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2606.07764 2026-06-09 cs.CY 新提交

Reimagining Open Source and Openness in AI: Co-Creating Responsible Technological Futures

重新构想人工智能中的开源与开放性:共创负责任的科技未来

Genevieve Smith, Hiral Patel, Steven Luo, Monica G. Bobra, Judy Brewer, Cathryn Carson, Isadora Cruxen, Shachee Doshi, Maximilian Gahntz, Nicholas Garcia, Natalia Luka, Meredith M. Lee, Min Kyung Lee, Woohyeuk Lee, Jarrod Millman, Ricardo Miron Torres, Chinasa T. Okolo, Cailean Osborne, Derek Slater, Katie Steen-James, Nikko Stevens, Jennifer Tridgell, David Gray Widder

AI总结 通过多部门参与式研讨会,研究不同利益相关者如何共同理解与协商AI中的负责任开放性,识别出关于开放目的、范围与运作的四类核心张力,并提出行动路径与研究路线图。

Comments To appear in the 2026 ACM Conference on Fairness, Accountability, and Transparency (FAccT '26)

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AI中文摘要

随着政策制定者、研究人员和实践者努力解决基础模型应如何开发和治理以平衡创新、问责和公共利益的问题,关于人工智能中开源和开放性的辩论愈演愈烈。然而,关于不同利益相关者如何集体理解和协商AI中的负责任开放性,特别是通过超越行业主导定义和框架的参与式过程,实证研究仍然有限。本文介绍了一个基于未来思维和参与式设计方法的多部门研讨会的发现。该研讨会共同创造了关于理想未来及AI角色的愿景,以及一套行动路径和一个专注于AI中负责任开源和开放性的研究路线图。本文做出三项关键贡献。首先,它实证记录了共同创造的愿景、行动和研究优先事项。其次,它识别出参与者在将高层次愿望转化为具体行动时出现的四类核心张力,揭示了关于开放目的(作为目的还是手段)、范围(扩展还是有意义访问)以及运作(强制性还是条件性,充分性还是依赖于治理和使用)的相互矛盾的解释。这些张力表明,负责任开放性不是一个单一的技术解决方案,而是一个由价值观、立场和优先事项塑造的协商性社会技术项目。第三,本文通过展示参与式未来方法如何能够揭示超越主流(主要是企业)叙事的多元愿景、行动和研究优先事项,推进了AI治理中的方法论方法,为开放性、权力和问责在实践中如何被协商提供了实证见解。

英文摘要

Debates over open source and openness in artificial intelligence have intensified as policymakers, researchers, and practitioners grapple with how foundation models should be developed and governed to balance innovation, accountability, and public interest. However, there has been limited empirical work examining how diverse stakeholders collectively understand and negotiate responsible openness in AI, particularly through participatory processes that extend beyond industry-led definitions and frameworks. This paper presents findings from a multi-sectoral workshop grounded in futures thinking and participatory design methods. The workshop generated co-created visions of desirable futures and the role of AI, alongside a set of action pathways and a research roadmap focused on responsible open source and openness in AI. This paper makes three key contributions. First, it empirically documents the co-created visions, actions, and research priorities. Second, it identifies four core tensions that emerged as participants translated high-level aspirations into concrete actions, revealing conflicting interpretations of openness regarding its purpose (as an end or a means), its scope (expansion versus meaningful access), and its operation (mandatory versus conditional, sufficient versus dependent on governance and use). These tensions illustrate that responsible openness is not a singular technical solution, but a negotiated sociotechnical project shaped by values, positionalities, and priorities. Third, the paper advances methodological approaches in AI governance by demonstrating how participatory futures methods can surface plural visions, actions, and research priorities that extend beyond dominant, largely corporate, narratives, offering empirical insight into how openness, power, and accountability are negotiated in practice.

2606.07763 2026-06-09 physics.flu-dyn nlin.CD 新提交

Cascades in the Kinetic Equation for the Majda-McLaughlin-Tabak model

Majda-McLaughlin-Tabak模型动力学方程中的级联

Gregorio Tibone, Giorgio Krstulovic, Miguel Onorato

AI总结 通过数值模拟MMT模型的波动力学方程,验证了波湍流理论在参数空间内外的预测,并发现了一个新的稳定稳态,同时揭示了低维和高维系统中不可修复的发散。

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AI中文摘要

Majda-McLaughlin-Tabak (MMT) 模型族已被证明是波湍流理论的有效基准,因为测试理论思想所需的计算成本低,并且可以调节方程的非线性和色散特性。在这里,我们数值研究了与MMT模型相关的波动力学方程 (WKE),并进行模拟以研究湍流级联。我们在波动力学方程被证明适定的参数空间区域内外,数值验证了波湍流理论的预测。我们还观察到一个新的稳定稳态,位于预期没有级联解的区域,据我们所知,该区域以前未被探索过。此外,根据最近的工作,我们研究了波动力学方程的次主导阶修正;我们发现了在一维MMT模型中,以及更一般地在具有凹幂律色散关系的高维系统中,存在不可修复的发散。

英文摘要

The Majda-McLaughlin-Tabak (MMT) family of models has proven to be an efficient ground for benchmarking wave turbulence theory, thanks to the low computational cost required to test theoretical ideas and the possibility of tuning nonlinearity and dispersive properties of the equations. Here, we study numerically the wave kinetic equation (WKE) associated with the MMT model and perform simulations to study turbulent cascades. We confirm numerically the predictions of wave turbulence theory, both in the parameter space region where the wave kinetic equation was proven to be well posed and outside of it. We also observe a new stable stationary state in a region where no cascade solutions are expected, a region that, to the best of our knowledge, has not been explored before. Moreover, following recent work, we study next-to-leading-order corrections to the wave kinetic equation; we uncover incurable divergences in the one-dimensional MMT model and, more generally, in higher-dimensional systems with concave power-law dispersion relations.

2606.07761 2026-06-09 cs.CR cs.AR 新提交

ScaleDisturb: Exploiting Temporal Asymmetry to Amplify Read Disturbance in Modern DRAM Chips

ScaleDisturb:利用时间不对称性放大现代DRAM芯片中的读干扰

Jikun Wang, Haocong Luo, Ataberk Olgun, İsmail Emir Yüksel, A. Giray Yağlıkçı, Yu Liang, F. Nisa Bostancı, Mohammad Sadrosadati, Onur Mutlu

AI总结 提出一种新的DRAM访问模式ScaleDisturb,通过不对称延长两个攻击行的打开时间放大读干扰,在更少的行激活次数下引发比特翻转,并降低攻击难度。

Comments To appear in DSN 2026

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AI中文摘要

DRAM遭受读干扰现象(例如RowHammer和RowPress),其中重复访问或持续保持打开一个DRAM行(攻击行)会在其他物理上邻近的未访问行(受害行)中诱发比特翻转。这种干扰机制在软件栈中实际可利用,并随着密度持续缩放而在代际间恶化。DRAM读干扰对内存访问模式高度敏感,然而先前的工作仅在有限的访问模式集合下探索读干扰。我们提出ScaleDisturb,一种新的DRAM访问模式,通过不对称地延长两个攻击行的打开时间来放大DRAM读干扰。我们对196个DDR4和3个HBM2 DRAM芯片的严格实验表征表明,ScaleDisturb (1) 与最先进的内存访问模式相比,在显著更少的行激活次数下导致比特翻转,(2) 使所有测试的DRAM芯片上的读干扰攻击更容易,(3) 随着DRAM制造技术缩小到更小的节点尺寸,增加DRAM对读干扰的脆弱性。我们展示了一个真实系统上的概念验证攻击,其中利用ScaleDisturb的用户级程序比最先进的RowHammer和RowPress内存访问模式诱导更多的比特翻转。我们描述并评估了四种在ScaleDisturb存在下缓解读干扰比特翻转的解决方案,并呼吁对此主题进行更多研究。

英文摘要

DRAM suffers from read disturbance phenomena (e.g., RowHammer and RowPress), where repeatedly accessing or continuously keeping open a DRAM row (aggressor row) induces bitflips in other physically nearby unaccessed rows (victim rows). The disturbance mechanism is practically exploitable from the software stack and worsens across generations with continued density scaling. DRAM read disturbance is highly sensitive to memory access patterns, yet prior work explores read disturbance under only a limited set of access patterns. We present ScaleDisturb, a new DRAM access pattern that can amplify DRAM read disturbance by asymmetrically extending the open time of two aggressor rows. Our rigorous experimental characterization of 196 DDR4 and 3 HBM2 DRAM chips shows that ScaleDisturb (1) leads to bitflips at significantly fewer row activations, compared to state-of-the-art memory access patterns, (2) makes read disturbance attacks easier across all tested DRAM chips, (3) increases DRAM vulnerability to read disturbance as DRAM manufacturing technology scales down to smaller node sizes. We showcase a proof-of-concept attack on a real system where a user-level program leveraging ScaleDisturb induces more bitflips than state-of-the-art RowHammer and RowPress memory access patterns. We describe and evaluate four solutions for mitigating read disturbance bitflips in the presence of ScaleDisturb and call for more research on the topic.

2606.07759 2026-06-09 astro-ph.IM 新提交

SynIM: a high-performance GPU-accelerated Python library for synthetic interaction and tomographic reconstruction matrices in next-generation adaptive optics

SynIM:用于下一代自适应光学中合成交互与断层重建矩阵的高性能GPU加速Python库

Guido Agapito, Fabio Rossi, Alfio Puglisi

AI总结 提出SynIM库,利用GPU加速和亚像素对齐技术,高效计算高保真合成矩阵,在MCAO模拟中实现与全物理光学模型等效的闭环性能。

Comments 9 pages, 2 figures. Submitted to SPIE Astronomical Telescopes + Instrumentation 2026, Conference 14150: Adaptive Optics Systems X

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AI中文摘要

下一代自适应光学(AO)系统,如MORFEO(ELT)和MAVIS(VLT),用于8-40米级望远镜,要求高校准精度。控制数千个执行器使得实验校准因白天开销、环境干扰和光机像差而不可行。因此,基于模型(合成)校准已成为强制性标准。我们提出SynIM,一个开源Python库,用于计算高保真合成交互、投影和协方差矩阵。SynIM通过CuPy利用GPU加速处理高阶系统的巨大维度。其核心创新是通过复合仿射变换和绝对亚像素网格对齐处理空间几何。通过将DM和WFS的偏移、旋转和放大合并为单一操作,SynIM最小化插值伪影。SynIM引入了一个优化的数值导数引擎用于斜率计算,该引擎在亚像素级别数学上对齐空间网格,紧密模拟Shack-Hartmann传感器的物理行为。在高空间频率下,它优于几何估计器(如G-tilt telescoping sum),同时带来显著的计算加速。关键的是,端到端MCAO模拟表明,使用SynIM构建的重建器提供的闭环AO性能与全物理光学模型几乎等效。SynIM原生支持SCAO、GLAO、MCAO和LTAO配置。它具有优化的多WFS批处理、MMSE断层重建器模块,并与SPRINT完全兼容用于在线跟踪。目前驱动MORFEO、MAVIS、AOF、KAPA和WST的设计和运行策略,SynIM是下一代AO校准的重要工具。

