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2605.26566 2026-05-27 math.NA cs.NA

Exact-curved Lagrange finite elements for the Poisson problem in two dimensions

二维泊松问题的精确弯曲拉格朗日有限元

Hiroki Ishizaka

AI总结 针对二维弯曲域上的泊松问题,提出一种精确弯曲拉格朗日有限元框架,通过分解单元映射为仿射核心与弯曲映射,实现插值分析并证明误差估计。

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AI中文摘要

我们针对二维弯曲域上的泊松问题,开发了一种精确弯曲拉格朗日有限元框架。单元映射分解为 $F_K=Ψ_K\circΦ_{T_K}$,其中 $Φ_{T_K}$ 将参考三角形映射到仿射核心,$Ψ_K$ 将仿射核心映射到物理弯曲单元。这种分解将仿射缩放与曲率效应分离,使得插值分析可以首先在仿射核心上进行,然后转移到精确弯曲单元。对于协调线性拉格朗日单元,我们在精确弯曲三角形上证明了局部 $L^2$ 和 $H^1$ 插值估计。这些估计用物理单元上的传输方向导数表示,并且在所陈述的半正则性假设下,常数与仿射核心的各向异性形状无关。然后将这些插值估计应用于推导泊松问题的能量范数和 $L^2$ 误差估计。单位圆盘上的数值结果说明了直边与弯曲几何表示之间的差异:弯曲几何显著减少了几何误差,而主导的有限元误差仍然由 $\mathbb{P}^1$ 近似控制。

英文摘要

We develop an exact-curved Lagrange finite element framework for the Poisson problem on two-dimensional curved domains. The element map is factorised as $ F_K=Ψ_K\circΦ_{T_K}$, where $Φ_{T_K}$ maps the reference triangle to an affine core and $Ψ_K$ maps the affine core to the physical curved element. This factorisation separates affine scaling from curvature effects and allows the interpolation analysis to be carried out first on the affine core and then transferred to the exact curved element. For conforming linear Lagrange elements, we prove local $L^2$- and $H^1$-interpolation estimates on exact curved triangles. The estimates are expressed in terms of transported directional derivatives on the physical element, and the constants are independent of the anisotropic shape of the affine core under the stated semi-regularity assumptions. These interpolation estimates are then applied to derive energy-norm and $L^2$-error estimates for the Poisson problem. Numerical results on the unit disk illustrate the difference between straight-sided and curved geometric representations: the curved geometry reduces the geometric error substantially, while the leading finite element error remains governed by the $\mathbb{P}^1$ approximation.

2605.26565 2026-05-27 math.AG math.AC math.RT

Equivariant Maximal Cohen-Macaulay sheaves on the minimal orbit closures

最小轨道闭包上的等变极大Cohen-Macaulay层

Shang Xu

AI总结 本文研究单李代数中最小幂零轨道闭包上的极大Cohen-Macaulay层,通过辛分解上的向量丛分类和稳定子群的不可约表示构造等变层,并推广到经典类型和例外情形。

Comments 27 pages

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AI中文摘要

本文研究单李代数中最小幂零轨道闭包上的极大Cohen-Macaulay层。对于$A_n$型奇点,我们首先分类其辛分解上的向量丛,使得其前推为极大Cohen-Macaulay。然后通过稳定子群的不可约表示构造等变极大Cohen-Macaulay层。我们比较了这两种方法在极大Cohen-Macaulay Weil除子情形下的结果,并将等变构造推广到经典类型$B_n$、$C_n$和$D_n$。最后,我们为任意单李代数公式化该构造,并在例外情形中显式实现。

英文摘要

In this paper, we study maximal Cohen-Macaulay sheaves on closures of minimal nilpotent orbits in simple Lie algebras. For singularities of type $A_n$, we first classify vector bundles on their symplectic resolutions whose pushforwards are maximal Cohen-Macaulay. We then construct equivariant maximal Cohen-Macaulay sheaves via irreducible representations of the stabilizer group. We compare these two approaches in the case of maximal Cohen-Macaulay Weil divisors, and extend the equivariant construction to the classical types $B_n$, $C_n$, and $D_n$. Finally, we formulate the construction for an arbitrary simple Lie algebra and carry it out explicitly in the exceptional cases.

2605.26564 2026-05-27 astro-ph.SR

A Modified Multi-Level Tracking Scheme for the Detection of Sunspot Umbral Dots

一种改进的多层跟踪方案用于检测太阳黑子本影点

Rohan Eugene Louis, Amit Chaturvedi

AI总结 提出一种改进的多层跟踪方法,通过改变阈值条件并利用局部强度极大值来检测太阳黑子本影点,得到更小的有效直径和填充因子,但强度直方图与常规方法几乎一致。

Comments Accepted for publication in The Astrophysical Journal: 15 pages, 12 figures

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AI中文摘要

本影点(UDs)是太阳黑子和孔隙本影核心中的小尺度对流侵入。过去已使用不同方法确定UDs的物理性质。通常使用的方法之一是多层跟踪(MLT),该方法从最高强度水平开始,在等间距强度水平上标记空间结构,同时向下进行。本文探索了对常规MLT的一种改进方法,该方法也使用局部强度极大值,并改变阈值条件以包围一个UD,使得弥散UD不会显得比视觉上更大。比较了这两种MLT方法得到的UDs物理性质。这些方法应用于Hinode上搭载的50厘米太阳光学望远镜获取的四个太阳黑子的高分辨率蓝连续谱图像。此外,我们首次引入基于密度的空间聚类程序,以确定两种跟踪方法产生的差异。改进的MLT方法得到的有效直径中值范围为250-310公里,平均比常规MLT方法小70-90公里。改进方法中较低的有效直径与降低的UD填充因子12%-13%相关,而常规方法得到17%-19%。然而,这些差异仍在早期工作引用的数值范围内。另一方面,两种方法得到的UD平均强度直方图几乎相同。两种方法得到的UD空间聚类也显示出非常相似的结果。然而,UD存在优先的空间集中,特别是在本影核心高度不规则且靠近微弱亮桥的位置。UD局部聚类对太阳黑子演化阶段及其磁场复杂性的依赖性需要进一步探索。

英文摘要

Umbral dots (UDs) are small-scale convective intrusions in the umbral core of sunspots and pores. Different methods have been used in the past to determine the physical properties of UDs. One of the methods typically used is multi-level tracking (MLT), which tags spatial structures at equi-spaced intensity levels from the highest level while progressing downward. A modified approach to the regular MLT is explored in this article that also uses the local intensity maxima with a change in the threshold condition to enclose a UD, such that diffuse UDs do not appear extended than they visually appear. The physical properties of UDs from these two MLT approaches are compared. The methods are implemented on high-resolution blue continuum images of four sunspots from the 50-cm Solar Optical Telescope on board Hinode. In addition, we introduce a density-based, spatial clustering routine for the first time to ascertain the differences resulting from the two tracking methods. The modified MLT approach yields an effective diameter with median values ranging from 250-310 km which is on average 70-90 km smaller than the regular MLT approach. The lower effective diameter in the modified method is associated with a reduced UD fill fraction of 12%-13% while the regular method yields 17-19%. However, these differences are still within the range of values cited by earlier works. On the other hand, the histogram of the mean intensity of UDs from both methods is nearly identical. The spatial clustering of UDs from both methods also shows very similar results. There is, however, a preferential spatial concentration of UDs, particularly at locations where the umbral core is highly irregular and in the vicinity of faint light bridges. The dependency of the localized clustering of UDs on the evolutionary phase of the sunspot and its magnetic complexity needs to be further explored.

2605.26563 2026-05-27 cs.SE

TrajAudit: Automated Failure Diagnosis for Agentic Coding Systems

TrajAudit:智能体编码系统的自动化故障诊断

Minxing Wang, Xiaofei Xie, Yintong Huo

AI总结 针对仓库级编码轨迹中噪声多、上下文长的问题,提出TrajAudit框架,通过模式匹配过滤和测试报告先验知识辅助,实现高效故障诊断,在RootSE基准上定位准确率提升24.4个百分点,令牌消耗降低18%。

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AI中文摘要

智能体系统已被广泛研究以自动化软件工程任务,如错误修复。随着这些系统日益处理复杂任务,理解它们失败的位置和原因对于迭代改进和操作可靠性至关重要。现有的自动化故障诊断方法利用任务执行轨迹,但其有效性随着轨迹长度和复杂性的增加而显著下降。特别是对于仓库级编码任务,轨迹中充满了噪声,例如冗余的程序结构和冗长的代码上下文。此外,这些轨迹非常长,而长上下文推理仍然是LLM的已知弱点。为了解决这两个挑战,我们提出了TrajAudit,这是首个针对仓库级编码轨迹的故障诊断框架。TrajAudit采用了一个调查智能体,由两个模块支持:一个通过模式匹配和关键词检测过滤与失败无关的信息,另一个从测试失败报告中生成初步诊断作为先验知识,帮助智能体处理嘈杂的长上下文。调查智能体还可以按需调用工具检索过滤后的内容,确保关键信息得以保留,同时最小化噪声。我们还引入了RootSE,一个包含93个来自软件维护任务的真实智能体故障实例的基准,代表了迄今为止最复杂的轨迹诊断基准。在RootSE上的实验表明,TrajAudit在定位准确率上超过所有现有基线24.4个百分点以上,同时令牌消耗至少减少18%,证明了其实用有效性。我们希望这项工作能够引起社区对智能体软件工程中失败管理的关注,并为未来研究提供基础资源。

英文摘要

Agentic systems have been widely studied to automate software engineering jobs such as bug fixing. As these systems increasingly tackle complex tasks, understanding where and why they fail becomes essential for iterative refinement and operational reliability. Existing automated failure diagnosis approaches leverage task execution trajectories, yet their effectiveness degrades substantially as trajectory length and complexity increase. For repository-level coding tasks specifically, trajectories are laden with noise, such as redundant program structure and verbose code context. Moreover, these trajectories are very long, while long-context reasoning remains a known weakness of LLMs. To address these two challenges, we propose TrajAudit, the first failure diagnosis framework for repository-level coding trajectories. TrajAudit employs an investigator agent supported by two modules: one filters failure-irrelevant information through pattern matching and keyword detection, and the other generates a preliminary diagnosis from test failure reports as prior knowledge, helping the agent handle noisy long contexts. The investigator agent can further invoke tools to retrieve filtered content on demand, ensuring that critical information is preserved while noise is minimized. We also introduce RootSE, a benchmark of 93 real-world agentic failure instances sourced from software maintenance tasks, representing the most complex trajectory diagnosis benchmark to date. Experiments on RootSE show that TrajAudit outperforms all existing baselines by over 24.4 percentage points in localization accuracy, while reducing token consumption by at least 18%, demonstrating its practical effectiveness. We hope this work draws community attention to failure management in agentic software engineering and provides a foundational resource for future research.

