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2606.09530 2026-06-09 cs.CE 新提交

Reduced integration with scaled boundary parametrization for virtual elements at finite strains

有限应变下基于缩放边界参数化的虚拟单元减缩积分

Njomza Pacolli, Bjorn Sauren, Jannick Kehls, Sven Klinkel, Stefanie Reese, Hagen Holthusen

AI总结 提出一种基于减缩积分与缩放边界参数化的虚拟单元法稳定技术,通过泰勒展开实现弱形式解析积分,仅需每段一个积分点,数值算例验证了精度。

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AI中文摘要

本文提出了一种基于减缩积分与缩放边界参数化的虚拟单元法(VEM)替代稳定技术。为此,对截面中心的本构量进行泰勒级数展开,实现了弱形式的解析积分,并将每段所需的积分点减少至仅一个。通过多个数值算例(包括非线性分片测试)展示了所提公式的精度。考虑了不同加载条件(如大变形压缩)和材料条件(如超弹性各向异性和弹塑性)。使用双二次Serendipity有限元公式(Q2)和带沙漏稳定的低阶有限元公式(Q1STc+)进行比较。虽然高阶形函数未满足分片测试,但该公式得到了良好结果并能准确捕捉结构响应。此外,当物理单元类似于预分配母单元时,该公式表现更佳。弹塑性材料行为下的非对称缺口试件算例表明,所提公式能够捕捉非弹性行为。

英文摘要

This contribution presents an alternative stabilization technique for the virtual element method (VEM) based on reduced integration combined with a scaled boundary parametrization. To this end, a Taylor series expansion of the constitutive quantities with respect to the sectional center is carried out, enabling analytical integration of the weak form and reducing the need for integration points to only one per section. The accuracy of the proposed formulation is shown by several numerical examples, including a non-linear patch test. Different loading, e.g. compression under large deformations, and material conditions, such as hyperelastic anisotropy and elasto-plasticity, are considered. The biquadratic serendipity finite element formulation (Q2) and the low-order finite element formulation with hourglass stabilization (Q1STc+) are used for comparison. While the patch test was not fulfilled using higher order shape functions, the formulation led to good results and was able to capture the structure's response accurately. Furthermore, the formulation performed better when the physical element resembled the pre-assigned parent elements. The example of the asymmetrically notched specimen under elasto-plastic material behavior showed that the proposed formulation is able to capture inelasticities.

2606.09529 2026-06-09 cs.NE 新提交

Hybrid Metaheuristic Combining the Dragonfly Algorithm and Tabu Search for the Traveling Salesman Problem

混合元启发式算法:结合蜻蜓算法与禁忌搜索求解旅行商问题

Ammar Bouketta

AI总结 提出一种混合元启发式算法,将蜻蜓算法(全局搜索)与禁忌搜索(局部搜索)结合,用于求解旅行商问题,在TSPLIB实例上相比单独算法性能提升。

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AI中文摘要

旅行商问题(TSP)是一个经典的NP-hard组合优化问题,旨在找到访问每个城市恰好一次并返回起点的最短哈密顿回路。本文提出了一种混合元启发式算法,将基于群体智能的全局搜索方法蜻蜓算法(DA)与基于记忆的局部搜索技术禁忌搜索(TS)相结合。该方法采用高层接力混合(HRH)方案,首先使用DA探索解空间并生成有前景的初始路径,然后TS通过邻域改进和禁忌记忆对该解进行精炼。该混合方法在标准TSPLIB基准实例(包括burma14、att48和ch150)上进行了评估,并与单独的DA、单独的TS以及几种经典元启发式算法(如遗传算法、蚁群优化、粒子群优化和随机搜索)进行了比较。还进行了系统的网格搜索过程,以研究主要超参数对解质量和执行时间的影响。实验结果表明,与单独的DA和TS相比,所提出的混合方法在测试实例上能够改善路径质量,突出了全局探索与局部利用相结合的优势。然而,结果也表明性能对参数设置和问题规模仍然敏感,这促使需要在更大的基准和更强的TSP特定基线上进行进一步验证。

英文摘要

The Traveling Salesman Problem (TSP) is a classical NP-hard combinatorial optimization problem that aims to find the shortest Hamiltonian cycle visiting each city exactly once and returning to the starting point. This paper proposes a hybrid metaheuristic for the TSP by combining the Dragonfly Algorithm (DA), a swarm-intelligence-based global search method, with Tabu Search (TS), a memory-based local search technique. The proposed method follows a High-Level Relay Hybridization (HRH) scheme, in which DA is first used to explore the solution space and generate a promising initial tour, while TS subsequently refines this solution through neighbourhood-based improvement and tabu memory. The hybrid approach is evaluated on standard TSPLIB benchmark instances, including burma14, att48, and ch150, and compared with standalone DA, standalone TS, and several classical metaheuristics such as Genetic Algorithm, Ant Colony Optimization, Particle Swarm Optimization, and Random Search. A systematic grid-search procedure is also conducted to study the influence of the main hyperparameters on solution quality and execution time. The experimental results indicate that the proposed hybrid can improve tour quality compared with the standalone DA and TS on the tested instances, highlighting the benefit of combining global exploration with local exploitation. However, the results also suggest that performance remains sensitive to parameter settings and problem size, motivating further validation on larger benchmarks and stronger TSP-specific baselines.

2606.09528 2026-06-09 cs.SE 新提交

Relocate and Emulate: Re-Hosting Android's Application Layer

重新定位与模拟:重新托管Android应用层

Thomas Sutter, Timo Kehrer, Bernhard Tellenbach, Marc Rennhard

AI总结 提出一种系统化方法,将Android框架和预装软件从真实设备固件迁移到完全模拟环境中,生成供应商风格模拟器镜像,实现可扩展、可复现的动态分析。

Comments Conference: IEEE International Conference on Software Analysis, Evolution and Reengineering

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AI中文摘要

Android应用层的动态分析通常依赖物理设备,限制了可扩展性和可重复性。为弥补这一不足,我们引入了一种系统化的重新托管方法,将Android框架和预装软件从真实设备固件迁移到完全模拟的环境中。我们的方法通过定制的提取和注入策略,将供应商特定组件集成到Android开源项目(AOSP)构建系统中,生成保留系统完整性和运行时兼容性的供应商风格模拟器镜像。这使得我们能够在多个SDK版本上动态执行真实世界的框架和应用层组件,包括专有二进制文件和预装应用。我们在SDK 31-33的184个固件样本上评估了该方法,取得了较高的构建和启动成功率,剩余失败主要发生在核心服务初始化阶段,原因包括基线策略限制、缺少依赖、设备保护检查或模拟器约束。然而,模块化设计允许针对特定固件扩展注入策略,支持更广泛的兼容性和未来关于自动化、自适应重新托管的研究。尽管我们认识到通过工程化供应商特定解决方案存在优化潜力,但我们的研究证明了供应商风格模拟器用于可扩展、可重复动态分析的可行性。

英文摘要

Dynamic analysis of Android's application layer typically relies on physical devices, limiting scalability and reproducibility. To compensate, we introduce a systematic re-hosting method that relocates the Android framework and pre-installed software from real device firmware into a fully emulated environment. Our approach integrates vendor-specific components into the Android Open Source Project (AOSP) build system using tailored extraction and injection strategies, producing vendor-flavoured emulator images that preserve system integrity and runtime compatibility. This enables dynamic execution of real-world framework and application-layer components, including proprietary binaries and pre-installed apps, across multiple SDK versions. We evaluate our method on 184 firmware samples from SDK 31-33. It achieves high build and boot success rates, with residual failures primarily occurring during core-service initialization due to baseline strategy limitations, missing dependencies, device-protection checks, or emulator constraints. However, the modular design allows injection strategies to be extended for specific firmware, supporting broader compatibility and future research on automated, adaptive re-hosting. Though we identified potential for optimization through engineering vendor-specific solutions, our research demonstrates the feasibility of vendor-flavoured emulators for scalable, reproducible dynamic analysis.