英文摘要

Next-generation Adaptive Optics (AO) systems for 8-40m class telescopes, such as MORFEO (ELT) and MAVIS (VLT), demand high calibration accuracy. Controlling thousands of actuators makes experimental calibration unfeasible due to daytime overheads, environmental disturbances, and opto-mechanical aberrations. Consequently, model-based (synthetic) calibration has become the mandatory standard. We present SynIM, an open-source Python library designed for computing high-fidelity synthetic Interaction, Projection, and Covariance Matrices. SynIM leverages GPU acceleration via CuPy to handle the massive dimensionality of high-order systems. A core innovation is its handling of spatial geometry via composite affine transformations and absolute sub-pixel grid alignment. By merging DM and WFS shifts, rotations, and magnifications into a single operation, SynIM minimizes interpolation artifacts. SynIM introduces an optimized numerical derivative engine for slope computation that mathematically aligns spatial grids at the sub-pixel level, closely mimicking the physical behavior of Shack-Hartmann sensors. It outperforms geometric estimators like the G-tilt telescoping sum at high spatial frequencies, while yielding a substantial computational speed-up. Crucially, end-to-end MCAO simulations demonstrate that reconstructors built with SynIM deliver closed-loop AO performance practically equivalent to full physical optics models. SynIM natively supports SCAO, GLAO, MCAO, and LTAO configurations. It features optimized multi-WFS batch processing, modules for MMSE tomographic reconstructors, and full compatibility with SPRINT for online tracking. Currently driving the design and operational strategies for MORFEO, MAVIS, AOF, KAPA, and WST, SynIM stands as an essential tool for next-generation AO calibration.

2606.07758 2026-06-09 eess.SY cs.SY math.OC 新提交

Koopman meets input-output data: Data-driven output-feedback control of nonlinear systems with closed-loop guarantees

Koopman遇见输入输出数据:具有闭环保证的非线性系统数据驱动输出反馈控制

Robin Strässer, Julian Berberich, Manuel Schaller, Karl Worthmann, Frank Allgöwer

AI总结 针对非线性系统,提出一种仅利用输入输出测量数据、无需状态测量的输出反馈控制器设计方法,结合Koopman算子理论与扩展状态表示,实现闭环指数稳定。

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AI中文摘要

从输入输出测量数据中数据驱动控制非线性系统仍然是一个基本挑战,因为现有具有严格闭环保证的方法主要需要访问完整的状态测量。在本文中,我们通过提出一种用于非线性系统的数据驱动输出反馈控制器设计方法来解决这一差距,该方法在仅基于测量的输入输出数据操作的同时提供可证明的闭环保证。我们的方法将Koopman算子理论与从输入输出轨迹构建的非线性系统的扩展状态表示相结合。这使得我们能够直接从数据中获得双线性代理模型,在该模型上可以应用鲁棒状态反馈设计方法。通过利用底层非线性系统的可观测性,我们建立了扩展状态的指数稳定性,这反过来意味着原始系统状态指数收敛到原点。最后,我们在数值模拟中验证了我们的理论发现。

英文摘要

Data-driven control of nonlinear systems from input-output measurements remains a fundamental challenge, as existing approaches with rigorous closed-loop guarantees predominantly require access to full state measurements. In this paper, we address this gap by proposing a data-driven output-feedback controller design method for nonlinear systems that provides provable closed-loop guarantees while operating solely on measured input-output data. Our approach combines Koopman operator theory with an extended state representation of the nonlinear system constructed from input-output trajectories. This allows us to obtain a bilinear surrogate model directly from data, on which robust state-feedback design methods can be applied. By exploiting the observability of the underlying nonlinear system, we establish exponential stability of the extended state, which in turn implies exponential convergence of the original system state to the origin. Finally, we validate our theoretical findings in numerical simulations.

2606.07757 2026-06-09 math.PR cond-mat.stat-mech 新提交

REM universality and Poisson-Dirichlet Gibbs weights for linear random energy

线性随机能量的REM普适性与Poisson-Dirichlet Gibbs权重

Francesco Concetti, Simone Franchini

AI总结 研究线性随机能量模型的REM普适性,证明经独立稀疏化后能量水平收敛到指数强度的泊松点过程,并识别Gibbs权重收敛到Poisson-Dirichlet分布,淬火自由能出现冻结相变。

Comments 5 pages, 1 figure

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AI中文摘要

我们研究哈密顿量 $H_n(h,σ)=\sum_{i=1}^n h_i(σ_i-m)$,其中 $(h_i)$ 是独立同分布的实随机变量,$(σ_i)$ 是独立同分布的伊辛自旋。我们考虑经过独立稀疏化后保留指数数量($e^{O(n)}$)构型的能级。我们证明,在依赖于 $(h_i)$ 的中心化后,所得点过程依分布收敛到具有指数强度的泊松点过程。因此,能级渐近地具有随机能量模型(REM)的能级。我们的结果扩展了先前的结果,其中该模型的REM普适性仅针对 $e^{-O(n)}$ 量级的能量涨落或随机选择的 $e^{o(\sqrt n)}$ 个构型建立。我们还识别了极限Gibbs权重,它收敛到Poisson-Dirichlet分布,以及淬火自由能,它在 $β=\tildeλ$ 处表现出冻结相变。证明以压缩形式给出;完整细节见伴随预印本。

英文摘要

We study the Hamiltonian $H_n(h,σ)=\sum_{i=1}^n h_i(σ_i-m), $ where $(h_i)$ are i.i.d.\ real random variables and $(σ_i)$ are i.i.d.\ Ising spins. We consider the energy levels obtained after an independent thinning that retains an exponential number of configurations ($e^{O(n)}$). We prove that, after an $(h_i)$-dependent centering, the resulting point process converges in distribution to a Poisson point process with exponential intensity. Thus, the energy levels asymptotically has the one of the Random Energy Model (REM). Our results extend previous ones, where REM universality for this model was established only either for energy fluctuations of order $e^{-O(n)}$ or for $e^{o(\sqrt n)}$ randomly selected configurations. We also identify the limiting Gibbs weights, which converge to a Poisson--Dirichlet law, and the quenched free energy, which exhibits a freezing transition at $β=\tildeλ$. The proofs are presented here in compressed form; full details are given in the companion preprint.

2606.07755 2026-06-09 astro-ph.IM 新提交

MORFEO wavefront error budget

MORFEO波前误差预算

Guido Agapito, Lorenzo Busoni, Cédric Plantet, Giulia Carlà, Jean-Pierre Véran

AI总结 本文介绍了MORFEO(ELT多共轭自适应光学中继)的波前误差预算结构,详细分析了大气湍流、光学表面等主要误差源,并用于支持端到端模拟和科学能力评估。

Comments 9 pages, 3 figures, 3 tables. Submitted to Adaptive Optics for Extremely Large Telescopes 8, October 27 to 31, 2025 Viña del Mar, Chile

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AI中文摘要

MORFEO(用于ELT观测的多共轭自适应光学中继,原名MAORY)是ESO极大望远镜(ELT)的多共轭自适应光学模块,旨在为其首光相机MICADO在近红外波段提供衍射极限性能。凭借其12个波前传感器和三个变形镜,MORFEO成为有史以来为天文观测开发的最大、最复杂的自适应光学系统。其设计和验证的一个关键方面是构建全面的波前误差(WFE)预算,该预算定义了系统在各种运行条件下的预期性能。在这项工作中,我们介绍了MORFEO WFE预算的结构,详细说明了残余误差的主要贡献者以及评估每个项所采用的方法。分析包括大气湍流、光学表面、对准公差、控制残差和校准不确定性的贡献。我们还讨论了推导预算时使用的外部条件、系统配置和关键假设,强调了需求与仪器设计选择之间的相互作用。重要的是,由此产生的误差预算正被用于支持MORFEO辅助观测的端到端模拟,为评估系统的科学能力和指导未来观测策略的定义提供必要输入。

英文摘要

MORFEO (Multi-conjugate adaptive Optics Relay For ELT Observations, formerly MAORY) is the multi-conjugate adaptive optics module of the ESO Extremely Large Telescope (ELT), designed to deliver diffraction-limited performance in the near-infrared for its first-light camera MICADO. With its 12 wavefront sensors and three deformable mirrors, MORFEO stands as the largest and most complex adaptive optics system ever developed for astronomical observations. A key aspect of its design and verification is the construction of a comprehensive wavefront error (WFE) budget, which defines the system's expected performance under a range of operating conditions. In this work, we present the structure of the MORFEO WFE budget, detailing the main contributors to the residual error and the methodology adopted to evaluate each term. The analysis includes contributions from atmospheric turbulence, optical surfaces, alignment tolerances, control residuals, and calibration uncertainties. We also discuss the external conditions, system configurations, and key assumptions used in the derivation of the budget, highlighting the interplay between requirements and instrument design choices. Importantly, the resulting error budget is being used to support end-to-end simulations of MORFEO-assisted observations, providing essential input for assessing the scientific capabilities of the system and guiding the definition of future observing strategies.

2606.07754 2026-06-09 nucl-ex nucl-th 新提交

Short-range correlated pair formation and nuclear shell structure

短程关联对形成与核壳层结构

D. Nguyen, C. Yero, H. Szumila-Vance, F. Hauenstein, N. Swan, L. B. Weinstein, J. Kahlbow, A. Schmidt, E. Piasetzky, O. Hen, C. Ayerbe Gayoso, E. Cohen, P. Datta, A. Denniston, B. R. Devkota, M. Diefenthaler, C. Fogler, B. R. Gamage, D. Higinbotham, I. Korover, C. Morean, M. Nycz, M. Satnik, S. Seeds, P. Sharp, M. Suresh, A. S. Tadepalli, R. Wagner, E. W. Wertz

AI总结 通过电子散射实验测量不同核素的高缺失动量质子,发现短程关联质子对形成概率不仅依赖于核不对称性,还显著受核壳层结构影响,且随质量数A增加的趋势在不同壳层区域斜率不同。

Comments 5 pages, 3 figures, to be submitted to Physics Review Letters

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AI中文摘要

短程关联(SRC)核子对——由两个核子之间的短暂高动量相互作用引起——主要由相对动量较大、质心动量较小的中子-质子对主导。然而,决定哪些核子形成此类对的潜在动力学仍不确定。先前的测量表明,质子配对概率随核不对称性N/Z强烈增加,但无法排除其随核质量A增加的可能性。我们测量了从一系列具有不同壳层构型、A和N/Z的选定核(包括9Be、10B、11B、12C、40Ca、48Ca、54Fe和197Au)中通过电子散射敲出的高缺失动量质子。出乎意料的是,我们发现虽然配对概率随A增加,但增加的斜率从Be到C以及从40Ca到Fe远大于从Be到Au。这表明长程核壳层结构对短程核子配对概率的重要性。

英文摘要

Short-range correlated (SRC) nucleon pairs - caused by brief, high-momentum interactions between two nucleons - are dominated by neutron-proton pairs with large relative and smaller center-of-mass momenta. However, the underlying dynamics that determines which nucleons form such pairs remains uncertain. Previous measurements showed that proton pairing probabilities increased strongly with nuclear asymmetry N/Z, but could not rule out an increase with nuclear mass A. We measured high-missing-momentum protons knocked out in electron scattering from selected nuclei with a range of shell configurations, A, and N/Z, including 9Be, 10B, 11B, 12C, 40Ca, 48Ca, 54Fe and 197Au. Unexpectedly, we found that while the pairing probability increased with A, the slope of the increase was much greater from Be to C and from 40Ca to Fe, than from Be to Au. This shows the importance of long-range nuclear shell structure on the probability of short-range nucleon pairing.