2605.26558 2026-05-27 cs.AR

Cassandra: Enabling Reasoning LLMs at Edge via Self-Speculative Decoding

Cassandra: 通过自推测解码在边缘设备上实现推理型大语言模型

Soongyu Choi, Yuntae Kim, Muyoung Son, Joo-Young Kim

AI总结 提出Cassandra算法-硬件协同设计的自推测解码框架,通过细粒度数据选择和无训练剪枝与尾数截断构建高性能草稿模型,实现低批量场景下高达2.41倍加速。

Comments To appear at ISCA 2026

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AI中文摘要

推测解码已成为加速大语言模型(LLMs)的一种有前景的无损方法。随着推理型LLMs在解码阶段的开销日益增加,且基于近似的方法会降低准确性,无损推测解码对于高效推理变得至关重要。然而,现有方法在没有额外训练的情况下仍难以提供强大的低批量性能,限制了在消费级设备上的实际部署。为应对这一挑战,我们提出Cassandra,一种针对低批量场景优化的算法-硬件协同设计的自推测解码框架。Cassandra通过细粒度数据选择构建高性能、无需训练的草稿模型。利用优化的剪枝和尾数截断,它在模型权重和键值(KV)缓存中识别出最显著的值,从而在全精度并行验证之前实现快速的候选令牌生成。与先前基于层跳过或结构化KV压缩的自推测解码方法不同,Cassandra实现了显著更高的效率。为进一步减少Cassandra表示与标准浮点格式之间的格式转换开销,我们还引入了一个轻量级编码器-解码器硬件模块,旨在与商用GPU和NPU无缝集成。实验结果表明,与BF16基线相比,Cassandra无需额外训练即可实现高达2.41倍的加速。此外,在运行于NVIDIA GeForce RTX 4090上的Llama 3 8B模型中,与最先进的推测解码方法Eagle-3相比,Cassandra在相同内存预算下生成的令牌数多出1.81倍。

英文摘要

Speculative decoding has emerged as a promising lossless approach for accelerating Large Language Models (LLMs). As reasoning LLMs increasingly suffer from decode-stage overhead and approximation-based methods degrade accuracy, lossless speculative decoding has become essential for efficient inference. However, existing methods still struggle to deliver strong low-batch performance without additional training, limiting practical deployment on consumer devices. To address this challenge, we propose Cassandra, an algorithm-hardware co-designed self-speculative decoding framework optimized for low-batch scenarios. Cassandra constructs a high-performance, training-free draft model through fine-grained data selection. Using optimized pruning and mantissa truncation, it identifies the most salient values in both model weights and the Key-Value (KV) cache, enabling rapid candidate token generation before full-precision parallel verification. Unlike prior self-speculative decoding methods based on layer skipping or structured KV compression, Cassandra achieves significantly higher efficiency. To further reduce the overhead of format conversion between Cassandra representations and standard floating-point formats, we also introduce a lightweight encoder-decoder hardware module designed for seamless integration with commercial GPUs and NPUs. Experimental results show that Cassandra achieves up to 2.41x speedup over the BF16 baseline without additional training. Furthermore, on Llama 3 8B running on an NVIDIA GeForce RTX 4090, Cassandra generates 1.81x more tokens under the same memory budget compared to Eagle-3, a state-of-the-art speculative decoding method.

2605.26557 2026-05-27 cond-mat.mtrl-sci cond-mat.mes-hall physics.bio-ph

Near-Infrared-Triggered Photodynamic Antibacterial Therapy Using Rose Bengal-Coated Upconverting Nanoparticles

近红外触发孟加拉玫瑰红包覆上转换纳米颗粒的光动力抗菌疗法

Pratik Deshmukh, Nandini Ahuja, Bhumika Sharma, Khageswar Sahu, Srinibas Satapathy, Shovan Kumar Majumder

AI总结 本研究通过水热法合成LaF3:Er3+,Yb3+上转换纳米颗粒并包覆孟加拉玫瑰红,利用近红外光激发产生单线态氧,实现对耐甲氧西林金黄色葡萄球菌的高效光动力杀菌。

Comments 20 pages, 9 figures

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AI中文摘要

抗菌光动力疗法(aPDT)是一种有前景的灭活抗生素耐药细菌的方法,依赖于特定波长的光激活光敏剂(PS)。该过程产生活性氧,最终诱导细胞死亡。然而,传统aPDT受限于可见光穿透深度浅,限制了其在软组织和骨科组织治疗中的有效性。为克服这一限制,可使用近红外(NIR)吸收的PS。但NIR吸收的裸PS在注射后体内稳定性差、因亲水性导致的微生物靶向效果不佳以及非靶点组织损伤等问题。通过将NIR光与上转换纳米颗粒(UCNPs)结合可缓解这一问题,UCNPs介导NIR转换为可见光以有效激活PS。本研究采用水热法合成了LaF3:Er3+,Yb3+纳米颗粒,并包覆孟加拉玫瑰红(RB)——一种有前景的用于aPDT的亲水性PS,以评估NIR触发aPDT的潜力。合成的UCNPs的表征确认了晶体结构、尺寸分布和成功的RB功能化。光物理研究表明UCNPs与RB之间的高效能量转移,导致体外单线态氧(1O2)的产生。针对耐甲氧西林金黄色葡萄球菌(MRSA)——一种与软组织和骨科感染相关的超级细菌——的抗菌研究显示,在NIR照射下具有显著的光杀菌功效,表明RB包覆的UCNPs在aPDT应用中的潜力。

英文摘要

Antimicrobial photodynamic therapy (aPDT) is a promising modality for inactivation of antibiotic resistant bacteria, relying on the activation of a photosensitizer (PS) by light of a specific wavelength. This process results in the formation of reactive oxygen species, which ultimately induce cell death. However, aPDT in its conventional form, is limited by the shallow penetration of visible light, restricting its effectiveness for treatment of soft tissue and orthopaedic tissues. To overcome this limitation, near-infrared (NIR) absorbing PS can be used. However, poor stability in vivo after injection, ineffective microbial targeting due to hydrophilic nature and off-site tissue damage are the issues with use of NIR absorbing bare PSs. This issue can be mitigated by combining NIR light with a upconverting nanoparticles (UCNPs), which mediate in conversion of NIR into visible light for effective PS activation. In this study, LaF$_3$:Er$^{3+}$,Yb$^{3+}$ nanoparticles were synthesized using a hydrothermal method and coated with Rose Bengal (RB), a promising hydrophilic PS for aPDT, to evaluate the potential for NIR-triggered aPDT. Characterization of the synthesized UCNPs confirmed the crystalline structure, size distribution and successful RB functionalization. Photophysical studies demonstrated efficient energy transfer between UCNPs and RB, leading to singlet oxygen ($^1$O$_2$) generation in vitro. Antibacterial studies against Methicilin resistant Staphylococcus aureus (MRSA), a superbug of implicated soft tissue and orthopaedic infections, revealed significant photo-bactericidal efficacy upon NIR irradiation, indicating the potential of RB-coated UCNPs for aPDT applications.

2605.26556 2026-05-27 math.CO math.AT math.RT

Motivic Segre classes of Schubert cells and the connective formal group law

Schubert 胞腔的动机 Segre 类与连接形式群律

Raj Gandhi

AI总结 利用连接形式群律定义 d 步旗簇中 Schubert 胞腔的动机 Segre 类的单参数 β 形变,并给出 d=1 时的有理函数表示和组合公式。

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AI中文摘要

我们使用连接形式群律定义了 $d$ 步旗簇中 Schubert 胞腔的动机 Segre 类的单参数 ($\beta$-)形变。该 $\beta$-形变在 $\beta=1$ 时退化为 Schubert 胞腔的动机 Segre 类,在 $\beta=0$ 时退化为 Schubert 胞腔的 Segre-Schwartz-MacPherson 类。对于 $d=1$ 情形,我们利用可解格点模型定义了 $\beta$-形变类的有理函数表示,并利用 Knutson-Tao 拼图证明了 $\beta$-形变基中结构常数的组合公式。该拼图公式的证明涉及类型 $\widehat{a}_2$ 的多参数量子群表示的 intertwiner。我们通过证明典范元素满足 GKM 型条件,表明我们的 $\beta$-形变可视为旗簇余切丛的等变代数配边环中典范元素的商。

英文摘要

We use the connective formal group law to define a one-parameter ($β$-)deformation of the motivic Segre classes of Schubert cells in the $d$-step flag variety. This $β$-deformation specializes to the motivic Segre classes of Schubert cells when $β=1$ and to the Segre-Schwartz-MacPherson classes of Schubert cells when $β=0$. We define rational function representatives for the $β$-deformed classes in the $d=1$ case in terms of a solvable lattice model, and we prove a combinatorial formula for the structure constants in the $β$-deformed basis in the $d=1$ case using Knutson-Tao puzzles. The proof of the puzzle formula involves intertwiners for representations of the multi-parameter quantum group of type $\widehat{a}_2$. We show that our $β$-deformations can be viewed as quotients of canonical elements in a quotient of the equivariant algebraic cobordism ring of the cotangent bundle of the flag variety by proving that the canonical elements satisfy a GKM type condition.

