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2605.20508 2026-05-21 stat.ME astro-ph.HE astro-ph.IM physics.data-an stat.AP

Compensator-Based Inference for Signal Detection Under Unknown Background

基于补偿器的信号检测推断:在未知背景下的应用

Aritra Banerjee, Sara Algeri

AI总结 本文提出了一种新的信号检测方法,通过估计补偿器参数而非背景分布来简化推断过程,从而更有效地传播不确定性。

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AI中文摘要

在未知背景存在的情况下检测新信号的问题在科学发现中普遍存在,尤其是在物理科学中尤为突出。迄今为止大多数解决方案都集中在估计背景分布并利用该估计来推断信号。通过研究该问题的几何结构,本文证明估计背景分布对于推断信号强度并非绝对必要。相反,只需估计一个参数,称为补偿器,即可弥补对背景的不完全了解,显著简化了问题的复杂性,并使不确定性传播成为可能。所提出的补偿器被证明在所提出的设置以及基于似然的方法中都控制推断的保守性。

英文摘要

The problem of detecting new signals in the presence of an unknown background is ubiquitous in scientific discoveries and is especially prominent in the physical sciences. Most solutions proposed thus far to address the problem focus on estimating the background distribution and using that estimate to infer the signal. By studying the geometry of the problem, this article demonstrates that estimating the background distribution is somewhat unnecessary for inferring the signal intensity. Instead, it suffices to estimate a single parameter, referred to as the compensator, to account for the incomplete knowledge on the background, substantially simplifying the problem's complexity and enabling proper uncertainty propagation. Such a compensator is shown to govern the conservativeness of the inference, both in the proposed setup and in likelihood-based approaches.

2605.20507 2026-05-21 physics.ins-det

Procurement and Purification of Liquid Argon for the LEGEND-200 Experiment

LEGEND-200实验的液态氩采购与纯化

Malgorzata Harańczyk, Patrick Krause, Tomasz Mróz, Laszlo Papp, Krzysztof Pelczar, Stefan Schönert, Mario Schwarz, Christoph Vogl, Grzegorz Zuzel, Marco Balata, Nina Burlac

AI总结 LEGEND-200实验需要高纯度液态氩以实现有效的背景鉴别。本文介绍了专用液态氩纯化系统的设计、建造和性能,以及为填充LEGEND-200低温恒温器至91吨总容量所需的液态氩采购和纯化过程。纯化系统基于铜催化剂和分子筛去除氧气和水。从质量为5.5的液态氩开始,有效闪烁光三重态寿命τ_t约为0.9μs,最终纯度对应τ_t=1.3μs。在完全填充LEGEND-200低温恒温器后,测得的有效三重态寿命为1.16μs。显著的减少是由于意外受损的液态氩运输引入的残留氮杂质。通过LEGEND液态氩监测装置(LLAMA)防止了过量的氮气流入,该装置在填充过程中作为三个独立纯度监测器之一发挥作用。

Comments 15 pages, 12 figures

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AI中文摘要

LEGEND-200 requires high-purity liquid argon for effective background discrimination. In this paper, we present the design, construction, and performance of a dedicated liquid argon purification system, along with the procurement and purification of liquid argon for filling the LEGEND-200 cryostat to its total capacity of 91 t. The purifier is based on copper catalyst and molecular sieve to remove oxygen and water. Starting with liquid argon of 5.5 quality, featuring an effective scintillation light triplet lifetime $τ_t$ of about 0.9 $μ$s, we achieved a final purity corresponding to $τ_t$ = 1.3 $μ$s. After complete filling of the LEGEND-200 cryostat, the measured effective triplet lifetime was 1.16 $μ$s. The notable reduction is caused by a residual nitrogen impurity introduced by an accidentally spoiled liquid argon delivery. An excessive nitrogen influx was prevented by the LEGEND Liquid Argon Monitoring Apparatus (LLAMA), which served as one of the three independent purity monitors during the filling campaign.

英文摘要

LEGEND-200 requires high-purity liquid argon for effective background discrimination. In this paper, we present the design, construction, and performance of a dedicated liquid argon purification system, along with the procurement and purification of liquid argon for filling the LEGEND-200 cryostat to its total capacity of 91 t. The purifier is based on copper catalyst and molecular sieve to remove oxygen and water. Starting with liquid argon of 5.5 quality, featuring an effective scintillation light triplet lifetime $τ_t$ of about 0.9 $μ$s, we achieved a final purity corresponding to $τ_t$ = 1.3 $μ$s. After complete filling of the LEGEND-200 cryostat, the measured effective triplet lifetime was 1.16 $μ$s. The notable reduction is caused by a residual nitrogen impurity introduced by an accidentally spoiled liquid argon delivery. An excessive nitrogen influx was prevented by the LEGEND Liquid Argon Monitoring Apparatus (LLAMA), which served as one of the three independent purity monitors during the filling campaign.

2605.20505 2026-05-21 cs.SE cs.CY

Privacy-by-Design Adaptive Group Assignment for Digital Lifestyle Coaching at Scale

为大规模数字生活方式指导设计的隐私优先自适应小组分配

Nariman Mani, Salma Attaranasl

AI总结 本文提出了一种以利益相关者为中心的架构和自适应同伴组分配方法,用于在保护隐私的同时进行个性化的生活方式指导。该方法通过将用户分为四个受限制的视角,分别实施不同的访问控制和风险配置,并利用基于保险箱的受隐私约束的上下文带异步算法来分配用户到合适的同伴组,同时保持教练容量和稳定性限制。

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AI中文摘要

数字生活方式指导系统必须在用户行为和参与度演变的同时个性化同伴支持,同时防止个人可识别信息(PII)和敏感健康信息泄漏到分析和人工智能管道中。这产生了实际的张力:个性化需要纵向可追溯性,而隐私工程需要最小化、分离和受控再识别。我们提出了PRISM-Coach,一种以利益相关者为中心的架构和自适应同伴组分配方法,用于隐私保护的生活方式指导。PRISM-Coach将每个用户分为四个受限制的视角:身份、操作、学习和指导,每个视角都有不同的访问控制和风险配置。基于这种分离,系统使用基于保险箱的受隐私约束的上下文带异步算法来分配用户到合适的同伴组,在教练容量和稳定性限制下,并利用一个具有人类在环的指导助手,生成去标识化的摘要和草稿信息,而无需将原始PII或PHI发送到外部人工智能服务。我们将在一个商业部署的生活方式指导平台上实现PRISM-Coach,并使用约2800名用户的三年遥测数据和应用程序内需求评估调查对其进行评估。在总体层面,每日检查入组率从0.35增加到0.68,参与度上升至1.35基线。在匹配的19周比较窗口中,AI增强的工作流程在静态分组下实现0.74的依从性,比0.48高,且平均体重减轻更多:5.2公斤对3.1公斤。调查结果显示,82%的人报告了积极的感知效益,92%的人在透明度披露后报告了隐私信心的增加。这些结果使PRISM-Coach成为日常健康中隐私优先自适应学习系统的实用蓝图。

英文摘要

Digital lifestyle coaching systems must personalize peer support as user behavior and engagement evolve while preventing personally identifiable information (PII) and sensitive health information from leaking into analytics and AI pipelines. This creates a practical tension: personalization requires longitudinal linkability, while privacy engineering requires minimization, separation, and controlled re-identification. We present PRISM-Coach, a stakeholder-centered architecture and adaptive peer-group assignment method for privacy-preserving lifestyle coaching. PRISM-Coach separates each user into four bounded views: Identity, Operational, Learning, and Coaching, each with distinct access controls and risk profiles. Building on this separation, the system uses vault-based controlled identity restoration, a privacy-constrained contextual bandit to assign users to eligible peer groups under coach-capacity and stability constraints, and a human-in-the-loop coaching assistant that generates de-identified summaries and draft messages without sending raw PII or PHI to external AI services. We instantiate PRISM-Coach in a commercially deployed lifestyle coaching platform and evaluate it using three years of telemetry from approximately 2,800 users and an in-app needs assessment survey. At the population level, daily check-in adherence increases from 0.35 to 0.68, and engagement rises to 1.35 baseline. In a matched 19-week comparison window, the AI-enabled workflow achieves adherence of 0.74 versus 0.48 under static grouping and higher average weight loss: 5.2 kg versus 3.1 kg. Survey results show that 82% report positive perceived benefit, and 92% report increased privacy confidence after transparency disclosures. These results position PRISM-Coach as a practical blueprint for privacy-by-design adaptive learning systems in everyday wellness.

