitzé Valenzuela-Stookey

AI总结 研究劳动力市场统计歧视模型中信息与先验误解的相互作用,分解信息量增加对平均工资的影响为工具成分和感知修正成分,并分析其对工资差距的影响。

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AI中文摘要

我们研究了Phelps-Aigner-Cain型劳动力市场统计歧视模型中信息与先验(错误)感知的相互作用。我们将可观测信息关于工人技能的信息量增加对平均工资的影响分解为一个非负的工具成分(反映由于工人与任务更好匹配而增加的剩余)和一个感知修正成分(捕捉额外信息如何减少关于工人群体技能分布的先验误解的重要性)。我们确定了感知修正项的符号:如果群体在先验上被低估(高估),则该项为非负(非正)。然后,我们考虑了对于在信息、感知或两者上存在差异但技能相同的群体之间工资差距的含义,并确定了改善信息缩小工资差距的条件。

英文摘要

We study the interplay of information and prior (mis)perceptions in a Phelps-Aigner-Cain-type model of statistical discrimination in the labor market. We decompose the effect on average pay of an increase in how informative observables are about workers' skills into a non-negative instrumental component, reflecting increased surplus due to better matching of workers with tasks, and a perception-correcting component capturing how extra information diminishes the importance of prior misperceptions about the distribution of skills in the worker population. We sign the perception-correcting term: it is non-negative (non-positive) if the population was ex-ante under-perceived (over-perceived). We then consider the implications for pay gaps between equally-skilled populations that differ in information, perceptions, or both, and identify conditions under which improving information narrows pay gaps.

2601.10221 2026-06-19 q-bio.NC 版本更新

Cognitive Field Theory of Learning, Inference, and Emergence

学习、推理与涌现的认知场论

Byung Gyu Chae

AI总结 提出一种认知场论,将认知视为由自适应动力学时间尺度的红外组织调控的非平衡集体现象,通过引入时间尺度态密度(TDOS)描述推理、记忆和涌现智能的层级集体动力学。

Comments 46 pages, 3 figures

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AI中文摘要

生物和人工系统中的学习、推理、记忆和涌现通常使用不同的理论框架描述,从神经场模型到循环和注意力架构。这里我们发展了一种认知场论,其中认知作为由自适应动力学时间尺度的红外组织调控的集体非平衡现象出现。从具有稳态稳定化和自适应流形几何的随机认知场方程出发,我们表明集体认知动力学由嵌入在高维认知流形中的缓慢弛豫红外模式组织。整合潜在慢记忆区产生延迟自能反馈和非局域记忆核,控制长期上下文持久性和集体认知相干性。我们引入时间尺度态密度(TDOS)作为基本描述符,表征构成推理、记忆和自适应推理基础的集体弛豫模式的分布。学习和自适应持续重组红外TDOS,选择性地稳定支持上下文组织和递归集体动力学的弱阻尼集体区。在临界点附近,红外TDOS通常发展出与缓慢弛豫集体模式积累相关的宽而平坦的结构,产生无标度时间组织和增强的集体相干性。在此框架内,记忆形成、自适应推理和涌现智能作为集体红外动力学组织的层级阶段出现。

英文摘要

Learning, inference, memory, and emergence in biological and artificial systems are often described using disparate theoretical frameworks. Here we develop a cognitive field theory in which cognition is described as a collective nonequilibrium phenomenon governed by the geometry and collective spectrum of a learned cognitive manifold. Starting from a stochastic cognitive-field equation on an adaptive Riemannian manifold, we derive an effective cognitive field theory incorporating nonlocal memory kernels and retarded self-energy feedback. The learned cognitive geometry generates a complex collective spectrum characterized by the time-scale density of states $ρ(λ,ω)$, whose relaxation and circulation sectors govern memory persistence and temporal coherence. Integrating out latent slow collective modes produces non-Markovian memory feedback that renormalizes the cognitive forgetting gap $r_{\rm cog}$, enhances collective susceptibility, and drives the system toward a protected near-critical regime characterized by long-time contextual persistence and scale-free temporal organization. The observable cognitive field emerges as a macroscopic order parameter, $ϕ=Ae^{iψ}$, whose amplitude encodes collective cognitive organization and whose phase encodes temporal coherence across distributed collective modes. Within this framework, learning organizes cognitive geometry, cognitive geometry generates a collective spectrum, and the resulting memory feedback stabilizes a memory-dressed cognitive field. The theory provides a unified dynamical description of learning, memory, inference, selfhood, and emergent intelligence in terms of the infrared organization of collective cognitive dynamics.

