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2605.01443 2026-05-05 math-ph math.MP quant-ph

A position dependent mass Hamiltonian and abstract ladder operators

具有位置依赖质量的哈密顿量和抽象阶梯算符

Fabio Bagarello, Emanuele Balistreri, Antonino Faddetta

AI总结 本文探讨了位置依赖质量粒子的一维哈密顿量,利用抽象阶梯算符方法寻找本征值和本征向量,分析伪玻色子算符的作用并构造双相干态。

Comments In press in J. Physics A

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AI中文摘要

我们考虑了一个粒子在一维空间中具有位置依赖质量的哈密顿量H,并应用最近提出的所谓抽象阶梯算符策略,试图找到其本征值和本征向量。我们不假设H是自共轭的,而专注于可因子化的算符情况。然后我们展示伪玻色子算符在这一分析中起着重要作用,并构造这些算符的双相干态。讨论了具体的例子。

英文摘要

We consider the Hamiltonian $H$ of a particle in one dimension with a position dependent mass for which we apply the recent strategy of the so-called {\em abstract ladder operators}, in the attempt to find its eigenvalues and eigenvectors. We don't assume that $H$ is self-adjoint, while we focus on the case of a factorizable operator. We show then that pseudo-bosonic operators play a relevant role in this analysis, and we construct bi-coherent states attached to these operators. Explicit examples are discussed.

2605.01440 2026-05-05 quant-ph

Spectral functions on a quantum computer through system-environment interaction

通过系统-环境相互作用在量子计算机上计算谱函数

Etienne Granet, Ramil Nigmatullin, David T. Stephen, Henrik Dreyer

AI总结 本文提出通过量子计算直接建模ARPES实验中的系统-环境相互作用,高效计算谱函数,减少采样次数,适用于离子阱量子计算机。

Comments 9 pages + supplemental

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AI中文摘要

通过角度分辨光电发射光谱(ARPES)测量的谱函数为材料带结构提供了关键见解。与理论比较需要计算某些平衡态下的动态一阶函数,这在经典计算中具有挑战性。在量子计算机上测量这些函数面临多个问题,使用标准技术时采样开销很大。我们提出了一种在量子计算机上高效测量谱函数的方法,通过直接建模ARPES实验中涉及的系统与环境的相互作用。我们开发了量子电路,其局部期望值与谱函数A(k,ω)成正比,适用于所有动量k和特定频率ω。尽管有qubit和两qubit门的开销,我们的方法所需的采样次数比以前的方法少O(N)倍,从而在运行时间上快O(N)倍,并特别适用于离子阱量子计算机。该算法需要实现费米傅里叶变换(FFT)。我们为通用的基数-n FFT编写了高效的门分解,并在硬件上对基数-3在27个qubit上的情况进行了基准测试。最后,我们在Quantinuum System Model H2离子阱系统上演示了该算法,在27个站点的一维系统上计算了谱函数,使用了54个qubit。

英文摘要

Spectral functions measured with angle-resolved photoemission spectroscopy (ARPES) provide key insight to elucidate the band structure of materials. Comparison with theory requires computing dynamical one-point functions in some equilibrium state, which can be classically challenging. Their measurement on quantum computers poses multiple problems and comes with a large sampling overhead when standard techniques are used. We introduce an efficient way of measuring spectral functions on a quantum computer by directly modeling the interaction of the system with the environment involved in ARPES experiments. We develop quantum circuits whose local expectation values are proportional to the spectral function $A(k,ω)$ for all momentum $k$ and a specific chosen frequency $ω$. Although coming with a qubit and two-qubit gate overhead, our approach requires $O(N)$ times less sampling than previous approaches, translating into a factor $O(N)$ faster in runtime, and is particularly adapted to ion-trap quantum computers. The algorithm requires to implement a fermionic Fourier transform (FFT). We write out an efficient gate decomposition for generic radix-$n$ FFT and benchmark it on hardware for radix-$3$ on $27$ qubits. We finally demonstrate our algorithm on a Quantinuum System Model H2 ion-trap system, computing the spectral function on a one-dimensional system of $27$ sites, using $54$ qubits.

2605.01439 2026-05-05 nlin.CD

Optimizing Reservoir Computing for Reconstructing Ergodic Properties

优化用于重建遍历性质的回声计算

Akira Kawano, Ilia Soroka, Greg J. Stephens

AI总结 本文提出通过最小化重构不变分布误差来优化回声计算,以准确重建长时统计特性,如Lyapunov指数,并在部分观测情况下展示其有效性。

Comments 18 pages, 9 figures, 1 table

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AI中文摘要

回声计算是一种强大的动态系统建模框架,因其通用性和计算效率而受到青睐。然而,实现具有准确长时统计(即气候)的预测是一个重大挑战,这对于推断遍历性质如Lyapunov指数至关重要。一种常见方法是通过最大化预测时间来优化回声的宏观参数,如谱半径。但本文显示,即使在多个Lyapunov时间尺度上具有准确预测,也不保证正确的长时统计。相反,我们通过最小化重构不变分布(或其投影)的误差来选择回声属性,这可以从数据中轻松获得。我们证明,这种方法能够重现模型动态系统的Lyapunov指数,包括Logistic映射、标准映射和双摆,即使在部分观测情况下。我们进一步表明,递归连接和由此产生的回声记忆仅在部分观测情况下是必需的。我们引入了一种时间尺度,能够可靠地区分系统和回声动力学。在秀丽隐杆线虫C. elegans的姿态时间序列中,我们展示了我们的方法能够定量重现混沌行为吸引子,但需要进一步约束最大条件Lyapunov指数以确保回声始终保持与复杂生物输入的一致同步。

英文摘要

Reservoir computing is a powerful framework for modeling dynamical systems due to its universality and computational efficiency. However, a major challenge is achieving a forecast with accurate long-time statistics, or climate, which is essential for inferring ergodic properties such as Lyapunov exponents. A common approach is to optimize the reservoir's macroscopic parameters, such as the spectral radius, by maximizing prediction time. But here we show that even predictions accurate over multiple Lyapunov times do not guarantee the correct long-time statistics. Instead, we choose reservoir properties by minimizing the error in the reconstructed invariant distribution (or its projections), which is easily available from data. We demonstrate that this approach reproduces the Lyapunov exponents of model dynamical systems, including the logistic and standard maps, as well as the double pendulum, even with partial observations. We further show that recurrent connections, and resulting reservoir memory, are only required in the partially-observed case. We introduce a temporal scaling which reliably separates system and reservoir dynamics. In the posture time series of the nematode C. elegans we show that our approach quantitatively reproduces a chaotic behavioral attractor, but this requires a further constraint on the maximal conditional Lyapunov exponent to ensure the reservoir remains consistently synchronized to the complex biological input.

2605.01438 2026-05-05 quant-ph

Spectral Minimax Direct Fidelity Estimation for Generic Target States

光谱最小最大直接保真度估计用于通用目标状态

Hyunho Cha, Jungwoo Lee

AI总结 本文提出了一种针对任意目标状态的精确光谱替换方法,在非适应性单次复制测量模型下优化保真度估计,通过单个算子恒等式表征无偏线性估计器,并将精确最小最大问题转化为半正定规划,实现更优的估计方差。

Comments 6 pages

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AI中文摘要

直接保真度估计受益于针对固定目标定制测量,但操作感知的阴影重要性采样(OASIS)方法优化了结果导向的线性规划替代品,而非物理状态的精确最坏方差。我们提出了一种针对任意目标状态的精确光谱替换方法,在相同的非适应性单次复制测量模型下。具体而言,我们通过单个算子恒等式表征无偏线性估计器,确定固定重建系数下的状态最优采样规律,并将精确最小最大问题转化为半正定规划。所得到的离线设计和在线估计器作为算法呈现,并通过局部Pauli测量实现。在去极化噪声下的数值模拟表明,我们的精确光谱优化在估计方差方面优于OASIS替代品。

英文摘要

Direct fidelity estimation benefits from tailoring measurements to a fixed target, but the operator-aware shadow importance sampling (OASIS) method optimizes an outcome-wise linear-program surrogate rather than the exact worst-case variance over physical states. We propose an exact spectral replacement for arbitrary target states under the same non-adaptive single-copy measurement model. Specifically, we characterize unbiased linear estimators by a single operator identity, determine the state-wise optimal sampling law for fixed reconstruction coefficients, and convert the exact minimax problem into a semidefinite program. The resulting offline design and online estimator are presented as an algorithm and implemented with local Pauli measurements. Numerical simulations under depolarizing noise demonstrate that our exact spectral optimization outperforms the OASIS surrogate in terms of estimation variance.