2605.20504 2026-05-21 math.CO

Box Progressions, Abelian Power-Free Morphisms and A Sieve Technique for the Template Method

盒序列、阿贝尔幂自由映射以及模板方法的筛技术

Sadık Eyidoğan, Haydar Göral, Nihan Tanısalı

AI总结 本文研究了在盒子中分配球体时是否存在k个球体其标签和盒子标签各自形成k项等差数列的问题,通过识别阿贝尔幂自由映射的固定点,提出了新的条件来判断映射的阿贝尔k幂自由性,并结合模板方法开发了筛技术以减少需检查的父节点数量,展示了该技术在验证阿贝尔幂自由性方面的有效性。

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AI中文摘要

给定由正整数枚举的球体和盒子,我们考虑将球体按顺序分配到盒子中。我们固定ℓ≥2。按盒子标签递增的顺序,将每个盒子分配下一个r个最小的球体,其中1≤r≤ℓ。给定整数k≥3,是否存在自然数N,使得在任何将N个球体放入盒子的放置中,存在k个球体其标签和盒子标签各自形成k项等差数列?我们通过识别阿贝尔幂自由映射的固定点来回答这个问题。我们提出了充分条件,使得映射是阿贝尔k幂自由的。我们的条件扩展了Dekking在二元字母上的结果,并提供了一种更弱但更有效的替代方案,以Carpi的结果。结合Dekking的结果与Currie和Rampersad的模板方法,我们开发了一种筛技术,显著减少了必须检查的父节点数量以确定阿贝尔幂自由性。我们然后识别了一个二元映射,其是阿贝尔16幂自由(但不是阿贝尔15幂自由)且具有阿贝尔14幂自由的固定点,展示了我们的技术在验证阿贝尔幂自由性方面的有效性。此外,我们提供了一个并非阿贝尔幂自由的二元映射,但其具有阿贝尔5幂自由的固定点。这些结果提供了新的映射示例,其固定点表现出比相应映射更强的阿贝尔幂自由性。

英文摘要

Given balls and boxes both enumerated by the positive integers, we consider a sequential allocation of the balls into the boxes. We fix $\ell \ge 2$. Proceeding in increasing order of box labels, assign to each box the next $r$ smallest balls for some $ 1\leq r\leq\ell$. Given an integer $k\ge 3$, is there a natural number $N$ such that in any placement of $N$ balls into boxes, there exist $k$ balls whose labels and box labels each form a $k$-term arithmetic progression? We address this question by identifying abelian power-free fixed points of morphisms over a binary alphabet. We present sufficient conditions under which a morphism is abelian $k$-power-free. Our conditions extend Dekking's result over a binary alphabet and offer a weaker, yet more effective alternative to Carpi's. Combining Dekking's result with the template method of Currie and Rampersad, we develop a sieve technique that significantly reduces the number of parents that must be examined to establish abelian power-freeness. We then identify a binary morphism that is abelian 16-power free (but not abelian $15$-power free) with an abelian 14-power free fixed point, demonstrating the strength of our technique in verifying abelian power-freeness. Furthermore, we give a binary morphism which is not abelian power-free, yet has an abelian $5$-power free fixed point. These results offer novel examples of morphisms whose fixed points exhibit stronger abelian power-freeness than the corresponding morphisms.

2605.20503 2026-05-21 astro-ph.GA

The chemo-dynamical complexity of ω Centauri: different kinematics for different populations

ω人形星团的化学动力学复杂性:不同群体的差异动力学

G. Pagnini, P. Bianchini, P. Di Matteo, A. Mastrobuono-Battisti

AI总结 研究ω人形星团中不同化学亚群体的空间和动力学特征,揭示其复杂的形成历史。

Comments Submitted to A&A

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AI中文摘要

ω人形星团的起源仍然是恒星动力学和化学演化的关键开放问题。其大的丰度差异和多个群体表明其形成历史比典型球状星团更复杂。我们研究了APOGEE DR17中识别出的化学亚群体是否表现出不同的空间和动力学特征。我们使用高斯混合模型分析了APOGEE DR17红巨星星的八维化学丰度空间。所得化学成分结合了Gaia的自行和APOGEE的径向速度以推导出三个可观测方向的内在平均速度和速度分散。我们测量了每个化学定义群体的全球动力学量和径向剖面,从内区扩展到约4个半光半径。高斯混合模型识别出五个化学成分,当通过径向累积分布分析时,自然分为两个更广泛的家族,分别以较低和较高的铝富集为特征。这两个家族在空间和动力学特性上有显著差异:富含铝的星体更集中在中心区域,表现出更强的径向各向异性,而贫铝星体则更接近各向同性。尽管有这些显著差异,这两个群体共享相同的旋转模式。这项工作是首次将详细的化学标记与从星团内部到边缘的内部动力学联系起来的ω人形星团的化学动力学研究。一个涉及矮星系势场中的分层组装和中心集中、化学富集的恒星形成过程的形成路径为观察到的化学动力学复杂性提供了自然解释。

英文摘要

The origin of ω Centauri remains one of the key open problems in stellar dynamics and chemical evolution. Its large abundance spreads and multiple populations suggest a formation history more complex than that of a typical globular cluster. We investigate whether the chemical sub-populations identified in APOGEE DR17 also exhibit distinct spatial and kinematic signatures. We analyse a sample of APOGEE DR17 red-giant stars using a Gaussian Mixture Model in an eight-dimensional chemical-abundance space. The resulting chemical components are combined with Gaia proper motions and APOGEE line-of-sight velocities to derive intrinsic mean velocities and velocity dispersions in all three observable directions. We measure both global kinematic quantities and radial profiles for each chemically defined group, extending from the inner regions to ~ 4 half-light radii. The Gaussian Mixture Model identifies five chemical components, which, when examined through their radial cumulative distributions, naturally group into two broader families characterised by lower and higher aluminium enrichment. The two families differ significantly in their spatial and kinematic properties: the Al-rich stars are more centrally concentrated and exhibit stronger radial anisotropy than the Al-poor stars, which remain closer to isotropy over the radial range probed. Despite these significant differences, the two populations share a common rotation pattern. This work represents the first chemo-dynamical study of ω Cen linking detailed chemical tagging to internal kinematics from the inner regions to the cluster outskirts. A formation path involving both hierarchical assembly within a dwarf-galaxy potential and centrally concentrated, chemically enriched star formation offers a natural explanation for the observed chemo-dynamical complexity.

2605.20501 2026-05-21 physics.comp-ph cs.NA math.NA math.OC

Adaptive Multi-Fidelity Structural Optimization under Fluid-Structure Interaction

适应性多保真结构优化在流固耦合中的应用

Aditya Narkhede, Erick Rivas, Kevin Wang

AI总结 本文提出了一种适应性多保真优化方法,结合高保真流固耦合分析与轻量化的替代模型,用于在流固耦合环境下进行结构和车辆设计优化,通过减少计算成本并保持精度来提高设计效率。

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AI中文摘要

在流固耦合(FSI)环境下设计结构和车辆通常需要高保真耦合分析。尽管设计变量涉及结构,但计算成本主要由流体求解器主导,使迭代优化成本过高。本文提出了一种适应性多保真优化方法,结合高保真FSI分析与轻量化的替代模型用于流体诱导载荷,以及一个决策模型,用于在替代模型和高保真流体评估之间进行选择。在优化过程中,完成的FSI分析逐步更新一个非侵入性的替代模型,基于最近邻搜索和径向插值。开发了一种混合拉格朗日-欧拉映射函数,用于在结构设计之间转移流体载荷。表面取向的演变通过将牵引向量分解为局部正交基来处理。采用适应性高斯过程回归模型来预测替代模型的误差并量化不确定性,允许在风险意识下选择何时需要耦合分析。随着设计评估接近最优解,替代模型的精度自然提高,从而减少对流体求解器的依赖。它不需要离线训练,在所有设计评估中保留高保真结构模型,并确保最终设计由高保真FSI分析评估。该基本思想通过简化模型问题进行了理论证明,显示主导误差是流体附加质量的单调递增、凹形且有界的函数。该框架在两个基准问题上进行了演示。对于在冲击载荷下柔性面板的形状优化,结果表明计算成本减少了80%,同时保持在完全高保真FSI优化的2.3%以内精度。

英文摘要

The design of structures and vehicles subject to fluid-structure interaction (FSI) often requires high-fidelity coupled analysis. While the design variables pertain to the structure, the computational cost is dominated by the fluid solver, making iterative optimization prohibitively expensive. This paper presents an adaptive multi-fidelity optimization method combining high-fidelity FSI analysis with a lightweight surrogate for fluid-induced loads and a decision model that selects between surrogate and high-fidelity fluid evaluations. During optimization, completed FSI analyses incrementally update a non-intrusive surrogate model based on nearest-neighbor search and radial interpolation. A hybrid Lagrangian-Eulerian mapping function is developed to transfer fluid loads between structural designs. The evolution of surface orientation is handled by decomposing the traction vectors into local orthonormal bases. An adaptive Gaussian process regression model is employed to predict surrogate error and quantify uncertainty, allowing risk-aware selection of when coupled analysis is required. As design evaluations cluster near the optimum, the accuracy of the surrogate model naturally improves, thereby reducing the reliance on the fluid solver. It requires no offline training, preserves the high-fidelity structural model in all design evaluations, and ensures that the final design is evaluated by high-fidelity FSI analysis. The fundamental idea is justified theoretically using a simplified model problem, which shows that the leading-order error is a monotonically increasing, concave, and bounded function of the fluid added mass. The framework is demonstrated on two benchmark problems. For shape optimization of a flexible panel under shock loading, results show an $80\%$ reduction in computational cost while maintaining accuracy within $2.3\%$ of fully high-fidelity FSI optimization.