2606.07752 2026-06-09 cond-mat.mes-hall cond-mat.quant-gas cond-mat.str-el quant-ph 新提交

Detecting Exciton Condensation through Charge Transport in Semiconductor Heterostructures

通过半导体异质结构中的电荷输运检测激子凝聚

Caterina Zerba, Léo Mangeolle, Michael Knap

AI总结 提出利用掺杂载流子的电荷输运探测过渡金属硫族化物异质结构中的激子凝聚,发现电阻率降低和霍尔电阻率符号反转等独特实验特征。

Comments 6+7 pages, 3+1 figures

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AI中文摘要

半导体异质结构中激子凝聚的直接证据仍然难以捉摸。这里我们提出将掺杂载流子的电荷输运作为过渡金属硫族化物异质结构中激子凝聚的探针,并识别出独特的实验特征。首先,凝聚抑制了载流子散射的相空间,导致电阻率降低,这为激子凝聚提供了一个通用的诊断方法。其次,在具有可调固态Feshbach共振的异质结构中,凝聚诱导的掺杂载流子与三子束缚态之间的杂化定性改变了输运性质。特别是,在共振附近,这种杂化产生了负有效质量以及相应的霍尔电阻率符号反转。这些结果确立了电荷输运作为检测和表征半导体异质结构中激子凝聚的一种有前景的途径。

英文摘要

Direct evidence of exciton condensation in semiconductor heterostructures remains elusive. Here we propose charge transport of doped carriers as a probe of exciton condensation in transition-metal dichalcogenide heterostructures and identify distinct experimental signatures. First, condensation suppresses the phase space for carrier scattering, leading to a reduction in resistivity, that provides a general diagnostic of exciton condensation. Second, in heterostructures with a tunable solid-state Feshbach resonance, condensate-induced hybridization between doped carriers and trion bound states qualitatively modifies transport. In particular, near resonance, this hybridization yields a negative effective mass and a corresponding sign reversal of the Hall resistivity. These results establish charge transport as a promising route for detecting and characterizing exciton condensation in semiconductor heterostructures.

2606.07750 2026-06-09 astro-ph.GA 新提交

Euclid Quick Data Release (Q1): The impact of AGN emission on SED-derived physical properties

欧几里得快速数据发布(Q1):AGN发射对SED导出的物理性质的影响

Euclid Collaboration, B. Laloux, A. Bongiorno, M. Salvato, V. Allevato, M. Mezcua, W. Roster, T. Matamoro Zatarain, S. Paltani, R. Shirley, F. Tarsitano, C. Saulder, S. Fotopoulou, C. Andonie, J. Buchner, F. La Franca, V. Le Brun, F. Ricci, D. Scott, F. Shankar, M. Siudek, J. G. Sorce, L. Spinoglio, Y. Toba, A. Viitanen, L. Wang, G. Zamorani, S. Andreon, N. Auricchio, C. Baccigalupi, M. Baldi, A. Balestra, S. Bardelli, P. Battaglia, A. Biviano, M. Bolzonella, E. Branchini, M. Brescia, S. Camera, G. Cañas-Herrera, V. Capobianco, C. Carbone, J. Carretero, S. Casas, M. Castellano, G. Castignani, S. Cavuoti, K. C. Chambers, A. Cimatti, C. Colodro-Conde, G. Congedo, C. J. Conselice, L. Conversi, Y. Copin, A. Costille, F. Courbin, H. M. Courtois, M. Cropper, A. Da Silva, H. Degaudenzi, G. De Lucia, H. Dole, F. Dubath, C. A. J. Duncan, X. Dupac, S. Escoffier, M. Fabricius, M. Farina, R. Farinelli, S. Ferriol, F. Finelli, P. Fosalba, N. Fourmanoit, M. Frailis, E. Franceschi, M. Fumana, L. Gabarra, S. Galeotta, K. George, B. Gillis, C. Giocoli, J. Gracia-Carpio, A. Grazian, F. Grupp, S. Gwyn, S. V. H. Haugan, H. Hoekstra, W. Holmes, F. Hormuth, A. Hornstrup, K. Jahnke, M. Jhabvala, B. Joachimi, S. Kermiche, A. Kiessling, B. Kubik, M. Kümmel, M. Kunz, H. Kurki-Suonio, A. M. C. Le Brun, S. Ligori, P. B. Lilje, V. Lindholm, I. Lloro, M. Magliocchetti, G. Mainetti, D. Maino, E. Maiorano, O. Mansutti, S. Marcin, O. Marggraf, M. Martinelli, N. Martinet, F. Marulli, R. J. Massey, N. Mauri, E. Medinaceli, S. Mei, Y. Mellier, M. Meneghetti, E. Merlin, G. Meylan, P. Monaco, A. Mora, M. Moresco, C. Moretti, L. Moscardini, R. Nakajima, C. Neissner, R. C. Nichol, S. -M. Niemi, C. Padilla, F. Pasian, K. Pedersen, W. J. Percival, V. Pettorino, A. Pezzotta, S. Pires, G. Polenta, M. Poncet, L. A. Popa, C. Porciani, L. Pozzetti, G. D. Racca, F. Raison, A. Renzi, J. Rhodes, G. Riccio, I. Risso, E. Romelli, M. Roncarelli, R. Saglia, Z. Sakr, D. Sapone, B. Sartoris, P. Schneider, T. Schrabback, M. Scodeggio, A. Secroun, G. Seidel, S. Serrano, E. Sihvola, P. Simon, C. Sirignano, G. Sirri, J. Steinwagner, P. Tallada-Crespí, A. N. Taylor, I. Tereno, N. Tessore, S. Toft, R. Toledo-Moreo, F. Torradeflot, I. Tutusaus, L. Valenziano, J. Valiviita, T. Vassallo, A. Veropalumbo, Y. Wang, J. Weller, A. Zacchei, E. Zucca, M. Ballardini, E. Bozzo, C. Burigana, R. Cabanac, M. Calabrese, A. Cappi, T. Castro, J. A. Escartin Vigo, J. García-Bellido, R. Maoli, J. Martín-Fleitas, M. Maturi, R. B. Metcalf, M. Pöntinen, V. Scottez, M. Sereno, M. Tenti, M. Viel, M. Wiesmann, Y. Akrami, I. T. Andika, G. Angora, S. Anselmi, M. Archidiacono, F. Atrio-Barandela, L. Bazzanini, D. Bertacca, M. Bethermin, L. Bisigello, A. Blanchard, L. Blot, M. Bonici, M. L. Brown, S. Bruton, A. Calabro, B. Camacho Quevedo, F. Caro, C. S. Carvalho, F. Cogato, S. Conseil, A. R. Cooray, S. Davini, F. De Paolis, G. Desprez, A. Díaz-Sánchez, S. Di Domizio, J. M. Diego, M. Y. Elkhashab, A. Enia, Y. Fang, A. Finoguenov, F. Fontanot, A. Franco, T. Gasparetto, E. Gaztanaga, F. Giacomini, F. Gianotti, G. Gozaliasl, M. Guidi, C. M. Gutierrez, A. Hall, C. Hernández-Monteagudo, H. Hildebrandt, J. Hjorth, L. K. Hunt, J. J. E. Kajava, Y. Kang, V. Kansal, D. Karagiannis, K. Kiiveri, J. Kim, C. C. Kirkpatrick, S. Kruk, M. Lattanzi, L. Legrand, F. Lepori, G. Leroy, G. F. Lesci, J. Lesgourgues, L. Leuzzi, T. I. Liaudat, S. J. Liu, X. Lopez Lopez, J. Macias-Perez, E. A. Magnier, C. Mancini, A. Manjón-García, F. Mannucci, C. J. A. P. Martins, L. Maurin, M. Miluzio, A. Montoro, G. Morgante, C. Murray, S. Nadathur, K. Naidoo, P. Natoli, A. Navarro-Alsina, S. Nesseris, D. Paoletti, F. Passalacqua, K. Paterson, A. Pisani, D. Potter, G. W. Pratt, S. Quai, M. Radovich, G. Rodighiero, K. Rojas, S. Sacquegna, M. Sahlén, D. B. Sanders, E. Sarpa, A. Schneider, D. Sciotti, E. Sellentin, L. C. Smith, K. Tanidis, C. Tao, G. Testera, R. Teyssier, S. Tosi, A. Troja, M. Tucci, A. Venhola, D. Vergani, G. Verza, P. Vielzeuf, S. Vinciguerra, N. A. Walton

AI总结 利用欧几里得近红外测光和多成分SED拟合,提出量化AGN和宿主星系物理参数可靠性的新方法,应用于约100万Q1 AGN候选体,构建了含可靠性值的属性星表。

Comments accepted in A&A, 27 pages, 16 figures

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AI中文摘要

欧几里得快速数据发布(Q1)是研究活动星系核(AGN)及其宿主星系的强大数据集。通过多成分光谱能量分布(SED)拟合推导其物理性质对AGN而言是一项具有挑战性的任务,但欧几里得近红外测光极大地促进了这一工作。这里我们提出一种新方法,通过结合QSO和星系的观测SED构建AGN的模拟SED,来量化SED导出参数(如AGN的bolometric和单色光度、宿主恒星质量$M_\star$、恒星形成率(SFR)和比恒星形成率(sSFR))的可靠性。我们将该方法应用于约100万个Q1 AGN候选体,构建了一个AGN和宿主星系属性的星表,并附有各自的可靠性值。在可靠性阈值为0.5时,我们发现88%的源具有稳健的恒星质量,76%具有可靠的AGN光度。此外,通过SED拟合,我们还测量了总中红外通量中的AGN比例$f_{\rm AGN}$,并使用其下限选择AGN。$f_{\rm AGN, \\, low} > 0.075$的阈值产生了85%的完备性和纯净度。与颜色-颜色AGN选择相比,该方法受红移演化影响较小,并能探测更暗的星等。此外,通过比较不同识别方法下的AGN和宿主星系参数,我们发现所探测的恒星质量和AGN光度范围可能相当不同。这凸显了在研究AGN及其在星系演化中的作用时,结合不同方法并考虑其选择偏差的重要性。最后,对于X射线探测样本,我们展示了X射线与中红外光度关系,以及恒星质量与bolometric光度随红移的相关性,与先前结果吻合良好。