2605.01437 2026-05-05 physics.space-ph

Statistical analysis of solar energetic particle rise times using Earth and Mars observations and constraints on particle transport parameters

基于地球和火星观测的太阳高能粒子上升时间的统计分析及对粒子输运参数的约束

Yihang Cao, Jingnan Guo, Yuming Wang, Zhuxuan Zou, Yongjie Zhang, Cunhui Li

AI总结 本文利用地球和火星多卫星观测数据,建立不同能量SEP事件上升时间的统计关系,发现其遵循幂律关系,火星的更平坦幂律表明太阳距离增加时能量依赖性减弱,从而约束了平行扩散模型中刚性依赖的平行自由程。

Comments accepted by A&A

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AI中文摘要

太阳高能粒子(SEP)在星际空间的传播受到太阳风湍流的调节,这种湍流显著影响粒子扩散和能量演变通过散射过程。传统的基于绝对通量测量的分析在区分源加速和后续传输方面存在固有困难,而时间特征如起始时间和峰值时间受影响较小,更适合研究SEP传输。本研究利用SOHO/ERNE和天问一号/MEPA在2020年11月至2025年3月的数据,选取75个1 AU处和58个近火星的SEP事件。对于每个能量范围,起始时间通过线性拟合确定,峰值时间通过滑动中位数滤波结合Savitzky-Golay平滑提取;两者的差值给出SEP上升时间。与纯扩散方程预测相比,研究了地球和火星的上升时间统计行为。尽管事件选择不确定性存在,SEP上升时间仍遵循清晰的幂律关系与能量相关。火星更平坦的幂律表明,随着太阳距离增加,能量依赖性减弱。利用这些经验关系,我们约束了平行扩散模型中平行自由程的刚性依赖性。结果表明,火星的湍流散射接近刚性无关的区域,反映了从地球到火星湍流演化的耗散主导状态。

英文摘要

The propagation of solar energetic particles (SEPs) in interplanetary space is modulated by solar wind turbulence, which significantly influences particle diffusion and energy evolution through scattering processes. Traditional analyses based on absolute flux measurements face inherent difficulties in disentangling source acceleration from subsequent transport, while temporal features such as onset and peak times are less affected and better suited for studying SEP transport. This study establishes a statistical relationship between the rise time of SEP events at different energies using multi-satellite observations at Earth and Mars. We use data from SOHO/ERNE and Tianwen-1/MEPA between November 2020 and March 2025, selecting 75 SEP events at 1 AU and 58 near Mars. For each energy range, onset times are determined by linear fitting, and peak times are extracted via a sliding median filter combined with Savitzky-Golay smoothing; the difference gives the SEP rise time. Comparing with the pure diffusion equation prediction, we examine the statistical behavior of rise time at Earth and Mars. Despite event selection uncertainties, SEP rise time follows a clear power-law relation with energy. The flatter power-law at Mars indicates weaker energy dependence with increasing solar distance. Using these empirical relations, we constrain the rigidity dependence of the parallel mean free path within the parallel diffusion model. Our results show that turbulence scattering at Mars approaches a rigidity-independent regime, reflecting turbulence evolution toward a dissipation-dominated state from Earth to Mars.

2605.01436 2026-05-05 gr-qc astro-ph.HE

Constraints on Einstein-aether gravity from the precision timing of PSR J1738+0333

从PSR J1738+0333的高精度脉冲星定时数据对爱因斯坦-以太引力的约束

Massimo Vaglio, Amodio Carleo, Abhimanyu Susobhanan, Enrico Barausse, Bilel Ben Salem, Alessandro Corongiu, Paulo C. C. Freire, Delphine Perrodin

AI总结 利用PSR J1738+0333的高精度脉冲星定时数据,结合多个射电望远镜的观测,研究爱因斯坦-以太引力中的洛伦兹违反效应,获得目前最严格的强场约束。

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AI中文摘要

我们利用EPTA第二数据发布和NANOGrav 9年发布更新的高精度脉冲星定时观测数据,结合Arecibo、Green Bank、Nancay、Parkes和Westerbork的TOAs,对爱因斯坦-以太引力进行约束。我们的方法考虑了洛伦兹违反引起的保守和耗散的首次后牛顿修正;这里我们应用该方法处理PSR J1738+0333的数据,使用贝叶斯定时管道Vela处理完整的TOA数据集。我们对二体质量、后开普勒参数和质心速度分量进行联合后验采样,然后应用重采样方案将后验传播到基本理论参数上,获得目前为止单个脉冲星双星系统最严格的强场约束。

英文摘要

We constrain Einstein-aether gravity -- a Lorentz-violating extension of General Relativity in which a dynamical, unit timelike vector field selects a preferred frame -- using updated high-precision pulsar timing observations of PSR J1738+0333 from EPTA second Data Release and the NANOGrav 9-year release, in combination with ToAs from Arecibo, Green Bank, Nancay, Parkes, and Westerbork. Our method accounts for both conservative and dissipative first post-Newtonian corrections arising from Lorentz violation; here we apply it to PSR J1738+0333 using the Bayesian timing pipeline Vela to process the full ToA dataset. We sample the joint posterior over binary component masses, post-Keplerian parameters and center-of-mass velocity components, and then apply a resampling scheme to propagate posteriors into robust constraints on the fundamental theory parameters, obtaining the most stringent strong-field bounds on the Einstein-aether coupling constants from a single binary pulsar system to date.

2605.01435 2026-05-05 math.CO

Variants of Wythoff's Games with Different Terminal Sets

威斯霍夫博弈的不同终止集变种

Kahori Komaki, Ryohei Miyadera, Aoi Murakami

AI总结 本文研究了经典威斯霍夫博弈的变种,通过改变终止集定义,利用斐波那契数列描述P态,无需递归。

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AI中文摘要

本文研究了经典威斯霍夫博弈的一种变种。经典形式是两人轮流从两堆石子中取走石子,每次可从一堆或两堆中取走石子,若同时从两堆取石子,则必须等量取走。最后取走石子者获胜。等价地,我们考虑在大型网格上放置一个棋后,每位玩家可以将棋后向左上角移动,每次可垂直、水平或对角线移动任意步数。获胜者是将棋后移动到左上角终端位置(0,0)的玩家。设k为正整数,我们考虑终端集为{(x,y):x,y为非负整数且x+y<=k}的威斯霍夫博弈变种。该变种的P态集合由斐波那契数列描述,无需递归。

英文摘要

We study a variant of the classical Wythoff's game. The classical form is played with two piles of stones, from which two players take turns to remove stones from one or both piles. When removing stones from both piles, an equal number must be removed from each. The player who removes the last stone or stones is the winner. Equivalently, we consider a single chess queen placed somewhere on a large grid of squares. Each player can move the queen toward the upper-left corner of the grid, either vertically, horizontally, or diagonally in any number of steps. The winner is the player who moves the queen to the terminal position in the upper-left corner, the position (0,0) in our coordinate system. Let k be a positive integer, and we consider the variant of Wythoff's game with the terminal set {(x,y):x,y are non-negative integers and x+y <=k}. The set of P-positions of this variant is described by the Fibonacci sequence without using recursion.

2605.01433 2026-05-05 quant-ph

Online Estimation of Partial Transpose Moments via Fast Classical Updates

通过快速经典更新在线估计部分转置矩

Hyunho Cha, Jungwoo Lee

AI总结 本文提出通过快速经典更新方法,在线估计部分转置矩,该方法在保持内存的同时将计算复杂度降低到亚立方级,适用于混合态纠缠认证和PT矩基于相位诊断。

Comments 6 pages

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AI中文摘要

部分转置(PT)矩是通过局部Pauli经典阴影可获得的最实用的非线性量之一,因为它们直接支撑混合态纠缠认证和最近基于PT矩的相位诊断。Marso等人提出的在线框架将精确的PT矩统计量重写为固定内存递推,每次新的阴影快照后更新一小组累积矩阵。其更新成本与光子数量无关,但每个步骤将输入的部分转置快照视为通用密集矩阵。因此,算术成本与希尔伯特空间维度立方成正比。我们证明,同一估计器可以在每次快照时以亚立方时间更新,同时保持相同的内存。关键点是累积矩阵变得密集,但新鲜的部分转置快照仍可分解为局部因子。右乘以该因子化快照可通过精确的列对扫掠执行。对于第二PT矩,我们进一步通过利用Pauli基更新优化该过程。

英文摘要

Partial-transpose (PT) moments are among the most practically relevant nonlinear quantities accessible from local Pauli classical shadows, because they directly underpin mixed-state entanglement certification and recent PT-moment-based phase diagnostics. The online framework of Marso \emph{et al.} rewrote the exact PT-moment statistic into a fixed-memory recurrence that updates a small collection of accumulated matrices after each new shadow snapshot. Its update cost is independent of the shot number, but each step treats the incoming partially transposed snapshot as a generic dense matrix. Therefore, the arithmetic cost scales cubically with the dimension of the Hilbert space. We show that the same estimator can be updated exactly in subcubic time per shot while retaining the same memory. The key point is that the accumulated matrices become dense, but the fresh partially transposed snapshot still factorizes into local factors. Right-multiplication by that factorized snapshot can therefore be executed by exact column-pair sweeps. For the second PT moment, we further optimize the process by utilizing a Pauli basis update.