2605.20500 2026-05-21 cs.SE

A Multi-Layer Testing Framework for Automated Data Quality Assurance in Cloud-Native ELT Pipelines

面向云原生ELT流水线的多层测试框架:自动化数据质量保障

Ismail Gargouri, Hassan Reza

AI总结 本文提出一种多层测试框架,结合 orchestration 层验证、dbt 声明性测试、LLM 生成的语义测试以及 DuckDB 与 Snowflake 之间的跨存储一致性检查,通过 Apache Airflow 协调,显著提升了数据质量验证的覆盖率和效率。

Comments 11 pages, 5 figures, 3 tables

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AI中文摘要

在云原生提取-加载-转换(ELT)流水线中确保数据质量正变得愈发具有挑战性,由于异构数据源、演变的模式和多后端执行环境。本文提出一个统一的、多层测试框架,整合了 orchestration 层验证、声明式 dbt 测试、大语言模型(LLM)生成的语义测试以及 DuckDB 与 Snowflake 之间的跨存储一致性检查,通过 Apache Airflow 协调。受控异常注入实验表明,仅手动的基准检测了16个注入异常中的7个。相比之下,手动扩展的比较器和所提出的 LLM 增强配置均检测了所有16个,相对于基准,检测率提高了128.57%。迁移后跨存储验证确认了所有三个精心挑选的表之间完全一致。25个LLM生成的测试断言中,9个被分类为有用,4个为冗余,12个为可执行但低价值。整个工作流在八个仪器化流水线阶段中执行了106.58秒。这些结果表明,LLM驱动的语义测试合成可以显著增强验证覆盖率,同时在生产ELT环境中保持操作实用性。

英文摘要

Ensuring data quality in cloud-native Extract-Load-Transform (ELT) pipelines is increasingly challenging due to heterogeneous data sources, evolving schemas, and multi-backend execution environments. This paper presents a unified, multi-layer testing framework that integrates orchestration-level validation, declarative dbt tests, large language model (LLM)-generated semantic tests, and cross-store consistency checking between DuckDB and Snowflake, orchestrated through Apache Airflow. Controlled anomaly-injection experiments demonstrate that a manual-only baseline detected 7 of 16 injected anomalies. In contrast, both a manually expanded comparator and the proposed LLM-augmented configuration detected all 16, representing a 128.57% relative improvement in detection rate over the baseline. Post-migration cross-store validation confirmed exact agreement across all three curated tables. Of 25 LLM-generated test assertions, 9 were classified as useful, 4 as redundant, and 12 as executable but low-value. The complete workflow executed in 106.58 seconds across eight instrumented pipeline stages. These results demonstrate that LLM-driven semantic test synthesis can materially strengthen validation coverage while remaining operationally practical for production ELT environments.

2605.20499 2026-05-21 physics.gen-ph

Beyond minimal coupling for charged scalars? Modified electrodynamics and London-penetration tests

超越最小耦合:修正电磁学与伦敦渗透测试

F. Minotti, G. Modanese

AI总结 本文探讨了针对带电标量场的修正耦合机制,提出了一种基于全局守恒电流的线性耦合方式,并通过实验数据验证了修正框架对磁渗透深度的影响,同时保持了超导电磁学的关键特性。

Comments 15 pages

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AI中文摘要

尽管标准最小耦合在狄拉克费米子上表现良好,但应用于标量场时存在已知的『特殊性』:线性于$A_μ$的项不等于相互作用理论的守恒诺特电流。我们最近提出选择不同的电磁相互作用原理,即线性耦合$A_μJ^μ$,其中$J^μ$是一个(全局)守恒电流,接受必须放弃电磁学部分的完整局部规范不变性,转而采用扩展电磁学(阿罗洪-玻姆型)以一致耦合非局部守恒电流的后果。我们提出了提议修正耦合的物理动机,并讨论了降低规范不变性的普遍后果。然后我们聚焦于凝聚态的中心主张:对于玻色子带电凝聚体,修正框架预测磁渗透深度$λ o λ/\sqrt{2}$,同时保持超导电磁学和其他关键定性特征(包括GL参数的等效缩放)不变。最后,我们分析了基于独立测量载流子密度与有效质量比$n_s/m^*$的伦敦长度一致性检验数据。我们比较了五种材料的『光学』渗透深度$λ_{\mathrm{opt}}$(由THz超流谱权重推断)与『磁性』深度$λ_{\mathrm{mag}}$(通过LE-μSR、TF-μSR、微波方法等独立测量获得)。Nb、YBCO和Ba(Fe,Co)$_2$As$_2$的数据证实了假设$λ_{\mathrm{opt}}>λ_{\mathrm{mag}}$,比值接近1.4;Pb的数据不明确,而MgB$_2$的数据表明$λ_{\mathrm{opt}}\simeqλ_{\mathrm{mag}}$,与标准理论预测一致。

英文摘要

While standard minimal coupling works well for Dirac fermions, its application to scalar fields features a known ``peculiarity'': the term linear in $A_μ$ does not coincide with the conserved Noether current of the interacting theory. We recently proposed choosing a different principle for electromagnetic interactions, namely a linear coupling $A_μJ^μ$ with $J^μ$ a (globally) conserved current, accepting the consequence that one must abandon full local gauge invariance in the electromagnetic sector and adopt an extended electrodynamics (of Aharonov--Bohm type) that can couple consistently to non-locally-conserved currents. We present the physical motivations offered for proposing the modified coupling and discuss general consequences of reducing gauge invariance. We then focus on the central condensed-matter claim: for bosonic charged condensates, the modified framework predicts a rescaled magnetic penetration depth $λ\to λ/\sqrt{2}$, while leaving other key qualitative features of superconducting electrodynamics and the type-I/type-II distinction unchanged (up to an equivalent rescaling of the GL parameter). Finally, we analyze experimental data for a London-length consistency check based on independent measurements of the ratio $n_s/m^\ast$ between carrier density and effective mass. We compare for five materials an ``optical'' penetration depth $λ_{\mathrm{opt}}$ inferred from IR/THz superfluid spectral weight with a ``magnetic'' depth $λ_{\mathrm{mag}}$ obtained independently (LE-$μ$SR, TF-$μ$SR, microwave methods, etc.). Data for Nb, YBCO and Ba(Fe,Co)$_2$As$_2$ confirm the hypothesis $λ_{\mathrm{opt}}>λ_{\mathrm{mag}}$, with a ratio not far from 1.4; data for Pb are inconclusive while data for MgB$_2$ indicate $λ_{\mathrm{opt}}\simeqλ_{\mathrm{mag}}$ as predicted by the standard theory.

2605.20498 2026-05-21 astro-ph.EP astro-ph.IM

JWST Observations of Asteroid 2024 YR4 Rule Out a 2032 Lunar Impact and Demonstrate a New Regime for Planetary Defense Follow-up

詹姆斯·韦伯望远镜对小行星2024 YR4的观测排除了2032年月球撞击的可能性,并展示了行星防御后续工作的新阶段

Julien de Wit, Andrew S. Rivkin, Marco Micheli, Davide Farnocchia, Artem Y. Burdanov, Bryan Holler, David J. Tholen, Thomas Mueller, Maxime Devogele, Dawn Graninger, Heidi B. Hammel, Stefanie N. Milam, Isaac S. Narrett, Petr Pravec, Cristina A. Thomas

AI总结 通过对小行星2024 YR4的JWST观测,排除了2032年月球撞击的可能性,并展示了在发现十米级天体的新背景下,行星防御后续工作的关键作用。

Comments Published by The Astrophysical Journal Letters

Journal ref 2026 ApJL 1003 L21

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AI中文摘要

在发现结束时,大约60米的近地天体2024 YR4与2032年12月22日近距离接近期间存在非零概率的月球撞击。虽然对地球没有威胁,但这种规模的月球撞击可能对地球轨道基础设施以及月球附近的人类探索产生影响。我们提供了2026年2月18日和26日的JWST/NIRCam观测数据,延长了观测时间跨度八个月,将2032年月球接近的不确定性降低了超过30倍,并构成了迄今为止最暗的近地天体检测,达到V≈30.5,超过了地面观测的V≈27的限制。更新的轨道解预测了与月球中心的距离为22900±800公里(1σ),从而排除了月球撞击的可能性。尽管由于参考恒星数量有限以及饱和和拖尾效应存在挑战,我们通过三种独立的分析方法得出天体位置,证明在小于50毫弧秒的水平上具有一致性。这些观测扩展了在地面无法访问的时间段的轨道时间跨度,将危险评估的时间线提前了两年,相对于下一次可行的地面恢复。这种能力在新兴的行星防御阶段中至关重要,该阶段由下一代调查发现的十米级天体所定义。这些天体更加常见,但迅速变得无法通过地面后续观测进行访问。在此阶段,危险评估可能受到后续观测的限制,需要有针对性的空间观测,如本文所展示的,以可靠地约束在操作相关的时间尺度上的撞击概率。

英文摘要

At the end of its discovery apparition, the $\sim$60 m near-Earth object 2024 YR4 was associated with a non-zero probability of lunar impact during its 2032 December 22 close approach. While posing no threat to Earth, a lunar impact of this scale could have consequences for Earth-orbiting infrastructure, as well as for human exploration on and around the Moon. We present new JWST/NIRCam observations from 2026 February 18 and 26 that extend the observational arc by eight months, reduce the uncertainty in the 2032 lunar encounter by a factor $>$30, and constitute the faintest detection of a near-Earth object to date, reaching $V \sim 30.5$ -- beyond the $V \sim 27$ ground-based limit. The updated orbit solution yields a predicted miss distance of $22{\,}900 \pm 800$ km (1$σ$) from the center of the Moon, thus ruling out a lunar impact. Despite challenges due to the limited number of reference stars and saturation and trailing effects, we derive astrometric positions with three independent analysis methods, demonstrating consistency at the $\lesssim$50 mas level. These observations extend the orbital arc at epochs when the object is not accessible from the ground, advancing the timeline for hazard assessment by two years relative to the next feasible ground-based recovery. This capability is critical in an emerging regime of planetary defense characterized by the discovery of decameter-scale objects by next-generation surveys. These objects are far more common but rapidly become inaccessible to ground-based follow-up. In this regime, hazard assessment can become follow-up-limited, requiring targeted space-based observations, such as those demonstrated here, to reliably constrain impact probabilities on operationally relevant timescales.