英文摘要

The Euclid Quick Data Release (Q1) is a powerful dataset to study active galactic nuclei (AGN) and their host galaxies. Deriving their physical properties through multi-component spectral energy distribution (SED) fitting is a challenging task for AGN, but it is greatly aided by the Euclid near-infrared photometry. Here we present a new method to quantify the reliability of SED-derived parameters, such as AGN bolometric and monochromatic luminosities, host's stellar mass $M_\star$, star-formation rate (SFR) and specific star-formation rate (sSFR), by using mock SEDs of AGN built by combining observed SEDs of QSOs and galaxies. We apply this methodology to the ${\sim}1$ million Q1 AGN candidates, constructing a catalogue of AGN and host galaxy properties, alongside their respective reliability values. With a reliability threshold at 0.5, we find 88\% of sources with robust stellar masses and 76\% with reliable AGN luminosities. Moreover, through SED fitting we also measure the AGN fraction $f_{\rm AGN}$ of the total mid-infrared flux and we use its lower-limit to select AGN. A $f_{\rm AGN, \, low} > 0.075$ threshold yields 85\% completeness and purity. Comparable to colour-colour AGN selections, this method has the advantage of being less affected by redshift evolution and exploring fainter magnitudes. Additionally, by comparing the AGN and host galaxy parameters across different identification methods, we find that the probed range in stellar mass and AGN luminosity can be quite different. This highlights the importance of combining different approaches and accounting for their selection biases when studying AGN and their role in galaxy evolution. Finally, for the X-ray detected sample, we present the X-ray to mid-IR luminosity relation, and the correlation between stellar mass and bolometric luminosity as a function of redshift, in good agreement with previous results.

2606.07749 2026-06-09 hep-ph 新提交

Flavor phenomenology of light dark particles

轻暗粒子的味现象学

Robert Ziegler

AI总结 综述亚GeV类轴子粒子在味破坏耦合下的产生与探测,强调味物理在探索轻暗物质中的核心作用,并给出实验室、天体物理和宇宙学约束的综合调查。

Comments 85 + 22 pages, review article

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AI中文摘要

我们回顾了轻暗粒子的味现象学,重点关注具有亚GeV质量和一般味破坏耦合的类轴子粒子。这样的态可以自然地来自一般味对称性的自发破缺,并且由暗物质或强CP问题所驱动,其中QCD轴子作为一个典型例子。轻暗粒子可以在标准模型粒子的两体衰变中产生,产生缺失能量信号,这些信号不仅可以在高精度味实验中观测到,还可以在核心坍缩超新星和宇宙微波背景中探测到。这些衰变由维度-5算符控制,这使得专门的实验室搜索对高达$10^{12} {\rm GeV}$的非常大紫外标度敏感,因此与天体物理和宇宙学探测高度互补。我们提供了所有相关通道中所得限制和前景的全面调查,强调了味物理在探索轻暗物质景观中的核心作用。

英文摘要

We review the flavor phenomenology of light dark particles, focusing on axion-like particles with sub-GeV masses and generic flavor-violating couplings. Such states can naturally emerge from the spontaneous breaking of generic flavored symmetries, and are motivated by dark matter or the Strong CP Problem, with the QCD axion serving as a paradigmatic example. Light dark particles can be produced in two-body decays of Standard Model particles, giving rise to missing energy signals that can not only be observed in high-precision flavor experiments, but also be probed in core-collapse supernovae and the cosmic microwave background. These decays are controlled by dimension-five operators, which makes dedicated laboratory searches sensitive to very large UV scales up to $10^{12} {\rm GeV}$ and thus highly complementary to astrophysical and cosmological probes. We provide a comprehensive survey of the resulting limits and prospects across all relevant channels, highlighting the central role of flavor physics in exploring the landscape of light dark matter.

2606.07748 2026-06-09 math.CO cs.DM 新提交

Decomposing tournaments into comparability graphs

将锦标赛分解为可比图

Pierre Aboulker, Logan Crew, Julien Duron, Xinyue Fan, Hugo Jacob, Rémy Kimbrough, Hidde Koerts, Benjamin Moore, Sophie Spirkl, Stéphan Thomassé

AI总结 引入有向图的偏序分解数pod,证明dic(D) ≤ diomega(D)^{pod(D)},并应用于锦标赛,得到多项式dic有界性,解决相关问题。

Comments 10

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AI中文摘要

在这篇笔记中,我们引入了有向图 $D$ 的\emph{偏序分解数},记作 $pod(D)$,定义为最小的整数 $k$,使得 $A(D)=A(P_1)\cup\cdots\cup A(P_k)$,其中 $P_1,\ldots,P_k$ 是 $V(D)$ 上的偏序。我们证明了对每个有向图 $D$,有 $\dic(D)\le \diomega(D)^{pod(D)}$。特别地,每个具有有界 $pod$ 的有向图类都是多项式 $\dic$ 有界的。我们将此应用于锦标赛,证明如果 $\mathcal C$ 是一个具有有界二色数的锦标赛类,那么 $\mathcal C$ 在替换下的闭包是多项式 $\dic$ 有界的,从而推进了 Aubian、Charbit、Lopes 和第一作者提出的问题。作为 $pod$ 的进一步应用,我们证明了有界维数的偏序锦标赛是 $\dic$ 有界的,推导了一个显式锦标赛族的有向团数的多项式下界,从而回答了 Gutowski 和 Rams 的一个猜想,并证明了具有有界 $pod$ 的锦标赛具有有界支配数。

英文摘要

In this note, we introduce the \emph{partial order decomposition number} of a digraph $D$, denoted $pod(D)$, defined as the minimum integer $k$ such that $A(D)=A(P_1)\cup\cdots\cup A(P_k)$, where $P_1,\ldots,P_k$ are partial orders on $V(D)$. We prove that $\dic(D)\le \diomega(D)^{pod(D)}$ for every digraph $D$. In particular, every class of digraphs with bounded $pod$ is polynomially $\dic$-bounded. We apply this to tournaments, showing that if $\mathcal C$ is a class of tournaments with bounded dichromatic number, then the closure of $\mathcal C$ under substitution is polynomially $\dic$-bounded, thereby making progress on a question of Aubian, Charbit, Lopes, and the first author. As further applications of $pod$, we prove that poset tournaments of bounded dimension are $\dic$-bounded, derive polynomial lower bounds on the directed clique number of an explicit family of tournaments, thereby answering a conjecture of Gutowski and Rams, and show that tournaments with bounded $pod$ have bounded domination number.

2606.07745 2026-06-09 astro-ph.CO astro-ph.IM 新提交

CMBolic: Symbolic emulators for the Cosmic Microwave Background. I. Lensing

CMBolic:宇宙微波背景的符号仿真器。I. 透镜效应

David M. J. Vokrouhlicky, Constantinos Skordis, Deaglan J. Bartlett, Harry Desmond, Pedro G. Ferreira

AI总结 提出CMBolic符号仿真器,通过解析函数模拟CMB透镜势功率谱,在扩展ΛCDM模型中达到与神经网络仿真器相当的精度,并将贝叶斯参数估计运行时间从2周缩短至3分钟。

Comments 14 pages, 9 figures. Code available at https://github.com/dvokrouhlicky/CMBolic

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AI中文摘要

我们展示了CMBolic的第一部分:一套符号宇宙微波背景(CMB)仿真器。在此实例中,我们模拟了广泛使用的扩展ΛCDM模型的CMB透镜势功率谱$C_\ell^{ϕϕ}$,该模型同时包含大质量中微子和使用Chevallier-Polarski-Linder(CPL)参数化建模的演化暗能量。我们实现了与现有神经网络仿真器相当的精度,并且由于我们的仿真器是模型参数和多极$\ell$的解析函数,因此具有更易处理的额外优势。在$2\leq \ell \leq 5500$范围内评估的独立验证谱上,CMBolic在ΛCDM子空间实现了$0.27\\%$的平均绝对分数误差,在整个扩展参数空间实现了$0.32\\%$。该仿真误差远低于CMB第四代实验最乐观的噪声预测。我们使用ACT DR6和Planck的仅透镜似然函数,将CMBolic应用于贝叶斯推断的宇宙学参数估计。我们展示了CMBolic与玻尔兹曼代码CLASS获得的后验分布之间的极好一致性。这证明了CMBolic在宇宙学参数估计中的实际用途,将运行时间从2周减少到不到3分钟。

英文摘要

We present the first installment of CMBolic: a suite of symbolic cosmic microwave background (CMB) emulators. In this instance, we emulate the CMB lensing potential power spectrum $C_\ell^{ϕϕ}$ for the widely used extended $Λ$CDM model which simultaneously includes massive neutrinos and evolving dark energy modelled using the Chevallier-Polarski-Linder (CPL) parameterization. We achieve comparable precision to existing neural network emulators, with the added benefit of simpler handling as our emulators are analytic functions of the model parameters and multipole $\ell$. On independent validation spectra evaluated in the range $2\leq \ell \leq 5500$, CMBolic achieves mean absolute fractional errors of $0.27\%$ in the $Λ$CDM subspace and $0.32\%$ across the full extended parameter space. This emulation error is well below even the most optimistic noise forecasts from CMB Stage 4 experiments. We apply CMBolic to cosmological parameter estimation with Bayesian inference using the lensing-only likelihoods from ACT DR6 and Planck. We show excellent agreement between the posteriors obtained by CMBolic and the Boltzmann code CLASS. This demonstrates the practical use of CMBolic on cosmological parameter estimation, reducing the runtime from 2 weeks to under 3 minutes.