2605.26555 2026-05-27 physics.app-ph

Chips in the Flatland : 2D Semiconductors for Future Computing Electronic

平面中的芯片:用于未来计算电子的二维半导体

Narin Trakarnvanich, Mitra Sanchali, Tong Su, Haiyu Meng, Jing Lu, Kah-Wee Ang, Lain-Jong Li, Chit Siong Lau, Yee Sin Ang

AI总结 本文综述了二维半导体从器件物理到集成电路芯片设计的进展,强调了多尺度紧凑建模在连接器件物理与电子设计自动化中的关键作用,并指出了实现功能性计算芯片的瓶颈与突破。

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AI中文摘要

随着晶体管缩放进入埃时代并接近其基本物理极限,二维半导体已成为未来计算中有前途的沟道材料候选者。尽管二维半导体的器件物理已被严格探索,但将这些纳米器件转化为全功能集成电路仍是一个 largely uncharted frontier。本综述弥合了二维半导体中以材料和器件为中心的突破与电路级芯片设计之间的鸿沟,这是一个迄今为止阻碍高性能单个晶体管转化为功能芯片的死亡之谷。我们追踪了二维半导体场效应晶体管从基本布尔逻辑系列和标准单元到复杂芯片架构的演变,包括RISC-V和单片CMOS微处理器的最新里程碑。关键的是,我们强调了多尺度紧凑建模(涵盖半经典、量子混合和数据驱动方法)作为器件物理与可扩展芯片开发的电子设计自动化工作流之间必要联系的重要作用。通过总结近期突破并识别二维半导体在制造和无晶圆厂轨迹中的瓶颈,本综述提供了见解,激励将概念验证的二维晶体管转化为全功能计算芯片,为未来由二维半导体赋能的埃时代计算技术铺平道路。

英文摘要

As transistor scaling approaches its fundamental physical limits in the Angstrom era, two-dimensional (2D) semiconductors have emerged as the promising channel material candidates for future computing. While the device physics of 2D semiconductors have been rigorously explored, translating these nanodevices into fully functional integrated circuits remains a largely uncharted frontier. This review bridges the gap between material- and device-centric breakthroughs and circuit-level chip design in 2D semiconductors, a valley of death that has so far prevented translation of high-performance individual transistors into functional chips. We track the evolution of 2D semi-conductor field-effect transistors from basic Boolean logic families and standard cells to complex chip architectures, including recent milestones in RISC-V and monolithic CMOS microprocessors. Critically, we highlight the indispensable role of multiscale compact modeling, spanning semiclassical, quantum-hybrid and data-driven approaches, as the necessary link between device physics and the electronic design automation workflows for scalable chip development. By summarizing recent breakthroughs and identifying the bottlenecks in both fab and fabless trajectories of 2D semiconductors, this review shall provide insights that motivates the translation of proof-of-concept 2D transistors into fully functional computing chips, paving a way towards future Angstrom era computing technology empowered by 2D semiconductors.

2605.26553 2026-05-27 astro-ph.HE

Constraining the Supernova Remnant Environment of FRB 190520B with Dispersion Measure and Scattering Timescale

利用色散量和散射时标约束FRB 190520B的超新星遗迹环境

Jia-Peng Wei, Chen Deng, Gwenael Giacinti, Ze-Cheng Zou, Chen-Ran Hu, Yong-Feng Huang, Jin-Jun Geng

AI总结 通过色散量和散射时标约束FRB 190520B周围超新星遗迹的物理参数,发现其具有浅抛射轮廓和年轻年龄(79.8–169.8年)。

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AI中文摘要

FRB 190520B是一个重复快速射电暴源,其大的色散量(DM)和时间展宽表明其周围环境致密且演化中。本文检验了FRB 190520B起源于大质量恒星核坍缩的可能性,其中心引擎嵌入一个在星风环境中膨胀的超新星遗迹(SNR),该SNR的演化由自相似解描述。我们利用FRB 190520B的观测DM和散射时标约束其周围SNR的物理参数和宿主星系DM。考虑了四种抛射轮廓和五种散射方案,共20个典型情况。发现仅6个情况被保留并提供可接受的拟合。所有保留情况都具有浅抛射轮廓和年轻的源年龄$t_0=79.8$–$169.8~{\rm yr}$。所有六个情况的抛射质量均较大,而动能和质量损失率范围很广。长期DM演化比详细散射演化拟合得更好。散射残差的上漂行为表明SNR内部存在额外成分或更复杂的结构。所有保留情况在所采用的散射理论内是自洽的,且暴周介质在推断的源年龄之前对GHz暴变得透明。

英文摘要

FRB 190520B is a repeating fast radio burst source whose large dispersion measure (DM) and temporal broadening suggest a dense and evolving local environment. In this work, we test the possibility that FRB 190520B originates from the core-collapse of a massive star so that its central engine is embedded in a supernova remnant (SNR) expanding into a wind environment, whose evolution is described by the self-similar solution. We use the observed DM and scattering timescale of FRB 190520B to constrain the physical parameters of its surrounding SNR and host-galaxy DM. Twenty typical cases are considered, arising from four ejecta profiles and five scattering prescriptions. It is found that only 6 cases are retained and provide acceptable fits. All retained cases have a shallow ejecta profile and a young source age of $t_0=79.8$--$169.8~{\rm yr}$. The ejecta mass is inferred to be large for all six cases, while the kinetic energy and mass-loss rate span a wide range. The secular DM evolution is reproduced better than the detailed scattering evolution. The up-drift behavior of the scattering residual suggests an additional component or more complicated structures inside the SNR. All retained cases are self-consistent within the adopted scattering theory and the circum-burst medium becomes transparent for GHz bursts before the inferred source ages.

2605.26551 2026-05-27 q-bio.NC cond-mat.dis-nn physics.bio-ph

Random neural networks match observed dimensionality of neural population recordings and motivate stronger experimental tests

随机神经网络匹配神经群体记录的观测维度并激励更强的实验检验

Zehui Zhao, Michael J Pasek, Ilya M Nemenman

AI总结 通过将有限测量时间和行为上下文变异性纳入动态平均场理论,证明随机神经网络预测的维度与大规模记录一致,并指出流形方向相似性比维度对网络结构更敏感。

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AI中文摘要

随机连接的神经网络长期以来作为研究神经群体集体动力学的理论工具,但与实验的定量比较仍然有限。最近的技术进步使得解析跨神经元的群体相关性成为可能,而随机神经网络等最小模型预测了它们的通用结构。两者是否定量一致尚未得到检验。在这项工作中,我们通过建立在动态平均场理论的最新进展基础上,并将两个额外的实验相关特征纳入模型:有限测量时间和跨行为上下文的变异性,检验了最小结构的随机神经网络能否解释神经群体记录中活动的低维度。我们表明,当包含这些因素时,从大规模记录中测量的维度与随机模型预测的值一致。然而,当前的记录持续时间使得难以利用维度来区分连接结构。我们进一步表明,分析预测的维度随外部输入强度非单调变化,并且在不同行为背景下记录的神经流形之间的方向相似性可能比维度对网络结构更敏感。总之,这些结果为实验设计提供了定量指导,以推断群体活动背后的连接结构。

英文摘要

Randomly connected neural networks have long served as a theoretical tool for studying collective dynamics in neural populations, yet quantitative comparisons to experiments remain limited. Recent technological advances have made it possible to resolve population-wide correlations across neurons, and minimal models such as random neural networks predict their generic structure. Whether the two agree quantitatively remains untested. In this work, we examine whether a minimally structured random neural network can account for the low dimensionality of activity in neural population recordings by building on recent developments in Dynamical Mean-Field Theory and incorporating two additional experimentally relevant features into the model: finite measurement time and variability across behavioral contexts. We show that, when these factors are included, the dimensionality measured from large-scale recordings is consistent with the values predicted by random models. However, current recording durations make it difficult to use dimensionality to discriminate among connectivity structures. We further show that analytically predicted dimensionality varies non-monotonically with external input strength, and that the orientation similarity between neural manifolds recorded under different behavioral contexts can be more sensitive to network structure than dimensionality is. Together, these results provide quantitative guidance for experimental design to infer the connectivity structure underlying population activity.

2605.26547 2026-05-27 math.OC

High-Probability Guarantees for Random Zeroth-Order Gradient Descent on Smooth Functions

光滑函数上随机零阶梯度下降的高概率保证

Haishan Ye

AI总结 针对具有Lipschitz梯度的确定性目标,提出一种双查询高斯有限差分方法,并给出其在高概率下的有限时域分析,证明在强凸、凸和非凸条件下达到ε-次优点的函数查询复杂度。

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AI中文摘要

随机零阶方法通常在期望下进行分析,但黑箱马尔可夫转换可能给出误导性的高概率保证,特别是迫使有限差分平滑半径随置信参数缩小。本文对具有Lipschitz梯度的确定性目标,直接给出了双查询高斯有限差分方法的有限时域高概率分析。该方法使用经典的两点估计器以及归一化步长\(\eta_t=1/(4L\norm{\bu_t}^2)\)。我们证明,在强凸性下,给定显式的有限差分平滑半径条件,该方法以至少\(1-δ\)的概率找到\(\varepsilon\)-次优点,所需函数查询次数为\(\cO((dL/\mu)\log(1/\varepsilon)+\log(1/δ))\)。我们还针对光滑凸目标建立了在水平集到解距离半径条件和路径平滑半径条件下的高概率保证。对于下有界光滑非凸目标,轨迹平均值的平稳性以\(\cO(L\Delta_0(d+\log(1/δ))/\varepsilon)\)次函数查询得到保证。证明结合了自适应高斯方向投影和的低尾界与累积有限差分平滑误差的高尾界。

英文摘要

Randomized zeroth-order methods are classically analyzed in expectation, but a black-box Markov conversion can give misleading high-probability guarantees, in particular by forcing the finite-difference smoothing radius to shrink with the confidence parameter. This paper gives a direct finite-horizon high-probability analysis of a two-query Gaussian finite-difference method for deterministic objectives with Lipschitz gradients. The method uses the classical two-point estimator together with the normalized stepsize \(η_t=1/(4L\norm{\bu_t}^2)\). We prove that it finds an \(\varepsilon\)-suboptimal point with probability at least \(1-δ\) using \(\cO((dL/μ)\log(1/\varepsilon)+\log(1/δ))\) function queries under strong convexity, subject to an explicit finite-difference smoothing-radius condition. We also establish high-probability guarantees for smooth convex objectives under a level-set distance-to-solution radius condition and a pathwise smoothing-radius condition. For lower-bounded smooth non-convex objectives, the trajectory average is certified in stationarity with \(\cO(LΔ_0(d+\log(1/δ))/\varepsilon)\) function queries. The proofs combine lower-tail bounds for adaptive sums of Gaussian directional projections with upper-tail bounds for accumulated finite-difference smoothing errors.