2605.01431 2026-05-05 eess.SY cs.SY

Point-to-Cloud NMPC with Smooth Avoidance Constraints

点到云NMPC与平滑避障约束

Brener G. Ferreira, Vinicius M. Gonçalves, Marcelo A. Santos, Guilherme V. Raffo

AI总结 本文提出一种基于非线性模型预测控制的有限时间最优控制策略,用于跟踪设定点,结合平滑点到云距离度量,实现复杂几何环境下的可靠避障行为。

Comments Accepted for publication at the 2026 European Control Conference (ECC 2026)

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AI中文摘要

本文提出了一种基于非线性模型预测控制框架的有限时间最优控制策略,用于设定点跟踪,该策略集成了避障能力。所提出的公式采用平滑的点到云距离度量,确保在存在复杂和非凸几何区域时也能获得连续可微且数值条件良好的梯度。这种平滑性使安全约束能够通过控制屏障函数一致且可微地进行公式化,从而在闭环系统中实现可靠的避障行为。此外,引入了静止的人工变量以在变化的设定点下保持可行性。所提出的方法通过无人机的数值实验得到验证,展示了在复杂环境中准确的跟踪和平滑的障碍物避障性能。

英文摘要

This paper proposes a finite-horizon optimal control strategy for set-point tracking using a nonlinear model predictive control framework with integrated avoidance capabilities. The formulation employs a smooth point-to-cloud distance metric that ensures continuously differentiable and numerically well-conditioned gradients, even in the presence of regions with complex and nonconvex geometries. This smoothness allows safety constraints to be formulated consistently and differentiably through control barrier functions, resulting in a reliable avoidance behavior for the closed-loop system. Additionally, stationary artificial variables are introduced in the optimal control problem to preserve feasibility under changing set-points. The proposed approach is validated through numerical experiments of an aerial robot, demonstrating accurate tracking and smooth obstacle avoidance in complex environments.

2605.01426 2026-05-05 gr-qc

A note on methods for computing the critical curve of Kerr-like black holes

关于计算 Kerr-like 黑洞临界曲线方法的注记

Siddharth Kumar Sahoo, Indrani Banerjee

AI总结 本文比较了三种临界曲线定义,发现远距离观测时三种定义一致,但有限距离观测时存在差异,且等离子体影响下Bardeen定义与其它定义有分歧,探讨了四维坐标系变化对临界曲线的影响。

Comments 36 pages, 7 figures; Comments are welcome

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AI中文摘要

本文系统比较了Bardeen、de Vries以及Grenzebach等人对Kerr-like黑洞临界曲线(阴影)的天体坐标定义。发现三种定义在真空或周围存在非均匀等离子体的远距离观测下一致,但在有限距离观测时存在差异:Bardeen定义的临界曲线最小,de Vries定义的临界曲线最大。当考虑均匀等离子体时,使用Bardeen定义计算的临界曲线在大距离下偏离其他两个定义,且随着等离子体密度增加而收缩,与de Vries和Grenzebach等人定义以及先前引力透镜研究预测的行为相矛盾。我们假设临界曲线位于观测者天空平面推导了de Vries定义,并解释其与Grenzebach等人定义的差异。进一步探讨了四维坐标系变化对临界曲线的影响。使用Bardeen和Carter四元组,我们绘制了等离子体存在下Schwarzschild和Kerr黑洞的临界曲线,指出四元组变化仅引起临界曲线的水平位移。

英文摘要

This study systematically compares Bardeen's, de Vries's, and Grenzebach et al.'s celestial coordinate definitions of the critical curve ("shadow") of Kerr-like black holes. We find that all three definitions agree for black holes in vacuum or surrounded by inhomogeneous plasma observed from large distances. However, they diverge for observers located at a finite distance: Bardeen's definition yields the smallest critical curve, while de Vries's yields the largest. When homogeneous plasma is considered, critical curve computed using Bardeen's definition deviates from the other two even at large distances and contracts compared to the vacuum case with increasing plasma density. This is in clear contradiction with the behaviour predicted by de Vries's, Grenzebach et al.'s definitions, and previous gravitational lensing studies. We derive de Vries's definition assuming a critical curve on the observer's sky plane and explain its discrepancy with Grenzebach et al.'s definition. We further explore the effect of the change of tetrad on the critical curve. Using Bardeen and Carter tetrads, we plot the critical curve for Schwarzschild and Kerr black holes in the presence of plasma, highlighting that tetrad changes introduce only a horizontal shift in the critical curve.

2605.01422 2026-05-05 cond-mat.stat-mech cond-mat.soft

Microscopic theory of soft run-and-tumble particles

软游动-翻转粒子的微观理论

Rosalba Garcia-Millan, Ziluo Zhang, Luca Cocconi, Marius Bothe, Letian Chen, Zigan Zhen, Gunnar Pruessner

AI总结 研究软游动-翻转粒子在强排斥和大自推力下的有效相互作用,通过微正则展开计算顶点并分析稳态特性。

Comments 25 pages, 7 figures

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AI中文摘要

软、排斥性的游动-翻转粒子在缺乏吸引力的情况下表现出有效的有效相互作用,因为它们似乎会相互粘连。这种有效吸引力在足够强的排斥和大自推力下出现。本文通过系统计算有效相互作用顶点,补充了之前关于两个软游动-翻转粒子之间有效吸引力的论文。我们报告了通过在相互作用耦合附近进行扰动展开,迭代计算有效相互作用顶点,逐次加入环修正。我们利用有效相互作用顶点计算两点相关函数,完全表征稳态。其他可观测值,如结构因子、重叠概率和熵产率也进行了计算。

英文摘要

Soft, repulsive run-and-tumble particles display emergent effective interactions as they appear to stick to each other in spite of the absence of attractive forces. This effective attraction emerges at strong enough repulsion and large self-propulsion. Complementing a companion paper that characterises effective attraction between two soft run-and-tumble particles [Garcia-Millan et al., Effective attraction by repulsion (2026)], here we provide a thorough derivation of our microscopic theory, which is an exact representation of the particle dynamics. We report the systematic calculation of the effective interaction vertices iteratively, in a perturbation expansion about the interaction couplings, by adding, order by order, loop corrections. We use the effective interaction vertices to calculate the two-point correlation function, fully characterising the stationary state. Other observables, such as the structure factor, overlap probability and entropy production rate are calculated as well.

2605.01421 2026-05-05 cond-mat.stat-mech cond-mat.soft

Effective attraction by repulsion

有效吸引通过排斥

Rosalba Garcia-Millan, Luca Cocconi, Ziluo Zhang, Marius Bothe, Letian Chen, Zigan Zhen, Gunnar Pruessner

AI总结 研究通过排斥作用引发的有效吸引现象,揭示了在软颗粒模型中,随着排斥力增强,有效吸引作为高阶修正出现,从而导致相分离。

Comments 7 pages, 3 figures

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AI中文摘要

排斥性自驱粒子倾向于聚集,导致运动性诱导相分离(MIPS)。类比于平衡相分离,MIPS的起始被认为与粒子间有效吸引的转变有关。通过精确的微观理论,我们量化了最小模型中有效吸引的出现:两个在周期域内的软运行- tumble粒子。我们显示,随着排斥力增加,主导行为是有效排斥,而有效吸引作为配对势的重整化高阶修正出现。

英文摘要

Repulsive self-propelled particles tend to cluster, leading to Motility-Induced Phase Separation (MIPS). By analogy with equilibrium phase separation, the onset of MIPS has been associated with a transition to effective attraction between particles. Using an exact microscopic theory, we quantify the emergence of effective attraction in a minimal model: two soft run-and-tumble particles in a periodic domain. We show that, as repulsion increases, the leading-order behaviour is that of effective repulsion, while effective attraction emerges as a higher-order contribution to the renormalisation of the pair potential.