2606.09527 2026-06-09 cond-mat.mtrl-sci cond-mat.soft 新提交

Controlled component segregation in vapor-deposited organic semiconductor glass mixtures

气相沉积有机半导体玻璃混合物中的受控组分偏析

Shinian Cheng, Yejung Lee, Lian Yu, Mark D. Ediger, Dean M. DeLongchamp, Camille E. Bishop

AI总结 研究TPD与TCTA二元有机半导体混合物在共沉积玻璃薄膜中的组分偏析行为,发现动力学抑制的成核生长机制导致从均匀混合到相分离的可调形态。

Comments 32 pages, 7 figures

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AI中文摘要

多组分气相沉积有机玻璃在有机电子应用中至关重要,但在纳米和介观尺度上实现受控组分偏析仍然是一个挑战,阻碍了高性能器件的理性开发。在本研究中,我们研究了TPD(N,N'-双(3-甲基苯基)-N,N'-二苯基联苯胺)和TCTA(三(4-咔唑-9-基苯基)胺)的二元有机半导体混合物。尽管在液态本体中可混溶,这两种有机半导体的共沉积玻璃薄膜表现出从均匀到明显相分离结构的一系列偏析行为。我们采用差示扫描量热法和共振软X射线散射(RSoXS)研究组分偏析行为,并使用美国国家标准与技术研究院RSoXS模拟套件,结合原子力显微镜,解释能量依赖的RSoXS谱。我们的结果表明,共沉积TPD-TCTA薄膜中的组分偏析是由于动力学抑制的成核生长机制,这与之前报道的在本体中强烈不混溶的TPD-DO37(分散橙37)混合物的偏析机制形成对比。这项工作展示了有机半导体玻璃中可调分子聚集的实例,使得从均匀混合到相分离的连续形态成为可能。

英文摘要

Multicomponent vapor-deposited organic glasses are essential in organic electronic applications, but achieving controlled component segregation at the nano- and mesoscale remains a challenge, hindering the rational development of high-performance devices. In this study, we investigate binary organic semiconductor mixtures of TPD (N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine) and TCTA (Tris(4-carbazoyl-9-ylphenyl)amine). Despite being miscible in the bulk liquid state, the co-deposited glassy films of these two organic semiconductors exhibit a range of segregation behaviors, from homogenous to clearly phase-separated structures. We employed differential scanning calorimetry and resonant soft X-ray scattering (RSoXS) to study the component segregation behavior and used the National Institute of Standards and Technology RSoXS Simulation Suite, paired with Atomic Force Microscopy, to interpret the energy-dependent RSoXS spectra. Our results indicate that component segregation in co-deposited TPD-TCTA films is due to a kinetically-arrested nucleation-and-growth mechanism, in contrast to the segregation mechanism of a previously reported TPD-DO37 (disperse orange 37) mixture which is strongly immiscible in bulk. This work provides a demonstration of tunable molecular aggregation in organic semiconductor glasses, enabling access to a continuum of morphologies from homogeneously mixed to segregated phases.

2606.09526 2026-06-09 cs.LO cs.PL 新提交

When Types Intersect and Effects Get Handled

当类型相交且效果被处理

Ugo Dal Lago, Taro Sekiyama, Stefano Catozi

AI总结 本文为带代数效果和处理器的λ-演算引入了一种新的交集类型系统,该系统具有行为性质,满足主题归约和扩展,能刻画终止项并可将可达性问题归约到类型推断,同时诱导出一个简单类型系统,其类型可靠且HOMC问题可判定。

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AI中文摘要

我们为带有代数效果和处理器的$λ$-演算引入了一种新的交集类型系统。该系统本质上是行为性的,具有交集类型系统的经典性质,特别是主题归约和扩展。因此,它刻画了其求值过程终止的项集合,同时允许将可达性问题归约到类型推断。这个新系统是首个针对带处理器的演算具有这些特征的系统,它诱导出一个简单类型系统,虽然不能保证终止,但类型可靠,并且允许可判定的HOMC问题,这与类似类型系统如Dal Lago和Ghyselen的HEPCF不同。

英文摘要

We introduce a novel intersection type system for a $λ$-calculus with algebraic effects and handlers. The system, inherently behavioral in nature, enjoys the classical properties of intersection type systems, in particular subject reduction and expansion. It thus characterizes the set of terms whose evaluation process terminates and, at the same time, allows reducing the reachability problem to type inference. This new system, the first with these features for a calculus with handlers, induces a system of simple types which, although not guaranteeing termination, is type sound and admits a decidable HOMC problem, unlike similar type systems like Dal Lago and Ghyselen's HEPCF.

2606.09524 2026-06-09 math.GR 新提交

On the Quartic-free A-groups

关于四次自由A-群

Prashun Kumar

AI总结 研究四次自由A-群的结构,并确定可解四次自由A-群的导长。

Comments 7 pages

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AI中文摘要

一个有限群被称为四次自由的,如果它的阶不被任何素数$p$的$p^4$整除。一个有限群被称为$A$-群,如果它的所有Sylow子群都是阿贝尔群。本文的目的是提供四次自由$A$-群的显式结构。此外,在提供显式结构的过程中,我们还确定了可解四次自由$A$-群的导长。

英文摘要

A finite group is said to be quartic-free if its order is not divisible by $p^4$ of any prime $p$. A finite group is called an $A$-group if all of its Sylow subgroups are abelian. Objective of this paper is to provide explicit structure of a quartic-free $A$-group. Further in the process of providing the explicit structure we also determine the derived length of a solvable quartic-free $A$-group.

2606.09523 2026-06-09 physics.optics cond-mat.mes-hall quant-ph 新提交

Single plasmon transport in one dimensional nanowire

一维纳米线中的单等离激元输运

A. A. Dıaz-Valles, B. Rousseaux, S. Guérin, H. Jauslin, A. Leray, G. Colas des Francs

AI总结 提出统一理论框架,结合量子化电磁格林张量与有效非厄米哈密顿模型,研究一维纳米线中单等离激元输运,分析多发射器系统对反射透射谱的优化,实现低至2%的透射率和耦合损耗降低至三分之一。

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AI中文摘要

我们引入了一个统一的理论框架,用于一维纳米线中的单等离激元输运,将量子化电磁格林张量形式与有效非厄米哈密顿模型联系起来。该方法自然地包含了传播的表面等离激元极化激元、高阶模式耗散通道和固有损耗。我们研究了通过耦合到色散纳米线的原子链传播的单等离激元脉冲的稳态和时空动力学。我们分析了耦合到银纳米线的量子发射器的反射和透射谱中的模态贡献,该配置被提议作为单等离激元晶体管,并且我们证明了优化的多发射器系统具有显著优势。对于一个量子发射器在电信波长下耦合到银纳米线的情况,我们预测在实际条件下单等离激元透射率低至7%,原子量子比特布居数为12%。使用Löwdin正交化程序扩展到多发射器系统,能够一致地处理集体相互作用。我们表明,仅用五个发射器优化定位即可增强等离激元调制,实现2%的透射率,同时与单发射器情况相比,将耦合损耗降低至三分之一。我们的结果为分析和设计等离激元波导量子电动力学系统奠定了坚实的基础。

英文摘要

We introduce a unified theoretical framework for single-plasmon transport in one-dimensional nanowires, bridging the quantized electromagnetic Green's tensor formalism with effective non-Hermitian Hamiltonian models. This approach naturally incorporates propagating surface plasmon polaritons, high-order modes dissipative channels, and intrinsic losses. We investigate both the stationary regime and the spatio-temporal dynamics of a single-plasmon pulse travelling through an atomic chain coupled to a dispersive nanowire. We analyze modal contributions to reflection and transmission spectra for quantum emitter coupled to a silver nanowire, a configuration proposed as a single-plasmon transistor, and we demonstrate that optimized multi-emitter systems offer significant advantages. In case of one quantum emitter coupled to a silver nanowire at telecom wavelengths, we predict a single-plasmon transmittivity down to 7\% under realistic conditions, and an atomic qubit population of 12\%. Extension to multi-emitter systems using a Löwdin orthogonalization procedure enables a consistent treatment of collective interactions. We show that optimized positioning with just five emitters enhances plasmon modulation, achieving a transmittivity of 2\% but also reduces coupling losses to one-third compared to the single-emitter case. Our results establish a robust foundation for analyzing and designing plasmonic waveguide quantum electrodynamics systems.

2606.09522 2026-06-09 cs.IT math.IT 新提交

Constructions of Quantum $(r,δ)$-LRCs from cyclic codes

从循环码构造量子 $(r,δ)$-LRCs

Rajendra Prasad Rajpurohit, Maheshanand Bhaintwal

AI总结 本文利用循环码的对偶包含条件构造量子局部可恢复码,给出三族显式构造,其中两类达到量子Singleton型界。

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AI中文摘要

经典 $(r,δ)$ 局部可恢复码(LRCs)在分布式数据存储系统中发挥核心作用,因为它们通过访问少量幸存符号实现擦除的高效恢复。受其在未来量子数据存储中的潜在应用以及量子局部可恢复码(qLRCs)近期理论进展的启发,我们研究了从经典循环 $(r,δ)$-LRCs 构造 qLRCs 的方法。我们的方法识别出定义集满足对偶包含条件的循环 LRCs,使其能够作为有效的 CSS 成分。我们给出了三族显式的 $(r,δ)$-qLRCs,其中两类在码为纯时相对于量子 Singleton 型界是最优的,从而提供了最优示例。此外,构造2和3中给出的码在所需域大小方面没有长度限制。

英文摘要

Classical $(r,δ)$ locally recoverable codes (LRCs) play a central role in distributed data storage systems as they enable an efficient recovery from erasures by accessing a small number of surviving symbols. Motivated by their prospective use in future quantum data storage and by recent theoretical progress on quantum locally recoverable codes (qLRCs), we investigate the construction of qLRCs from classical cyclic $(r,δ)$-LRCs. Our approach identifies cyclic LRCs whose defining sets satisfy a dual-containing condition, allowing them to serve as valid CSS ingredients. We present three explicit families of $(r,δ)$-qLRCs, two of which are optimal with respect to the quantum Singleton-like bound, whenever the codes are pure, thereby providing optimal examples. Additionally, the codes presented in Constructions 2 and 3 have no bound on their lengths with respect to the field size required to obtain these codes.