2605.26545 2026-05-27 eess.SP

Receiver-Centric TDOA Localization Framework for DAB Signals under Synchronization Impairments

面向同步损伤下DAB信号的接收端中心TDOA定位框架

Mustafa Furkan Beker, Abdullah Tan, Khaled Walid Elgammal, Mehmet Kemal Ozdemir

AI总结 针对GNSS拒止环境中的同步损伤问题,提出基于DAB信号的接收端中心多通道TDOA定位框架,利用空符号和相位参考符号实现同步,通过双差分、峰值旁瓣比加权和偏差校正提高鲁棒性,并采用CT-EKF滤波提升精度。

Comments Accepted for presentation at SIU 2026. 4 pages, 4 figures

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AI中文摘要

在全球导航卫星系统(GNSS)拒止环境中,地面机会信号(SoOP)为定位提供了替代方案,但时钟偏移、漂移和多径等同步损伤限制了性能。本文提出了一种基于数字音频广播(DAB)信号的接收端中心多通道到达时间差(TDOA)定位框架。该方法利用DAB空符号进行粗定时,利用相位参考符号(PRS)进行精细同步,随后进行子样本到达时间(TOA)估计。双差分公式消除了接收机间的时钟偏移,而基于峰值旁瓣比(PSR)的加权提高了鲁棒性。偏差校正步骤减轻了多径引起的误差。最后,协调转弯扩展卡尔曼滤波器(CT-EKF)进一步优化位置估计。结果表明,与采用高斯-牛顿估计的传统TDOA相比,该方法在具有挑战性的条件下提高了精度。

英文摘要

In Global Navigation Satellite System (GNSS)-denied environments, terrestrial signals of opportunity (SoOP) offer an alternative for positioning, but synchronization impairments such as clock offsets, drift, and multipath limit performance. This paper proposes a receiver-centric multi-channel time-difference-of-arrival (TDOA) localization framework based on Digital Audio Broadcasting (DAB) signals. The method exploits the DAB null symbol for coarse timing and the phase reference symbol (PRS) for fine synchronization, followed by sub-sample time-of-arrival (TOA) estimation. A double-difference formulation removes inter-receiver clock offsets, while a peak-to-sidelobe ratio (PSR)-based weighting improves robustness. A bias correction step mitigates errors due to multipath. Finally, a coordinated-turn extended Kalman filter (CT-EKF) further refines position estimates. Results show improved accuracy over conventional TDOA with Gauss-Newton estimation, especially in challenging conditions.

2605.26544 2026-05-27 quant-ph

Adaptive Shot Allocation for Recursive QAOA via Reinforcement Learning

基于强化学习的递归QAOA自适应测量分配

Euimin Lee, Shiho Kim

AI总结 针对递归QAOA中测量资源浪费问题,提出基于强化学习的自适应测量分配策略,在加权Max-Cut问题上实现36%的测量数减少且保持成功率。

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AI中文摘要

递归QAOA(RQAOA)通过使用浅层量子电路估计成对相关性并递归消除变量,直到经典求解器能够处理剩余实例,从而解决组合优化问题。每个消除步骤都需要测量次数,总测量成本随递归阶段数量增长。在近期量子设备上,增加测量次数会直接导致更严重的硬件级噪声(如读出误差和退相干),因此测量高效的执行不仅是降低成本的手段,更是直接影响解决方案可靠性的因素。虽然测量减少在NISQ算法中已被广泛研究,但RQAOA递归循环内的逐步测量控制却鲜受关注。我们将这种逐步分配问题建模为序列决策问题,并针对深度为1的RQAOA在加权Max-Cut实例上提出两种策略。一种手工设计的启发式方法基于步骤难度的局部指标分配测量次数,而一种表格型双Q学习智能体在拉格朗日约束目标下学习调整此基线的残差策略。两种方法均在固定预算公平协议下评估,该协议使所有策略的每步预算相等,且保持消除规则不变,从而隔离自适应测量控制的贡献。在一组涵盖不同规模和结构的加权图实例上,启发式方法相比均匀分配减少了约23%的总测量次数,而强化学习策略实现了36%的减少,且每次成功的有效测量次数低于两种基线。该改进在训练中未见的问题规模上仍然保持,表明强化学习能够在递归量子优化中发现高效、实例自适应的测量策略。

英文摘要

Recursive QAOA (RQAOA) solves combinatorial optimization problems by using shallow quantum circuits to estimate pairwise correlations and recursively eliminate variables until a classical solver can handle the residual instance. Each elimination step requires measurement shots, and the total shot cost grows with the number of recursive stages. On near-term quantum devices, increasing shot counts can translate directly into greater exposure to hardware-level noise sources such as readout errors and decoherence, making shot-efficient execution not merely a cost-reduction measure but a factor with direct implications for solution reliability. While shot reduction has been studied broadly across NISQ algorithms, step-wise measurement control inside the recursive loop of RQAOA has received little attention. We formulate this step-wise allocation as a sequential decision problem and propose two strategies for depth-1 RQAOA on weighted Max-Cut instances. A hand-crafted heuristic assigns shots based on local indicators of step difficulty, and a tabular Double Q-learning agent learns a residual policy that adjusts this baseline under a Lagrangian-constrained objective. Both methods are evaluated under a fixed-cap fairness protocol that equalizes the per-step budget across all strategies, and the elimination rule itself is kept unchanged so that the contribution of adaptive measurement control can be isolated. On a diverse set of weighted graph instances spanning a range of sizes and structures, the heuristic reduces total shots by approximately 23% relative to uniform allocation, and the RL policy achieves a 36% reduction with a lower effective shots per success ratio than both baselines. The improvement persists on problem sizes not seen during training, suggesting that reinforcement learning can discover efficient, instance-adaptive measurement strategies in recursive quantum optimization.

2605.26541 2026-05-27 cond-mat.soft

Super-Arrhenius Dynamic Slowdown Revealed by Slow Variable Modulation in the Fragile Supercooled Liquid

脆弱过冷液体中慢变量调制揭示的超阿伦尼乌斯动力学减缓

Zhiye Tang, Shubham Kumar, Shinji Saito

AI总结 通过分析Kob-Andersen Lennard-Jones模型中跳跃粒子的慢变量分布,揭示了非泊松动力学与空间关联增长如何导致超阿伦尼乌斯动力学减缓。

Journal ref J. Chem. Phys. 164, 144504 (2026)

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AI中文摘要

脆弱过冷液体中的超阿伦尼乌斯动力学减缓仍然是凝聚态物理学中未解决的核心问题之一。在本研究中,我们分析了典型脆弱玻璃形成液体——Kob-Andersen Lennard-Jones (KALJ) 模型中的粒子跳跃动力学。以跳跃粒子的位移作为反应坐标,我们证明了随着温度降低,非泊松动力学的出现。在轻度过冷区域,跳跃粒子第一配位壳层的外部区域在跳跃运动期间表现出显著的分布偏移。通过将该分布作为慢变量,将生存概率与其慢涨落极限进行比较,我们确认该区域的粒子调节了跳跃动力学,增强了跳跃速率的涨落,从而随着过冷过程的进行诱导了动力学减缓。随着温度降低,这种行为扩展到第二配位壳层及更远的区域,加剧了动力学减缓。这种负责动态无序的慢变量的空间增长与静态关联长度的增加密切相关。这些结果为KALJ模型中的超阿伦尼乌斯动力学减缓提供了微观机制。

英文摘要

The super-Arrhenius dynamic slowdown in fragile supercooled liquids remains one of the central unresolved questions in condensed matter physics. In this study, we analyze particle jump dynamics in a prototypical fragile glass-forming liquid, the Kob-Andersen Lennard-Jones (KALJ) model. Using the displacement of jumping particles as the reaction coordinate, we demonstrate the emergence of non-Poissonian dynamics as the temperature decreases. In the mildly supercooled regime, the outer region of the first coordination shell of a jumping particle exhibits a significant distribution shift during the jump motion. By comparing the survival probability with its slow-fluctuation limit using this distribution as a slow variable, we confirm that particles in this region modulate the jump dynamics, enhance the jump rate fluctuations, and thereby induce the dynamic slowdown as supercooling proceeds. As the temperature decreases, this behavior extends to the outer regions of the second coordination shell and beyond, intensifying the dynamic slowdown. This spatial growth of the slow variables responsible for dynamic disorder exhibits close correspondence with an increase in the static correlation length. These results provide a microscopic mechanism for the super-Arrhenius dynamic slowdown in the KALJ model.

2605.26539 2026-05-27 cs.SE cs.CR

FuzzPilot: Plateau-Triggered Recipe Validation for Structured Text Fuzzing

FuzzPilot: 用于结构化文本模糊测试的高原触发式配方验证

Zhiyi Yao

AI总结 FuzzPilot 通过高原触发式配方验证,在覆盖率停滞时利用快照和微测试评估变异配方,以提升 AFL++ 的模糊测试效率。

Comments 41 pages, 7 figures, 7 tables. Preliminary cJSON-only evaluation (N=5 main, N=3 ablation; descriptive statistics, no significance claims). Code and 25-run artifacts at https://github.com/Qiao-Zhiyi/fuzz_agent (tag paper01-arxiv-v1). Venue-version Stage-1 pilot on libxml2, sqlite3, openssl_x509 currently in flight; v2 will report those results

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AI中文摘要

FuzzPilot 是 AFL++ 的一个控制器,它将昂贵的推理移出变异热路径。当覆盖率停滞时,它会快照语料库,准备候选变异配方,在短期的独立 AFL++ 微测试中评估它们,并仅推广具有正验证奖励的配方。配方是 JSON 数据,而非生成的代码:原生自定义变异器使用操作符权重、字节范围、语料库选择规则和字典令牌。候选配方可以来自本地规则或语言模型代理,其中包含 Ghidra 导出的常量和反编译上下文作为目标提示。本预印本报告了一个刻意狭窄的 cJSON 评估。我们比较了 vanilla AFL++ 和完整的 FuzzPilot 代理,每组进行五次 14,400 秒的重复实验。cJSON 已饱和:基线 AFL++ 在约 2,500 秒的中位数时间达到暴露的 269 条边的上限。因此,实验并未表明语言模型提议能提高覆盖率或泛化到 cJSON 之外。在此范围内,FuzzPilot 保持了吞吐量(中位数 execs_per_sec 约为基线的 1.06 倍),显示描述性更短的中位数高原时间(1,384 秒对比 2,532 秒),但在 N=5 时差异不显著(Mann-Whitney p=0.42)。验证门评估了 20 个模型提议的配方,由于所有奖励为零,没有推广任何配方。观察到的高原减少更可能归因于控制器的快照和重启机制,而非模型或配方变异器。此版本最好作为可审计的实现报告和正在进行中的非饱和目标评估的基线。

英文摘要

FuzzPilot is a controller for AFL++ that moves expensive reasoning out of the mutation hot path. When coverage plateaus, it snapshots the corpus, prepares candidate mutation recipes, evaluates them in short isolated AFL++ micro-campaigns, and promotes only recipes with positive validation reward. Recipes are JSON data, not generated code: a native custom mutator consumes operator weights, byte ranges, corpus-selection rules, and dictionary tokens. Candidate recipes can come from local rules or from a language-model agent, with Ghidra-derived constants and decompiled context as target hints. This preprint reports a deliberately narrow cJSON evaluation. We compare vanilla AFL++ and the full FuzzPilot agent over five 14,400 s repetitions per arm. cJSON is saturated: baseline AFL++ reaches the exposed 269-edge ceiling at a median of about 2,500 s. The experiments therefore do not show that language-model proposals improve coverage or generalize beyond cJSON. Within this scope, FuzzPilot preserves throughput (median execs_per_sec about 1.06x baseline), shows a descriptively shorter median plateau (1,384 s versus 2,532 s), but the difference is not statistically significant at N=5 (Mann-Whitney p=0.42). The validation gate evaluated 20 model-proposed recipes and promoted none because all rewards were zero. The observed plateau reduction is more likely due to controller snapshot and restart machinery than to the model or recipe mutator. This version is best read as an auditable implementation report and baseline for ongoing non-saturated-target evaluation.