2605.01419 2026-05-05 cs.AR

Understanding Simulated Architecture via gem5 Call-Stack Profiling

通过gem5调用堆栈分析理解模拟架构

Johan Söderström, Rashid Aligholipour, Yuan Yao

AI总结 本文提出一种轻量级框架,通过分析gem5调用堆栈揭示模拟系统行为,发现TimingSimpleCPU效率低下及缓存一致性协议死锁问题。

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AI中文摘要

理解gem5中模拟架构的行为对研究复杂集成计算系统至关重要。然而,传统分析方法只能间接观察模拟系统内部。本文展示通过分析gem5自身调用堆栈提供了一种强大但未被充分利用的视角:模拟器自身的调用堆栈直接反映被模拟系统的活动,揭示传统统计可能忽略的见解。由于gem5高度分层和复杂的软件设计模式,调用堆栈分析具有挑战性。为此,我们引入一个基于Linux perf_event接口的专用轻量级分析框架,该框架在整个模拟过程中采样gem5的运行时调用堆栈,实时解析符号,并将样本合并为分层调用树表示,支持高层次结构视图和聚焦的组件特定分析。此外,所有分析都在独立进程中运行,避免对模拟本身造成侵入性更改和开销。我们应用该框架到gem5的三种主要CPU模型——AtomicSimpleCPU、TimingSimpleCPU和O3CPU——以及Ruby内存系统,揭示了传统gem5统计难以观察的行为。我们的案例研究发现,TimingSimpleCPU由于使用锁存缓存模型效率低下,尽管其概念简单,但其模拟速度不如全乱序核心。此外,我们的工具使检测缓存一致性协议死锁和活锁变得简单,这些问题通常难以识别,因为模拟要么看似正常运行,要么突然终止,使确定这些条件发生的时间困难。

英文摘要

Understanding the behavior of simulated architectures in gem5 is critical for studying complex, deeply integrated computing systems. However, conventional analysis methods provide only an indirect view of the simulated system internals. In this work, we show that call-stack profiling of gem5 itself offers a powerful yet underutilized perspective: the simulator's own call-stack directly reflects the activity of the simulated system, exposing insights that conventional statistics may overlook. Profiling gem5's call-stacks is challenging due to its highly layered and complex software design patterns. To address this, we introduce a specialized, lightweight profiling framework built on Linux's perf_event interface which samples gem5's runtime call-stacks throughout the simulation, resolves symbols on the fly, and merges samples into a hierarchical call-tree representation supporting both high-level structural views and focused, user-defined, component-specific analysis. Moreover, all profiling is performed in a separate process running alongside the main gem5 process, avoiding intrusive changes and overheads to the simulation itself. We apply our framework to gem5's three major CPU models -- AtomicSimpleCPU, TimingSimpleCPU, and O3CPU -- together with the Ruby memory system, and uncover behaviors that are not easily observable in conventional gem5 statistics. Our case studies reveal, for example, that TimingSimpleCPU is inefficient due to its use of a lockup-cache model and, despite its conceptual simplicity, does not simulate faster than a full out-of-order core. In addition, our tool makes it straightforward to detect cache coherence protocol deadlock and livelock -- issues that are otherwise difficult to identify, since the simulation either appears to run normally or terminates abruptly, making it hard to pinpoint when these conditions occur.

2605.01414 2026-05-05 cs.NI

Dynamic Task and Resource Scheduling Towards Green Space-Air-Ground-Sea Integrated Network

动态任务与资源调度面向绿色空天地海一体化网络

Yufei Ye, Shijian Gao, Xinhu Zheng, Liuqing Yang

AI总结 本文提出一种动态任务与资源调度方法,用于优化空天地海一体化网络中的任务执行延迟,通过分层任务卸载算法和前瞻性切换策略提升卫星资源利用率。

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AI中文摘要

在6G无所不在连接的背景下,空天地海一体化网络(SAGSIN)成为为资源受限海洋环境提供关键服务的新范式。为高效实现这一范式,我们提出了一种创新的动态任务和资源调度方法,用于为船舶提供计算支持并最小化整体任务执行延迟。为解决多层任务调度的挑战,专门开发了一种分层任务卸载算法,适应实时多维系统动态,并整合了前瞻性切换策略,从而适应性地控制向卫星卸载的数据量,防止切换后拥堵并提高卫星资源利用率。此外,无人机和基站的带宽分配、无人机轨迹以及计算资源分配被联合优化,以增强低空设备间的连接性,并促进面向需求的资源分配以支持绿色网络发展。仿真结果验证了所提方法更好地适应动态系统资源,并与基准相比实现了至少23%的平均任务延迟降低。

英文摘要

In the context of 6G ubiquitous connectivity, the space-air-ground-sea integrated network (SAGSIN) emerges as a new paradigm to provide critical services for resource-limited ocean environments. To realize this paradigm efficiently, we propose an innovative dynamic task and resource scheduling approach for green SAGSIN that delivers computing support for vessels while minimizing overall task execution delay. To address the challenge of multi-layer task scheduling, a layer-wise task offloading algorithm is developed specifically for SAGSIN. It adapts to real-time, multi-dimensional system dynamics and integrates an anticipatory handover strategy that adaptively controls the amount of data offloaded to the satellite, thereby preventing post-handover congestion while improving satellite resource utilization. Furthermore, the bandwidth allocation of uncrewed aerial vehicles and base station, UAV trajectories, and computing resource allocation are jointly optimized to enhance connectivity among low-altitude devices and facilitate demand-driven resource allocation for green network development. Simulation results verify that the proposed method better adapts to dynamic system resources and achieves at least a 23% reduction in average task delay compared with benchmarks.

2605.01413 2026-05-05 gr-qc

Acausal exact vacuum solutions in nonlocal gravity

非局部引力中的非因果精确真空解

Zhe Zhao, Leonardo Modesto, Cosimo Bambi

AI总结 本文研究非局部引力中一种允许闭合类时曲线的Goedel型宇宙作为精确解,揭示了非局部形式因子的特殊性对因果性违反的影响,指出物质的存在打破经典退化。

Comments 13 pages

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AI中文摘要

非局部引力是一种有希望的超可重整化或有限量子引力理论,与单位arity一致。本文聚焦经典运动方程,明确展示了一种特定的Goedel型宇宙子类在真空中的精确解。结果与量子层面的明确理论一致,但仅在特殊且较大的非局部形式因子下实现。因此,自身可重整化要求并非避免因果性违反的充分指导原则。从物理角度看,因果性违反从非局部基本尺度扩展到宏观尺度。因此,物质的存在打破了米克塞和Goedel宇宙之间的经典退化。最后,我们证明在非微扰量子层面,从平坦到Goedel宇宙的转变极其微小。

英文摘要

Nonlocal gravity is a promising super-renormalizable or finite quantum gravity theory consistent with unitarity. In this paper, we focus on the classical equations of motion and explicitly show that a particular subclass of Gödel-type Universes, where closed time-like curves are allowed, is an exact solution of nonlocal gravity in vacuum. The result is consistent with a well defined theory at quantum level, but it is realized only with a special, although large, class of nonlocal form factors. Therefore, by itself the renormalizability requirement is not a sufficient guiding principle in vacuum whether we want to avoid the causality violation. From the physical point of view, the causality violation takes place from the non locality fundamental scale to macroscopic scales. Therefore, it is the presence of matter to break the classical degeneracy between the Minkowski and the Gödel Universe. Finally, we have shown that at the non-perturbative quantum level the transition from a flat to a Gödel Universe is ridiculously small.

2605.01412 2026-05-05 math.NT

A logarithmic structure theorem for multiplicative functions with small partial sums

关于具有小部分和的乘法函数的对数结构定理

Dimitris Koukoulopoulos

AI总结 本文研究了具有小部分和的乘法函数,证明了存在参数m和Q_j,使得在特定区间内关于f(p)的实部求和有界,并将参数与狄利克雷级数零点位置相关联。

Comments 18 pages

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AI中文摘要

设D∈N,A>D+1,Q≥3。考虑满足|∑_{n≤x}f(n)|≤x(logQ)^{A-D-1}/(logx)^A对所有x≥Q成立,且|Λ_f|≤DΛ的乘法函数f:N→C的类。证明存在参数m∈{0,1,…,D}和Q=Q_D≤Q_{D-1}≤…≤Q_m<Q_{m+1}=∞,使得对于所有j=m,m+1,…,D和所有紧区间I⊂[Q_{j+1},Q_j),有∑_{p∈I}Re(f(p)+j)/p=O_{A,D}(1)。当|∑_{n≤x}f(n)|≤x^{1-1/logQ}/(logx)^{D+1}对所有x≥Q成立时,将参数m和Q_j与狄利克雷级数∑_{n≥1}f(n)/n^s在球B(1,1/logQ)内的零点位置相关联。这些结果推广了作者当D=1时的工作。其证明基于作者与Soundararajan以及Sachpazis之前的成果。

英文摘要

Let $D\in\mathbb{N}$, let $A>D+1$, and let $Q\geqslant3$. Consider the class of multiplicative functions $f:\mathbb{N}\to\mathbb{C}$ such that $|\sum_{n\leqslant x}f(n)|\le x(\log Q)^{A-D-1}/(\log x)^A$ for all $x\geqslant Q$, and such that $|Λ_f|\leqslant DΛ$, where $Λ_f$ is defined via the Dirichlet convolution identity $f\log=Λ_f*f$ and $Λ$ denotes von Mangoldt's function. We prove there exist parameters $m\in\{0,1,\dots,D\}$ and $Q=Q_D\leqslant Q_{D-1}\le \cdots\leqslant Q_m<Q_{m+1}=\infty$ such that $\sum_{p\in I} \mathrm{Re}(f(p)+j)/p=O_{A,D}(1)$ for all $j=m,m+1,\dots,D$ and all compact intervals $I\subset[Q_{j+1},Q_j)$. Moreover, when $|\sum_{n\leqslant x}f(n)|\le x^{1-1/\log Q}/(\log x)^{D+1}$ for all $x\geqslant Q$, we relate the parameters $m$ and $Q_j$ to the location of zeroes of the Dirichlet series $\sum_{n\geqslant1} f(n)/n^s$ in the ball $B(1,1/\log Q)$. These results generalize work of the author when $D=1$. Their proof builds on earlier work of the author with Soundararajan, and of Sachpazis.