2606.07744 2026-06-09 hep-ph nucl-th 新提交

Open quantum system approach to the transverse momentum broadening of a colour dipole

开放量子系统方法研究颜色偶极子的横向动量展宽

François Arleo, Pietro Benzoni, Paul Caucal, Pol Bernard Gossiaux

AI总结 利用开放量子系统形式,研究夸克-反夸克对在稠密QCD等离子体中的传播,推导出Lindblad演化方程,发现准因子化行为,并阐明颜色退相干的关键角度与时间。

Comments 62 pages, 9 figures

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AI中文摘要

利用开放量子系统形式,我们研究了一个夸克-反夸克对在大小为$L$、横向动量展宽输运系数为$\hat q$的稠密QCD等离子体中的传播,并推导了系统密度矩阵的Lindblad演化方程。我们关注的是该有效颜色偶极子的开角$θ_{q\bar q}$满足$θ_{q\bar q}\ll 1$的增强区域。在夸克-反夸克相对横向动量$p_\perp$远大于不平衡$q_\perp$以及介质典型横向动量尺度$Q_s=\sqrt{\hat q L}$的关联极限下,我们证明得到的Wigner分布表现出准因子化:一个描述产生$q\bar q$对的硬劈裂的硬因子与描述介质诱导展宽的横向动量不平衡$q_\perp$分布之间的因子化。该因子化被一个“颜色退相干”因子破坏,该因子通过比值$θ_{q\bar q}/θ_c$控制$q_\perp$分布对$θ_{q\bar q}$的依赖,其中$θ_c \sim (\hat q L^3)^{-1/2}$。开放量子系统方法使我们能够阐明这个临界角$θ_c$及其关联的临界时间$t_c$在颜色和运动学空间中密度矩阵的真正量子退相干中的作用:特别地,$t_c$同时控制颜色空间中密度矩阵非对角元的抑制以及单态和八重态之间的转变。然而,我们发现颜色退相干比密度矩阵的完全退相干更早发生,从而标志着系统中经典行为的开始。最后,我们研究了Lindblad方程中$p_\perp$的量子扩散项对超越准因子化图像的修正,并发现这些修正是温和的。

英文摘要

Using the open quantum systems formalism, we study the propagation of a quark-antiquark pair propagating through a dense QCD plasma of size $L$ and transverse momentum broadening transport coefficient $\hat q$, and we derive the Lindblad evolution equation for the density matrix of the system. We focus on the boosted regime where the opening angle $θ_{q\bar q}$ of this effective colour dipole satisfies $θ_{q\bar q}\ll 1$. In the correlation limit where the quark-antiquark relative transverse momentum $p_\perp$ is much larger than the imbalance $q_\perp$ as well as the medium typical transverse momentum scale $Q_s=\sqrt{\hat q L}$, we demonstrate that the resulting Wigner distribution displays quasi factorisation between a hard factor describing the hard splitting producing the $q\bar q$ pair and the transverse momentum imbalance $q_\perp$-distribution encoding the broadening induced by the medium. The factorisation is violated by a "colour decoherence" factor that controls the $θ_{q\bar q}$ dependence of the $q_\perp$-distribution through the ratio $θ_{q\bar q}/θ_c$, with $θ_c \sim (\hat q L^3)^{-1/2}$. The open quantum systems approach enables us to clarify the role of this critical angle $θ_c$ and its associated critical time $t_c$ in the genuine quantum decoherence of the density matrix in colour and kinematic space: in particular, $t_c$ controls both the suppression of the off-diagonal elements of the density matrix in colour space and the transition between singlet and octet states. We find, however, that colour decoherence sets in earlier than the full decoherence of the density matrix, thereby marking the onset of classical behaviour in the system. Finally, we investigate the corrections beyond the quasi-factorised picture due to the quantum diffusion term in $p_\perp$ of the Lindblad equation and we find that these corrections are mild.

2606.07743 2026-06-09 hep-ph 新提交

Detector performance at SHiP for cascade-produced long-lived particles

SHiP实验中级联产生长寿命粒子的探测器性能

Matei Climescu, Yehor Kyselov, Maksym Ovchynnikov

AI总结 研究SHiP实验中级联产生软长寿命粒子对可观测事件率的抑制,通过半解析计算和探测器级模拟量化两种代表性情况,发现级联贡献在大多数质量下不占主导,并探讨了恢复部分事件率的可能方法。

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AI中文摘要

先前的研究表明,SHiP实验厚靶中的级联产生可能会显著增加在 fiducial 体积内衰变的轻长寿命粒子(LLP)的数量。然而,级联产生的LLP通常是软的,因此子粒子层面的接受度和重建效应会强烈抑制可观测事件率。我们针对两个代表性情况量化了这种抑制:电磁级联中产生的类光子轴子粒子,以及次级介子衰变中产生的重中性轻子。我们将半解析事件率计算与电磁量热器中ALP重建的探测器级研究相结合。对于标称的SHiP探测器设计,级联ALP最多在最低质量下提供比初级产生适度的增强;在较高质量下,级联贡献变得次要或可忽略。对于来自次级K介子的HNL,在施加子粒子几何接受度后,级联贡献已经次要。我们还确定了恢复部分级联事件率的可能方法,包括放宽事件选择标准和主动靶子探测器。

英文摘要

Previous studies have shown that cascade production in the thick target of the SHiP experiment may substantially enhance the number of light long-lived particles (LLPs) decaying in the fiducial volume. However, cascade-produced LLPs are typically soft, so daughter-level acceptance and reconstruction effects can strongly suppress the observable event rate. We quantify this suppression for two representative cases: photophilic axion-like particles produced in electromagnetic cascades, and heavy neutral leptons produced in decays of secondary kaons. We combine a semi-analytic event-rate calculation with a detector-level study of ALP reconstruction in the electromagnetic calorimeter. For the nominal SHiP detector design, cascade ALPs give at most a moderate enhancement over primary production, and only at the lightest masses; at higher masses, the cascade contribution becomes subdominant or negligible. For HNLs from secondary kaons, the cascade contribution is already subdominant after imposing daughter-level geometric acceptance. We also identify possible ways to recover part of the cascade event rate, including relaxed event-selection criteria and an active-target subdetector.

2606.07742 2026-06-09 hep-ph astro-ph.HE 新提交

Core Composition Effects on the QCD Axion Mass Limit from Neutron Star Cooling

核心成分对中子星冷却的QCD轴子质量极限的影响

Fernando Arias-Aragón, Federico Nola

AI总结 研究不同状态方程下重子(超子和Δ共振态)对中子星核心成分的影响,发现QCD轴子质量极限变化温和,DFSZ模型下可能进入IAXO灵敏度窗口。

Comments 27 pages, 9 figures, 2 tables

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AI中文摘要

中子星是非常致密的介质,其中可能产生轴子。这已被用于设定QCD轴子质量极限,通常假设星核中仅存在中子、质子、电子和μ子。考虑到中子星内部的极端条件,可以合理认为其他粒子,如超子和Δ共振态,可能以实粒子形式存在。在这项工作中,我们研究了当使用不同的状态方程,允许重粒子出现在中子星核心时,QCD轴子(即KSVZ和DFSZ不可见轴子)质量极限如何改变。我们发现这种依赖性通常很温和,从而增强了已知极限的可靠性。此外,在DFSZ情景下,它可能将极限推入IAXO的灵敏度窗口。这将使该实验能够区分中子星核心的成分,如果在那个窗口内观测到轴子的话。

英文摘要

Neutron stars are very dense media in which axions may be produced. This has been used to set limit on the QCD axion mass, usually under the assumption that only neutrons, protons, electrons, and muons appear in the star core. Given the extreme conditions reached within neutron stars, it is reasonable to consider that other particles, such as hyperons and $Δ$ resonances, may exist on-shell. In this work, we study how the limit on the mass of QCD axions, namely KSVZ and DFSZ invisible axions, is altered when different equations of state are used, allowing for heavier particles to appear in the neutron star core. We find that this dependence is in general mild and thus reinforces the reliability of the known limit. Additionally, in the DFSZ scenario, it may drive the limit within the sensitivity window for IAXO. This would allow this experiment to discern the composition of neutron star cores if an axion were to be observed within that window.

2606.07741 2026-06-09 astro-ph.GA 新提交

Clumps in a Cocoon: Geometry and Mixing Set the Universal X-ray to H$α$ Surface Brightness Ratio

茧中的团块:几何与混合决定了X射线到Hα面亮度比的普适性

Zirui Chen, S. Peng Oh, Drummond B. Fielding, Lachlan Lancaster, Yuan Li, Brent Tan

AI总结 通过三维风洞模拟,发现冷相碎裂成Hα发射团块,热相形成茧状结构,混合层中气体停留时间决定X射线亮度,从而解释观测到的X射线与Hα面亮度比约为3的普适性。

Comments 6 pages, 3 figures. Submitted to MNRAS Letters

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AI中文摘要

最近的观测揭示,在星系风、冲压剥离尾和星系团纤维中,X射线与Hα面亮度比具有普适性,${\rm SB}_{\rm X}/{\rm SB}_{{\rm H}\alpha}\sim 3$。这令人惊讶,因为Hα示踪冷($\sim 10^4$ K)气体,而X射线示踪更热($\sim 10^{6}$--$10^{7}$ K)的气体。平面平行混合层模型无法恢复这一比值,可能相差数个数量级。受近期关于几何控制多相气体温度概率分布函数的工作(Chen & Oh 2026)启发,我们运行了高密度对比度($\chi\sim 10^3$)区域的三维风洞模拟。在此极限下,冷相碎裂成许多小的Hα发射团块,而X射线发射气体在其周围形成体积填充的茧。在尾宽尺度上平滑后,测量的面亮度比收敛到观测值,这可以在理论上得到理解。Hα光度分数由原子物理决定,而X射线光度分数由气体在X射线发射带中的停留时间决定。该停留时间远短于X射线温度下的冷却时间,但大致与压力成反比,表明它与混合级联中较低温度出口的冷却时间相关。这一框架自然解释了为何观测比值量级为1,并且对气体压力的变化具有鲁棒性。

英文摘要

Recent observations reveal a universal X-ray to H$α$ surface-brightness ratio, ${\rm SB}_{\rm X}/{\rm SB}_{\rm Hα}\sim 3$, in galactic winds, ram-pressure stripped tails, and cluster filaments. This is surprising because H$α$ traces cold ($\sim 10^4$ K) gas while X-rays trace much hotter ($\sim 10^{6}$--$10^{7}$ K) gas. Plane-parallel mixing-layer models do not recover this ratio, and can be off by orders of magnitude. Motivated by recent work showing that geometry controls the temperature PDF of multiphase gas (Chen & Oh 2026), we run 3D wind-tunnel simulations in the high density contrast ($χ\sim 10^3$) regime. In this limit, the cold phase shatters into many small H$α$-emitting clumps, while X-ray-emitting gas forms a volume-filling cocoon around them. After smoothing on the tail-width scale, the measured surface-brightness ratio converges to the observed value, which can be understood theoretically. The H$α$ luminosity fraction is set by atomic physics, whereas the X-ray luminosity fraction is set by the residence time of gas in the X-ray-emitting band. This residence time is much shorter than the cooling time at X-ray temperatures, but scales roughly inversely with pressure, suggesting that it is tied to the cooling time at a lower-temperature outlet of the mixing cascade. This framework naturally explains why the observed ratio is order unity, and robust to changes in gas pressure.