2606.09519 2026-06-09 math.AP 新提交

Global existence for a Zakharov type system in a domain

区域中Zakharov型系统的全局存在性

Nobutatsu Kobayashi, Masahito Ohta

AI总结 研究三维一般区域中Zakharov型系统的初边值问题,在初始数据小假设下,通过高阶能量估计和Cauchy序列构造,直接得到唯一全局强解,并给出高阶Sobolev范数增长估计。

Comments 12 pages

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AI中文摘要

我们研究三维一般区域中Zakharov型系统的初边值问题。在初始数据的小假设下,我们构造了一个唯一的全局强解。该解是通过基于高阶能量估计和在适当Banach空间中构造Cauchy序列的直接方法获得的,没有使用紧性方法。此外,我们得到了解的高阶Sobolev范数增长的估计。

英文摘要

We study an initial-boundary value problem for a Zakharov type system in three space dimensions in a general domain. Under a smallness assumption on the initial data, we construct a unique global strong solution. The solution is obtained by a direct approach based on higher-order energy estimates and the construction of a Cauchy sequence in suitable Banach spaces, without employing compactness methods. Furthermore, we obtain estimates on the growth of higher-order Sobolev norms of solutions.

2606.09518 2026-06-09 math.CO 新提交

Strong counterexamples to a supersaturation question of Ma-Yuan

Ma-Yuan 超饱和问题的强反例

Wanfang Chen, Long-Tu Yuan

AI总结 针对 Ma-Yuan 关于超饱和问题的猜想,构造了图 H_t 使得 h_{H_t}(n,1) < c(n,H_t) 对无穷多 n 成立,且比值可任意小。

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AI中文摘要

对于图 $F$,设 $h_F(n,q)$ 为 $n$ 顶点且边数为 $\mathrm{ex}(n,F)+q$ 的图中 $F$ 的最小拷贝数,其中 $\mathrm{ex}(n,F)$ 是 $n$ 顶点 $F$-free 图的最大边数。设 $c(n,F)$ 为在极值 $F$-free 图中添加一条边所得到的最小拷贝数。Mubayi 的超饱和猜想预测,在稳定性假设下,$h_F(n,q)\ge q\\,c(n,F)$。Ma 和 Yuan 最近对每个固定的 $q\ge4$ 构造了稳定的图反例;他们问是否对于每个包含圈的图 $F$,单边等式 $h_F(n,1)=c(n,F)$ 仍然成立。\n 我们对他们的问题给出了否定答案。对于每个整数 $t\ge6$,令 $H_t$ 由 $t$ 顶点路径通过将每条边替换为一个 $3t$ 页的书得到,对不同路径边使用不相交的页顶点。则对于无穷多个 $n$,有 $h_{H_t}(n,1)<c(n,H_t)$。此外,通过取 $t$ 足够大,比值 $h_{H_t}(n,1)/c(n,H_t)$ 可以在无穷多个 $n$ 上任意小。

英文摘要

For a graph $F$, let $h_F(n,q)$ be the minimum number of copies of $F$ in an $n$-vertex graph with $\mathrm{ex}(n,F)+q$ edges, where $\mathrm{ex}(n,F)$ is the maximum number of edges in an $n$-vertex $F$-free graph. Let $c(n,F)$ be the minimum number of copies obtained by adding one edge to an extremal $F$-free graph. Mubayi's supersaturation conjecture predicts, under a stability hypothesis, that $h_F(n,q)\ge q\,c(n,F)$. Ma and Yuan recently constructed stable graph counterexamples for every fixed $q\ge4$; they asked whether the one-edge equality $h_F(n,1)=c(n,F)$ might still hold for every graph $F$ containing a cycle. We give a negative answer to their question. For each integer $t\ge6$, let $H_t$ be obtained from the $t$-vertex path by replacing each edge with a $3t$-page book, using disjoint page vertices for different path edges. Then $h_{H_t}(n,1)<c(n,H_t)$ for infinitely many values of $n$. Moreover, by taking $t$ large, the ratio $h_{H_t}(n,1)/c(n,H_t)$ can be made arbitrarily small along infinitely many values of $n$.

2606.09515 2026-06-09 astro-ph.IM 新提交

Control problem in millimeter-wave adaptive optics

毫米波自适应光学中的控制问题

Ichiro Jikuya, Yoichi Tamura

AI总结 针对毫米波自适应光学中的波前误差补偿问题,提出统一控制框架,采用抗饱和比例积分控制律,通过解耦策略简化设计,并引入手动调焦和余弦相似度指标等实用工具,数值模拟验证了有效性。

Comments 44 pages, 20 figures. Accepted for publication in JATIS

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AI中文摘要

毫米波自适应光学(MAO)对于高精度大口径亚毫米望远镜至关重要,它通过将波前误差捕获为空间离散的额外路径长度(EPL)波动来实现实时补偿。本文提出了一个统一的控制理论框架来解决EPL补偿问题。首先,我们将光学驱动系统建模为一个被控对象,其中输入命令通过表示机械响应延迟的一阶系统和表征执行器到传感器耦合的测量矩阵与测量的EPL相关联。我们从数学上将控制任务表述为一个渐近扰动抑制问题,特别针对低频扰动(如热变形和风致变形)。其次,我们提出了一种抗饱和比例积分(AWPI)控制律。通过采用解耦策略,设计简化为解耦标量灵敏度函数的环路整形问题,确保了稳定裕度和对常值扰动的渐近抑制。集成了抗饱和机制以在从饱和恢复期间保持控制连续性,防止驱动命令中出现不希望的不连续性。第三,我们引入了实用的操作工具:手动调焦方案允许操作员在不干扰反馈回路的情况下进行干预,以及余弦相似度指数用于量化特定Zernike模式的可抑制性。数值模拟结合了三轴副反射镜驱动和五点EPL测量,展示了方向相关的扰动抑制和对冯·卡门模型风湍流的抑制,验证了所提框架在实际望远镜应用中的有效性。

英文摘要

Millimeter-wave Adaptive Optics (MAO) is essential for high-precision large-aperture submillimeter telescopes, requiring real-time compensation of wavefront errors by capturing them as spatially-discrete excess path length (EPL) fluctuations. This paper presents a unified control-theoretic framework for the EPL compensation problem. We first model the optical drive system as a plant where input commands relate to measured EPL through a first-order system representing mechanical response delay and a measurement matrix characterizing the actuator-to-sensor coupling. We mathematically formulate the control task as an asymptotic disturbance suppression problem, specifically targeting low-frequency disturbances such as thermal and wind-induced deformations. Second, we propose an Anti-Windup Proportional-Integral (AWPI) control law. By employing a decoupling strategy, the design is reduced to a loop-shaping problem for decoupled scalar sensitivity functions, ensuring both stability margins and asymptotic disturbance suppression of constant-valued disturbances. The anti-windup mechanism is integrated to maintain control continuity during the recovery from saturation, preventing undesirable discontinuities in the drive command. Third, we introduce practical operational tools: a manual focus adjustment scheme that allows observer intervention without interfering with the feedback loop, and the cosine similarity index to quantify the suppressibility of specific Zernike modes. Numerical simulations, incorporating a three-axis secondary reflector drive and five-point EPL measurements, demonstrate direction-dependent disturbance rejection and the suppression of von Karman-modeled wind turbulence, validating the effectiveness of the proposed framework for real-world telescope applications.

2606.09513 2026-06-09 math.FA 新提交

Spectra of $1/k$-Contractions via Characteristic Functions

通过特征函数的 $1/k$-压缩算子的谱

Abhay Jindal, Poornendu Kumar

AI总结 本文通过特征函数给出了欧几里得球上具有有限缺陷的 $1/k$-压缩算子的Taylor联合谱的下界估计,并在Corona性质下得到精确刻画,应用于CNP空间商模的谱确定。

Comments 16 pages

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AI中文摘要

欧几里得球上的酉不变完全Nevanlinna--Pick (CNP)核 $k$ 导出了Hilbert空间上的一类自然算子组,称为 $1/k$-压缩算子。我们通过关联的特征函数,建立了具有有限缺陷的 $1/k$-压缩算子的Taylor联合谱的下界估计。在 $k$ 满足Corona性质的附加假设下,该下界估计与Clouâtre--Timko [Adv. Math., 2023]的上界估计一致,从而得到了Taylor联合谱关于特征函数的精确刻画。作为应用,我们确定了CNP空间的商模的Taylor联合谱。证明中的一个关键要素是这些空间的Beurling--Lax--Halmos定理,该定理以特征函数的形式建立。

英文摘要

A unitarily invariant complete Nevanlinna--Pick (CNP) kernel $k$ on the Euclidean ball gives rise to a natural class of operator tuples on Hilbert spaces, known as $1/k$-contractions. We establish a lower estimate for the Taylor joint spectrum of $1/k$-contractions with finite defect in terms of the associated characteristic function. Under the additional assumption that $k$ satisfies the Corona property, this lower estimate coincides with an upper estimate due to Clouâtre--Timko [Adv. Math., 2023], yielding an exact characterization of the Taylor joint spectrum in terms of the characteristic function. As an application, we determine the Taylor joint spectrum of quotient modules of CNP spaces. A key ingredient in the proof is a Beurling--Lax--Halmos theorem for these spaces, established in terms of characteristic functions.