2605.01411 2026-05-05 quant-ph math-ph math.MP

Quantum jump trajectories, hybrid systems, non-Hermitian evolutions, quantum/classical walks

量子跃迁轨迹、混合系统、非厄米特演化的量子/经典行走

Alberto Barchielli

AI总结 本文提出了一种通用方法来构建量子跃迁轨迹的随机主方程,并讨论了其与量子/经典混合系统及量子滤波理论的关系,通过引入典型轨迹的概念,递归构建非线性随机主方程的解,并利用排除概率密度描述跳跃相关的概率。

Comments 54 pages

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AI中文摘要

量子跃迁类型的随机主方程以一般方式被提出,并讨论了其与量子/经典混合系统及量子滤波理论的联系。通过引入“典型轨迹”的概念,我们展示了如何递归地构建非线性随机主方程(条件状态)的解。此外,通过“排除概率密度”的概念,我们可以描述所有与跳跃相关的概率,特别是跳跃的等待时间和其概率分布。这种通用的公式和混合系统概念使不同领域得以统一和推广:非厄米特哈密顿量下的演化、随机时间间杂的量子通道单元动力学、量子再生成过程、连续时间开放量子行走、利布拉德速率方程等。

英文摘要

Quantum stochastic master equations of jump type are formulated in a general way and connections with quantum/classical hybrid systems and quantum filtering theory are discussed. By introducing the notion of ``typical trajectory", we show how to recursively construct the solution of the non-linear stochastic master equation (the conditional state). Moreover, by the notion of ``exclusive probability densities" we can describe all the probabilities related to the jumps, in particular, the waiting times of the jumps and their probability distributions. This general formulation and the idea of hybrid system allow to unify and generalize different fields: evolutions under non-Hermitian Hamiltonians, unitary dynamics interspersed by quantum channels at random times, quantum renewal processes, continuous time open quantum walks, Lindblad rate equation, ...

2605.01410 2026-05-05 math.CO cs.DM

Facial diagrams and cycle double cover

面图与环双覆盖

Babak Ghanbari, Robert Šámal

AI总结 通过研究立方图在任意曲面上的圆2单元嵌入,探讨环双覆盖猜想。分析扭操作并推导奇边数量的界限。

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AI中文摘要

通过研究立方图在任意曲面上的圆2单元嵌入,探讨环双覆盖猜想。分析扭操作并推导奇边数量的界限。

英文摘要

We approach the cycle double cover conjecture by looking for a circular 2-cell embedding of cubic graphs on an arbitrary surface. It is easy to see that if such an embedding exists, we can get to it from an arbitrary starting 2-cell embedding by repeating ``twists of an edge''. We study this twisting operation in detail and deduce bounds on the number of singular edges (edges where a face meets itself).

2605.01405 2026-05-05 astro-ph.HE gr-qc

Black Hole Supernovae Outcomes Across a Wide Progenitor Range

黑洞超新星在广阔前身体范围内的结果

Oliver Eggenberger Andersen, Evan O'Connor, Liubov Kovalenko, Haakon Andresen, Sean M. Couch

AI总结 研究通过23次轴对称核心坍缩模拟,探讨黑洞超新星是否仅出现在高致密高质量前身体中,发现其在广泛范围内出现,且CO核心质量与残骸质量存在趋势,但CO核心并非最终黑洞质量的充分代理。

Comments 19 pages, 13 figures

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AI中文摘要

黑洞超新星(BHSN)是指核心坍缩事件中,在冲击波复苏但爆炸尚未完成时形成黑洞(BH)的过程,已成为多维模拟的自然结果。然而,它们仍然是核心坍缩中最少研究的产物之一。本文评估这些现象是否仅出现在最致密且质量最大的前体中,或者是否系统性地出现在更广泛的前体结构中。我们进行了23次长期轴对称核心坍缩模拟,前体质量范围为19.51-60个太阳质量,致密性范围为0.31 ≤ ξ₂.₅ ≤ 0.63。我们发现18个BHSN结果覆盖了几乎全部ZAMS质量范围,对应的前体致密性为0.40 ≤ ξ₂.₅ ≤ 0.63。黑洞形成发生在坍缩后约0.7秒至4.4秒之间。黑洞形成后,我们继续演算至至少5000秒。最终爆炸能量范围为约2×10⁴⁹至3×10⁵¹ erg,而最终黑洞引力质量范围为约3至26个太阳质量。我们发现残骸质量与CO核心质量之间存在明显趋势,但显示CO核心单独不足以作为最终黑洞质量的充分代理,尤其是对于CO核心分布的低质量和高质量端点。除了最高CO核心质量模型外,没有单一球坐标能清晰区分喷流物和残骸物质。最后,我们比较了二维轴对称模型和三维模型,讨论了两种几何形状之间的差异。

英文摘要

Black hole supernovae (BHSNe), the term we use for core-collapse events in which black hole (BH) formation occurs after shock revival but before the explosion is complete, have emerged as a natural outcome of multidimensional simulations as these calculations have been extended to seconds after bounce. Yet they remain one of the least studied outcomes of core collapse. Here, we assess whether they are confined to the most compact and massive progenitors, whose birth rates are low, or whether they arise systematically across a wider range of progenitor structures. We perform 23 long-term axisymmetric core-collapse simulations of progenitors spanning 19.51-60$\,M_\odot$ and compactnesses $0.31 \lesssim ξ_{2.5} \lesssim 0.63$. We find 18 BHSN outcomes across nearly the full ZAMS mass range considered, corresponding to progenitors with $0.40 \lesssim ξ_{2.5} \lesssim 0.63$. BH formation occurs between $\sim0.7$ s and $\sim4.4$ s after bounce. After BH formation, we continue the evolution with an excision treatment to at least 5000 s. The final explosion energies span $\sim2\times10^{49}$-$3\times10^{51}$ erg, while the final BH gravitational masses span $\sim3$-$26\,M_\odot$. We find a clear remnant-mass trend with CO-core mass, but show that the CO core alone is not an adequate proxy for the final BH mass, especially for progenitors at the low- and high-mass ends of the CO-core distribution. Except for the highest CO-core mass models, no single spherical mass coordinate cleanly separates ejecta from remnant material. Finally, a 2D axisymmetric and a 3D model are compared as we discuss differences between the two geometries.

2605.01398 2026-05-05 math.NT math.CO

Bowen--Franks groups and minus class groups of cyclotomic number fields with prime conductor

Bowen--Franks 组与具有素导数的环形数字段的减类组

Antonio Lei, Katharina Müller, Daniel Vallières

AI总结 本文构造了一个有向图,其 torsion 部分与环形数字段的减类组密切相关,两者在幂次上具有相同基数,并且在张量后具有相同的同构分量。

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AI中文摘要

令 $p$ 为一个奇有理素数,考虑导数为 $p$ 的环形数字段 $K = \mathbb{Q}(ζ_{p})$。我们构造了一个有 $p-1$ 个顶点的有向图 $Y$,其对应的 Bowen--Franks 组的 torsion 部分与 $K$ 的减类组密切相关。特别地,两个群的基数在显式幂次下相同。此外,两者都是 $\mathrm{Gal}(K/\mathbb{Q})$-模,并且在张量后与适当的 $\ell$-adic 场的 valuation 环中,它们的同构分量的基数相等。

英文摘要

Let $p$ be an odd rational prime and consider the cyclotomic number field $K = \mathbb{Q}(ζ_{p})$ of conductor $p$. We construct a directed graph $Y$ on $p-1$ vertices for which the torsion part of the corresponding Bowen--Franks group is closely related to the minus part of the class group of $K$. In particular, both groups have the same cardinality up to an explicit power of $p$. Furthermore, they are both $\mathrm{Gal}(K/\mathbb{Q})$-modules, and we prove the equality of the cardinalities of their isotypic components after tensoring them with the valuation ring of an appropriate $\ell$-adic field for $\ell \nmid p-1$.