2606.07740 2026-06-09 cond-mat.mes-hall hep-th 新提交

Phase diagram of magnetic $S^3$ Skyrmions on three-dimensional lattices and the toroidal antiSkyrmion

三维晶格上磁性 $S^3$ 斯格明子的相图与环形反斯格明子

Niccolò Francini, Stefano Bolognesi, Sven Bjarke Gudnason, Roberto Menta

AI总结 研究三维磁性斯格明子的推广模型,通过两种广义DMI项发现球形和轴对称斯格明子,以及反禁闭现象,并通过蒙特卡洛模拟绘制有限温相图,首次发现环形反孤子。

Comments 14+4 pages, 11 figures

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AI中文摘要

磁性斯格明子是由Dzyaloshinskii-Moriya相互作用(DMI)稳定并存在于手性磁体中的平面孤子。我们研究其自然的三维推广:一个从 $\mathbb{R}^3$ 到 $S^3$ 的sigma模型,具有四分量磁化矢量,由作为广义DMI的单导数项稳定。我们利用最近发现的两种SO(3)不变的广义DMI:一个支持球对称刺猬斯格明子的“$\alpha$-项”和一个支持轴对称斯格明子的“$\beta$-项”,该斯格明子分裂成两个由负张力磁弦连接的半斯格明子,我们称之为“反禁闭”现象。我们推导出在长波长下重现两种连续理论的立方晶格离散化,并使用蒙特卡洛模拟绘制有限温相图。我们识别出自旋螺旋相、磁弦晶格相、斯格明子晶格相和反斯格明子晶格相,以及具有局域在弦弯曲处的分数$S^3$电荷的混合拓扑区域。据我们所知,我们首次发现了单位电荷的环形(反)孤子。我们的结果为序参量流形为$S^3$的系统中三维拓扑磁性纹理建立了理论和计算框架。

英文摘要

Magnetic Skyrmions are planar solitons stabilized by the Dzyaloshinskii-Moriya interaction (DMI) and realized in chiral magnets. We study their natural three-dimensional generalization: a sigma model from $\mathbb{R}^3$ to $S^3$ with a four-component magnetization vector, stabilized by a one-derivative term which is a generalized DMI. We utilize two SO(3)-invariant generalized DMIs discovered recently: an "$α$-term" supporting a spherically symmetric hedgehog Skyrmion and a "$β$-term" supporting an axially symmetric Skyrmion that splits into two half-Skyrmions connected by a magnetic string of negative tension, a phenomenon we call "anti-confinement". We derive a cubic-lattice discretization that reproduces both continuum theories at long wavelengths and use Monte Carlo simulations to map the finite-temperature phase diagram. We identify spin-spiral, magnetic-string-lattice, Skyrmion-lattice, and antiSkyrmion-lattice phases, as well as a mixed-topology regime with fractional $S^3$ charges localized at string bends. We find, for the first time in the literature to the best of our knowledge, a toroidal (anti-)soliton of unit charge. Our results establish a theoretical and computational framework for three-dimensional topological magnetic textures in systems whose order-parameter manifold is $S^3$.

2606.07739 2026-06-09 hep-ph hep-ex 新提交

Searches for GeV-Scale ALPs at RHIC

在RHIC上搜索GeV量级的轴子类似粒子

Kaori Fuyuto, Claudio Andrea Manzari, Hitoshi Murayama

AI总结 提出利用RHIC的超外围Au+Au碰撞数据,通过共振过程γγ→a→γγ搜索轴子类似粒子,模拟信号与背景,估计对ALP-光子耦合的灵敏度,覆盖未探索参数空间。

Comments 9 pages, 8 figures and 1 table

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AI中文摘要

我们指出,在相对论重离子对撞机(2000-2026年运行)收集的超外围Au+Au碰撞数据可用于搜索通过共振过程$γγ\to a \to γγ$与光子耦合的轴子类似粒子。利用重离子碰撞中双光子亮度的$Z^4$增强以及RHIC可实现的低光子能量阈值,我们模拟了信号和背景过程(后者主要由光-光散射、强子共振产生和误识别的$e^+e^-$对主导),并基于PHENIX实验收集的现有$1.9~\text{nb}^{-1}$数据估计了ALP-光子耦合$g_{aγγ}$的上限。我们发现对质量范围$2~\text{GeV} \lesssim m_a \lesssim 5~\text{GeV}$、耦合$g_{aγγ} \gtrsim 4\times 10^{-4}~\text{GeV}^{-1}$的ALP具有灵敏度,探测了先前未探索的参数空间区域。获取更大亮度的数据集可显著扩展此搜索的灵敏度,这激励了对PHENIX及其他实验在RHIC收集的超外围碰撞数据进行专门分析。

英文摘要

We point out that ultra-peripheral Au+Au collision data collected at the Relativistic Heavy Ion Collider, operational during 2000-2026, can be used to search for axion-like particles coupled to photons via the resonant process $γγ\to a \to γγ$. Exploiting the $Z^4$ enhancement of the two-photon luminosity in heavy-ion collisions and the low photon energy thresholds achievable at RHIC, we simulate signal and background processes, the latter dominated by light-by-light scattering, hadronic resonance production, and misidentified $e^+e^-$ pairs, and estimate upper limits on the ALP-photon coupling $g_{aγγ}$ assuming $1.9~\text{nb}^{-1}$ of existing data collected by the PHENIX experiment. We find sensitivity to ALP masses in the range $2~\text{GeV} \lesssim m_a \lesssim 5~\text{GeV}$ with couplings $g_{aγγ} \gtrsim 4\times 10^{-4}~\text{GeV}^{-1}$, probing previously unexplored regions of parameter space. Access to larger luminosity datasets could substantially extend the sensitivity of this search, motivating a dedicated analysis of ultra-peripheral collision data collected at RHIC by PHENIX as well as other experiments.

2606.07738 2026-06-09 hep-th math-ph math.MP 新提交

New Exotic Operators in the Spectrum of Wilson Lines in General Representations

一般表示中威尔逊线谱的新奇算子

Daniele Artico, Carlo Meneghelli, Michele Savi, Rudolfs Treilis

AI总结 本文发现,在足够丰富的表示中,威尔逊线支持一类新的算子插入,并证明在N=4 SYM中这些算子具有位移超多重态的量子数,通过分析beta函数和OPE系数,表明这些变形是边缘相关的。

Comments 12 pages of which 4 for main body and 8 for the 6 appendices, 1 table. Comments are welcome

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AI中文摘要

威尔逊线是规范理论的基本探针。我们证明,在足够丰富的表示中,它们支持一大类新的算子插入。对于$\mathcal{N}=4$ SYM中的半BPS线,这些算子中的许多具有位移超多重态的量子数。它们的一维超初级场定义了缺陷理论的自然变形。通过分析相关的beta函数,并将其与特定的OPE系数联系起来,我们证明这些变形是边缘相关的。我们通过对任意规范群和表示的这些算子的四点函数进行弱耦合计算来支持我们的发现。

英文摘要

Wilson lines are fundamental probes of gauge theories. We show that, in sufficiently rich representations, they support a large new class of operator insertions. For half-BPS lines in $\mathcal{N}=4$ SYM many of these operators have the quantum numbers of the displacement supermultiplet. Their dimension-one superprimaries define natural deformations of the defect theory. By analyzing the associated beta functions, and relating them to specific OPE coefficients, we show that the deformations are marginally relevant. We support our finding with a weak-coupling computation of the four-point function of these operators for any gauge group and representation.

2606.07737 2026-06-09 hep-th math-ph math.AG math.MP 新提交

Moduli spaces of type II twists

II型扭变的模空间

Fabian Hahner

AI总结 通过分类十维(1,1)超庞加莱代数中平方零元素在Spin群作用下的轨道,完整分类了平坦背景中IIA超重力的扭变超荷,并结合IIB结果完成II型超重力扭变模空间的描述,讨论了其十一维起源及与弦世界片扭变的关系。

Comments 23 pages

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AI中文摘要

我们通过确定十维(1,1)超庞加莱代数中平方零元素在Spin群作用下的轨道,提供了平坦背景中IIA超重力扭变超荷的完整分类。结合最近关于IIB的结果,这完成了II型超重力扭变模空间的描述。此外,我们讨论了这些扭变作为从十一维降维的起源。利用超弦的纯旋量形式,我们将靶空间分类与世界片扭变联系起来,并识别了混合A/B模型的超重力对应物。最后,我们推导了联系IIA和IIB扭变的T对偶作用。

英文摘要

We provide a complete classification of twisting supercharges for type IIA supergravity in a flat background by determining the orbits of square-zero elements in the (1,1) super Poincaré algebra in ten dimensions under the action of the Spin group. Together with recent results for type IIB, this completes the description of the moduli space of twists for type II supergravities. Further, we discuss the origins of these twists as dimensional reductions from eleven dimensions. Using the pure spinor formulation of the superstring, we relate the target space classification to worldsheet twists and identify supergravity counterparts of mixed A/B models. Finally, we work out the action of T-duality that relates twists of type IIA with those of type IIB.

2606.07736 2026-06-09 quant-ph cond-mat.stat-mech 新提交

Exact metastability in a class of driven-dissipative quantum many-body systems

一类驱动-耗散量子多体系统中的精确亚稳态

David D. Noachtar, Aashish A. Clerk

AI总结 针对具有隐藏时间反演对称性的驱动-耗散开放量子系统,提出利用非平衡稳态的特殊纯化来解析预测耗散一级相变附近的慢时间尺度,并通过具体模型验证了该方法的准确性。

Comments 19 + 14 pages, 9 + 3 figures, 0 + 1 tables

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AI中文摘要

多体量子系统中的亚稳态及其相关的指数长时标近年来引起了广泛关注。本文聚焦于一类由具有隐藏时间反演对称性(一种量子细致平衡形式)的林德布拉德算符描述的驱动-耗散多体开放量子系统。例子包括边界驱动的相互作用自旋链、玻色子晶格模型和驱动-耗散集体自旋模型。我们提出,对于此类系统,耗散一级相变附近的慢时标可以通过非平衡稳态的特殊纯化进行解析预测。通过对具有集体和局域衰变的耗散横向场伊辛模型以及驱动-耗散非线性腔模型的详细研究,我们展示了该猜想的准确性。我们的结果为一系列系统(包括半经典或路径积分瞬子方法难以处理的情况)提供了对亚稳态和慢动力学的定量见解。

英文摘要

Metastability in many-body quantum systems and its associated exponentially-long timescales have been the subject of considerable recent interest. Here, we focus on a class of driven-dissipative many-body open quantum systems described by a Lindbladian having hidden time-reversal symmetry (a form of quantum detailed balance). Examples include boundary-driven interacting spin chains, bosonic lattice models and driven-dissipative collective spin models. We suggest that for such systems, slow timescales in the vicinity of a dissipative first-order phase transition can be analytically predicted using a special purification of the non-equilibrium steady state. We show the accuracy of our conjecture through detailed studies of a dissipative transverse-field Ising model with collective and local decay, and a driven-dissipative nonlinear cavity model. Our results allow quantitative insights into metastability and slow dynamics for a range of systems, including cases where semiclassical or path-integral instanton approaches are intractable.