2606.09512 2026-06-09 math.NT 新提交

Abelian surfaces of small conductor from genus 3 double covers

来自亏格3双覆盖的小导子阿贝尔曲面

Raymond van Bommel, Céline Maistret, Jia Shi, Andrew V. Sutherland

AI总结 通过亏格1曲线的亏格3双覆盖的Prym构造了约50万个Q上小导子阿贝尔曲面的数据库,并提供了对坏约化素数的控制方法。

Comments 20 pages; to appear in ANTS XVII

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AI中文摘要

我们描述了从亏格1曲线的亏格3双覆盖的Prym构造约50万个Q上小导子阿贝尔曲面数据库的方法。我们的构造使用了一种能够在一定程度上控制坏约化素数的方法。

英文摘要

We describe the construction of a database of roughly half a million abelian surfaces over Q of small conductor arising as Pryms associated to a genus 3 double cover of a genus 1 curve. Our construction uses a method that provides a degree of control over the primes of bad reduction.

2606.09510 2026-06-09 hep-th gr-qc hep-ph 新提交

Effective scalaron--photon interaction in $f(R)$ gravity

在 $f(R)$ 引力中的有效标量场-光子相互作用

Yuri Shtanov

AI总结 研究 $f(R)$ 引力中标量场与规范场的有效耦合,利用 Fujikawa 方法推导出迹反常诱导的相互作用,发现当标量场质量远小于圈内粒子质量时,有效耦合消失,解释了文献中关于标量场衰变率的差异。

Comments 24 pages, 4 figures

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AI中文摘要

我们重新审视了最小耦合到标准模型的 $f(R)$ 引力中标量场与规范场的有效耦合,重点关注标量场衰变为两个光子。将标量场视为 Jordan 框架度规的内在组成部分,我们分析了其与能量-动量张量耦合产生的量子效应。在此框架下,迹反常对标量场-规范玻色子相互作用有贡献。使用 Fujikawa 方法,我们推导了与物质场在 Jordan 和 Einstein 框架之间变换相关的反常诱导贡献,首先在 QED 中,然后在完整标准模型中。得到的有效标量场-光子相互作用与包含迹反常的直接微扰计算结果一致,而与仅考虑经典能量-动量张量迹的结果不同。当标量场质量远小于圈中循环粒子质量时,图贡献抵消了反常诱导项,导致有效耦合消失,并强烈抑制标量场衰变为光子的衰变率。这些结果澄清了文献中关于标量场与无质量规范场有效耦合差异的起源。这些差异源于在 $f(R)$ 引力中实现量子圈效应的不等价方案,导致不同的标量场-规范场相互作用,对标量场暗物质现象学有直接影响。

英文摘要

We revisit the effective coupling of the scalaron to gauge fields in $f(R)$ gravity minimally coupled to the Standard Model, focusing on the scalaron decay into two photons. Treating the scalaron as an intrinsic component of the Jordan-frame metric, we analyse quantum effects arising from its coupling to the energy--momentum tensor. In this framework, the trace anomaly contributes to the scalaron--gauge boson interaction. Using Fujikawa's method, we derive the anomaly-induced contribution, associated with the transformation of matter fields between the Jordan and Einstein frames, first in QED and then in the full Standard Model. The resulting effective scalaron--photon interaction agrees with direct perturbative calculations that include the trace anomaly and differs from the result obtained when only the classical trace of the energy--momentum tensor is taken into account. In the limit where the scalaron mass is much smaller than the masses of particles circulating in the loop, the diagrammatic contribution cancels the anomaly-induced term, leading to a vanishing effective coupling and a strong suppression of the scalaron decay rate into photons. These results clarify the origin of discrepancies in the literature concerning the effective scalaron coupling to massless gauge fields. The discrepancies arise from inequivalent prescriptions for implementing quantum loop effects in $f(R)$ gravity, leading to different scalaron--gauge field interactions with direct implications for scalaron dark-matter phenomenology.

2606.09509 2026-06-09 cs.NE 新提交

Local Search on Vertex Coloring for Bipartite Graphs

二分图顶点着色的局部搜索

Johanna Gasse

AI总结 研究局部搜索在二分图顶点着色问题上的能力,分析不同结构二分图的局部搜索景观,并引入灰盒变异算子实现完全二分图上的最优着色,期望运行时间Θ(n log n)。

Comments 57 pages; This is my Bachelor's Thesis submitted at the Digital Engineering Faculty of the University of Potsdam on September 1st, 2025

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AI中文摘要

局部搜索是一种众所周知的优化启发式方法。在本论文中,我们探讨了其在顶点着色问题上的能力,这是一个在理论分析和实际应用中都具有相关性的$NP$-难问题。为了认识局部搜索在顶点着色问题中适用性的局限性,我们分析了不同结构二分图上的局部搜索景观。我们识别出确保仅存在全局最优的结构,以及允许存在非全局局部最优的结构,表明在一般二分图上,局部搜索可能返回任意差的结果。此外,我们分析了局部搜索在可找到局部最优的图上的能力。为此,我们引入了一种灰盒局部搜索变异算子,该算子以更高概率移除较少出现的颜色,并证明其在完全二分图上以期望运行时间$Θ(n \log n)$找到最优着色。这相对于黑盒随机局部搜索的指数级运行时间是一个巨大改进,表明灰盒变异算子可以改善局部搜索的运行时间。

英文摘要

Local search is a well-known heuristic method used in optimization. In this thesis, we explore its capabilities on the vertex coloring problem, an $NP$-hard problem with relevance in both theoretical analysis and practical application. To recognize limitations in the applicability of local search of the vertex coloring problem, we analyze local search landscapes on differently-structured bipartite graphs. We identify structures that ensure only global optima can exist as well as ones that enable the existence of non-global local optima, showing that on general bipartite graphs, it is possible for local search to return arbitrarily bad results. Further, we analyze the capabilities of local search on graphs where a local optimum can be found. To do so, we introduce a gray-box local search mutation operator that removes less frequent colors with higher probability and prove that it finds an optimal coloring on complete bipartite graphs in an expected run time of $Θ(n \log n)$. This is a drastic improvement to the exponential tun time of the black-box Random Local Search, showing that gray-box mutation operators can improve the run time of local search.

2606.09506 2026-06-09 cond-mat.mes-hall 新提交

Planar Hall effect in single and bilayer Rashba systems

单层和双层Rashba体系中的平面霍尔效应

Rahul Biswas, Sunit Das, Amit Agarwal

AI总结 研究单层和双层Rashba二维电子气中的平面霍尔效应,识别出塞曼耦合和能带几何通道两种机制,并计算了化学势和角度依赖的霍尔电导率。

Comments Comments are welcome

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AI中文摘要

平面霍尔效应(PHE)是由共面电场和磁场产生的各向异性磁输运响应。我们研究了具有Rashba自旋轨道耦合的单层和双层二维电子气(2DEG)中的PHE,并识别出两种不同的机制:塞曼耦合和能带几何通道。在塞曼通道中,面内磁场扭曲了Rashba自旋轨道耦合的能带色散,产生各向异性的载流子速度,从而产生有限的PHE。在不对称的Rashba双层中,层间电子离域产生了有限的平面贝里曲率和轨道磁矩分量,从而产生了能带几何PHE通道。利用半经典玻尔兹曼输运理论,我们计算了两种机制下平面霍尔电导率的化学势和角度依赖性。对称性分析表明,主导响应与磁场成二次关系,并表现出特征性的$π$周期角度依赖性。对于所考虑的参数范围,塞曼诱导的贡献占主导地位,而能带几何通道提供了不对称Rashba双层特有的对称性允许的贡献。我们的结果揭示了自旋轨道耦合二维材料中各向异性磁输运的微观起源。

英文摘要

The planar Hall effect (PHE) is an anisotropic magnetotransport response generated by coplanar electric and magnetic fields. We investigate the PHE in single- and bilayer two-dimensional electron gases (2DEGs) with Rashba spin-orbit coupling and identify two distinct mechanisms: Zeeman coupling and a band geometric channel. In the Zeeman channel, an in-plane magnetic field distorts the Rashba spin-orbit-coupled band dispersion and generates anisotropic carrier velocities, producing a finite PHE. In an asymmetric Rashba bilayer, interlayer electronic delocalization generates finite planar Berry curvature and orbital magnetic moment components, giving rise to a band geometric PHE channel. Using semiclassical Boltzmann transport theory, we calculate the chemical potential and angular dependence of the planar Hall conductivity for both mechanisms. Symmetry analysis shows that the leading response is quadratic in the magnetic field and exhibits the characteristic $π$-periodic angular dependence. For the parameter regime considered here, the Zeeman-induced contribution dominates, while the band geometric channel provides a distinct symmetry-allowed contribution unique to asymmetric Rashba bilayers. Our results reveal microscopic origins of anisotropic magnetotransport in spin-orbit-coupled two-dimensional materials.