2605.01397 2026-05-05 math.FA

Weak Minimizing Property and the Compact Perturbation Property for the Minimum Modulus

弱极小性与最小模的紧扰动性质

Anselmo Raposo, Geivison Ribeiro

AI总结 本文研究了最小模的弱极小性和紧扰动性质,证明了(c₀,c₀)不满足紧扰动性质,并展示了一个非极小达到算子在紧扰动下最小模严格增加的现象,且该现象不局限于c₀。

Comments 5 pages, Banach space, reflexive Banach space, min-attaining operator, compact pertubation

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AI中文摘要

对于算子T:X→Y,定义m(T)=inf{‖Tx‖:x∈S_X}。若序列(x_n)∈S_X满足‖Tx_n‖→m(T),则称其为T的极小序列。弱极小性(WmP)要求所有具有非弱零极小序列的算子均能达到其最小模。近期,Han引入了最小模的紧扰动性质(CPPm),要求对于不达到最小模的算子T,有sup{m(T+K):K∈K(X,Y)}=m(T)。本文证明(c₀,c₀)不满足CPPm,并构造了一个非极小达到算子,其最小模在紧扰动下严格增加。此外,若X=K⊕∞Y且Y非反射性,则(X,X)不满足CPPm。

英文摘要

For an operator $T:X\to Y$, denote $m(T)=\inf\{\|Tx\|:x\in S_X\}$. A sequence $(x_n)$ in $S_X$ is said to be minimizing for $T$ if $\|Tx_n\|\to m(T)$. The weak minimizing property (WmP), introduced by Chakraborty, requires that every operator admitting a non-weakly null minimizing sequence attains its minimum modulus. More recently, Han~\cite{Han2026} introduced the Compact Perturbation Property for the minimum modulus (CPPm), which requires that for every operator $T:X\to Y$ that does not attain its minimum modulus, \[ \sup_{K\in\mathcal{K}(X,Y)} m(T+K)=m(T). \] In~\cite{Han2026}, it is shown that $(\ell_1,\ell_1)$ fails both properties, while $(c_0,c_0)$ fails the WmP. However, whether $(c_0,c_0)$ has the CPPm was left open (Problem~3.6). In this paper, we give a negative answer to this question by proving that $(c_0,c_0)$ does not have the CPPm. The proof is constructive, exhibiting a non-min-attaining operator whose minimum modulus is strictly increased by a rank-one compact perturbation. Moreover, we show that this phenomenon is not specific to $c_0$: if $X=\mathbb{K}\oplus_\infty Y$ with $Y$ non-reflexive, then the pair $(X,X)$ fails the CPPm.

2605.01396 2026-05-05 math.AT

Moment-angle manifolds associated to neighbourly triangulations of spheres

与球体邻近三角剖分相关的动量-角流形

Amaranta Membrillo Solis, Stephen Theriault

AI总结 研究显示,奇维球体的邻近三角剖分所关联的动量-角流形可同伦等价于两个球面乘积的连通和,解决了Buchstaber和Panov提出的问题。

Comments 16 pages

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AI中文摘要

我们证明,与奇维球体的邻近三角剖分相关的动量-角流形在同伦上等价于两个球面乘积的连通和,解决了Buchstaber和Panov提出的问题。所用方法完全基于同调理论,可推广到广义动量-角流形的情形。

英文摘要

We show that a moment-angle manifold associated to a neighbourly triangulation of an odd dimensional sphere is homotopy equivalent to a connected sum of products of two spheres, resolving a problem of Buchstaber and Panov. The methods are entirely homotopy theoretic, allowing for an extension to a corresponding result in the case of generalized moment-angle manifolds.

2605.01390 2026-05-05 astro-ph.EP

The atmosphere of the warm Neptune GJ 436 b probed with ESPRESSO

通过ESPRESSO探测暖海王星GJ 436 b的大气层

E. Herrero-Cisneros, M. R. Zapatero Osorio, J. Sanz-Forcada, R. Allart, T. Azevedo Silva, S. Cristiani, A. R. Costa Silva, Y. C. Damasceno, P. Di Marcantonio, P. Figueira, J. I. González Hernández, B. Lavie, M. Lendl, G. Lo Curto, C. J. A. P. Martins, E. Pallé, F. Pepe, A. Psaridi, R. Rebolo, J. Rodrigues, N. C. Santos, J. V. Seidel, A. Sozzetti, A. Suárez Mascareño

AI总结 研究通过ESPRESSO光谱观测GJ 436 b大气层中原子和分子物种的存在,发现无显著信号,但检测到可能的Fe I信号,但其低显著性暗示噪声来源。

Comments Accepted in A&A. 17 pages, 11 figures, 5 tables in the main body (24 pages, 24 figures, 5 tables including appendices)

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AI中文摘要

目标:识别暖海王星大小行星GJ 436 b大气层中的原子和分子物种。方法:利用传输光谱观测GJ 436 b两次完整凌星,覆盖3800至7880埃波长范围。通过直接检测行星吸收特征和与理论光谱的交叉相关,搜索原子(H I, Li I, Na I, Mg I, V I, Cr I, Fe I, Fe II)和分子(TiO, VO)物种。结果:未发现任何物种的强行星检测,与无特征光学光谱一致。通过结合所有ESPRESSO观测得出上限。检测到凌后恒星耀斑,主要影响色球线。在第一次凌星中发现可能的Fe I信号(S/N = 3.4 ± 0.2),风速约为-18.6 km/s,对于冷行星来说异常大。该弱信号在第二次凌星中未出现,结合其低显著性,暗示噪声来源。在更不可能的场景中,特征在第二次凌星中被更高恒星活动状态抑制,T1信号峰值为1300 K,高于GJ 436 b的平衡温度。最终结果意味着中性铁丰度与或超过宿主恒星。

英文摘要

Aims. We aim to identify the presence of atomic and molecular species in the upper atmosphere of the warm Neptune-sized transiting planet GJ 436 b, which has a radiative equilibrium temperature of 690 K and a mass of 25.4 Earth masses. Methods. Using transmission spectroscopy, we observed two full transits of GJ 436 b with the ESPRESSO spectrograph, covering the wavelength range from 3800 to 7880 Angstrom. We searched for traces of atomic (H I, Li I, Na I, Mg I, V I, Cr I, Fe I, and Fe II) and molecular (TiO, VO) species by directly detecting planetary absorption features and by cross-correlating the planetary spectrum with theoretical spectra computed for each investigated species. Results. Our analysis reveals no strong planetary detection for any of the species, consistent with a featureless optical spectrum. We derived upper limits by combining all ESPRESSO observations. Post-transit stellar flares were detected on both nights, primarily affecting chromospheric lines. A tentative Fe I signal appears in the first transit (S/N = 3.4 +/- 0.2) at a wind velocity of about -18.6 km/s, which is unexpectedly large for a cool planet. This weak signal is not present in the second transit and, combined with its low significance, suggests an origin in noise. In the less probable scenario where the feature is suppressed during the second transit by the higher stellar activity state, the T1 tentative signal peaks at 1300 K, which is above the equilibrium temperature of GJ 436 b. Ultimately, this result would imply a neutral iron abundance comparable to or exceeding that of the host star.

2605.01389 2026-05-05 cs.IT eess.SP math.IT

RIS Optimization and Scaling Laws in Multi-Operator Systems: Is Quadratic Scaling Achievable?

多运营商系统中的RIS优化与缩放规律:二次缩放是否可行?