2605.26536 2026-05-27 cond-mat.mtrl-sci cond-mat.mes-hall physics.app-ph

Conditions for domain-free negative capacitance

无畴负电容的条件

Prasanna Venkatesan Ravindran, Priyankka Gundlapudi Ravikumar, Asif Islam Khan

AI总结 本文通过分析铁电-介电异质结构中的畴壁能参数,提出实现理想无畴负电容的临界条件,并强调通过高通量设计与工程控制畴壁能的重要性。

Journal ref IEEE Transactions on Electron Devices 70.8 (2023): 4493-4496

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AI中文摘要

尽管负电容已在铁电-介电异质结构中以电容增强的形式得到证实,但迄今为止所有实验证据都表明其中存在畴。在此,我们探讨的问题是:在铁电-介电异质结构中实现理想、无畴负电容的条件是什么?我们的主要主张是,对于给定厚度的铁电层和介电层,存在一个畴壁能参数的临界值——高于该值时,系统将稳定在理想且鲁棒的无畴负电容状态,并且能够抵抗畴的形成。我们的分析表明,要实现理想的负电容,应致力于通过高通量设计、发现和工程化铁电材料,从理论和实验两方面全面理解控制畴壁能的方法。

英文摘要

While negative capacitance has been demonstrated in ferroelectric-dielectric heterostructures in the form of capacitance enhancement, all experimental evidence, to date, suggests the existence of domains therein. Here, we address the question: what are the conditions to achieve ideal, domain-free negative capacitance in ferroelectric-dielectric heterostructures? Our main claim is that for given thicknesses of the ferroelectric and the dielectric layers, there is a critical value of domain wall energy parameter -- above which the system would be stabilized in an ideal and robust domain-free negative capacitance state and would be robust against domain formation. Our analyses suggest that to achieve ideal negative capacitance, efforts should lie in understanding the means to control the domain wall energy on all fronts, both theory and experiments via high throughput design, discovery, and engineering of ferroelectrics.

2605.26534 2026-05-27 eess.SY cs.SY

Learning Safe-by-Design Neural Network Controllers

学习安全设计的神经网络控制器

Yang Zhao, Jungeun Lee, Jeong hwan Jeon, Sze Zheng Yong

AI总结 提出联合学习神经网络控制器和神经网络参数化控制障碍函数参数的方法,避免在线二次规划安全滤波器,实现安全约束的可靠满足。

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AI中文摘要

由控制障碍函数(CBF)构建的安全滤波器通常附加到预训练的神经网络控制器上,以强制执行安全要求。然而,这种具有手动调整、固定CBF参数的解耦设计往往无法适应底层控制器,导致过于保守的解决方案。因此,给定一个有效的CBF,我们通过联合学习神经网络控制器和神经网络参数化的CBF参数来解决这些限制,通过构造强制执行所得仿射安全约束,并避免运行时在线二次规划(QP)安全滤波器。为了进一步提高计算效率和可扩展性,我们引入了一种轻量级投影架构,该架构无需完全枚举约束即可强制执行约束。广泛的仿真评估表明,在降低计算成本的同时,实现了可靠、可扩展的安全约束满足。

英文摘要

Safety filters constructed from control barrier functions (CBFs) are commonly appended to pre-trained neural network controllers to enforce safety requirements. However, this decoupled design with hand-tuned, fixed CBF parameters often fails to adapt to the underlying controller, yielding overly conservative solutions. Thus, given a valid CBF, we address these limitations by jointly learning a neural network controller and neural-network-parameterized CBF parameters, enforcing the resulting affine safety constraints by construction and avoiding an online quadratic program (QP) safety filter at run time. To further improve computational efficiency and scalability, we introduce a lightweight projection architecture that enforces constraints without full constraint enumeration. Extensive simulation evaluations demonstrate reliable, scalable safety constraint satisfaction at reduced computational cost.

2605.26532 2026-05-27 stat.ME

Global Average Treatment Effects for Individualized Randomization Experiments with Aggregate Data

基于聚合数据的个体随机实验的全局平均处理效应

Shuguang Yu, Ting Li, Yuchen Lu, Chengchun Shi, Fan Zhou, Zhichao Zou, Peng Zhen, Hongtu Zhu

AI总结 针对个体随机实验中存在时空干扰且仅能获取聚合数据的问题,提出IRE-VCDP模型以估计全局平均处理效应(GATE),并给出估计与推断方法及理论保证。

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AI中文摘要

个体随机实验是在复杂环境中优化个性化决策的在线平台的核心。然而,在双边市场中,由于强烈的时间和跨单元干扰,标准的处理效应估计往往无效,而当由于隐私或系统限制只能获得聚合数据时,这一问题更加复杂。为了解决这些问题,我们仅使用来自处理组和对照组的群体级数据来识别全局平均处理效应(GATE)。我们首先基于聚合观测建立识别条件,然后提出个体随机实验变系数决策过程(IRE-VCDP)模型,该模型通过供需动态来解释干扰。在此框架基础上,我们开发了GATE估计和统计推断的完整程序,并给出了所提检验的理论保证。利用来自领先网约车平台的数据进行的大量模拟和真实实验证明了我们方法的有效性。

英文摘要

Individualized randomized experiments are central to online platforms for optimizing personalized decisions in complex environments. In two-sided markets, however, standard treatment effect estimation is often invalid due to strong temporal and cross-unit interference, a challenge compounded when only aggregated data are available because of privacy or system constraints. To address these issues, we identify the Global Average Treatment Effect (GATE) using only group-level data from treatment and control groups. We first establish identification conditions based on aggregated observations, and then propose the Individualized Randomized Experiment Varying Coefficient Decision Process (IRE-VCDP) model, which accounts for interference through supply-demand dynamics. Building on this framework, we develop a complete procedure for estimation and statistical inference of the GATE, along with theoretical guarantees for the proposed test. Extensive simulations and real-world experiments using data from a leading ridesharing platform demonstrate the effectiveness of our approach.

2605.26531 2026-05-27 eess.SP

Multi-/Uni-Cast Non-Orthogonal Multiple Access-Based INAC

基于多播/单播非正交多址的集成导航与通信

Yaoyu Zhang, Xin Sun, Tianwei Hou, Anna Li, Sofie Pollin, Yuanwei Liu, Arumugam Nallanathan

AI总结 提出一种基于多播/单播非正交多址(MUC-NOMA)的集成导航与通信(INAC)信号结构,通过共享伪噪声序列和功率分配策略实现信号级融合,并推导了误码率和定位精度的闭式表达式。

Comments 14 pages,10 figures,journal

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AI中文摘要

随着卫星通信与导航的快速发展,迫切需要将两种技术集成到同一卫星系统中,以实现可靠的通信和精确的导航服务。通过结合多播/单播(MUC)和非正交多址(NOMA)技术,我们提出了一种新颖的基于MUC-NOMA的集成导航与通信(INAC)信号结构,其中导航和通信信号共享一个公共伪噪声(PN)序列,从而在信号级别上集成卫星通信与导航。根据不同的功率分配策略,定义了两种场景:面向多播的(MO-)INAC和面向单播的(UO-)INAC,分别将更大比例的功率分配给多播或单播信号。为减轻同信道干扰,我们在接收端采用连续干扰消除(SIC),并为所提出的INAC信号设计了一种信号处理算法。随后,推导了导航和通信信号的误码率(BER)以及导航信号的定位精度的闭式表达式。为获得更深入的见解,评估了功率分配因子和通信速率的影响。分析结果表明:i)在MO-INAC场景中,当更多功率分配给多播信号时,导航信号的定位和BER性能优异;ii)在UO-INAC场景中,当更多功率分配给单播信号时,共享资源中的干扰减少;iii)测距精度随通信数据速率的增加而降低。数值结果证实了MO-INAC场景在MEO卫星上的优越BER和定位精度。

英文摘要

With the rapid development of satellite communication and navigation, there is an urgent need to integrate both technologies to achieve reliable communication and precise navigation services within the same satellite system. By combining multi-/uni-cast (MUC) and non-orthogonal multiple access (NOMA) technologies, we propose a novel MUC-NOMA-based integrated navigation and communication (INAC) signal structure, in which the navigation and communication signals share a common pseudo noise (PN) sequence, thereby integrating satellite communication and navigation at the signal level. According to different power allocation strategies, two scenarios are defined: multi-cast-oriented (MO-) INAC and uni-cast-oriented (UO-) INAC, where a greater portion of power is assigned to either the multi-cast or the uni-cast signal, respectively. To mitigate co-channel interference, we employ successive interference cancellation (SIC) at the receiver and design a signal processing algorithm for the proposed INAC signal. Then, closed-form expressions are subsequently derived for the bit error rates (BER) of both the navigation and communication signals, along with the positioning accuracy of the navigation signal. To gain further insights, the impacts of power allocation factors and communication rates are evaluated. Our analysis results show that: i) In the MO-INAC scenario, the positioning and BER performance of navigation signal are excellent when more power is assigned to the multi-cast signal; ii) In the UO-INAC scenario, interference in the shared resources is reduced when more power is assigned to the uni-cast signal; iii) The ranging accuracy decreases as the communication data rate increases. Numerical results confirm the superior BER and positioning accuracy of the MO-INAC scenario for MEO satellites.