2606.09505 2026-06-09 eess.SY cs.SY math.OC 新提交

Guaranteed Fast Implementation of the Split Covariance Intersection Filter: Nested Newton Method Thanks to the Fourth-Order Convexity of w-Optimization

分裂协方差交集滤波器的保证快速实现:由于w-优化的四阶凸性而提出的嵌套牛顿法

Hao Li

AI总结 本文证明分裂协方差交集滤波器中的w-优化问题具有四阶凸性,并基于此提出嵌套牛顿法,实现保证快速的滤波器实现。

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AI中文摘要

分裂协方差交集滤波器(Split CIF)是通用数据融合的有用工具,有潜力应用于各种工程任务。Split CIF中涉及的w-优化问题关系到Split CIF的性能和实现效率。已知w-优化问题具有理想的凸性(更明确地说,在本文上下文中是二阶凸性)。本文证明w-优化问题进一步具有更理想的四阶凸性,基于此可以实现Split CIF的保证快速实现。新的实现方法被称为嵌套牛顿法,也在本文中提出。

英文摘要

The split covariance intersection filter (Split CIF) is a useful tool for general data fusion and has the potential to be applied in a variety of engineering tasks. The w-optimization problem involved in the Split CIF concerns the performance and implementation efficiency of the Split CIF. It is known that the w-optimization problem enjoys the desirable property of convexity (or more clearly, the second-order convexity in this paper's context). This paper proves that the w-optimization problem further enjoys a more desirable property namely the fourth-order convexity, thanks to which a guaranteed fast implementation of the Split CIF can be realized. The new implementation is coined as the nested Newton method, which is also presented in this paper.

2606.09504 2026-06-09 eess.SP 新提交

Hierarchical Federated Learning for Unsupervised Waveform Classification over Tactical MANETs

面向战术MANET的无监督波形分类的分层联邦学习

Charles E. Thornton, Daniel J. Jakubisin

AI总结 提出一种分层联邦学习框架,在瑞利衰落、随机移动和多跳路由损失的战术MANET中,通过无监督去噪卷积自编码器实现波形分类,两阶段聚合协议减少传输比特约12%,并发现信道驱动的子采样可作为隐式正则化器。

Comments 6 pages, 3 figures

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AI中文摘要

在竞争性战术环境中,分布式射频感知需要跨移动节点的协作学习。在自组织网络中,学习必须在没有持久回程、地面真值标签或可靠通信链路的情况下进行。传统的联邦学习方法假设理想的链路条件或有监督的训练目标,这些在部署的MANET平台上都不成立。本文提出了一种分层联邦学习框架,用于在受瑞利衰落、随机路点移动性和多跳路由损失影响的战术MANET上进行无监督波形分类。每个节点在原始IQ观测上训练局部去噪卷积自编码器,无需标签交换,通过自监督重构目标学习紧凑表示。两阶段聚合协议选举基于连接性的中继聚合器,与OLSR多点中继选择一致,在转发到移动服务器代理之前压缩集群级模型更新。仿真结果表明,在等效分类性能下,网络内聚合相比中继转发联邦平均减少了约12%的尝试传输比特。值得注意的是,非IID数据下的随机信道驱动子采样充当了隐式正则化器,两种MANET条件在无监督表示质量上匹配或超过了理想联邦平均。这表明适度的链路损失可以部分补偿异构网络中的客户端漂移。性能通过使用KMeans归一化互信息和线性探针准确性分析学习到的潜在嵌入来评估。

英文摘要

Distributed radio frequency sensing in contested tactical environments demands collaborative learning across mobile nodes. In ad-hoc networks, learning must occur without persistent backhaul, ground truth labels, or reliable communication links. Traditional federated learning approaches assume either ideal link conditions or supervised training objectives, neither of which holds in practice for deployed MANET platforms. This paper presents a hierarchical federated learning framework for unsupervised waveform classification over tactical MANETs subject to Rayleigh fading, random waypoint mobility, and multi-hop routing loss. Each node trains a local denoising convolutional autoencoder on raw IQ observations without label exchange, learning compact representations through a self-supervised reconstruction objective. A two-stage aggregation protocol elects connectivity-based relay aggregators consistent with OLSR multipoint relay selection, compressing cluster-level model updates before forwarding to a mobile server proxy. Simulation results demonstrate that in-network aggregation reduces attempted transmission bits relative to relay-forward federated averaging by around 12% at equivalent classification performance. Notably, stochastic channel-driven subsampling under non-IID data acts as an implicit regularizer, with both MANET conditions matching or exceeding ideal federated averaging on unsupervised representation quality. This suggests that moderate link loss can partially compensate for client drift in heterogeneous networks. Performance is assessed on analysis of the learned latent embeddings using KMeans normalized mutual information and linear probe accuracy.

2606.09503 2026-06-09 hep-ph 新提交

NNLO QCD predictions for $t\bar t W$ production at hadron colliders

强子对撞机上 $t\ar t W$ 产生的 NNLO QCD 预言

Matteo Becchetti, Dhimiter Canko, Xiang Chen, Vsevolod Chestnov, Maximilian Delto, Sara Ditsch, Massimiliano Grazzini, Stefan Kallweit, Tiziano Peraro, Mattia Pozzoli, Chiara Savoini, Lorenzo Tancredi, Simone Zoia

AI总结 本文首次基于广义主导色极限下直接计算的双圈振幅,给出了 $t\ar t W$ 产生的 NNLO QCD 预言,解决了此前理论预测与实验测量之间的差异。

Comments 12 pages, 1 figure, 2 tables

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AI中文摘要

顶-反顶夸克对与 $W$ 玻色子联合产生是欧洲核子研究中心大型强子对撞机(LHC)目前研究的最重末态之一。其产生率的测量结果一直超过标准模型预言。由于进入双圈修正的两圈振幅的复杂性,该过程的次次领头阶(NNLO)QCD 计算迄今对两圈贡献采用了动力学近似。我们首次基于广义主导色极限下所需两圈振幅的直接计算,给出了 NNLO QCD 预言。

英文摘要

The production of a top-antitop quark pair in association with a $W$ boson constitutes one of the heaviest final states currently studied at the Large Hadron Collider (LHC) at CERN. Measurements of its production rate have consistently exceeded Standard Model predictions. Owing to the complexity of the two-loop amplitudes entering the double-virtual correction, next-to-next-to-leading-order (NNLO) QCD calculations for this process have so far employed dynamical approximations for the two-loop contribution. We present NNLO QCD predictions based, for the first time, on a direct computation of the required two-loop amplitudes in the generalised leading-colour limit.

2606.09502 2026-06-09 math.NA cs.NA 新提交

Second-order bulk-surface splitting for the wave equation with kinetic boundary conditions

具有动力学边界条件的波动方程的二阶体-面分裂

R. Altmann, R. Morandin

AI总结 针对具有动力学边界条件的半线性波动方程,提出一种基于方程耦合系统解释和离散状态差分公式的二阶体-面分裂格式,证明能量稳定性和二阶收敛性,并通过数值验证。

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AI中文摘要

本文致力于对具有动力学边界条件的半线性波动方程的二阶体-面分裂格式进行数值分析。该构造基于将方程解释为耦合系统,并根据离散状态在系统方程中的确切位置实施不同的差分公式。这产生了一个4步格式,将体动力学和面动力学解耦。我们在弱CFL条件下证明了能量稳定性和二阶收敛性,并通过数值验证了这些结果。

英文摘要

This paper is devoted to the numerical analysis of a second-order bulk--surface splitting scheme for the semi-linear wave equation with kinetic boundary conditions. The construction is based on the interpretation of the equations as coupled system and the implementation of different difference formulae for the discrete states depending on their exact position in the system equations. This results in a 4-step scheme which decouples bulk and surface dynamics. We prove energy stability and second-order convergence under a weak CFL condition and validate these results also numerically.