Zheyu Wu, Matteo Nerini, Bruno Clerckx

AI总结 本文研究了由通用可重构智能表面(RIS)辅助的多运营商无线通信系统,探讨了RIS在多运营商共存时的干扰问题,并提出了一种RIS设计框架以实现二次缩放。

Comments 15 pages, 6 figures, submitted to IEEE for possible publication

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AI中文摘要

本文研究了由通用可重构智能表面(RIS)辅助的多运营商无线通信系统,包括传统单连接RIS和超越对角线RIS(BD-RIS)。具体而言,我们考虑了一个系统,其中多个运营商在同一区域的不同频段上共存,每个运营商有一个单天线基站,而其中一个运营商通过RIS为其单天线用户提供服务。在这样的系统中,RIS可能会无意中反射非服务运营商的信号,导致运营商间干扰和有效信道的快速波动。为了解决这个问题,我们提出了一种实用的RIS设计框架,该框架在最大化服务运营商接收到的信号功率的同时,强制非服务运营商的RIS反射信道保持固定。我们推导了由此产生的优化问题的闭式解,基于一种新的技术来处理耦合的单位元和线性等式约束。我们进一步给出了接收到信号功率的缩放律分析。对于两个运营商系统,接收到的信号功率在组连接的BD-RIS(组大小Gs≥2)中与RIS元素数量呈二次方关系增长,而传统单连接RIS则仅呈线性增长。更一般地,对于一个L运营商系统,有L-1个非服务运营商,缩放律转换发生在Gs=L时,当Gs≥L时实现二次缩放,否则为线性缩放。这些结果表明,在多运营商系统中,只有具有足够互连的BD-RIS架构才能实现二次缩放。仿真结果验证了分析,并展示了BD-RIS在多运营商系统中的显著优势。特别是,在一个具有128个元素RIS的两运营商系统中,组连接的BD-RIS(Gs=2)在传统RIS上实现了13dB的增益。

英文摘要

This paper studies multi-operator wireless communication systems aided by general reconfigurable intelligent surface (RIS), including both conventional single-connected RIS and beyond-diagonal RIS (BD-RIS). Specifically, we consider a system where multiple operators coexist in the same area over different frequency bands, each with a single-antenna base station, while one operator serves its single-antenna user with the aid of an RIS. In such a system, the RIS may unintentionally reflect signals from the non-serving operators, leading to inter-operator interference and rapid fluctuations of their effective channels. To address this issue, we propose a practical RIS design framework that maximizes the received signal power of the serving operator while enforcing fixed RIS-reflected channels of the non-serving operators. We derive closed-form solutions to the resulting optimization problem, based on a novel technique to deal with the coupled unitary and linear equality constraints. We further give scaling law analysis of the received signal power. For a two-operator system, the received signal power scales quadratically with the number of RIS elements for group-connected BD-RIS with group size Gs>=2, whereas for conventional single-connected RIS it scales only linearly. More generally, for an L-operator system with L-1 non-serving operators, the scaling-law transition occurs at Gs=L, where quadratic scaling is achieved when Gs>=L, and linear scaling otherwise. These results demonstrate that, in a multi-operator system, quadratic scaling is achievable only with BD-RIS architectures having enough interconnections. Simulation results validate the analysis and show the significant gain of BD-RIS over conventional RIS in multi-operator systems. In particular, group-connected BD-RIS with Gs=2 achieves a 13dB gain over conventional RIS in a two-operator system with a 128-element RIS.

2605.01388 2026-05-05 physics.optics

Tracking doublon-holon dynamics in high-harmonic generation from Mott insulators

在Mott绝缘体中通过高调和生成跟踪双子-空穴动力学

Tao-Yuan Du, Hui-Ru Li, Bo Li, Ruifeng Lu

AI总结 研究强相关Mott绝缘体中的高调和生成,利用精确对角化和时间依赖密度矩阵传播分析一维Hubbard链的动力学,揭示了双子-空穴激发通道及填充依赖的相变特性。

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AI中文摘要

通过精确对角化和时间依赖密度矩阵传播对激光驱动的一维Hubbard链进行研究,探讨强相关Mott绝缘体中的高调和生成。通过投影到平衡Hubbard带,利用双子人口及其动力学作为诊断工具,分析了带内(类反铁磁波)和带间(双子-空穴生成)激发通道。出现填充依赖的相变:稀疏填充下呈现Bloch-like带内响应,中间填充呈现混合动力学,接近半填充时带间主导的高调和生成具有平台和截止。在考虑的参数范围内,增加相互作用强度U通过扩大Mott间隙和关联诱导的局域化强烈抑制带间贡献。带内和带间电流分解揭示了低于Mott间隙(Δ_Mott)的相反流以及选择性抑制带间相干的特性,增强净双子积累。时频分析揭示了量子轨迹的填充依赖特性,表现为不同的低于Δ_Mott发射。基于双子的分析提供了平衡自旋-电荷分离与非平衡强场响应之间的透明联系,并阐明了去相位如何修改带间相干和双子积累。

英文摘要

High-harmonic generation (HHG) in strongly correlated Mott insulators is investigated using exact diagonalization and time-dependent density-matrix propagation of a laser-driven one-dimensional Hubbard chain. By projecting onto equilibrium Hubbard bands, we use the doublon population and its dynamics as a diagnostic to analyze intraband (spin-wave-like) and interband (doublon-holon creation) excitation channels. A filling-dependent crossover emerges: Bloch-like intraband response at dilute filling, mixed dynamics at intermediate filling, and interband-dominated HHG with plateau and cutoff near half filling. In the considered parameter range, increasing interaction strength $U$ strongly suppresses interband contributions through the enlarged Mott gap and correlation-induced localization. Intra- and interband current decomposition reveals opposing flows below the Mott gap (Δ_{\mathrm{Mott}}) and selective dephasing suppression of interband coherence, enhancing net doublon accumulation. Time-frequency analysis uncovers the filling-dependent features of quantum trajectories, manifesting in distinct below-Δ_{\mathrm{Mott}} emission. This doublon-based analysis provides a transparent link between equilibrium spin-charge separation and nonequilibrium strong-field response, and clarifies how dephasing modifies interband coherence and doublon accumulation.

2605.01385 2026-05-05 math-ph math.MP

The Haar measure of the $p$-adic rotation group $\textrm{SO}(3)_p$ via nautical angles

通过航海角度研究 $p$-adic 旋转群 $\textrm{SO}(3)_p$ 的海尔测度

Lorenzo Guglielmi, Stefano Mancini, Vincenzo Parisi, Ilaria Svampa

AI总结 本文通过航海参数化方法,构造了$p$-adic旋转群$\textrm{SO}(3)_p$的显式海尔测度,利用其与$p$-adic四元数模标量群的同构性,推导变量变换公式并计算雅可比行列式,最终得到归一化测度的因子化密度形式。

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AI中文摘要

我们研究了通过航海(卡丹)参数化方法对紧致 $p$-adic 旋转群 $\textrm{SO}(3)_p$ 上的海尔测度的显式构造。利用其与 $p$-adic 四元数模标量群 $\mathbb{H}_p^\times/\mathbb{Q}_p^\times$ 的拓扑群同构性,我们推导了相应的变量变换公式,并在 $p$-adic 设定下计算了相关的雅可比行列式,将其与已知的 $p$-adic 四元数乘法群 $\mathbb{H}_p^\times$ 上的海尔测度结合。这得到了 $\textrm{SO}(3)_p$ 在航海坐标下的归一化海尔测度的显式公式,其密度在三个角度上具有因子化形式。我们的构造提供了一种适用于非阿基米德模型应用的具体工具,其中需要显式角描述的不变积分。

英文摘要

We study the explicit construction of the Haar measure on the compact $p$-adic rotation group $\textrm{SO}(3)_p$ by nautical (Cardano) parametrization. Exploiting its topological group isomorphism with $\mathbb{H}_p^\times/\mathbb{Q}_p^\times$ of $p$-adic quaternions modulo scalars, we derive the corresponding change of variables formulas and compute the associated Jacobian in the $p$-adic setting, which we combine with the known Haar measure on the multiplicative group of $p$-adic quaternions $\mathbb{H}_p^\times$. This yields an explicit formula for the normalized Haar measure on $\textrm{SO}(3)_p$ in nautical coordinates, with a factorized density in the three angles. Our construction provides a concrete tool suited for applications of non-Archimedean models where an explicit angular description of invariant integration is required.

2605.01384 2026-05-05 q-fin.CP

SBCA: Cross-Modal BERT-driven Actor-Critic for Multi-Asset Portfolio Optimization

SBCA:跨模态BERT驱动的Actor-Critic多资产组合优化框架

Jinfeng Pan, Jiahao Chen

AI总结 本文提出SBCA框架,通过跨模态门控融合机制整合价格数据与文本语义,结合风险与交易成本约束,提升多资产组合优化效果。

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AI中文摘要

传统模型受限于线性假设和多模态信息整合不足。本文提出SBCA框架,采用跨模态门控融合机制整合价格时间序列特征和文本语义特征,将下行风险和交易成本惩罚约束嵌入奖励函数,构建完整实证系统进行验证。实验表明SBCA在组合价值、年化收益、夏普比率和最大回撤方面优于等权重、持有买入和市场基准策略。消融研究验证Actor-Critic机制与跨模态融合模块的互补增强,成本敏感性分析确认模型在不同交易成本下的鲁棒性。SBCA为动态量化组合决策提供有效且可解释的端到端解决方案。

英文摘要

Portfolio optimization is constrained by linear assumptions and insufficient integration of multi-modal information in traditional models. This paper proposes a cross-modal BERT-driven Actor-Critic framework SBCA for multi-asset portfolio optimization to address the deficiencies of existing deep reinforcement learning DRL methods in fusing price data and financial text sentiment, as well as lacking practical trading constraints. The framework adopts a cross-modal gated fusion mechanism to adaptively integrate price time-series features and text semantic features, embeds downside risk and turnover penalty constraints into the reward function, and constructs a complete empirical system for validation. Experiments on 11-year U.S. stock multi-asset datasets show that SBCA outperforms equal weight, buy-and-hold and market benchmark strategies in portfolio value, annual return, Sharpe ratio and maximum drawdown. Ablation studies verify the complementary enhancement of Actor-Critic mechanism and cross-modal fusion module. Cost sensitivity analysis confirms the model's robustness under varying transaction costs. SBCA provides an effective and interpretable end-to-end solution for dynamic quantitative portfolio decision-making.