2605.20497 2026-05-21 cs.DC

Hypergraph Partitioning on GPU with Distinct Incident Hyperedges and Size Constraints

基于GPU的超图划分:具有不同入边超边和大小约束

Marco Ronzani, Cristina Silvano

AI总结 本文提出了一种基于GPU的多级超图划分算法,针对有限大小和每个分区不同入边超边的约束,利用GPU的层次化并行性,通过在内存中显式化超图的关联结构和唯一邻域,实现了高效的超图划分,实验结果显示在速度和连接性方面均有显著提升。

Comments 14 pages, submitted to IEEE TPDS

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AI中文摘要

超图划分是一个在工程中反复出现的NP难问题;其在大规模上的高效解决依赖于并行性。本文提出了一种以GPU为中心的算法,用于多级超图划分,旨在解决特定的问题约束:有限的大小和每个分区不同的入边超边。操纵超图需要深度嵌套的遍历和并发决策;我们的约束在其中进一步引入了集合操作。为此,我们围绕GPU的层次化并行性和问题的具体特性设计了算法。在形成分区时,我们将在内存中显式化超图的关联结构和唯一的邻域,以利用集合稀疏性和共享内存中的批量节点对评分。在细化分区时,我们将节点移动链化为改进的路径和循环,并通过并行减少的累积集合大小变化来检查其有效性。因此,我们的主导内核具有与本地超图参数成线性的跨度。结果表明,与顺序多级划分器相比,平均加速了380倍,并在连接性方面减少了1.2-2.0倍。通过少量修改,我们还支持k路平衡划分,运行速度比CPU方法快5倍,对于k=2,质量损失约为5%,在可比运行时间内优于现有的GPU划分器,且添加的约束处理逻辑没有可测量的开销。

英文摘要

Hypergraph partitioning is a recurring NP-hard problem in engineering; its efficient solution at scale hinges on parallelism. This work proposes a GPU-centric algorithm for multi-level hypergraph partitioning aimed at a specific set of problem constraints: limited size and distinct inbound hyperedges per partition. Manipulating hypergraphs requires deeply nested traversals and concurrent decision-making; our constraints impose further set operations amidst that. In turn, we design algorithms around the GPU's hierarchical parallelism and our problem's specifics. When forming partitions, we materialize the hypergraph's incidence structure and unique neighborhoods in memory to exploit set sparsity and batch node-pairing scores in shared memory. Upon refining partitions, we chain node moves into improving paths and cycles, checking their validity via cumulative set size variations reduced in parallel over moves. Thus, our dominant kernels exhibit a span linear in local hypergraph parameters. Results show an average 380x speedup and a 1.2-2.0x reduction in connectivity compared to a sequential multi-level partitioner. With minor changes, we also support k-way balanced partitioning, running 5x faster than CPU methods with a ~5% quality loss for k=2, outperforming an existing GPU partitioner at comparable runtime, with no measurable overhead from the added constraints handling logic.

2605.20493 2026-05-21 gr-qc hep-th

Electromagnetic duality degeneracy in dynamical black hole mergers

电磁双解在动态黑洞并合中的退化

José Ferreira, Gabriele Bozzola, Carlos A. R. Herdeiro, Vasileios Paschalidis, Miguel Zilhão

AI总结 本文研究了电磁双解在动态强引力环境中的表现,通过数值相对论模拟展示了电荷黑洞并合中的双解对称性,并发现双解配置的动力学相同而辐射极化旋转相同。

Comments 11 pages, 9 figures

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AI中文摘要

电磁双解是源自由爱因斯坦-麦克斯韦方程组的对称性,它旋转电场和磁场同时保持应力能张量不变。我们首次在动态强引力环境中实现了该对称性的非线性实现,通过在连续双解家族中进行带电黑洞并合的数值相对论模拟。从带电双星开始,通过双解旋转生成双极和磁极配置,并在共同的数值框架中进行演化。我们发现所有双解配置表现出相同时空动力学,而发射的电磁辐射通过极化旋转等于双解角度相关。我们的结果表明引力可观测量在电磁双解下具有退化性,并在辐射层面建立了双解配置的映射,证明电磁双解是动态爱因斯坦-麦克斯韦解的组织原则。

英文摘要

Electromagnetic duality is a symmetry of the source-free Einstein-Maxwell equations that rotates electric and magnetic fields while leaving the stress-energy tensor invariant. We present the first fully nonlinear realization of this symmetry in dynamical strong-gravity regimes by performing numerical relativity simulations of charged black hole mergers across a continuous duality family. Starting from electrically charged binaries, we generate dyonic and magnetically charged configurations via duality rotations and evolve them within a common numerical framework. We find that all dual configurations exhibit identical spacetime dynamics, while the emitted electromagnetic radiation is related by a rotation of its polarization equal to the duality angle. Our results demonstrate a degeneracy of gravitational observables under electromagnetic duality and provide a concrete mapping between dual configurations at the level of radiation, establishing electromagnetic duality as an organizing principle for dynamical Einstein-Maxwell solutions.

2605.20492 2026-05-21 gr-qc

Remarks on electrical Penrose process for magnetized Reissner-Nordström black hole

关于磁化Reissner-Nordström黑洞的电Penrose过程的若干评论

A. Baez, Nora Breton, I. Cabrera-Munguia

AI总结 本文研究了磁化Reissner-Nordström黑洞中电Penrose机制下的能量提取问题,推导了能量提取效率的通用表达式,并明确了磁场在控制能提取过程中的作用。

Comments 16 pages, 15 figures

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AI中文摘要

在电Penrose机制框架下,分析了磁化Reissner-Nordström黑洞的能量提取。外部磁场的存在诱导出轴对称配置和一个能提取能量的区域(即能区),即使在原本静态的时空背景下也能产生负能量态。通过分析粒子在径向运动转折点的衰变,我们推导出以度规系数和电磁势为变量的能量提取效率的一般表达式。该公式提供了一种直接识别能区的标准,我们显示磁场作为控制参数,同时调控能区的配置和过程的效率。特别是,确定了决定能量提取起始和抑制的临界磁场的解析表达式。我们的结果扩展了之前对磁化配置的电Penrose过程的分析,并澄清了外部场在增强或抑制从带电黑洞中提取能量中的作用。

英文摘要

The energy extraction from a magnetized Reissner-Nordström black hole is analyzed within the framework of the electric Penrose mechanism. The presence of an external magnetic field induces an axisymmetric configuration and an ergosphere (the region where energy extraction is possible) arises, allowing for negative energy states even in an otherwise static spacetime. By analyzing the decay of particles at turning points of the radial motion, we derive the general expression for the efficiency of the process in terms of the metric coefficients and the electromagnetic potential. This formulation provides a direct criterion for identifying the ergoregions and we show that the magnetic field acts as a control parameter that governs both the configuration of the ergosphere and the efficiency of the process. In particular, analytical expressions for the critical magnetic fields that determine the onset and suppression of energy extraction are determined. Our results extend previous analysis of the electric Penrose process for magnetized configurations and clarify the role of the external field in enhancing or inhibiting energy extraction from charged black holes.

2605.20491 2026-05-21 math.NA cs.NA physics.comp-ph quant-ph

A Simple GPU-Accelerated Solver for the Schrödinger Operator with Applications to Ground States and Hamiltonian Simulation

一个简单的GPU加速求解器用于Schrödinger算子及其在基态和哈密顿量模拟中的应用

Xinyu Liu, Xiangxiong Zhang

AI总结 本文提出了一种基于GPU的简单求解器,用于求解Schrödinger算子,并应用于基态计算和哈密顿量模拟,通过张量积直接求解方法和预条件共轭梯度法实现高效的数值计算。

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AI中文摘要

我们扩展了从拉普拉斯算子到Schrödinger算子$-Δ+ V$的张量积直接求解器。当势能$V_1$可分离时,通过每个轴的特征分解,可以在$d$维中以$O(N^{1+1/d})$的成本对算子$-Δ+ V_1$进行求逆或指数运算。在单个NVIDIA A100 GPU上,对于$10^9$自由度的3D问题,此计算成本不到1秒。对于不可分离的势能$V = V_1 + V_2$,相同的求解器提供预条件共轭梯度法(PCG)的预条件子$(-Δ+ V_1)^{-1}$,以及用于算子分裂时间积分器的传播器。对于有界$V_2$,我们证明预条件算子具有有界条件数和聚类谱,最多有有限个异常本征值,与网格大小和域大小无关(当$V_1$是限制性势能时)。这解释了实践中观察到的与网格和域无关的PCG迭代次数。我们应用此方法通过逆迭代法计算基态,通过$a_u$梯度流计算Gross-Pitaevskii能量,并通过近似qHOP和Magnus-2分裂方法在3D到9D上进行哈密顿量模拟。

英文摘要

We extend the tensor-product direct solver from the Laplacian to the Schrödinger operator $-Δ+ V$. When the potential $V_1$ is separable, the operator $-Δ+ V_1$ is inverted or exponentiated at cost $O(N^{1+1/d})$ in $d$ dimensions via per-axis eigendecomposition. On a single NVIDIA A100 GPU, this costs less than one second for $10^9$ degrees of freedom in 3D. For non-separable potentials $V = V_1 + V_2$, the same solver provides a preconditioner $(-Δ+ V_1)^{-1}$ for the preconditioned conjugate gradient (PCG) method and a propagator for operator-splitting time integrators. For bounded $V_2$, we prove that the preconditioned operator has a bounded condition number and a clustered spectrum with at most finitely many outlier eigenvalues, independently of the mesh size, and also independently of the domain size when $V_1$ is a confining potential. This explains the mesh- and domain-independent PCG iteration counts observed in practice. We apply this method to ground state computation via inverse iteration for linear problems and via the $a_u$ gradient flow for Gross--Pitaevskii energy in 3D, and also Hamiltonian simulation via the approximated qHOP and Magnus-2 splitting methods from 3D to 9D on a single NVIDIA GH200 GPU.