2605.26529 2026-05-27 cond-mat.mes-hall cond-mat.mtrl-sci

Anharmonic Quantum Transport Analysis of Thermal Transport Anomalies in Ultrathin Silicon Nanowires

超薄硅纳米线热输运异常的非谐量子输运分析

Lokanath Patra, Mayur Pratap Singh, Satish Kumar

AI总结 采用非谐非平衡格林函数结合密度泛函理论训练的神经进化势,揭示了超薄硅纳米线热导率随直径非单调变化的量子机制,包括Poiseuille-like声子流体动力学和低温准弹道输运。

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AI中文摘要

低维半导体中的热输运对于纳米电子学、量子器件和热电器件的热管理至关重要。最近的分子动力学(MD)研究在超薄硅纳米线(NWs)中发现了热导率(k)随直径的非单调依赖性。然而,经典MD方法在低温和强限制区域受到限制。本工作通过采用非谐非平衡格林函数(NEGF)模拟结合密度泛函理论训练的神经进化势,从完全量子力学的角度解释了这一异常现象。对于[001]和[110]取向的纳米线,在10-300 K温度范围内,k随直径d减小,在d_c = 6.24 nm和5.50 nm处达到最小值,然后随d增加。在室温下,这种行为源于限制区域中动量守恒的正常散射相对于Umklapp过程占主导地位,从而使得Poiseuille-like流体动力学声子流与边界散射竞争。在低温下,强径向限制使声子谱量子化,只有低频声子(< 2 THz)通过长波长模式的准弹道传播显著贡献于热输运,如谱热导所示。与经典MD相比(由于玻尔兹曼统计对高频振动的过度激发、忽略量子抑制以及高估量子限制更强的较细纳米线的热导率,经典MD在低温下不准确),NEGF框架即使在低温(如10 K)下也能提供定量准确性。

英文摘要

Thermal transport in low-dimensional semiconductors is crucial for advancing thermal management in nanoelectronics, quantum devices, and thermoelectric devices. Recent molecular dynamics (MD) studies have identified a nonmonotonic dependence of thermal conductivity (k) on diameter in ultrathin silicon nanowires (NWs). However, classical MD methods are limited at low temperatures and in strongly confined regimes. This work introduces a fully quantum-mechanical perspective on this anomaly by employing anharmonic non-equilibrium Green's function (NEGF) simulations combined with density-functional-theory-trained neuroevolution potentials. For [001]- and [110]-oriented NWs, k decreases with diameter d to a minimum at d_c = 6.24 nm and 5.50 nm, respectively, then rises with d, for a temperature range of 10-300 K. At room temperature, this behavior arises from dominant momentum-conserving normal scattering relative to Umklapp processes in confined regimes, thereby enabling Poiseuille-like hydrodynamic phonon flow that competes with boundary scattering. At cryogenic temperatures, strong radial confinement quantizes the phonon spectrum, and only low-frequency phonons (< 2 THz) significantly contribute to heat transport through quasi-ballistic propagation of long-wavelength modes, as demonstrated by the spectral thermal conductance. In contrast to classical MD, which is inaccurate at low temperatures due to overexcitation of high-frequency vibrations by Boltzmann statistics, neglect of quantum suppression, and overestimation of thermal conductivity in thinner NWs with stronger quantum confinement, the NEGF framework provides quantitative accuracy even at low temperatures, such as 10 K.

2605.26522 2026-05-27 quant-ph

A Resource Comparison of Logical T-State Preparation

逻辑T态制备的资源比较

Jianshuo Gao, Xiao Yuan, Yuan Yao

AI总结 本文比较了三种逻辑T态制备路径(魔法态蒸馏、魔法态培育和代码切换)的资源开销,基于现有结果保留原始成本单位,并分析了输出误差、单次尝试成本、预期每次接受输出成本、占用面积、延迟和报告完整性。

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AI中文摘要

逻辑T态制备是基于稳定子操作的容错架构中的一个主要开销来源。然而,现有协议是在不同的代码族、噪声模型、后选择规则和成本约定下报告的,使得直接比较变得困难。我们使用当前可用的结果比较了三种代表性的制备路径:魔法态蒸馏、魔法态培育和代码切换。我们没有将异构数据简化为单一成本指标,而是保留源原生成本单位,并记录每个配置的输出误差、单次尝试成本、预期每次接受输出成本、占用面积、延迟和报告完整性。在当前数据集中,蒸馏达到了最低的输出误差区间;代码切换在兼容行中实现了最低的报告单次尝试成本和最小的显式占用面积;而最近的RP2培育结果增加了输出误差在1e-6到1e-9之间的低成本培育点。作为一个简单的算法级案例研究,我们还在由Shor因式分解算法驱动的误差预算下检查了报告的制备路径,以将单态制备成本与完整工作负载需求联系起来。所得比较澄清了当前文献中支持的权衡,同时受限于基础论文的约定和覆盖范围。

英文摘要

Logical T state preparation is a major overhead source in fault tolerant architectures built from stabilizer operations. Existing protocols, however, are reported under different code families, noise models, postselection rules, and cost conventions, making direct comparison difficult. We compare three representative preparation routes: magic state distillation, magic state cultivation, and code switching, using currently available results. Rather than reducing heterogeneous data to a single cost metric, we retain source native cost units and record output error, single attempt cost, expected cost per accepted output, footprint, latency, and reporting completeness for each configuration. Within the current dataset, distillation reaches the lowest output error regime; code switching achieves the lowest reported single attempt cost and the smallest explicit footprint among the compatible rows; and recent RP2 cultivation results add low cost cultivation points with output errors between 1e-6 and 1e-9. As a simple algorithm level case study, we also examine the reported preparation routes under an error budget motivated by Shor factoring algorithm, in order to relate single state preparation costs to full workload requirements. The resulting comparison clarifies the trade offs currently supported across the literature, while remaining bounded by the conventions and coverage of the underlying papers.

2605.26521 2026-05-27 cs.SE

Testing Agentic Workflows with Structural Coverage Criteria

使用结构覆盖标准测试智能体工作流

Nafiseh Kahani, Mojtaba Bagherzadeh

AI总结 针对多智能体工作流的结构化测试问题,提出基于类型化协调图的覆盖驱动测试方法,通过DSPy生成可执行场景,有效检测工具访问、限制和委托路径的结构性回归。

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AI中文摘要

多智能体系统日益暴露显式的工作流结构:智能体、工具、工具访问规则、限制和委托路径。现有评估主要依赖端到端任务成功、基准分数、最终响应质量或提示级别检查,这些方法提供的证据有限,无法证明声明的协调结构已被实际执行。这使得评估测试套件的充分性或检测工具访问、限制和智能体间委托的结构性回归变得困难。我们通过一种针对多智能体工作流规范的结构化测试方法来解决这一差距。该方法将每个工作流表示为类型化协调图,推导出可达智能体、允许工具边、限制工具边和委托边上的覆盖义务,并使用基于DSPy场景生成的覆盖驱动测试来产生可执行测试。图固定了必须覆盖的内容;DSPy将这些义务实现为自然语言场景,其见证在运行时检查。我们针对OpenAI Agents SDK风格的工作流实现了该方法,并在十个SDK派生基准上进行了评估,这些基准包含49个可达智能体、47个工具和403个结构义务。在有限细化预算内,生成的场景见证了54/75的允许工具义务和36/48的委托义务。对抗性限制工具标准引发了23/248的限制调用违规,将限制在探测下成立的工作流与存在具体路由失败的工作流区分开来。这些结果表明,结构覆盖为多智能体工作流测试提供了有用的充分性层:它不取代语义或端到端评估,但揭示了声明的智能体、工具访问规则、限制和委托路径是否已被执行。

英文摘要

Multi-agent systems increasingly expose explicit workflow structure: agents, tools, tool-access rules, restrictions, and delegation paths. Existing evaluations rely largely on end-to-end task success, benchmark scores, final-response quality, or prompt-level checks, which provide limited evidence that this declared coordination structure has actually been exercised. This makes it difficult to assess test-suite adequacy or detect structural regressions in tool access, restrictions, and inter-agent delegation. We address this gap with a structural testing approach for multi-agent workflow specifications. The approach represents each workflow as a typed coordination graph, derives coverage obligations over reachable agents, allowed tool edges, restricted tool edges, and delegation edges, and uses coverage-driven generation with DSPy-based scenario realization to produce executable tests. The graph fixes what must be covered; DSPy realizes those obligations as natural-language scenarios whose witnesses are checked at runtime. We implement the approach for OpenAI Agents SDK-style workflows and evaluate it on ten SDK-derived benchmarks comprising 49 reachable agents, 47 tools, and 403 structural obligations. Generated scenarios witness 54/75 allowed-tool obligations and 36/48 delegation obligations within a bounded refinement budget. The adversarial restricted-tool criterion elicits 23/248 restricted-call violations, separating workflows whose restrictions hold under probing from workflows with concrete misrouting failures. These results show that structural coverage provides a useful adequacy layer for multi-agent workflow testing: it does not replace semantic or end-to-end evaluation, but reveals whether declared agents, tool-access rules, restrictions, and delegation paths have been exercised.