2606.09501 2026-06-09 physics.optics hep-th 新提交

Experimental observation of hyperbolic spacetime dynamics

双曲时空动力学的实验观测

Jonas Himmel, Coraline Bacq, Krishna Chand Maurya, Max Ehrhardt, Matthias Heinrich, Tom A. W. Wolterink, Pablo Basteiro, Rathindra Nath Das, René Meyer, Tobias Huber-Loyola, Andreas Pfenning, Sven Höfling, Johanna Erdmenger, Alexander Szameit

AI总结 利用光子平台模拟洛伦兹AdS时空中的狄拉克方程,首次实验观测到费米子波包的引力束缚和中心质量运动,揭示了测地线振荡与颤动频率对曲率和质量的依赖。

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AI中文摘要

理解弯曲时空中的量子动力学是量子力学与引力交叉领域的核心挑战。反德西特(AdS)时空在AdS/CFT对应中扮演关键角色,该对应将AdS体中的引力动力学与其边界上的共形场论(CFT)联系起来。尽管其基础重要性,直接实验访问洛伦兹AdS时空中的动力学量子现象至今仍遥不可及。在此,我们报告了利用光子平台首次实验模拟洛伦兹AdS时空中费米子波包动力学。通过将弯曲时空中的狄拉克方程映射到工程波导阵列中的光传播,我们直接观测到相对论波包的引力束缚,并实时解析其质心运动。我们识别出一种特征叠加:仅由时空曲率决定的慢速测地线振荡,以及由相对论粒子-反粒子干涉引起的快速颤动(Zitterbewegung)。测地线频率与费米子质量无关,而颤动频率则表现出对质量和曲率的独特联合依赖,揭示了曲率诱导的相对论量子动力学修正。我们的结果首次提供了对模拟洛伦兹符号AdS$_2$时空中费米子体动力学的定量实验访问。这建立了一个可扩展的模拟平台,可能用于探索全息动力学的各个方面。

英文摘要

Understanding quantum dynamics in curved spacetime is a central challenge at the intersection of quantum mechanics and gravity. Anti-de-Sitter (AdS) spacetime plays a pivotal role in the context of the AdS/CFT correspondence, which relates gravitational dynamics in the AdS bulk to a conformal field theory (CFT) living on its boundary. Despite its foundational importance, direct experimental access to dynamical quantum phenomena in Lorentzian AdS spacetime has so far remained out of reach. Here, we report the first experimental emulation of fermionic wave packet dynamics in Lorentzian AdS spacetime using a photonic platform. By mapping the Dirac equation in curved spacetime onto the propagation of light in engineered wave\-guide arrays, we directly observe gravitational confinement of relativistic wave packets and resolve their center-of-mass motion in real time. We identify a characteristic superposition of slow geodesic oscillations governed solely by spacetime curvature and fast Zitterbewegung arising from relativistic particle--antiparticle interference. While the geodesic frequency is independent of fermion mass, the Zitterbewegung frequency exhibits a distinct joint dependence on mass and curvature, revealing a curvature-induced modification of relativistic quantum dynamics. Our results provide the first quantitative experimental access to fermionic bulk dynamics in emulated AdS$_2$ spacetime with Lorentzian signature. This establishes a scalable analog platform that may potentially be used for exploring dynamical aspects of holography.

2606.09497 2026-06-09 physics.med-ph 新提交

Experimental Validation of Skull Acoustic Modelling Strategies for Transcranial Focused Ultrasound Simulation: A Cross-Comparison Study

经颅聚焦超声模拟中颅骨声学建模策略的实验验证:交叉比较研究

Han Li, Aidan J Horner, Xinyu Zhang, Zhihong Huang

AI总结 本研究实验比较了五种k-Wave颅骨模型在220-1000 kHz频率下的性能,发现峰值压力误差20%-31%,强度误差41%-77%,焦点体积误差11%-67%,定位偏差数毫米,线性映射模型压力误差最低但无模型在所有指标上一致占优。

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AI中文摘要

颅骨的精确声学建模对于模拟引导的经颅聚焦超声(tFUS)至关重要,但常用的颅骨参数化策略在复杂性和报告准确性上存在差异。本研究实验比较了五种k-Wave颅骨模型:两种体素级线性映射模型、两种三层模型和一种单层固定参数模型。测试了来自五个历史人类颅骨和两个Thiel-防腐人类颅骨的十九个感兴趣区域,频率为220 kHz、680 kHz和1000 kHz。使用声全息重建碗状表面源场,并将模拟的颅内压力场与针式水听器测量结果进行基准比较。在不同频率下,平均峰值压力误差范围为20%至31%,而强度误差达到41%至77%。-6 dB焦点体积误差范围为11%至67%,焦点位置偏差通常为几毫米。模拟通常预测的插入损耗小于测量值,表明倾向于低估颅骨相关衰减并高估透射的颅内暴露。具有固定衰减的线性映射模型给出了最低的频率平均压力误差,但没有任何模型在所有指标上显示出一致的优势。这些结果表明,当前的颅骨模型可以再现总体颅内波束模式,同时在暴露、焦点覆盖和目标定位方面保留显著的定量不确定性。

英文摘要

Accurate acoustic modelling of the skull is essential for simulation-guided transcranial focused ultrasound (tFUS), but commonly used skull parameterisation strategies differ in complexity and reported accuracy. This study experimentally compared five k-Wave skull models: two voxel-wise linear mapping models, two three-layer models, and one single-layer fixed-parameter model. Nineteen regions of interest from five historical and two Thiel-embalmed human skulls were tested at 220 kHz, 680 kHz, and 1000 kHz. Bowl-surface source fields were reconstructed using acoustic holography, and simulated intracranial pressure fields were benchmarked against needle-hydrophone measurements. Across frequencies, mean peak-pressure errors ranged from 20% to 31%, whereas intensity errors reached 41% to 77%. Errors in -6 dB focal volume ranged from 11% to 67%, and focal-position discrepancies were typically several millimetres. Simulations generally predicted smaller insertion losses than measured, indicating a tendency to underestimate skull-related attenuation and overestimate transmitted intracranial exposure. The linear mapping model with fixed attenuation gave the lowest frequency-averaged pressure error, but no model showed a consistent advantage across all metrics. These results show that current skull models can reproduce gross intracranial beam patterns while retaining substantial quantitative uncertainty in exposure, focal coverage, and target localisation.

2606.09496 2026-06-09 eess.SP 新提交

Orbital Plane Geometry and Information Conditioning for Doppler-Only LEO Positioning

仅多普勒低轨定位的轨道平面几何与信息条件

Charles E Thornton

AI总结 针对静止接收机利用低轨机会信号进行仅多普勒定位,提出将卫星贡献建模为轨道平面上的加权投影,推导信息矩阵的特征值、条件数和最坏情况克拉美-罗下界,揭示轨道平面二面角与信息强度对条件数的影响。

Comments 5 pages, 3 figures

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AI中文摘要

我们研究了静止接收机利用低轨机会信号进行仅多普勒定位的理想化信息模型。受卫星通过的多普勒测量主要提供相关轨道平面内信息的观察启发,我们将每个卫星的贡献建模为该平面上的加权投影。在该模型下,来自多颗卫星的联合信息矩阵是轨道平面投影算子的和。推导了特征值、条件数和最坏情况克拉美-罗下界的闭式表达式。对于两颗卫星,条件数由轨道平面之间的二面角和两条链路的相对信息强度决定。对通过积分多普勒Fisher信息矩阵的蒙特卡洛评估表明,所提出的替代模型捕捉了与轨道平面多样性相关的主要条件数趋势。结果提供了一个简单的几何框架,用于理解星座几何在仅多普勒定位系统中的作用。

英文摘要

We study an idealized information model for Doppler-only positioning with low earth orbit (LEO) signals of opportunity from a stationary receiver. Motivated by the observation that Doppler measurements from a satellite pass provide information primarily within the associated orbital plane, we model each satellite contribution as a weighted projection onto that plane. Under this model, the combined information matrix from multiple satellites is a sum of orbital-plane projection operators. Closed-form expressions are derived for the eigenvalues, condition number, and worst-case Cramer-Rao lower bound. For two satellites, the conditioning is governed by the dihedral angle between orbital planes and the relative information strengths of the two links. Monte Carlo evaluation of pass-integrated Doppler Fisher information matrices demonstrates that the proposed surrogate captures the dominant conditioning trends associated with orbital-plane diversity. The results provide a simple geometric framework for understanding the role of constellation geometry in Doppler-only positioning systems.

2606.09494 2026-06-09 q-bio.PE cond-mat.dis-nn 新提交

Percolation and clustering in ecological communities: A dynamical theory

生态群落中的渗流与聚类:一种动力学理论

Dario Sergo, Cédric Koller, Vittorio Erba, Lenka Zdeborová

AI总结 针对随机相互作用图上的竞争性生态系统,提出离散广义Lotka-Volterra模型,分析渗流簇的出现及存活位点的空间组织,揭示动力学可达性如何控制聚类与渗流的产生。

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AI中文摘要

具有结构化相互作用的生态群落表现出占据位点的渗流和聚类等集体现象。尽管这些效应已在实验和模拟中得到记录,但系统的分析理解仍然有限。在本文中,我们针对定义在随机相互作用图上的竞争性生态系统,发展了这些现象的动力学理论。我们引入了广义Lotka-Volterra模型的离散版本,该模型保留了连续生态动力学的主要宏观特征,同时允许分析处理。在此框架内,我们刻画了渗流簇的出现,并描述了存活位点的空间组织。我们的分析揭示了动力学能够达到哪些平衡态,并展示了这种动力学可达性如何控制聚类和渗流的开始。通过这样做,我们的框架为经典Lotka-Volterra理论提供了补充,为结构化群落的集体组织提供了动力学视角。

英文摘要

Ecological communities with structured interactions exhibit collective phenomena such as percolation and clustering of occupied sites. While these effects have been documented in experiments and simulations, systematic analytical understanding has remained limited. In this paper, we develop a dynamical theory of these phenomena for competitive ecological systems defined on random interaction graphs. We introduce a discrete version of the generalized Lotka-Volterra model that preserves key macroscopic features of continuous ecological dynamics while enabling analytical treatment. Within this framework, we characterize the emergence of percolating clusters and describe the spatial organization of surviving sites. Our analysis uncovers which equilibria can be reached by the dynamics and shows how this dynamical accessibility governs the onset of clustering and percolation. In doing so, our framework complements classical Lotka-Volterra theory by providing a dynamical perspective on the collective organization of structured communities.