2605.20489 2026-05-21 astro-ph.GA astro-ph.SR

Dynamical Cluster Assembly Framework (D-CAF): The Link Between Star Cluster Formation and Expansion Rates

动态星团组装框架(D-CAF):星团形成与扩张速率之间的联系

Juan P. Farias, Alison Sills

AI总结 本文提出D-CAF框架,通过模拟嵌入式恒星形成历史与年轻恒星系统的动力学演化之间的联系,研究星团形成和扩张速率的关系,揭示气体收缩对恒星系统生存和扩张的影响。

Comments 25 pages, 10 figures. Submitted to Apj

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AI中文摘要

我们介绍了动态星团组装框架(D-CAF),一种基于AMUSE的框架,旨在将嵌入式恒星形成历史与年轻恒星系统动力学演化联系起来。我们通过在演化的背景势中逐步形成恒星来建模恒星形成,其中全局气体演化从真实的磁流体动力学(MHD)模拟中提取。在本项工作中,我们专注于原生气体的全局演化及其对恒星人口的动力学影响。在所有探索的MHD设置中,我们发现气体在恒星形成过程中继续坍缩,增加了嵌入恒星人口的中心集中度和速度尺度,在气体排出之前。利用受控的直接N体模拟网格,我们表明这种嵌入式演化强烈调节了年轻恒星系统的生存和后来的扩张。特别是,气体收缩在气体排出之前缩短了恒星交叉时间,使相同的气体去除时间尺度对恒星来说更趋于绝热。我们发现,当前恒星关联的扩张仍保留了形成过程中达到的嵌入动力学状态的信息。扩张速率受在气体排出前达到的速度尺度限制,而将此速度场转化为扩张的效率取决于气体排出时间尺度。最后,我们表明,当完整运动学信息可用时,一些常用的扩张诊断可以直接追踪年轻恒星系统的物理扩张速率,从而有可能利用恒星运动学来约束嵌入式恒星形成的动态条件。

英文摘要

We introduce the Dynamical Cluster Assembly Framework (D-CAF), an AMUSE-based framework designed to connect embedded star formation histories to the dynamical evolution of young stellar systems. We model star formation through the gradual formation of stars inside an evolving background potential, where the global gas evolution is extracted from realistic magneto-hydrodynamical (MHD) simulations. In this first work, we focus on the global evolution of the natal gas and its dynamical imprint on the stellar population. Across all explored MHD setups, we find that the gas continues to collapse while stars are forming, increasing both the central concentration and velocity scale of the embedded stellar population before gas expulsion. Using a controlled grid of direct $N$-body simulations, we show that this embedded evolution strongly regulates both the survival and later expansion of young stellar systems. In particular, gas contraction shortens the stellar crossing time prior to gas expulsion, making the same gas-removal timescale effectively more adiabatic for the stars. We find that the present-day expansion of stellar associations still preserves information about the embedded dynamical state reached during formation. The expansion rate is limited by the velocity scale reached before gas expulsion, while the efficiency with which this velocity field is transformed into expansion depends on the gas-expulsion timescale. Finally, we show that some commonly used expansion diagnostics can directly trace the physical expansion rate of young stellar systems when full kinematic information is available, opening the possibility of using stellar kinematics to constrain the dynamical conditions of embedded star formation.

2605.20488 2026-05-21 math.AP math.SP

Essential spectrum for the $p-$Laplacian

$p$-Laplace算子的本质谱

Lorenzo Brasco, Luca Briani, Giovanni Franzina

AI总结 本文引入了Dirichlet $p$-Laplace算子的一种变分本质谱概念,并将其扩展到非线性设置中,通过Persson定理的推广,给出了本质谱底部的几何刻画,同时展示了在$p=2$时与经典理论的一致性,并计算了矩形条上Dirichlet $p$-Laplace算子的完整谱。

Comments 35 pages, no figures

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AI中文摘要

我们引入了Dirichlet $p$-Laplace算子的一种变分本质谱概念。然后我们将经典的Persson定理扩展到这种非线性设置中。该结果以sharp $L^p$ Poincaré常数“在无穷远处”来刻画本质谱的底部。我们还表明在$p=2$的情况下,我们构造的本质谱与经典理论完全一致。最后,作为例子,我们计算了矩形条上Dirichlet $p$-Laplace算子的完整谱:它是纯本质谱,没有嵌入本征值。证明中的论证是初等的,并且对于线性情况$p=2$来说也是全新的。

英文摘要

We introduce a variational notion of essential spectrum for the Dirichlet $p-$Laplacian. We then extend the classical Persson Theorem to this nonlinear setting. This result provides a geometric characterization of the bottom of the essential spectrum, in terms of the sharp $L^p$ Poincaré constant ``at infinity''. We also show that in the case $p=2$ our construction of the essential spectrum is perfectly consistent with the classical theory. Finally, as an example, we compute the full spectrum of the Dirichlet $p-$Laplacian on a rectilinear strip: it is purely essential, with no embedded eigenvalues. The arguments of the proofs are elementary and new already for the linear case $p=2$.

2605.20487 2026-05-21 astro-ph.GA

Milky Way Mapper decoded abundances -- I. Shared disc enrichment patterns

银河制图仪解码丰度 -- I. 共享盘状富集模式

Melissa K. Ness, Sarah Aquilina, Jennifer Mead, Emily Griffith, Catherine Manea, Jonathan Bird, Andrew R. Casey, Lucy, Lu, Kathryn V. Johnston, Michael R. Blanton, James W. Johnson, Maja Jablonska, Leticia Carigi, José G. Fernández-Trincado, Ricardo López Valdivia, Ying-Yi Song, Juna Kollmeier

AI总结 通过分析70,057颗红巨星的元素丰度,研究银河盘的恒星形成和富集历史,揭示了高精度的核合成通道,并展示了这些通道在不同年龄、金属licity和空间范围内的变化。

Comments accepted MNRAS

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AI中文摘要

银河盘中的元素丰度反映了其恒星形成和富集历史,但通过理论预测这些丰度受到不明确的核合成产率和不明确的化学演化模型的限制。大规模调查提供了许多丰度,使多维洞察成为可能。然而,拥有如此多的数据使联合可视化和物理解释变得更加复杂。在这里,我们利用银河制图仪调查([Fe/H] > -1)中70,057颗红巨星的70,057颗红巨星的元素丰度(O, Mg, Al, Si, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Ce, Nd)进行研究,使用16个元素。为了解决这些元素的联合解释挑战,我们构建了一个生成性数据驱动模型,将每颗恒星的丰度向量表示为几个(4)潜在的核合成模式的线性组合。这些模式在种群中共享,但不同恒星之间的比例不同。该模型能够准确生成测量的丰度,对于约80%(95%)的恒星,χ² < 3(5)。模型失败揭示了吸积材料和金属贫乏盘富集的多重通道的作用。我们关联了恢复的模式,这些模式代表高精度(σ_P ~ 3%)的核合成通道,并与特定的富集源相关联;(早期和晚期)核心坍缩超新星、Ia型超新星以及渐近巨星分支恒星。我们随后探讨了富集通道的主导性在年龄、金属licity和盘的空间范围内的变化,并表明富集模式紧密耦合到轨道属性。平均模式比例随富集变化而平滑变化,并在高-低α序列之间的山谷处快速变化。我们的结果为改进对银河系演化的理解提供了框架。

英文摘要

Elemental abundances in the Milky Way disc trace its star-formation and enrichment history, but predicting these abundances from theory is limited by uncertain nucleosynthetic yields and poorly constrained chemical evolution models. Large surveys provide many abundances that enable multi-dimensional insight. However, having so much data available complicates joint visualisation and physical interpretation. Here, we examine the element abundances of 70,057 red giant stars from the Milky Way Mapper survey ([Fe/H] $> -1$), using 16 elements (O,~Mg,~Al,~Si,~S,~K,~Ca,~Ti,~V, ~Cr, Mn,~Fe,~Co,~Ni,~Ce,~Nd). To tackle the challenges of joint-interpretation of these elements, we build a generative data-driven model, expressing each star's abundance vector as a linear combination of a few ($4$) latent nucleosynthetic patterns. These patterns are shared among the population but vary in fraction between stars. The model accurately generates the measured abundances, with $χ^2 < 3$ (5) for $\sim$ 80\% (95\%) of stars. Model failures, where stars' abundances are not generated by the latent basis reveal accreted material and the role of multiple channels of metal-poor disk enrichment. We associate the recovered patterns, which represent high-precision ($σ_P \sim 3$\%) nucleosynthetic channels, with specific enrichment sources; (early and late) core-collapse supernovae, supernovae Type Ia, and asymptotic giant branch stars. We subsequently explore how the dominance of enrichment channels varies across age, metallicity and spatial extent of the disk, and show that enrichment patterns tightly couple to orbital properties. Mean pattern fractions vary smoothly with enrichment, and change rapidly across the valley between the high- and low-$α$ sequences. Our results provide a framework for improving our understanding of Galactic evolution in the Milky Way.

2605.20486 2026-05-21 math.FA

The reach and limits of slope eikonal equations in compact spaces

斜率雷克方程在紧空间中的作用与局限

David Salas, Sebastián Tapia-García, Francisco Venegas M

AI总结 本文研究了斜率雷克方程在紧空间中是否总能有点wise解的问题,并提供了这些空间的纯度度量特征以及示例和反例来说明该概念的范围和限制。

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AI中文摘要

众所周知,雷克方程在完备长度空间中是良好设定的。在文献中研究的解的概念中,有一种可以通过局部(下降)斜率定义在任何度量空间中的解:函数使得其斜率在域的每个点与给定数据一致。在本文中,我们探讨了问题“能否刻画那些在紧度量空间中,任何斜率雷克方程(在标准假设下)总能有点wise解的类?”我们提供了这些空间的纯度度量特征,以及一些有趣的例子和反例,以说明该概念的范围和限制。

英文摘要

It is a well known fact that the eikonal equation is well posed in complete length spaces. Among the studied notions of solutions in the literature, there is one that can be defined in any metric space using the local (descent) slope and considering pointwise solutions: functionals such that their slope coincides with the prescribed data at every point of the domain. In this work we explore the question ``Can we characterize the class of compact metric spaces in which every slope eikonal equation (under standard assumptions) always admits a pointwise solution?''. We provide a purely metric characterization of these spaces, as well as some interesting examples and counterexamples that illustrate the reach and limitations of the concept.