2606.07734 2026-06-09 quant-ph 新提交

Exploring the landscape of compact magic-state distillation factories

探索紧凑型魔法态蒸馏工厂的景观

Hugo Jacinto, Xavier Valcarce, Victor Barizien, Élie Gouzien, Nicolas Sangouard

AI总结 本文利用经典纠错码框架研究魔法态蒸馏协议,通过SAT求解器推导出关于量子比特数、协议深度、工厂距离和输出错误率预因子的不可行定理,并提出了新的最小量子比特数蒸馏协议。

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AI中文摘要

使用尽可能少的物理量子比特和操作来生产高保真度的魔法态,是实现大规模容错量子计算的一个非常重要的挑战。除了新兴的替代方法(如培养)外,魔法态蒸馏对于实现极低错误率仍然至关重要。已知的蒸馏协议通常通过由三正交矩阵导出的量子码构建。在这里,利用魔法态蒸馏协议中存在的特定噪声结构,我们表明经典纠错码为推导这些协议提供了一个更简单的框架。这种表述特别适合于涉及固定数量量子比特的蒸馏协议的系统数值和分析研究。具体来说,我们使用SAT求解器推导了一系列不可行定理,这些定理将关键的性能指标联系起来,包括量子比特数、协议深度、工厂距离和输出错误率中的预因子。例如,我们证明任何使用少于8个量子比特的$T$-到-$T$态蒸馏协议最多只能检测3个错误,而任何使用少于8个量子比特的$T$-到-$\mathrm{CC}Z$态蒸馏协议最多只能检测2个错误。我们的结果还包括文献中给定距离下量子比特数最小的新蒸馏协议,即支持在10和11个量子比特上的距离4和5的$T$-到-$T$态协议,以及支持在9和10个量子比特上的距离3和4的$T$-到-$\mathrm{CC}Z$态蒸馏协议。

英文摘要

Producing high-fidelity magic states using the smallest possible amount of physical qubits and operations stands as a very important challenge to achieve fault-tolerant quantum computation at scale. Besides emerging proposals for alternative methods such as cultivation, magic state distillation remains essential for achieving very low error rates. Known distillation protocols are usually built through quantum codes derived from triorthogonal matrices. Here, exploiting the specific noise structure present in magic state distillation protocols, we show that classical error-correcting codes offer a simpler framework for deriving these protocols. This formulation is particularly well suited to systematic numerical and analytical studies of distillation protocols involving a fixed number of qubits. Specifically, we use a SAT solver to derive a series of no-go theorems that relate key figures of merit, including the number of qubits, the protocol depth, the factory distance, and the prefactor in the output error rate. For instance, we prove that any $T$-to-$T$ state distillation protocol using fewer than eight qubits can detect at most three errors, while any $T$-to-$\mathrm{CC}Z$ state distillation protocol using fewer than eight qubits can detect at most two errors. Our results also include new distillation protocols with the smallest number of qubits for a given distance in the literature, namely distance 4 and 5 $T$-to-$T$ state protocols supported on 10 and 11 qubits, as well as distance 3 and 4 $T$-to-$\mathrm{CC}Z$ state distillation protocols supported on 9 and 10 qubits.

2606.07733 2026-06-09 astro-ph.HE astro-ph.GA 新提交

The Effects of Cosmic Ray Protons on Galactic Nonthermal Filaments

宇宙线质子对银河系非热细丝的影响

Mohan Richter-Addo, Roark Habegger, Ellen Zweibel, Dylan M. Paré, David T. Chuss

AI总结 研究银河系中心非热细丝的形成机制,通过MHD模拟比较质子主导和轻子主导的宇宙线注入,发现两者差异不大,提出湍流间歇结构作为第三种形成机制。

Comments Submitted to ApJ, 17 pages, 11 figures, comments welcome

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AI中文摘要

银河系中心包含一组细丝,通常长度为几十秒差距,由宇宙线的同步辐射照亮。这些非热细丝(NTF)的起源尚不清楚。我们旨在区分两种注入机制:第一种机制认为NTF由脉冲星风云的喷流提供能量,且以轻子为主;第二种机制认为NTF由星际激波的加速粒子提供能量,且以质子为主。我们使用磁流体动力学(MHD)代码Athena++,并修改以考虑辐射和碰撞损失,模拟轻子和质子宇宙线物种的传播。我们改变磁场强度、等离子体密度和宇宙线扩散系数等参数,以确定银河系中心存在的条件范围如何影响宇宙线的传播、加热、等离子体流动以及观测到的同步辐射。我们发现质子主导和轻子主导的情况之间几乎没有可观测的差异,但将模型与观测到的细丝特性进行比较,促使我们考虑第三种形成机制:NTF的产生源于银河系中心湍流中的间歇结构。

英文摘要

The Galactic Center (GC) contains a collection of filaments that are typically tens of parsecs in length, illuminated by synchrotron radiation from cosmic rays (CR). The origin of these nonthermal filaments (NTFs) is unclear. We aim to distinguish two injection mechanisms: the first mechanism posits that NTFs are fueled either by jets from pulsar wind nebulae and are lepton-dominated; the second mechanism posits that NTFs are fueled by accelerated particles from interstellar shocks and are proton-dominated. We explore these mechanisms using the magnetohydrodynamics (MHD) code Athena++, modified to account for radiative and collisional losses, to simulate CR propagation with lepton and proton CR species. We vary parameters such as magnetic field strength, plasma density, and the CR diffusion coefficient to determine how the range of conditions present in the GC can affect CRs' propagation, heating, plasma flow, and the observed synchrotron emission. We find few observable differences between the proton- and lepton-dominated cases, but comparing the models with observed filament properties motivates consideration of a third formation mechanism: the generation of NTFs arise from intermittent structures in Galactic Center turbulence.

2606.07732 2026-06-09 cs.SE 新提交

The Windows IOCTL Census: A Corpus-Scale, Multi-Architecture Database of the Driver Control-Code Surface

Windows IOCTL 普查:驱动程序控制码界面的语料规模、多架构数据库

Michael J. Bommarito

AI总结 通过确定性、架构无关的静态分析,构建了27,087个签名Windows驱动程序的IOCTL控制码分发表数据库,覆盖x86和x64,并利用LLM对可达处理程序进行排序。

Comments 15 pages, 4 figures, 4 tables. Companion structural-tier dataset: huggingface.co/datasets/mjbommar/ioctl-census

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AI中文摘要

Windows 驱动程序通过 I/O 控制 (IOCTL) 代码暴露其内核,而缓冲区上未检查的长度会将无特权的调用转化为内核写入。研究社区拥有针对该界面的强大扫描器和已知恶意驱动程序的精选列表,但没有界面本身的地图。我们构建了这张地图。Windows IOCTL 普查是一个可查询的数据库,包含 27,087 个已签名 Windows 驱动程序的控制码分发表,通过一次确定性、架构无关的遍历(无需符号执行)恢复。读取提升的中间表示而非运行符号引擎,使其能够恢复整个语料库中 80% 的驱动程序的 x86 和 x64 分发表面,包括现有扫描器在 32 位上中止的部分。在 64 位通道上,它增加了处理程序可达性、污点和调用图。LLM 对可达处理程序进行排序以进行分流。我们将普查结果作为包含数千万行的公共数据集发布:27,087 个二进制文件、310 万个解码控制码、818 万个函数和 1595 万个调用边。

英文摘要

A Windows driver exposes its kernel through I/O control (IOCTL) codes, and a single unchecked length on the buffer behind one turns an unprivileged call into a kernel write. The research community has strong scanners for this surface and a curated list of known-bad drivers, but no map of the surface itself. We build that map. The Windows IOCTL Census is a queryable database of the control-code dispatch surface of 27,087 signed Windows drivers, recovered by one deterministic, architecture-neutral pass with no symbolic execution. Reading a lifted intermediate representation instead of running a symbolic engine lets it recover a dispatch surface for 80% of the corpus across x86 and x64, including the 32-bit half existing scanners abort on. On the 64-bit lane it adds handler reachability, taint, and the call graph. An LLM ranks the reachable handlers for triage. We release the census as a public dataset of tens of millions of rows: 27,087 binaries, 3.1M decoded control codes, 8.18M functions, and 15.95M call edges.

2606.07731 2026-06-09 nucl-th astro-ph.HE 新提交

NICER Constraints on Low density Interpolation and High density Continuation in Neutron Star Equations of State

NICER对中子星状态方程中低密度插值和高密度延续的约束

Federico Nola

AI总结 通过比较两种低密度分支与高密度延续,结合NICER质量半径后验、最大质量下限和Λ1.4约束,发现当前数据主要约束高密度延续,但也间接限制低密度匹配参数。

Comments 8 pages, 5 figures

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AI中文摘要

我们研究当前天体物理数据是否不仅约束中子星状态方程的高密度延续,还约束低密度匹配过程本身。为此,我们比较了两个通过共同高密度扩展传播的低密度分支,并将其与直接的NICER质量半径后验、最大质量下限以及$Λ_{1.4}$的有效约束进行对比。我们发现,两个分支的可观测预测仍然高度重叠,而NICER信息后验仍然对匹配参数施加了非平凡约束。因此,当前数据主要约束$n_1$以上的共享延续,但也间接限制了低密度匹配区域。

英文摘要

We investigate whether current astrophysical data constrain not only the high density continuation of the neutron star equation of state, but also the low density matching procedure itself. To this end, we compare two low density branches propagated through a common high density extension and confront them with direct NICER mass-radius posteriors, a lower bound on the maximum mass, and an effective constraint on $Λ_{1.4}$. We find that the observable predictions of the two branches remain strongly overlapping, while the NICER-informed posterior still induces a nontrivial constraint on the matching parameters. Current data therefore constrain primarily the shared continuation above $n_1$, but also indirectly restrict the low-density matching sector.