2606.09493 2026-06-09 physics.plasm-ph 新提交

Collisionless Bulk Electron Heating in Resonant Low-Voltage Capacitively Coupled Plasmas

共振低压电容耦合等离子体中的无碰撞体电子加热

Sarveshwar Sharma, Igor D. Kaganovich, Animesh Kuley, Sudip Sengupta, Alexander V. Khrabrov, Bhooshan Paradkar

AI总结 研究共振低压电容耦合等离子体中无碰撞功率吸收,发现体电子加热通过共振增强的射频电场、电子在势阱中的振荡及碰撞散射协同作用产生高能电子尾,显著提高电离率。

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AI中文摘要

我们研究了共振低压电容耦合等离子体(CCPs)中的无碰撞功率吸收。在这些射频(RF)放电中,鞘层电容几乎恰好平衡了等离子体电感,将总射频放电电压降低到仅几伏。然而,等离子体不仅存在于这种超低电压状态;它还产生离子,这些离子以显著超过施加射频电压幅值的动能轰击电极。这种反直觉的行为源于等离子体内部存在一个约40 V的显著静电势阱,它约束电子同时加速离子向电极运动。我们表明,在这些共振条件下,无碰撞电子加热表现出与传统的随机鞘层加热(通过电子-鞘层相互作用介导)范式根本不同的行为。相反,主要的能量传递机制是通过一种主要无碰撞过程在射频电场中的体电子加热,该过程源于以下因素的协同作用:(i)等离子体内部强烈放大的射频电场,(ii)电子在等离子体势阱中的振荡运动(弹跳),以及(iii)电子与中性原子碰撞导致的散射。这些现象共同导致电子能量分布函数中出现显著的高能尾,从而显著提高电离率。随着气体压力升高,共振被破坏。同时,最大功率吸收区域从等离子体核心向边缘和鞘层移动,伴随着高能电子群的消失和电离率的相应下降。

英文摘要

We investigate collisionless power absorption in resonant, low$-$pressure capacitively coupled plasmas (CCPs). In these radio-frequency (RF) discharges, the sheath capacitance almost exactly balances the plasma inductance, driving the total RF discharge voltage down to just a few volts. However, plasma persists not only in this ultra$-$low$-$voltage regime; it also generates ions that strike the electrodes with kinetic energies substantially exceeding the amplitude of the applied RF voltage. This counterintuitive behavior arises from the presence of a pronounced electrostatic potential well of approximately 40 V within the plasma bulk, which confines electrons while simultaneously accelerating ions toward the electrodes. We show that, under these resonant conditions, collisionless electron heating exhibits a fundamentally different behavior from the conventional paradigm of stochastic sheath heating mediated by electron$-$sheath interactions. Instead, the predominant energy transfer mechanism is bulk electron heating in RF electric fields via a primarily collisionless process that emerges from the synergistic action of: (i) a strongly amplified RF electric field within the plasma bulk, (ii) electron oscillatory motion (bouncing) within the plasma potential well, and (iii) electron scattering resulting from collisions with neutral atoms. Collectively, these phenomena give rise to a pronounced high$-$energy tail in the electron energy distribution function and thereby lead to a substantial enhancement of the ionization rates. As the gas pressure rises, the resonance is disrupted. At the same time, the region of maximum power absorption moves from the plasma core toward the edges and the sheath, which is accompanied by the disappearance of the high$-$energy electron population and a corresponding decrease in ionization rates

2606.09492 2026-06-09 math.CV math.AP 新提交

Jensen Deficits for Inhomogeneous Monge-Ampère Dirichlet Problems

非齐次Monge-Ampère Dirichlet问题的Jensen亏格

Frank Wikström

AI总结 针对Monge-Ampère下界约束的Perron包络,发展了非齐次形式的Edwards Jensen测度对偶性,通过Jensen亏格建立边界对偶公式,并应用于Alexandrov和Bedford-Taylor次解,证明Dirichlet解的连续性。

Comments 24 pages

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AI中文摘要

我们针对受Monge-Ampère下界约束的Perron包络,发展了Edwards Jensen测度对偶性的非齐次形式。允许的次解族是凸集但不是锥;然而,对偶测度仍然是齐次Jensen测度,右端通过标量Jensen亏格\[ B_{\mathcal{A}}(x,\mu) = \inf_{u\in\mathcal{A}} \left(\int_{\partial\Omega}u\\,d\mu-u(x)\right) \] 进入。在自然结构假设下,我们证明了边界对偶公式\[ \sup\{u(x):u\in\mathcal{A},\\ u\leq\phi\text{ on }E\} = \inf_{\mu\in J_x^\partial} \left( \int_{\partial\Omega}\phi\\,d\mu - B_{\mathcal{A}}(x,\mu) \right). \] 我们将该定理应用于实Alexandrov次解和具有连续密度的复Bedford-Taylor多重次调和次解。在一维实情形,亏格是Green势修正;在高维情形,它具有内在的应力和电流解释。在B-正则区域上,有界Bedford-Taylor逼近定理识别有界和连续竞争者,并给出相应Dirichlet解连续性的对偶证明。最后,对于光滑严格椭圆解,最优Jensen测度是线性化Monge-Ampère算子的调和测度,等价于非线性解映射的边界导数。

英文摘要

We develop an inhomogeneous form of Edwards' Jensen-measure duality for Perron envelopes constrained by Monge--Ampère lower bounds. The admissible subsolution families are convex but not cones; nevertheless, the dual measures remain the homogeneous Jensen measures, and the right-hand side enters through a scalar Jensen deficit \[ B_{\mathcal{A}}(x,μ) = \inf_{u\in\mathcal{A}} \left(\int_{\partialΩ}u\,dμ-u(x)\right). \] Under natural structural hypotheses we prove a boundary dual formula \[ \sup\{u(x):u\in\mathcal{A},\ u\leqφ\text{ on }E\} = \inf_{μ\in J_x^\partial} \left( \int_{\partialΩ}φ\,dμ - B_{\mathcal{A}}(x,μ) \right). \] We apply the theorem to real Alexandrov subsolutions and to complex Bedford--Taylor plurisubharmonic subsolutions with continuous density. In one real dimension the deficit is the Green-potential correction; in higher dimensions it has intrinsic stress and current interpretations. On B-regular domains, a bounded Bedford--Taylor approximation theorem identifies bounded and continuous competitors and yields a duality proof of continuity for the corresponding Dirichlet solution. Finally, for smooth strictly elliptic solutions, optimal Jensen measures are the harmonic measures of the linearized Monge--Ampère operators, equivalently the boundary derivatives of the nonlinear solution map.

2606.09491 2026-06-09 astro-ph.CO gr-qc hep-ph 新提交

Spectral distortion anisotropies from photon to dark photon conversions

光子到暗光子转换引起的谱畸变各向异性

Sara Evangelista, Jens Chluba, Bryce Cyr

AI总结 研究暗光子通过共振转换在宇宙微波背景中产生谱畸变各向异性,利用频率层次框架计算功率谱,发现暗光子质量控制信号形状,混合参数决定幅度,并给出普朗克数据约束。

Comments 37 pages, 14 figures, to be submitted to JCAP, comments welcome!

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AI中文摘要

暗光子是假设的暗扇区的规范玻色子,代表了标准模型最受研究的微小扩展之一,具有广泛的理论和观测意义。这里,我们考虑初始未占据的暗光子扇区通过共振光子到暗光子转换被占据的情景。这个过程在宇宙微波背景(CMB)中产生可观测的谱畸变,可用于约束这些模型。我们将之前对单极谱的谱畸变研究扩展到各向异性谱畸变,使用新开发的CosmoTherm频率层次(FH)框架。我们通过呈现整个暗光子参数空间中光子传递函数和畸变交叉功率谱的详细计算来说明物理机制。我们发现暗光子质量明确控制信号功率谱的形状(即多极依赖性),而信号的总体幅度由模型的动力学混合参数决定。利用这些结果,我们使用普朗克数据对最小暗光子模型施加互补限制,发现这些约束仅略弱于使用COBE/FIRAS数据对平均(单极)畸变获得的约束。此外,我们计算了对标准温度场的修正,认为红移大于$2\ imes 10^6$的转换可能增加等曲率型扰动,这可能在畸变各向异性热化的区域产生新的约束。

英文摘要

Dark photons are a gauge boson of a hypothetical dark sector, representing one of the most-studied minimal extensions of the Standard Model, with wide-ranging theoretical and observational implications. Here, we consider scenarios in which an initially unpopulated dark photon sector is populated via resonant photon to dark photon conversions. This process leads to observable spectral distortions in the cosmic microwave background (CMB), that can be used to constrain these models. We extend previous spectral distortion studies of the monopole spectrum to anisotropic spectral distortions, using the newly developed Frequency Hierarchy (FH) framework of CosmoTherm. We illustrate the physics by presenting detailed computations of the photon transfer functions and distortion cross power spectra throughout the dark photon parameter space. We find that the dark photon mass explicitly controls the shape (i.e., multipole-dependence) of the signal power spectra, while the overall amplitude of the signal is determined by the kinetic mixing parameter of the model. Using these results, we place complementary limits on the minimal dark photon model using data from Planck, finding that the constraints are only marginally weaker than those obtained with COBE/FIRAS data for the average (monopole) distortion. In addition, we compute the corrections to the standard temperature field, arguing that conversions at redshifts larger than $2\times 10^6$ may add iso-curvature type perturbations, which could lead to novel constraints in regimes where distortion anisotropies thermalize.