2505.22339 2026-06-19 math.AP math.DG 版本更新

The Dirichlet problem for Hessian quotient type curvature equations in Minkowski space

闵可夫斯基空间中Hessian商型曲率方程的Dirichlet问题

Mengru Guo, Yang Jiao

AI总结 针对非凸区域,在不假设下解和Serrin型条件下建立先验估计,证明闵可夫斯基空间中一类Hessian商型曲率方程Dirichlet问题的存在性。

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AI中文摘要

本文考虑闵可夫斯基空间中一类预定Hessian商型曲率方程的Dirichlet问题。对于非凸区域,我们通过建立先验估计,在不假设下解和Serrin型条件的情况下证明了存在性定理。

英文摘要

In this paper, we consider the Dirichlet problem for a class of prescribed Hessian quotient type curvature equations in Minkowski space. For non-convex domains, we prove the existence theorem by establishing the \emph{a priori} estimates without subsolution assumption and Serrin-type condition.

2601.13457 2026-06-19 physics.optics 版本更新

A unified multiscale 3D printer combining single-photon Tomographic Volumetric Additive Manufacturing and Two-Photon Polymerization

一种结合单光子断层体积增材制造与双光子聚合的统一多尺度3D打印机

Buse Unlu, Felix Wechsler, Ye Pu, Christophe Moser

AI总结 提出一种混合3D打印方法,结合双光子聚合的高分辨率与单光子断层体积增材制造的快速成型能力,实现毫米级结构上830纳米细节的多尺度制造。

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AI中文摘要

单光子聚合可快速光聚合厘米级结构,特征尺寸在数十微米量级,而双光子聚合(2PP)可在亚毫米尺度实现亚微米特征。现有的混合方法通常依赖于拼接或逐层制造,且常需单独的打印平台,使得中尺度制造耗时。本文介绍一种混合统一3D打印机,利用两种打印机制的互补优势,弥合尺度分辨率与制造时间之间的差距。我们提出将2PP用于高分辨率、局部空间控制,与单光子断层体积增材制造(TVAM)结合,实现快速、高通量的3D制造。在该方法中,TVAM首先通过过打印在玻璃棒上形成毫米级体积结构,随后在同一平台上进行高分辨率2PP。无需更换光刻胶或引入中间后处理步骤,我们展示了在TVAM打印的毫米级3D物体内部(嵌入)和表面通过2PP精细打印的结构。这里,TVAM以两种不同方式贡献:生成预聚合体积以促进后续2PP,以及在数秒内直接驱动指定区域的无层体积聚合。实验证明,这种双模式策略提供了一种跨越四个数量级尺度的中尺度方法,用于快速制造具有830纳米细节的毫米级结构。对于微光学、生物医学支架和组织工程等应用,大部分体积中数十微米的特征已足够,更高分辨率仅限于局部功能区域。

英文摘要

Single-photon polymerization ensures rapid photopolymerization of centimeter-scale structures with features on the order of tens of micrometers, whereas 2PP provides sub-micrometer features at sub-millimeter scales. Existing hybrid approaches combining these techniques typically rely on stitched or layer-by-layer fabrication and often require separate printing platforms, making mesoscale manufacturing time-consuming. Here, we introduce a hybrid unified 3D printer that leverages the complementary strengths of both printing mechanisms to bridge this scale resolution-fabrication time gap. We propose integrating 2PP for high-resolution, localized spatial control with single-photon TVAM for enabling rapid, high-throughput 3D fabrication. In this approach, TVAM first forms millimeter-scale volumetric structures attached on a glass rod, via overprinting, which is then accessible, on the same platform, for subsequent high-resolution 2PP. Without needing to change the photoresin or introducing intermediate post-processing steps, we proceed to demonstrate finely printed structures via 2PP, fabricated both inside (embedded within) and on the surface of the millimeter-scale 3D objects printed with TVAM. Here, TVAM contributes in two distinct ways: by generating a pre-polymerized volume that facilitates subsequent 2PP, and by directly driving layer-less volumetric polymerization in designated regions within seconds. We experimentally demonstrate that this dual-mode strategy provides a mesoscale approach spanning four orders of magnitude in scale for rapid fabrication of millimeter-scale structures featuring 830 nm details. For applications such as micro-optics, biomedical scaffolds and tissue engineering, tens-of-micrometer features are sufficient across the majority of the volume, with higher resolution confined to localized functional regions.