2605.20483 2026-05-21 eess.SP cs.SY eess.SY

A New Approach for ARMA Pole Estimation Using Higher-Order Crossings

利用高阶交叉的ARMA极点估计新方法

Timothy I. Salsbury, Ashish Singhal

AI总结 本文提出了一种利用高阶交叉来估计ARMA模型极点的新方法,通过自相关域将交叉事件计数转换为极点估计,其核心贡献是仅需存储原始数据的交叉计数即可完成极点估计,这对评估控制系统性能具有重要意义。

Journal ref Salsbury, Timothy I., and Ashish Singhal. "A new approach for ARMA pole estimation using higher-order crossings." Proceedings of the 2005, American Control Conference, 2005.. IEEE, 2005

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AI中文摘要

本文描述了一种新的方法,用于利用高阶交叉来估计ARMA模型的极点。该方法通过自相关域将交叉事件的计数转换为ARMA极点的估计。该方法的重要优势在于,交叉计数是唯一需要从原始数据中存储的特征。ARMA模型控制回路的极点对应于特征方程的根,因此对于评估控制性能具有重要价值。

英文摘要

The paper describes a new method for estimating the poles of an ARMA model using higher-order crossings. The method involves transforming counts of crossing events into estimates of ARMA poles via the autocorrelation domain. An important advantage of the method is that the crossing counts are the only features that need to be stored from the original data. The poles of an ARMA model of a control loop correspond to the roots of the characteristic equation and are thus useful for evaluating control performance.

2605.20481 2026-05-21 physics.ed-ph

Motion of a ball rolled over a shallow step

球体越过浅台阶的运动

Keith Zengel, Laruen Boehnert

AI总结 研究球体越过浅台阶时的运动规律,推导描述其运动的方程并验证实验结果,探讨球体在接触台阶边缘时是否发生滑动的影响。

Journal ref Phys. Teach. 61 (2023) 477-480

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AI中文摘要

一个被推向浅台阶上的球体会在垂直于台阶的方向上速度增加,这会导致球的轨迹偏转。本文推导了描述球体越过浅台阶的运动方程,并展示了我们的实验测试结果。这个简单的演示可以在任何有球和纸张堆的课堂中进行。先前的研究表明,一个被推向边缘的球体可以保持速度,如人们通常所认为的,但也可以经历速度的增加或减少。球体在接触边缘时可能无滑动地滚动,或者在离开边缘之前开始滑动。在本文中,我们将考虑球体在接触台阶边缘的整个过程中无滑动地滚动,然后接触较低的平台。我们考虑台阶高度相对于球体半径较小时,球体的运动在所有时间都容易观察,并且当遇到较低的平台时不会发生碰撞。这些浅台阶高度意味着我们可以假设球体在越过边缘时不会滑动。

英文摘要

A ball rolled over a shallow step will experience an increase in velocity along the direction perpendicular to the step. This causes a deflection in the ball's trajectory. In this paper we derive the equations that describe the motion of a ball rolled over a shallow step and present the results of our experimental test. This simple demonstration can be used in any classroom where the physics teacher has access to a ball and a stack of papers. Prior work has shown that a ball rolled over an edge can maintain its speed, as is commonly assumed, but it can also experience an increase or even decrease in speed. The ball can either roll without slipping while it is in contact with the edge, or else begin to slip before it leaves the edge. In this paper we will consider the case where the ball rolls without slipping the entire time it is in contact with the step edge, then contacts a lower platform. We work with shallow step heights relative to the radius of the ball so that the motion of the ball is easy to observe at all times, and so that the ball does not bounce when it encounters the lower platform. These shallow step heights mean that we can assume the ball does not slip as it moves over the edge.

2605.20480 2026-05-21 math.AG

Infinite transitivity and polynomial vector fields

无限传递性与多项式向量场

Rafael B. Andrist, Ivan Arzhantsev

AI总结 研究了多项式向量场的无限传递性,通过分析两个根子群的对角作用,证明了在$(\mathbb{C}^2)^m$上存在开轨道。

Comments 13 pages

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AI中文摘要

我们证明,对于许多根子群$H_1, H_2$的对,由$H_1, H_2$生成的群在$(\mathbb{C}^2)^m$上的对角作用对于任何正整数$m$都有开轨道。该结果基于对两个变量多项式在标准泊松括号下的李代数的研究。

英文摘要

We prove that for many pairs $H_1, H_2$ of root subgroups of the automorphism group $\text{Aut}(\mathbb{C}^2)$ the diagonal action of the group generated by $H_1, H_2$ on $(\mathbb{C}^2)^m$ has an open orbit for any positive integer $m$. The result is based on the study of the Lie algebra of polynomials in two variables with the standard Poisson bracket.

2605.20474 2026-05-21 physics.app-ph cond-mat.mtrl-sci

Ultrafast temperature diagnosis of dynamically compressed matter using millielectronvolt inelastic x-ray scattering beyond the first Brillouin zone

利用毫电子伏级非弹性X射线散射在第一布里渊区之外实现动态压缩物质的超快温度诊断

P. G. Heighway, J. S. Wark

AI总结 本文通过计算多层动态压缩目标的毫电子伏级X射线散射谱,研究了非弹性散射在中间q区域的复杂结构,并展示了如何利用Dornheim的拉普拉斯变换方法可靠地推断晶体温度,无论样品纹理如何。

Comments 19 pages, 9 figures in main article; 2 pages, 1 figure in supplementary material

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AI中文摘要

我们提出了多层动态压缩目标的毫电子伏级X射线散射谱的计算,该目标包括无结构的 ablator 层和晶体纹理样品层。我们的模型基于 Warren [B. E. Warren, Acta Crystallogr. 6, 803 (1953)] 的经典X射线热扩散散射公式,并包括弹性散射和一阶(单声子)非弹性散射对动态结构因子 $S(\mathbf{q},ω)$ 的贡献。我们专注于umklapp散射区域(即动量转移超出第一布里渊区),其中ablator散射被抑制,从而不会淹没感兴趣的晶体层的非弹性散射。我们证明,尽管在中间-q区域非弹性散射谱的结构更加复杂,但仍然可以可靠地利用Dornheim基于拉普拉斯变换的公式 [Dornheim et al., Phys. Plasmas 30, 042707 (2023)] 推断晶体温度,无论样品的纹理细节如何。

英文摘要

We present calculations of the millielectronvolt-scale x-ray scattering spectra of multilayered dynamic-compression targets comprising an unstructured ablator layer and a crystalline, textured sample layer. Our model builds on the classic formulation of x-ray thermal diffuse scattering by Warren [B. E. Warren, Acta Crystallogr. 6, 803 (1953)] and includes both elastic and first-order (single-phonon) inelastic scattering contributions to the dynamic structure factor $S(\mathbf{q},ω)$. We focus on the umklapp scattering regime (i.e., at momentum transfers outside the first Brillouin zone) where the ablator scattering that threatens to overwhelm the inelastic scattering from the crystalline layer of interest is suppressed. We show that, despite the considerably more complex structure of the inelastic scattering spectra in this intermediate-$q$ regime, it is still possible to reliably deduce the temperature of the crystal using Dornheim's Laplace-transform--based formalism [Dornheim et al., Phys. Plasmas 30, 042707 (2023)], regardless of the details of the sample's texture.

2605.20472 2026-05-21 physics.flu-dyn cs.NA math.NA

Entropy-stable discretizations for the compressible Euler equations using simple adaptive averages

利用简单的自适应平均进行可压缩欧拉方程的熵稳定离散化

Carlo De Michele, Ayaboe K. Edoh

AI总结 本文提出了一种利用简单自适应平均来稳定可压缩欧拉方程熵的方法,通过集中对流项实现非线性鲁棒性,并自然保持流方程的额外结构,如动能和压力平衡。

Comments 7 pages, 2 figures

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AI中文摘要

通过自适应地应用到密度和内部能量变量的平均值,实现了可压缩欧拉系统的熵稳定。该方法即使使用简化的对称平均(例如算术、几何或调和评估)及其相关的渐近熵守恒展开,也能实现非线性鲁棒性。所提出的方法通过集中对流项工作,可以自然地适应流方程的额外结构,如动能和压力平衡的保持。

英文摘要

Entropy stabilization of the compressible Euler system is achieved by adapting the averages that are applied to the density and internal energy variables. The approach achieves non-linear robustness despite the use of simplified symmetric means (e.g., arithmetic, geometric, or harmonic evaluations), including their related expansions for asymptotic entropy conservation. The proposed formulation works via centralized convective terms and can naturally adhere to additional structures of the flow equations such as kinetic-energy- and pressure-equilibrium-preservation.