2605.26518 2026-05-27 astro-ph.CO

Unveiling the dark matter nature with reionization relics

利用再电离遗迹揭示暗物质本质

Yao Zhang, Paulo Montero-Camacho, Catalina Morales-Gutiérrez, Heyang Long, Christopher M. Hirata, Yi Mao

AI总结 提出基于长寿命再电离遗迹的大尺度探针,通过Lyα森林和21厘米强度映射约束温暗物质质量下限。

Comments 19 pages, 10 figures

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AI中文摘要

暗物质约占宇宙的四分之一,但其物理本质仍然未知。温暗物质(WDM)是一类暗物质候选者,具有不可忽略的速度弥散,抑制了小尺度宇宙结构的形成。因此,当前的约束主要依赖于小尺度探针,如莱曼α(Lyα)森林以及银河系对卫星星系和恒星流的观测。我们提出了一种基于长寿命“再电离遗迹”的新型大尺度探针:由于星系际介质的热学和动力学演化取决于局部再电离红移,不均匀的再电离在Lyα森林不透明度和由21厘米强度映射追踪的再电离后HI中留下了额外的大尺度涨落。这些印记的强度通过小尺度气体演化和WDM驱动的再电离历史变化而依赖于WDM。例如,当包含再电离遗迹时,3 keV WDM的Lyα(21厘米)功率谱在k=0.05 Mpc^{-1}、z=4(z=5.5)处与冷暗物质相差约19%(约19%)。使用设计用于模拟暗能量光谱仪器(DESI)能力的协方差模型的Lyα森林,我们预测m_WDM>5.0 keV(95%)的约束,当与平方公里阵列(SKA)的21厘米强度映射观测结合时,约束改善至m_WDM>7.1 keV。下一代巡天可以进一步将当前最佳下限从9.7 keV加强到39 keV。

英文摘要

Dark matter constitutes roughly one-fourth of the Universe, yet its physical nature remains unknown. Warm dark matter (WDM), a class of dark matter candidates, has non-negligible velocity dispersion that suppresses the formation of small-scale cosmic structures. Current constraints therefore rely mainly on small-scale probes such as the Lyman-alpha (Ly$α$) forest and Milky Way observations of satellite galaxies and stellar streams. We propose a novel large-scale probe based on long-lived "reionization relics": because the thermal and dynamical evolution of the intergalactic medium depends on the local reionization redshift, patchy reionization imprints additional large-scale fluctuations in Ly$α$ forest opacity and post-reionization HI traced by 21 cm intensity mapping. The strength of these imprints depends on WDM through both small-scale gas evolution and WDM-driven changes in the reionization history. For example, the Ly$α$ (21 cm) power spectrum in 3 keV WDM differs from cold dark matter by ~19% (~19%) at $k=0.05\,{\rm Mpc^{-1}}$ at z=4 (z=5.5) when reionization relics are included. Using Ly$α$ forest with a covariance model designed to mimic the capabilities of the Dark Energy Spectroscopic Instrument (DESI), we forecast a constraint of $m_{\rm WDM}>5.0\,{\rm keV}$ (95%), which improves to $m_{\rm WDM}>7.1\,{\rm keV}$ when combined with 21 cm intensity-mapping observations from the Square Kilometre Array (SKA). The next-generation surveys can further strengthen the current best lower bounds from 9.7 to 39 keV.

2605.26517 2026-05-27 eess.SP

Integrated Positioning and Communications for PASS: A Robust Approach

PASS的集成定位与通信:一种鲁棒方法

Yaoyu Zhang, Xin Sun, Jun Wang, Tianwei Hou, Anna Li, Yuanwei Liu, Arumugam Nallanathan

AI总结 针对捏合天线系统(PASS),提出基于多波导的上行定位方法并分析下行通信性能,通过最小二乘和网格搜索算法实现定位,并揭示定位精度与通信速率之间的权衡。

Comments 13 pages,12 figures, journal

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AI中文摘要

捏合天线系统(PASS)沿介质波导动态激活和重新定位捏合天线(PAs),为集成定位与通信提供了前所未有的潜力。本文首次提出基于多波导的室内上行定位方法,并分析了下行通信性能。在视距信道和单个静止用户的假设下,考虑了两种可能场景:多波导单PA(MWSP)和多波导多PA(MWMP)。对于MWSP场景,开发了基于接收信号强度指示(RSSI)的测距方法和基于MWSP的最小二乘(LS)定位算法。为获得更深入的理解,对LS定位算法进行了全面的误差分析。随后,对于MWMP场景,推导了叠加信号的闭式表达式。根据信号功率,提出了基于MWMP的网格搜索算法,并分析了所提算法的估计误差。然后,基于用户的定位结果,重新定位PAs以提供下行通信服务,并分析了MWSP和MWMP场景的可达数据速率。数值结果验证了我们分析的正确性,表明:i) 对于MWSP场景,较小的几何精度因子(GDoP)导致较低的平均定位误差。此外,即使GDoP较大,与PAs距离几乎相等的区域也能达到最佳精度。ii) 对于MWMP场景,非平行波导部署提高了定位精度,尽管误差随PA数量增加而增加。iii) 噪声对数据速率有严重的双重影响。定位精度与通信性能之间存在权衡。

英文摘要

The pinching-antenna systems (PASS), which dynamically activate and relocate the pinching-antennas (PAs) along the dielectric waveguide, offer unprecedented potential for integrated positioning and communication. The multi-waveguide-based uplink positioning approaches for indoor environments are first proposed in this paper, and the downlink communication performance is analyzed. Two possible scenarios, multi-waveguide single-PA (MWSP) and multi-waveguide multi-PA (MWMP), are considered under the assumptions of line-of-sight channels and a single, stationary user. For the MWSP scenario, the received signal strength indication (RSSI)-based ranging method and the MWSP-based least square (LS) positioning algorithm are developed. To gain deeper insights, a comprehensive error analysis of the LS positioning algorithm is conducted. Subsequently, for the MWMP scenario, the closed-form expression of the superposed signal is derived. According to the signal power, the MWMP-based grid search algorithm is proposed and the estimation error of proposed algorithm is analyzed. Then, based on the user's positioning result, the PAs are relocated to provide downlink communication service, and the achievable data rate of MWSP and MWMP scenarios are analyzed. Numerical results validate the correctness of our analysis, which show that: i) For the MWSP scenario, a smaller geometric dilution of precision (GDoP) leads to a lower average positioning error. Furthermore, even when the GDoP is large, the regions where the distances to PAs are nearly equal achieve the best accuracy. ii) For the MWMP scenario, non-parallel waveguide deployment improves positioning accuracy, although errors increase with the number of PAs. iii) The noise has a serious double-impact on data rate. There is a trade-off between positioning accuracy and communication performance.

2605.26516 2026-05-27 econ.TH

State-Robust Nash Predictions In Population Games

群体博弈中的状态鲁棒纳什预测

Rui Sun, Junfei Guo

AI总结 本文引入状态鲁棒均衡(SRE)概念,用于在有限策略群体博弈中检验纳什预测对支付相关聚合状态误设的局部有效性,并证明其等价于局部最优反应不变性、无结构性暴露以及沿任意内点聚合状态误差的局部有效性。

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AI中文摘要

本文引入状态鲁棒均衡(SRE),这是对有限策略群体博弈中纳什预测的一种局部有效性检验,当支付相关的聚合状态可能被误设时。报告的策略和支付映射保持不变;仅用于评估支付比较的状态发生变化。SRE等价于局部最优反应不变性、无结构性暴露以及沿任意消失的内点聚合状态误差的有效性。在仿射博弈中,切锥、法锥和线性规划检验刻画了暴露特征,并识别出暴露群体、纯策略和聚合状态方向。主要含义是一个尖锐的负结果:鲁棒混合要求支持集上的局部支付恒等性;在一般仿射博弈中,SRE退化为严格纯纳什均衡,尽管弱边界均衡可以通过可行集保护存活。在具有多面体局部不确定性区域的仿射博弈中,相同的不等式为报告状态的有效性提供了确定性的有限诊断。

英文摘要

This paper introduces state-robust equilibrium (SRE), a local validity test for Nash predictions in finite-strategy population games when the payoff-relevant aggregate state may be misspecified. The reported prescription and payoff map are held fixed; only the state used to evaluate payoff comparisons varies. SRE is equivalent to local best-response invariance, absence of structural exposure, and validity along every vanishing interior aggregate-state error. In affine games, the tangent-cone, normal-cone, and linear-program tests characterize exposure and identify the exposing population, the pure strategy, and the aggregate-state direction. The main implication is a sharp negative result: robust mixing requires local payoff identity on the support; in generic affine games, SRE reduce to strict pure Nash equilibria, although weak boundary equilibria can survive through feasible-set protection. In affine games with polyhedral local uncertainty regions, the same inequalities yield a deterministic finite diagnostic for reported-state validity.

2605.26515 2026-05-27 stat.ME

Learning a directed acyclic graph with additive heteroscedastic errors

学习具有加性异方差误差的有向无环图

Xintao Xia, Li Chen, Yue Hu, Chunlin Li

AI总结 针对结构方程模型中的加性异方差误差,提出基于异方差性的因果方向识别方法,并设计迭代算法RESQUE,通过条件尺度系数在不同分位数上的不变性递归识别汇节点,理论保证拓扑顺序和图结构的恢复。

Comments 33 pages, 4 figures

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AI中文摘要

本文研究结构方程模型下具有加性异方差误差的有向无环图的因果发现。我们首先建立了位置-尺度噪声模型的新可识别性结果,表明异方差性可用于恢复因果方向。基于这些见解,我们提出了一种新颖的迭代过程——残差同时分位数估计(RESQUE),其中每次迭代由残差构建阶段和复合分位数回归阶段组成,通过条件尺度系数在不同分位数上的不变性递归识别汇节点。然后,我们建立了其在恢复拓扑顺序和图结构方面的理论保证,即使变量数量随样本量发散。模拟研究和基准数据集应用表明,RESQUE与现有方法相比表现良好,特别是当因果信息部分编码在方差分量中时。这些结果突出了利用结构化方差信号进行因果发现,并为超越基于均值建模的多变量因果发现提供了原则性框架。

英文摘要

This paper studies causal discovery for a directed acyclic graph under a structural equation model with additive heteroscedastic errors. We first establish new identifiability results for location-scale noise models, showing that heteroscedasticity can be leveraged to recover causal directions. Based on these insights, we propose a novel iterative procedure, Residual Simultaneous Quantile Estimation (RESQUE), where each iteration consists of a residual-construction stage and a composite quantile regression stage, enabling recursive identification of sink nodes via the invariance of conditional scale coefficients across quantiles. We then establish its theoretical guarantees for recovering topological order and graph structure, even when the number of variables diverges with the sample size. Simulation studies and application to benchmark datasets show that RESQUE performs favorably compared with existing methods, especially when causal information is partly encoded in the variance component. These results highlight exploiting structured variance signals for causal discovery and provide a principled framework for multivariate causal discovery beyond mean-based modeling.