2605.01380 2026-05-05 astro-ph.CO astro-ph.GA

A structural degeneracy explains reionization tensions and limits dark matter constraints

结构退化解释了再电离张力并限制了暗物质约束

Zihan Wang, Huanyuan Shan

AI总结 研究揭示再电离历史探测器对模型参数与观测的非可逆映射,限制暗物质约束,并提出仅空间拓扑敏感观测可打破退化。

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AI中文摘要

过去十年中,再电离研究持续存在因数两到五的推断电离逃逸分数f_esc和峰值恒星形成效率f_*0的分歧,且JWST发现意外明亮的z>10星系。本文展示这种分歧源于代数精确的结构退化:电离光子率dot{n}_ion ∝ f_esc × f_*0,使所有再电离历史探测器,包括汤姆逊光学深度、中性氢分数、紫外光子函数和类星体邻近区,仅对它们的乘积敏感,导致模型参数与观测之间本质上不可逆的映射。通过大规模N体模拟自我相互作用暗物质晕的10^9-10^11 M_⊙范围,证明了这种退化稳健性。尽管银河系尺度结构有显著变化,一旦有效电离发射率匹配,观测结果仍不可区分,严重限制基于再电离的暗物质探测。发现仅对电离区域空间拓扑敏感的观测可打破这种退化。结果为已发布约束的散射提供统一解释,并建立解释再电离观测及其对早期星系形成和暗物质影响的框架。

英文摘要

Over the past decade, reionization studies have yielded persistent factor-of-two-to-five disagreements in the inferred ionizing escape fraction $f_{\mathrm{esc}}$ and peak star formation efficiency $f_{*,0}$, compounded by JWST's discovery of unexpectedly bright $z>10$ galaxies. We show that this discrepancy arises from an algebraically exact structural degeneracy: the ionizing photon rate $\dot{n}_{\mathrm{ion}} \propto f_{\mathrm{esc}} \times f_{*,0}$ renders all reionization-history probes, including Thomson optical depth, neutral hydrogen fraction, UV luminosity function, and quasar proximity zones, sensitive only to their product, leading to an intrinsically non-invertible mapping between model parameters and observations. We demonstrate the robustness of this degeneracy using a large suite of N-body simulations of self-interacting dark matter haloes spanning $10^9$-$10^{11} M_\odot$. Despite substantial changes to galaxy-scale structure, observables remain indistinguishable once the effective ionizing emissivity is matched, severely limiting reionization-based dark matter probes. We identify that only observables sensitive to the spatial topology of ionized regions can break this degeneracy. Our results provide a unified explanation for the scatter among published constraints and establish a framework for interpreting reionization observations and their implications for early galaxy formation and dark matter.

2605.01379 2026-05-05 stat.ME

Federated generalized linear mixed models based on one-time shared summary statistics

基于一次性共享汇总统计量的联邦广义线性混合模型

Marie Analiz April Limpoco, Christel Faes, Niel Hens

AI总结 本文提出一种基于一次性共享汇总统计量的联邦广义线性混合模型估计方法,通过生成伪数据匹配真实但不可用数据的汇总统计量,实现高效且无生态偏倚的模型估计。

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AI中文摘要

数据隐私问题日益严峻,因为其限制了统计模型如广义线性混合模型所需的数据可用性。访问个人数据往往需要大量时间和精力,阻碍了研究进展和合作。现有不使用个体层面数据进行模型估计的方法要么易产生生态偏倚,无法处理异质性,或需迭代通信。本文提出一种基于一次性共享汇总统计量的广义线性混合模型估计方法,通过生成伪数据匹配真实但不可用数据的汇总统计量,利用这些伪数据进行模型估计。我们以线性、逻辑和泊松混合模型为例展示了该方法。我们的策略生成伪数据,其汇总统计量与实际但不可用数据匹配,然后用这些伪数据进行模型估计而非实际数据。所获得的估计值与实际数据得出的估计值在第三位小数以内相同,具有相似的偏差、覆盖率和预测性能。通信和资源效率使我们的方法区别于现有方法。

英文摘要

Data privacy has increasingly become a daunting challenge because it limits data availability, which is essential in estimating statistical models such as generalized linear mixed models. Access to personal data often involves considerable time, effort, and paperwork, which can impede research progress and collaboration. Existing approaches that do not use individual-level data for model estimation are either prone to ecological bias, cannot handle heterogeneity, or require iterative communication. In this paper, we propose an approach to estimate generalized linear mixed models based on summary statistics shared only once. We used linear, logistic, and Poisson mixed models as examples to demonstrate the methodology. Our strategy involves generating pseudo-data whose summary statistics match those of the actual but unavailable data. These pseudo-data are then used for model estimation instead of the actual data. The estimates we achieve are identical (up to the third decimal place) to those derived from actual data and have similar bias, coverage, and prediction performance. Communication and resource efficiency distinguish our approach from existing methods.

2605.01378 2026-05-05 q-bio.GN

PhenotypeToGeneDownloaderR: automated multi-source retrieval and validation of phenotype-associated genes

基于表型的基因下载器R:自动化多源检索和验证表型相关基因

Muhammad Muneeb, David B. Ascher

AI总结 本文提出PhenotypeToGeneDownloaderR,通过自动化基因检索、标准化和验证,生成候选基因集,用于下游优先级排序和解释。

Comments https://github.com/MuhammadMuneeb007/PhenotypeToGeneDownloaderR

详情
AI中文摘要

识别表型相关基因是构建聚类风险评分、富集检验、目标优先级排序和变异解释的常见第一步,但相关证据分布在异构数据库中,具有不同的接口、格式和证据模型。本文介绍了PhenotypeToGeneDownloaderR,一个以表型引导的R/Python管道,用于自动化基因检索、标准化、符号验证和跨源汇总分析。给定一个表型术语,该管道查询整合的生物数据库,标准化每个来源的输出,合并基因列表,验证检索到的符号与NCBI人类基因参考,并生成汇总表和可视化。在13个临床相关表型和13个数据库上,PhenotypeToGeneDownloaderR生成了136,487个原始基因检索,每个表型至少有一个来源返回基因。在所有13个表型中,114,345个输入符号中有100,175个经过直接或同义词验证后被保留,对应87.6%的验证率。跨源重叠较低,支持了整合证据源的互补性。与HPO/ClinVar/OMIM衍生的黄金标准相比,该管道恢复了1,039个已知的表型相关基因,对应98.4%的召回率。PhenotypeToGeneDownloaderR提供了一个轻量、可重复的上游框架,用于生成候选基因集,用于下游优先级排序和解释。该管道用R和Python实现,以MIT许可证发布,并可在https://github.com/MuhammadMuneeb007/PhenotypeToGeneDownloaderR上获得。

英文摘要

Identifying phenotype-associated genes is a common first step in polygenic risk score construction, enrichment testing, target prioritisation and variant interpretation, but relevant evidence is distributed across heterogeneous databases with different interfaces, formats and evidence models. Here, we present PhenotypeToGeneDownloaderR, a phenotype-guided R/Python pipeline for automated gene retrieval, harmonisation, symbol validation and cross-source summary analysis. Given a phenotype term, the pipeline queries integrated biological databases, standardises per-source outputs, combines gene lists, validates retrieved symbols against the NCBI human gene reference and generates summary tables and visualisations. Across 13 clinically relevant phenotypes and 13 databases, PhenotypeToGeneDownloaderR generated 136,487 raw gene retrievals, with at least one source returning genes for every phenotype. Across all 13 phenotypes, 100,175 of 114,345 combined input symbols were retained after direct or synonym-based validation, corresponding to an 87.6\% validation rate. Cross-source overlap was low, supporting the complementarity of integrated evidence sources. Against an HPO/ClinVar/OMIM-derived gold standard, the pipeline recovered 1,039 of 1,056 known phenotype-associated genes, corresponding to 98.4\% recall. PhenotypeToGeneDownloaderR provides a lightweight, reproducible upstream framework for generating candidate gene sets for downstream prioritisation and interpretation. The pipeline is implemented in R and Python, released under the MIT licence, and available at https://github.com/MuhammadMuneeb007/PhenotypeToGeneDownloaderR.