2605.20471 2026-05-21 math.PR

Note on the Weak Convergence of Hyperplane $α$-Quantile Functionals and Their Continuity in the Skorokhod J1 Topology

关于超平面α-分位函数的弱收敛及其在Skorokhod J1拓扑中的连续性注记

Pietro Maria Sparago

AI总结 本文研究了超平面α-分位函数在Skorokhod J1拓扑下的弱收敛性及其连续性,探讨了α-分位期权定价问题,并证明了在特定条件下,随机时间函数在通常意义下的弱收敛性。

Comments Originally published in Sparago, P. "Note on the Weak Convergence of Hyperplane $α$-Quantile Functionals and Their Continuity in the Skorokhod J1 Topology", J. Theor. Probab., 38(2025) https://doi.org/10.1007/s10959-024-01390-w. This version contains minor corrections to: (i) the statement of Th. 1; (ii) a typo in the statement of Th. 3; (iii) the statements of Prop. 3, Le. 5, and Prop. 6

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AI中文摘要

α-分位函数M_{t,α}最初由Miura在1992年引入,Akahori、Dassios和Yor在1995年分别推导了重要的分布结果,特别关注α-分位期权定价问题。本文将经典的单维设置扩展到R^d空间,引入超平面α-分位函数,并发现α-分位函数作为映射R^d值的cadlag函数到R的显式连续性集。这种规定允许我们使用连续映射,并断言如果R^d值的cadlag随机过程X几乎必然属于此类连续性集,则X^n ⇒ X(即在Skorokhod意义下的弱收敛)则M_{t,α}(X^n) →^w M_{t,α}(X)(即通常意义下的弱收敛)。我们进一步讨论了随机时间函数的收敛条件,即第一次α-分位函数被击中的时间,应用于收敛于Skorokhod拓扑的cadlag函数序列。该函数的布朗分布研究见Chaumont (J Lond Math Soc 59(2):729-741, 1999)和Dassios (Bernoulli 11(1):29-36, 2005)。最后证明,如果序列的极限过程是一个具有非平凡协方差结构的多维布朗运动,则该随机时间函数应用于序列的过程在通常意义下弱收敛,与α-分位函数一起。

英文摘要

The $α$-quantile of a stochastic process $M_{t,α}$ has been introduced in Miura (Hitotsubashi J Commerce Manag 27(1):15-28, 1992), and important distributional results have been derived in Akahori (Ann Appl Probab 5(2):383-388, 1995), Dassios (Ann Appl Probab 5(2):389-398, 1995) and Yor (J Appl Probab 32(2):405-416, 1995), with special attention given to the problem of pricing $α$-quantile options. We straightforwardly extend the classical monodimensional setting to $\mathbb{R}^d$ by introducing the hyperplane $α$-quantile, and we find an explicit functional continuity set of the $α$-quantile as a functional mapping $\mathbb{R}^d$-valued cadlag functions to $\mathbb{R}$. This specification allows us to use continuous mapping and assert that if a $\mathbb{R}^d$-valued cadlag stochastic process $X$ a.s. belongs to such continuity set, then $X^n \Rightarrow X$ (i.e., weakly in the Skorokhod sense) implies $M_{t,α}(X^n) \to^\textrm{w} M_{t,α}(X)$ (i.e., weakly) in the usual sense. We further the discussion by considering the conditions for convergence of a 'random time' functional of $M_{t,α}$, the first time at which the $α$-quantile has been hit, applied to sequences of cadlag functions converging in the Skorokhod topology. The Brownian distribution of this functional is studied, e.g., in Chaumont (J Lond Math Soc 59(2):729-741, 1999) and Dassios (Bernoulli 11(1):29-36, 2005). We finally prove the fact that if the limit process of a sequence of cadlag stochastic processes is a multidimensional Brownian motion with nontrivial covariance structure, such random time functional applied to the sequence of processes converges, jointly with the $α$-quantile, weakly in the usual sense.

2605.20466 2026-05-21 cs.DB cs.DC

Fifty Years of Transaction Processing Research (extended)

事务处理研究五十周年(扩展版)

Philip A. Bernstein

AI总结 本文回顾了事务研究的早期历史(包括作者自身的研究),解释了为何事务研究至今仍持续进行(尽管似乎已解决),并推测其未来发展方向。

Journal ref Philip A. Bernstein. 2025. Fifty Years of Transaction Processing Research. In Companion of the 2025 International Conference on Management of Data (SIGMOD-Companion '25), June 22-27, 2025, Berlin, Germany. ACM, New York, NY, USA

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AI中文摘要

在本文中,我回顾了一些事务研究的早期历史(包括一些我的研究),解释了为何事务研究至今仍然持续(尽管似乎已解决该问题),并推测其未来。本文是发表于2025年国际数据库管理会议(SIGMOD-Companion '25)会议手册的论文的扩展版。

英文摘要

In this short paper, I recount some early history of transaction research (including some of my own), explain why transaction research continues to this day (even though it seems to be a solved problem), and speculate about its future. This is an extended version of the paper that appeared in the Companion of the 2025 International Conference on Management of Data (SIGMOD-Companion '25).

2605.20465 2026-05-21 cs.HC

Art Card Game (ACG): Embedding Illustration in Gameplay to Mitigate Artist Self-Criticism

Art Card Game (ACG): 将插图嵌入游戏玩法以缓解艺术家自我批评

Catherine Mullings, Michael S. Bernstein

AI总结 本文提出了一种在创作流程中减少艺术家自我批评的方法:Art Card Game (ACG),通过将插图任务嵌入到卡牌定制游戏中,使玩家在游戏对抗中展示插图作品,从而提高创作自豪感和游戏乐趣,减少自我批评。

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AI中文摘要

持续的自我批评--严厉的自我评价性自我对话--可能会削弱插画师的表现和福祉。传统干预措施依赖于心理治疗方法(例如共情训练),但它们位于插画工作流程之外,需要时间、指导和技能转移。我们提出了一种在工作流程内的替代方法:评价性离心法,一种机制将自我批评性评估从本质上自我评价的任务(如插画)转移到替代活动。我们将在Art Card Game (ACG)中实现评价性离心法,该游戏将插画整合到卡牌定制游戏中:玩家插画的卡牌成为可玩资产,在一对一战斗中使用。在为期四天的随机对照研究中,针对业余和专业插画师(N=38),ACG在相同插画约束条件下但没有评价性离心机制(例如多人游戏、游戏玩法)的对照条件下表现更优,产生了显著更高的创作自豪感和活动乐趣。自豪感和乐趣--与较低自我批评相关的积极情绪状态--解释了ACG如何减少自我批评。我们讨论了适用于创意支持工具的设计启示,这些工具可以将评价性离心法应用于各种创意领域。

英文摘要

Persistent self-criticism--harsh evaluative self-talk--can undermine illustrators' performance and well-being. Traditional interventions draw on psychotherapeutic approaches (e.g., compassion training) but sit outside the illustration workflow, requiring time, facilitation, and skill transfer. We propose an in-workflow alternative: evaluative off-centering, a mechanism redirecting self-critical evaluation away from an inherently self-evaluative task (like illustration) by embedding it in an alternative activity. We instantiate evaluative off-centering in Art Card Game (ACG) that integrates illustration into a card customization game: players illustrate cards that become playable assets in a head-to-head battle. In a four-day randomized controlled study with hobbyist and professional illustrators (N=38), ACG outperformed a control condition with identical illustration constraints but no evaluative off-centering mechanisms (e.g. multiplayer, gameplay), yielding significantly higher pride in produced artwork and activity enjoyment. Pride and enjoyment--positive affect states linked to lower self-criticism--help explain how ACG reduces self-criticism. We discuss design implications for creativity support tools that apply evaluative off-centering across creative domains.

2605.20464 2026-05-21 quant-ph

One-Dimensional Nonlinear Quantum Walks

一维非线性量子漫步

Yujia Shi, Thomas G. Wong

AI总结 该研究探讨了一种连续时间量子漫步,其中在离散路径和环上的单个顶点处存在三次非线性项,证明了非线性量子漫步可以被任意高保真度地捕获,与线性量子漫步在单维中快速扩散形成对比,并提出了这种捕获可用于量子态传输中的定时,以及作为量子记忆的形式。

Comments 8 pages, 6 figures

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AI中文摘要

我们探讨了一种从离散路径和环上的单个顶点开始的连续时间量子漫步,其中存在三次非线性性。此类非线性性出现在由Gross-Pitaevskii方程或非线性光学波导阵列描述的玻色-爱因斯坦凝聚体中。我们证明了非线性量子漫步可以被任意高保真度地捕获,这取决于非线性项的系数。这与线性量子漫步形成对比,线性量子漫步在单维中以快速扩散著称。我们提出这种捕获可用于量子态传输中的定时,其中量子比特在节点上保持直到准备好转移,并且可以在接收节点再次保持。此方案也可以解释为一种量子记忆的形式,其中陷阱和转移对应于量子信息的存储和释放。

英文摘要

We explore a continuous-time quantum walk starting at a single vertex on the discrete path and cycle with a cubic nonlinearity. Such nonlinearities arise in Bose-Einstein condensates described by the Gross-Pitaevskii equation or by nonlinear optical waveguide arrays. We analytically prove that the nonlinear quantum walk can be trapped to arbitrary fidelity depending on the coefficient of the nonlinear term. This contrasts with linear quantum walks, which are known for spreading quickly in one dimension. We propose that this trapping can be used for timing in quantum state transfer, where a qubit is held at a node until it is ready to be transferred, and it can also be held again at the receiving node. This scheme can also be interpreted as a form of quantum memory, with the trap and transfer corresponding to the storage and release of quantum information.