2606.07730 2026-06-09 astro-ph.HE 新提交

The X-ray-to-UV relation does not evolve in homogeneous quasar samples

在均匀类星体样本中,X射线与紫外关系不演化

G. Risaliti, E. Lusso, E. Nardini, C. Niccolai, M. Ralowski, A. Sacchi, A. Shlentsova, M. Signorini, B. Trefoloni

AI总结 通过构建约2000个类星体的均匀样本,严格校正爱丁顿偏差,发现X射线-紫外关系在红移0.7-5范围内保持恒定,斜率为0.58±0.01,弥散0.15 dex。

Comments 10 Pages, 8 Figures. Submitted to A&A. Comments welcome

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AI中文摘要

我们提出了一个新的、高度均匀的类星体样本,包含X射线和紫外观测,旨在通过非线性X射线-紫外关系可靠估计距离。将斯隆数字巡天DR16类星体星表与XMM-Newton偶然源星表(4XMM--DR14)交叉匹配,我们采用严格的选择标准构建稳健样本:(1)紫外和(2)X射线颜色约束,分别避免消光和吸收;(3)移除宽吸收线和射电亮类星体;(4)排除z<0.7的源,以防止星系紫外污染;(5)拒绝X射线观测较浅的源。最后一步与爱丁顿偏差密切相关,至关重要,因为对于典型的类星体光谱能量分布,SDSS数据通常比X射线数据更深:忽略这种差异会在X射线-紫外关系参数中引入虚假的红移依赖性。我们的最终样本包含约2000个红移0.7-5的类星体。我们证明X射线-紫外关系在该红移范围内恒定,平均斜率为0.58±0.01,弥散为0.15 dex。我们的发现证实了该关系在宇宙时间内的内在稳定性,强调均匀性和稳健的爱丁顿偏差校正对于通量限制样本至关重要。事实上,在有效灵敏度极限附近优先探测比平均X射线更亮的源的影响随红移显著增加。因此,X射线-紫外关系中任何由此产生的演化趋势,特别是斜率变平的形式,要么是很大程度上虚假的效应,要么是混合了具有本质上不同光谱特性的类星体种群的结果。

英文摘要

We present a new, highly homogeneous quasar sample with X-ray and UV observations optimized to reliably estimate distances via the non-linear X-ray-to-UV relation. Cross-matching the Sloan Digital Sky Survey DR16 quasar catalog with the XMM-Newton serendipitous catalogue (4XMM--DR14), we employ strict selection criteria to build a robust sample: (1) UV and (2) X-ray colour constraints to avoid, respectively, extinction and absorption; (3) removal of broad absorption line and radio-bright quasars; (4) exclusion of sources at z<0.7 to prevent galactic UV contamination; and (5) rejection of sources with shallow X-ray observations. The latter step, closely related to the Eddington bias, is critical because SDSS data are generally deeper than X-ray data for typical quasar spectral energy distributions: ignoring such a discrepancy introduces a spurious redshift dependence in the X-ray-to-UV relation parameters. Our final sample contains about 2,000 quasars at z=0.7--5. We demonstrate that the X-ray-to-UV relation is constant across this redshift range, with a mean slope of 0.58\,$\pm$\,0.01 and a dispersion of 0.15 dex. Our findings confirm the intrinsic stability of this relation over cosmic time, emphasizing that both homogeneity and robust Eddington bias corrections are vital for flux-limited samples. In fact, the impact of the preferential detection of X-ray brighter-than-average sources near the effective sensitivity limits significantly grows with redshift. Any resulting evolutionary trend in the X-ray-to-UV relation, especially in the form a slope flattening, is therefore either a largely spurious effect, or the result of mixing populations of quasars with intrinsically different spectral properties.

2606.07729 2026-06-09 math.OC math.AP math.PR 新提交

Large-time behavior and accuracy of the Mean-Field Ensemble Kalman Filter in the Linear Detectable Setting

线性可检测设定下平均场集合卡尔曼滤波的大时间行为与精度

Franca Hoffmann, Sangmin Park, Andrew M. Stuart

AI总结 研究线性可检测条件下平均场集合卡尔曼滤波(MFEnKF)的长期行为,通过变分近似推导其更新规则,证明其向高斯测度子空间的严格收缩,并给出连续时间下几乎必然的精度保证。

Comments 35 pages

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AI中文摘要

集合卡尔曼滤波(EnKF)最初发展于地球科学领域,现广泛应用于各领域的状态和参数估计问题。它可视为最优贝叶斯滤波的一种鲁棒且实现成本低廉的替代方案。然而,尽管经验成功,其与最优滤波相关的性质的理论理解仍处于初级阶段。本文在线性设定下研究平均场集合卡尔曼滤波(MFEnKF)的行为,贡献了新的理论理解。在该设定下,对于高斯初始数据,MFEnKF与卡尔曼滤波本身一致。我们研究具有一般非高斯初始数据的MFEnKF。在信号噪声非退化且信号-观测对可检测的假设下,我们做出三项具体贡献。首先,我们通过使用协方差加权最优传输度量的贝叶斯更新的变分近似推导MFEnKF。其次,利用该度量,我们证明MFEnKF是向高斯测度子空间的严格收缩,在离散和连续时间下均以协方差给出显式几何速率。最后,在连续时间设定下,我们推导出MFEnKF的几乎必然精度的稳定形式:对于MFEnKF和最优滤波的任何一对(非退化)初始数据,两个滤波分布的任何一致连续矩在大时间下几乎对所有观测路径都一致。

英文摘要

The ensemble Kalman filter (EnKF), originally developed in the geophysical sciences, is now widely used for state and parameter estimation problems in various domains of application. It may be viewed as a robust, cheap-to-implement, alternative to the optimal, Bayesian, filter. However, despite its empirical successes, theoretical understanding of its properties, in relation to the optimal filter, is in its infancy. In this paper we contribute novel theoretical understanding, studying the behavior of the mean-field limit of the ensemble Kalman filter (MFEnKF) in the linear setting. In this setting the MFEnKF coincides with the Kalman filter itself, for Gaussian initial data. We study the MFEnKF with general, non-Gaussian, initial data. Under the assumptions of nondegeneracy of the signal noise and detectability of the signal-observation pair we make three specific contributions. First, we derive the MFEnKF via a variational approximation of the Bayes update using a covariance-weighted optimal transport metric. Secondly, we use this metric to show that the MFEnKF is a strict contraction towards the subspace of Gaussian measures, giving explicit geometric rates in terms of the covariances, in both discrete and continuous time. Finally, in the continuous-time setting, we deduce a stable form of almost sure accuracy of the MFEnKF: given any pair of (nondegenerate) initial data for the MFEnKF and the optimal filter, any uniformly continuous moments of the two filtering distributions coincide in large time, for almost every observation path.

2606.07719 2026-06-09 eess.SP 新提交

Hessian-matching Based Weighting for Attitude Determination Using Short-Range DoA Measurements with IMU Assistance

基于Hessian匹配的短距离DoA测量与IMU辅助姿态确定加权方法

Chenxin Tu, Hengchuan Zhang, Xiaowei Cui, Gang Liu, Mingquan Lu

AI总结 针对短距离场景下方向向量误差各向异性问题,提出基于Hessian匹配的标量加权策略,通过流形高斯-牛顿法求解协方差加权正交Procrustes问题,并引入IMU重力向量提升精度与鲁棒性。

Comments This work has been submitted to the IEEE for possible publication

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AI中文摘要

准确可靠的姿态确定(AD)对于在GNSS拒止环境中运行的无人车辆至关重要。短距离无线阵列可以从多个锚点提供到达方向(DoA)测量,通过对齐在机体和导航坐标系中表达的对应方向向量(DV)来实现AD。在短距离场景中,导航坐标系DV除了机体坐标系DV中由DoA引起的误差外,还继承了由锚点/车辆位置误差引起的不可忽略的不确定性。此外,由于投影和单位范数归一化,DV误差通常是各向异性的,这激发了总体最小二乘(TLS)的观点。本文识别了短距离AD中的关键建模区别,基于总DV误差开发了TLS一致的形式化,并通过流形高斯-牛顿法求解由此产生的协方差加权正交Procrustes问题。为了保持闭式加权Wahba解的效率和数值鲁棒性,我们进一步提出了基于Hessian匹配的标量加权策略,该策略将Wahba形式化的Hessian近似为TLS形式化,包括用于整体精度的全姿态策略和用于优先选择特定姿态分量的感兴趣方向(DOI)策略。最后,我们将IMU导出的重力作为额外的DV对用于静态初始化,从而得到扩展的Wahba和扩展的TLS形式化。仿真结果表明,与现有基线相比,所提出的Hessian匹配加权提高了精度和鲁棒性,并且重力DV增强进一步减少了姿态误差,并在有限锚点可用性下提高了解的可用性。

英文摘要

Accurate and reliable attitude determination (AD) is essential for unmanned vehicles operating in Global Navigation Satellite System (GNSS)-denied environments. Short-range wireless arrays can provide direction-of-arrival (DoA) measurements from multiple anchors, enabling AD by aligning corresponding direction vectors (DVs) expressed in the body and navigation frames. In short-range scenarios, navigation-frame DVs inherit non-negligible uncertainty induced by anchor/vehicle position errors in addition to DoA-induced errors in body-frame DVs. Moreover, due to projection and unit-norm normalization, the DV errors are generally anisotropic, which motivates a total least squares (TLS) viewpoint. This paper identifies the key modeling distinction in short-range AD, develops a TLS-consistent formulation based on the total DV error and solves the resulting covariance-weighted orthogonal Procrustes problem via a manifold Gauss--Newton method. To retain the efficiency and numerical robustness of the closed-form weighted Wahba solution, we further propose Hessian-matching based scalar weighting strategies that approximate the Hessian of Wahba formulation to the TLS formulation, including a full-attitude strategy for overall accuracy and a direction-of-interest (DOI) strategy for prioritizing a selected attitude component. Finally, we incorporate IMU-derived gravity as an additional DV pair for static initialization, leading to extended Wahba and extended TLS formulations. Simulation results demonstrate that the proposed Hessian-matching weighting improves accuracy and robustness compared with existing baselines, and that gravity-DV augmentation further reduces attitude errors and improves solution availability under limited anchor availability.

2606.07715 2026-06-09 econ.EM 新提交

Causality versus Serial Correlation: an Asymmetric Portmanteau Test

因果关系与序列相关:一个非对称的Portmanteau检验

Amedeo Andriollo

AI总结 针对遗漏变量下动态线性模型的弱外生性检验,提出非对称Portmanteau检验以区分弱外生性违反与反向因果关系,并应用于经济政策不确定性冲击。

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AI中文摘要

本文研究了在存在遗漏变量的情况下动态线性模型的设定检验。感兴趣的零假设是弱外生性:冲击在给定自身过去和遗漏变量过去的条件下条件期望为零。基于序列互相关二次型的现有检验存在大小扭曲,因为其方差包含了两个方向的对称依赖,包括从过去冲击到当前遗漏变量的因果关系(反向因果关系)。本文提出了一种非对称Portmanteau检验,该检验将弱外生性的违反与反向因果关系分离开来,在零假设下渐近正态,并且不需要联合动力学的参数设定。一项实证应用检验了经济政策不确定性冲击序列,并拒绝了其弱外生性。通过控制遗漏变量来解决这一失败,将估计的通胀反应从负变为正,暗示了供给侧冲击的解释。

英文摘要

This paper studies specification testing in dynamic linear models in the presence of omitted variables. The null hypothesis of interest is weak exogeneity: shocks have zero conditional expectation given their own past and the past of omitted variables. Existing tests based on quadratic forms of serial cross-correlations suffer from size distortions because their variance incorporates symmetric dependence in both directions, including causality from past shocks to present omitted variables (inverse causality). This paper proposes an asymmetric Portmanteau test that isolates violations of weak exogeneity from inverse causality, is asymptotically normal under the null, and does not require a parametric specification of the joint dynamics. An empirical application examines the Economic Policy Uncertainty shock series and rejects its weak exogeneity. Addressing this failure by controlling for omitted variables changes the estimated inflation response from negative to positive, suggesting a supply-side shock interpretation.