2605.26512 2026-05-27 astro-ph.EP

An SMA Molecular Inventory of the Edge-on Protoplanetary Disk Gomez's Hamburger

边缘型原行星盘 Gomez's Hamburger 的 SMA 分子清单

Erin M. Cusson, Lisa Wölfer, Richard Teague, Joshua B. Lovell, Chunhua Qi, Sean M. Andrews, Thomas J. Haworth, John D. Ilee, Marija R. Jankovic, Charles J. Law, Romane le Gal, Karin I. Öberg, David Wilner

AI总结 利用亚毫米波阵列对边缘型原行星盘 Gomez's Hamburger 进行宽带巡天,检测到11种分子并测量其盘积分通量,推断柱密度,发现其分子清单与大型原行星盘总体一致,未发现引力不稳定性证据。

Comments 15 pages, 7 figures; Accepted for publication in ApJ

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AI中文摘要

Gomez's Hamburger (IRAS 18059-3211, GoHam) 是一个大质量的边缘型原行星盘,可能具有引力不稳定性,并存在一个可能是形成巨行星位点的过密度区域,使其成为研究直接坍缩场景下行星形成的特别有趣源。在本研究中,我们结合多次亚毫米波阵列观测,以约1角秒的角分辨率进行宽带巡天,呈现了 GoHam 盘的分子清单。我们检测到11种不同分子,包括15条独立谱线,并测量了它们的盘积分通量。我们还在一系列固定激发温度下推断了几种物种的柱密度。我们发现 GoHam 的分子清单和选定分子的推断柱密度与大型原行星盘的总体大致一致。我们通过气相 H$_2$CO 丰度的可能增强来探索 GoHam 盘中假定的引力不稳定性,但未发现 GI 的决定性证据。本研究的结果可以指导未来对 GoHam 的更高分辨率研究,以及表征候选巨行星 GoHam b 的努力。

英文摘要

Gomez's Hamburger (IRAS 18059-3211, GoHam) is a massive, edge-on protoplanetary disk that is potentially gravitationally unstable and hosts an overdensity that may be the site of a forming giant planet, making it a particularly interesting source for the study of planet formation in the direct collapse scenario. In this study, we present a molecular inventory of GoHam's disk combining several Submillimeter Array observations for a wideband survey at an angular resolution on the order of ~1 arcsecond. We detect 11 different molecules, including 15 individual lines, and measure their disk-integrated fluxes. We also infer column densities for several species over a range of fixed excitation temperatures. We find that the molecular inventory of GoHam and the inferred column densities for select molecules are broadly consistent with the general population of large protoplanetary disks. We explore the putative gravitational instability (GI) in GoHam's disk via possible enhancements in the gas-phase H$_2$CO abundance, but find no definitive evidence of GI. The results of this study can guide future, higher-resolution studies of GoHam, as well as efforts to characterize the giant protoplanet candidate GoHam b.

2605.26511 2026-05-27 astro-ph.SR astro-ph.IM

Inversion of CHASE H$α$ Spectral Line during Solar Flares Based on RADYN Dataset via Deep Learning

基于RADYN数据集的深度学习反演太阳耀斑期间CHASE Hα谱线

W. Xu, Q. Hao, Z. Zheng, J. Hong, J. Hu, Y. Qiu, C. Li, M. D. Ding, C. Fang

AI总结 提出一种全连接神经网络,基于RADYN模拟合成数据训练,从Hα谱线快速反演物理参数,并成功应用于CHASE卫星观测的X7.1级耀斑分析。

Comments 10 pages, 12 figures, Accepted for publication in ATI

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AI中文摘要

太阳耀斑是最剧烈的太阳活动形式之一。理解耀斑期间太阳大气物理参数的演化是研究耀斑机制和提高预测能力的关键。然而,直接测量电子数密度、温度和等离子体速度等量仍然困难。本文介绍了一种新颖的全连接神经网络,基于辐射流体动力学代码(RADYN)模拟的合成数据进行训练,以实现从Hα谱线轮廓快速反演物理参数。光谱数据经过处理以匹配CHASE卫星的观测分辨率,使得模型能够无缝应用于实际观测。结果表明,模型与RADYN模拟高度一致,在各种耀斑条件下实现了低误差。此外,我们将所开发的模型应用于分析CHASE对2024年10月1日X7.1级太阳耀斑的观测。结果揭示了不同耀斑阶段关键参数的合理时空演化。这项工作展示了深度学习技术在快速可靠的谱线反演方面的潜力,为基于Hα数据的太阳耀斑诊断提供了新工具。

英文摘要

Solar flares represent one of the most intense forms of solar activity. Understanding the evolution of physical parameters in the solar atmosphere during flares is key to studying flare mechanisms and improving prediction capabilities. However, directly measuring quantities such as electron number density, temperature, and plasma velocity remains difficult. Here, we introduce a novel fully connected neural network, trained on synthetic data from the Radiative Hydrodynamics Code (RADYN) simulations, to perform rapid inversion of physical parameters from H$α$ spectral profiles. The spectral data were processed to align with the observational resolution of the CHASE satellite, enabling seamless application of the model to real-world observations. Results demonstrate a high degree of consistency with RADYN simulations, achieving low errors under diverse flare conditions. Furthermore, we applied the developed model to analyze CHASE observations of a class X7.1 solar flare on October 1, 2024. The results reveal reasonable spatial and temporal evolution of key parameters throughout different flare phases. This work demonstrates the potential of deep learning techniques for fast and reliable spectral inversion, providing new tools for solar flare diagnostics based on H$α$ data.

2605.26510 2026-05-27 cond-mat.mtrl-sci cond-mat.other

Modulation of charge density waves in a twisted vortex moire superlattice

扭转涡旋莫尔超晶格中电荷密度波的调制

Qian Fang, Yanhao Shi, Jingyi Duan, Hui Guo, Yikai Chen, Senhao Lv, Jiayi Wang, Zhongyi Cao, Jiayi Huang, Siyu Xu, Haitao Yang, Wei Jiang, Hui Chen, Hong-Jun Gao

AI总结 通过扫描隧道显微镜和第一性原理计算,研究单层VTe2与超导NbSe2形成的扭转涡旋莫尔超晶格中电荷密度波的重构与调制,揭示局部应变变化导致CDW态的不均匀性及其与超导的竞争。

Comments 20 pages, 4 figures

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AI中文摘要

范德华异质结构中的扭转莫尔超晶格为通过莫尔能带重构工程化关联态提供了强大平台。然而,全局相干的电子有序能否在纳米尺度上连续调控仍鲜有探索。小角度和近公度区域的重构莫尔结构具有连续变化的局部环境,为关联相的纳米尺度调控提供了新机遇。本文报道了单层VTe2与超导NbSe2之间形成的扭转涡旋莫尔超晶格中电荷密度波(CDW)态的调制。扫描隧道显微镜/谱学揭示,单层VTe2的本征长程CDW在单个莫尔原胞内重构为具有不同稳定性和相干性的不等价局域相,包括抑制的CDW有序和增强至室温的短程CDW关联。第一性原理计算表明,重构的CDW景观源于强局部应变变化,其中压缩应变显著稳定了电荷有序。此外,调制的CDW态与邻近诱导的超导性表现出竞争相互作用。我们的结果确立了涡旋莫尔超晶格作为低维量子材料中关联电子有序纳米尺度调控的多功能平台。

英文摘要

Twisted moire superlattices in van-der-Waals heterostructures provide a powerful platform for engineering correlated states through moire-band reconstruction. However, whether globally coherent electronic orders can be continuously manipulated at the nanoscale remains largely unexplored. Reconstructed moire structures in small-angle and near-commensurate regime feature continuously varying local environments, offering new opportunities for nanoscale manipulation of correlated phases. Here, we report the modulation of charge density wave (CDW) states in a twisted vortex moire superlattice formed between monolayer VTe2 and superconducting NbSe2. Scanning tunneling microscopy/spectroscopy reveals that the intrinsic long-range CDW of monolayer VTe2 is reconstructed into inequivalent local phases with distinct stability and coherence within a single moire unit cell, including suppressed CDW order and enhanced short-range CDW correlations persisting to room temperature. First-principles calculations show that the reconstructed CDW landscape originates from strong local strain variation, where compressive strain substantially stabilizes the charge order. Furthermore, the modulated CDW states exhibit competing interplay with proximity-induced superconductivity. Our results establish vortex moire superlattices as a versatile platform for nanoscale manipulation of correlated electronic orders in low-dimensional quantum materials.

2605.26507 2026-05-27 stat.ME

Improving inverse probability of censoring weighting for win statistics with composite survival outcomes

改进复合生存结局胜统计量的逆删失概率加权方法

Xi Fang, Fan Li

AI总结 针对复合终点胜统计量(胜率、净收益、胜率比)估计中逆删失概率加权法丢弃不确定对导致效率损失的问题,提出基于条件平局概率的部分观测对恢复估计器,并推导了大样本理论和闭合方差估计。

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AI中文摘要

胜统计量,包括胜率、净收益和胜率比,通过按临床重要性排序的组分结局依次比较患者对,仅在较高优先级结局平局时才考虑较低优先级结局,从而总结层次复合终点的治疗效果。将比较限制在预先指定的临床时间范围内,可得到与删失机制分离的明确定义的估计目标,而在估计过程中处理右删失至关重要。现有的逆删失概率加权方法完全丢弃不确定对,导致随删失和限制时间范围增加而增长的效率损失。我们提出一种新估计器,用给定观测数据下的条件平局概率替代较高优先级平局的确认,将部分观测对恢复为分数贡献。基于带有估计 nuisance 函数的两样本 U 统计量建立了大样本理论,并在新加权方案下得到了胜率、净收益和胜率比的闭合形式三明治方差估计。模拟显示,基于新估计器,从轻度删失到高删失率,效率增益显著增加,我们进一步将估计器应用于重新分析一项已完成的随机临床试验。

英文摘要

Win statistics, including the win ratio, net benefit, and win odds, summarize treatment effects on hierarchical composite endpoints by sequentially comparing patient pairs on component outcomes ordered by clinical importance, proceeding to lower priority components only when higher priority ones are tied. Restricting comparisons to a pre-specified clinical horizon yields well defined estimands separated from the censoring mechanism, and it is critically important to address right censoring during estimation. Existing inverse probability of censoring weighting methods discard indeterminate pairs entirely, incurring avoidable efficiency loss that grows with censoring and restriction horizon length. We propose a novel estimator that replaces the confirmation of higher priority ties with a conditional tie probability given the observed data, recovering partially observed pairs as fractional contributions. Large sample theory is developed based on two-sample U-statistics with estimated nuisance functions, and closed-form sandwich variance estimators are obtained for the win ratio, net benefit, and win odds under our new weighting scheme. Simulations demonstrate sizable efficiency gains growing sharply from light censoring to high censoring rate based on our new estimator, and we further apply our estimator to reanalyze a completed randomized clinical trial.