2605.20463 2026-05-21 physics.bio-ph

Effective strains enable rapid wound closure in jellyfish after injury

有效应变使受伤后的水母能迅速闭合伤口

Anne Materne, Zhiqi Shen, Chiara Sinigaglia, Carl D. Modes

AI总结 研究探讨了水母伤口闭合是否由组织力学而非组织重构或细胞增殖驱动,发现组织内应变可引发伤口闭合,为水母再生的生物物理机制提供了基础。

Comments 15 pages, 7 figures

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AI中文摘要

水母Clytia hemisphaerica具有惊人的再生能力,能在数小时内闭合甚至较大的伤口。这种快速的伤口闭合是否由组织力学而非组织重构或细胞增殖驱动尚存疑问。为此,我们通过在水母伞状体内部施加简单的预应变,测试是否能引发伤口闭合。为此,我们采用了计算模型中的弹簧格子模型,这是一种已用于研究组织力学问题的粗粒化弹性材料模型。我们发现,使用径向收缩(而非径向扩展)的应变,可在多种条件下引发伤口闭合。即使对于大切口和因此剩余的小块组织材料,这一结果也与实验发现一致。最后,我们推导了残余材料角度与可实现闭合量之间的解析表达式。这些结果为进一步研究水母再生的生物物理机制奠定了重要基础。

英文摘要

The jellyfish Clytia hemisphaerica possesses astounding regenerative capacities and is able to close even large wounds within a few hours. This rapid pace of wound closure raises the question whether tissue mechanics, rather than tissue restructuring or cell proliferation, might be underlying the process. We tested this possibility by asking if simple pre-strains within the jellyfish umbrella would be capable of initiating wound closure in a jellyfish body geometry. To this end, we employed an in silico spring lattice model, a coarse-grained model of elastic materials which has previously been established to study tissue mechanics problems. We found that, using radially contractile (but not radially extensile) strains, wound closure can indeed be initiated across a wide range of conditions. This is even true for large cut sizes and, hence, small pieces of remaining tissue material, in good agreement with the experimental findings. Finally, we derived an analytical expression for the expected amount of achievable closure as a function of the residual material angle. These results establish important foundations for further investigations of the biophysics underpinning jellyfish regeneration.

2605.20462 2026-05-21 cond-mat.mtrl-sci

Sub-10 mK "In-cell" Magnetic Refrigeration for Cryogen-free Cryostats

亚10毫开'在细胞内'磁制冷用于无液氦低温计

Alexander M. Donald, Nicolas Silva, Christopher J. Ollmann, Roch Schanen, Chao Huan, Sangyun Lee, Dominique Laroche, Richard P. Haley, Mark W. Meisel, Rasul Gazizulin

AI总结 本文提出了一种在无液氦低温计中实现亚10毫开温度的'在细胞内'磁制冷方法,通过有限的磁感应强度达到低于5毫开的温度,并讨论了该技术在高B/T条件下研究低维器件的应用潜力。

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AI中文摘要

本文介绍了一种'在细胞内'磁制冷的设计与实现,以在无液氦稀释制冷器中达到亚10毫开温度T。在有限的磁感应强度B(最高1T)下,可实现低于5毫开的超低温。在去磁过程后,低于5毫开的保持时间在约3至30小时之间变化。所开发的技术可用于在高B/T条件下研究超低电子温度的低维器件。

英文摘要

A design and implementation of "in-cell" magnetic refrigeration to achieve sub-10 mK temperatures T in cryogen-free dilution refrigerators is presented. The ultra low temperatures below 5 mK are attained in finite magnetic fields B up to 1 T. The holding time below 5 mK varies between about 3 to 30 hours, depending on the final magnetic field after demagnetization process. The developed technique can be used to study low dimensional devices at ultra low electron temperatures in the High B/T regime.

2605.20457 2026-05-21 cs.SI

The Structure and Dynamics of the Online MAHA-sphere

在线MAHA球体的结构与动态

Sabit Ahmed, Subigya Nepal, Henry Kautz

AI总结 本研究探讨了MAHA运动在线社区中意识形态的结构和动态,通过分析Reddit数据揭示了MAHA相关思想的交集、网络结构、参与模式、意见动态和语言差异,并发现疫苗怀疑可能成为更广泛反科学参与的入口。

Comments Submitted to [TBA]

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AI中文摘要

'Make America Healthy Again' (MAHA)运动在在线社区中创造了一个复杂的意识形态生态系统,其中倡导健康生活方式和全食饮食与疫苗怀疑和反科学态度并存。了解这些相互关联的信念如何互动、重叠和演变对于公共卫生沟通和干预至关重要。我们揭示了MAHA意识形态全谱系中功能重叠、网络结构、参与模式、意见动态和语言差异。利用覆盖六年时间的Reddit大规模数据,我们识别出12个MAHA相关主题,包括主流话题如运动、全食和屏幕使用,以及争议性话题如疫苗、口罩、转基因、氟化物等。我们开发了一个基于树状的少样本LLM流水线来对所有主题进行立场分类(支持、反对、中立),然后计算用户层面的意见分数以研究跨主题互动和意见变化。我们发现MAHA支持用户表现出强烈的跨主题捆绑和连贯的网络结构,而反MAHA用户则无法超出偶然情况。MAHA用户集中在少数主流子版块,但发布内容却广泛分布在MAHA相关社区中。在疫情期间,反氟化物和反口罩的帖子转为反疫苗帖子,后来转移到更广泛的反科学叙述,表明疫苗怀疑可能成为更广泛反科学参与的入口。支持和反MAHA社区也表现出不同的心理语言学特征,反映了更深层次的意识形态和修辞分歧。

英文摘要

The "Make America Healthy Again" (MAHA) movement has created a complex ideological ecosystem within online communities, where advocacy for healthier lifestyles and whole-food diets coexists with vaccine skepticism and anti-science attitudes. Understanding how these interconnected beliefs interact, overlap, and evolve is critical for public health communication and intervention. We uncover the functional overlaps, network structures, engagement patterns, opinion dynamics, and linguistic differences across the full spectrum of MAHA ideologies. Using large-scale Reddit data spanning six years, we identified 12 MAHA-adjacent themes, including mainstream topics such as exercise, whole food, and screen use, as well as contentious topics such as vaccines, masks, GMOs, fluoride, and others. We developed a tree-based few-shot LLM pipeline to classify stances (pro, anti, neutral) across all themes, then computed user-level opinion scores to examine cross-theme interactions and opinion shifts over time. We find that MAHA-aligned users exhibit strong cross-theme bundling and coherent network structure, whereas anti-MAHA users do not bundle beyond chance. MAHA users cluster in a few mainstream subreddits, but post in a wide ecosystem of MAHA-related communities. During the pandemic, anti-fluoride and anti-mask posters transitioned into anti-vaccination posts, and later moved to broader anti-science narratives, suggesting that vaccine skepticism may serve as an entry point into wider anti-science engagement. Pro- and anti-MAHA communities also exhibit distinct psycholinguistic profiles, reflecting deeper ideological and rhetorical divides.

2605.20455 2026-05-21 physics.ao-ph astro-ph.EP physics.class-ph physics.geo-ph physics.space-ph

Benchmarking Cylindrical Blast Wave Theory Against the OSIRIS-REx Sample Return Capsule Reentry

将圆柱爆波理论与OSIRIS-REx采样返回舱再入进行基准测试

Elizabeth A. Silber

AI总结 本文通过OSIRIS-REx采样返回舱再入事件的数据,评估了现有爆径公式在非烧蚀高速体中的适用性,并展示了信号周期作为约束爆径的稳健观测指标。

Comments 70 pages,

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AI中文摘要

基于圆柱爆波的弱冲击理论已被用于解释陨石次声波,但尚未系统地与一个具有已知参数的非烧蚀高速源进行基准测试。本研究的目标不是提出新的理论框架,而是评估现有爆径公式在高保真度地面真实数据集中的操作有效性。2023年9月24日的OSIRIS-REx采样返回舱再入提供了这样的基准,因为胶囊的几何形状、轨迹和次声波发射点可以从任务数据和射线追踪中确定,从而减少与烧蚀相关的源侧不确定性。利用39个次声波台站的观测数据,本基准测试评估了六种已发表的爆径(R_0)公式和三种弱冲击过渡系数(C)在一个分层大气传播模型中,以预测信号周期和峰值超压。基准测试确定Sakurai公式是最佳的非烧蚀体公式,当采用物理合适的C时,Jones/Plooster公式表现相当。Sakurai和Jones/Plooster分别产生线性周期中位绝对百分比残差为9%和11%。周期预测在这些传播距离上对C的敏感性很弱。在无烧蚀的情况下,常用的马赫-直径近似法会将R_0高估超过3倍。这些结果为将圆柱爆波理论应用于非烧蚀高速体建立了性能基准,并证明信号周期是约束R_0的稳健观测指标。

英文摘要

Weak shock theory based on cylindrical blast waves has been used to interpret meteor infrasound, but it has not been systematically benchmarked against a non-ablating hypersonic source with independently known parameters. The objective of this study is not to propose a new theoretical framework, but to evaluate the operational validity of the existing suite of blast radius formulations against a high-fidelity ground truth dataset. The OSIRIS-REx Sample Return Capsule reentry on 24 September 2023 provides such a benchmark because the capsule geometry, trajectory, and infrasound emission points are constrained from mission data and ray tracing, reducing source-side uncertainty associated with ablation. Using observations from 39 infrasound stations, this benchmarking study evaluates six published blast radius (R_0) formulations and three weak-shock transition coefficients (C) within a stratified atmospheric propagation model to predict signal period and peak overpressure. The benchmarking identifies the Sakurai formulation as the best-performing formulation for non-ablating bodies, with the Jones/Plooster formulation performing comparably when a physically appropriate C is adopted. Sakurai and Jones/Plooster yield linear-period median absolute percentage residuals of 9% and 11%, respectively. The period predictions show only weak sensitivity to C at these propagation distances. The Mach-diameter approximation commonly used in meteor studies overestimates R_0 by more than a factor of 3 in the absence of ablation. These results establish a performance baseline for applying cylindrical blast wave theory to non-ablating hypersonic bodies and demonstrate that the signal period is a robust observable for constraining R_0.