2606.09490 2026-06-09 physics.flu-dyn 新提交

Scaling laws and local enhancements of buoyancy flux in stratified turbulent flows

分层湍流中浮力通量的标度律与局部增强

Gyeongseob Song, Fabio Feraco, Raffaele Marino, Jorge L. Chau, Alain Pumir, Leonardo Primavera, Annick Pouquet, Pablo D. Mininni, Duane Rosenberg

AI总结 通过直接数值模拟研究分层湍流中浮力通量的标度行为,发现其空间分布具有强非高斯尾部,且偏度随浮力雷诺数呈幂律增长,域平均浮力通量随分层增强呈现对数增长并趋于小偏移。

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AI中文摘要

在分层存在的情况下,湍流不仅在尺度上表现出间歇性,而且在平均流尺度上也表现出间歇性,正如在大气和海洋中观察到的那样。我们通过使用不同强迫类型的Boussinesq方程的直接数值模拟进行大参数探索来研究此类流动。我们检查了两个Prandtl数(1和6),并在地球物理感兴趣的值范围内变化Froude数($Fr$),$0.01\le Fr \le 1$,对应于浮力Reynolds数($R_{IB}$)在$0.06\le R_{IB} \le 2300$范围内的变化。我们分析了浮力通量($B_f$)、混合效率、剪切参数和垂直动量通量对$R_{IB}$的依赖性。观察到$B_f$的时空分布具有强非高斯尾部,峰度达到$\approx 10^2$,表明即使在稳定分层下,分层地球物理流也可能沿重力方向具有高度可变的输运特性。这与大尺度垂直速度和温度的长时间间歇行为有关,这会产生局部湍流并增强耗散和输运。我们提供的证据表明,$B_f$的偏度随$R_{IB}$呈幂律增长,并在被动标量极限中饱和。我们还表明,域平均$B_f$表现出两种不同的趋势:随$R_{IB}$对数增长,以及随着分层增强而趋近于一个小偏移。一个关于能量和$B_f$时间演化的简单模型表明,垂直能与势能之间的缺陷驱动了强$B_f$事件。这一趋势直接导致对流不稳定性、二维和三维涡旋的形成,以及在周转时间尺度上的快速耗散,使得能量循环能够重新开始——这也以爆发形式发生。

英文摘要

In the presence of stratification, turbulent flows exhibit intermittency not only at small scales but also at large scales, comparable to the mean flow, as observed in the atmosphere and oceans. We study such flows through a large parametric exploration using direct numerical simulations of the Boussinesq equations with different forcing types. We examine two Prandtl numbers (1 and 6) and vary the Froude number ($Fr$) over a range of geophysical interest values, $0.01\le Fr \le 1$, corresponding to a variation in terms of the buoyancy Reynolds number ($R_{IB}$) of $0.06\le R_{IB} \le 2300$. We analyze the dependence on $R_{IB}$ of the buoyancy flux ($B_f$), the mixing efficiency, the shear parameters, and the vertical momentum flux. Strongly non-Gaussian tails in the spatio-temporal distribution of the $B_f$ are observed, with kurtosis reaching $\approx 10^2$, indicating the potential for stratified geophysical flows to be characterized by highly variable transport properties along the direction of gravity even under stable stratification. This is associated with long-time intermittent behavior of vertical velocity and temperature at large scale, which produces local turbulence and enhances dissipation and transport. We present evidence that the skewness of $B_f$ increases with $R_{IB}$ as a power-law and saturates in the passive-scalar limit. We also show that the domain-averaged $B_f$ exhibits two distinct trends: logarithmic growth with $R_{IB}$ and approach to a small offset as stratification strengthens. A simple model for the temporal evolution of energy and $B_f$ indicates that the defect between vertical and potential energy drives strong $B_f$ events. This trend directly leads to convective instabilities, the formation of two-dimensional and three-dimensional eddies, and rapid dissipation on a turnover timescale, allowing the energetic cycle to restart-also occurring in bursts.

2606.09488 2026-06-09 math.PR 新提交

The temporal stochastic block model

时间随机块模型

Sofiya Burova, Gábor Lugosi, Guillem Perarnau

AI总结 针对异质群体中的感染传播,提出时间随机块模型,研究通过递增路径可达集的大小和结构,证明了典型顶点可达集一阶渐近的精确结果及社区内到达比例。

详情
AI中文摘要

受理解异质群体中感染传播需求的驱动,我们考虑随机块模型的\emph{时间}版本,其中每条边配备一个随机标签,解释为时间戳。我们研究通过递增路径(即边时间戳严格递增的路径)的可达集的大小和结构,其中每个节点的连接数为$\log n$阶。我们证明了典型顶点可达集大小的一阶渐近以及每个社区中到达顶点比例的精确结果。我们还确定了具有一个或两个固定端点的最短和最长递增路径的典型长度。在典型顶点的可达集$S$为次线性大小的范围内,我们通过识别一个几乎生成树(即覆盖除$o(|S|)$个顶点外的所有顶点)来描述由$S$诱导的子图结构,该树分布为加权随机递归树,其高度、轮廓和度序列已知。特别地,当$|S|\ll \sqrt{n}$时,由$S$诱导的子图本身分布为此已知的加权随机递归树。

英文摘要

Motivated by the need to understand infection spreading in inhomogeneous populations, we consider a \emph{temporal} version of the stochastic block model, where each edge is equipped with a random label, interpreted as a timestamp. We study the size and structure of reachable sets via increasing paths (that is, paths whose edge timestamps are strictly increasing) where the connections per node are of the order of $\log n$. We prove tight results for the first order asymptotics of the size of the reachable set from a typical vertex, and the proportions of reached vertices in each community. We also determine the typical length of the shortest and longest increasing paths with one or two fixed endpoints. In the regime where the reachable set $S$ of a typical vertex is of sublinear size, we describe the structure of the subgraph induced by $S$ by identifying an almost spanning tree (i.e., spanning all but $o(|S|)$ vertices), that is distributed as a weighted random recursive tree, whose height, profile and degree sequence are known. In particular, when $|S|\ll \sqrt{n}$, the subgraph induced by $S$ is itself distributed as this well-understood weighted random recursive tree.

2606.09487 2026-06-09 physics.plasm-ph 新提交

Experimental validation of a fast control-oriented, physics-informed surrogate model for plasma equilibrium reconstruction in the TCV tokamak

TCV托卡马克中用于等离子体平衡重建的快速控制导向、物理信息代理模型的实验验证

M. Grandin, A. Mele, C. Galperti, D. Gonzales Castineiras, C. Heiß, A. Cenedese, TCV team, EUROfusion Tokamak Exploitation team

AI总结 提出一种物理信息神经网络代理模型替代平衡重建代码,实现低于100微秒推理时间,支持10kHz形状控制,并在TCV托卡马克上离线与实时验证。

Comments Code available at https://github.com/matgrand/liuqe-nn

详情
AI中文摘要

磁平衡重建提供了托卡马克中实时形状控制所需的等离子体状态估计。我们提出了一种快速、物理信息神经网络代理模型,替代EPFL TCV托卡马克的\texttt{liuqe}平衡重建代码\cite{liuqe1},推理时间低于100~$\bm\mu$s,实现10~kHz形状控制。该模型在约10,000个TCV放电数据上训练,覆盖等离子体形状的全部运行范围。其模块化分支/主干架构将磁测量编码与空间坐标处理解耦,通过自动微分预测磁通图实现物理信息正则化。该代理模型已在TCV实时控制系统上编译部署,并针对\texttt{liuqe-rt}和\texttt{lih}模型进行了离线与实时验证,显示出相当的精度。通过实时软件在环\texttt{fge}\cite{fge1}评估的闭环性能表明,在多种控制策略下具有控制等效行为。

英文摘要

Magnetic equilibrium reconstruction provides the plasma state estimate required for real-time shape control in tokamaks. We present a fast, physics-informed neural network surrogate of the \texttt{liuqe} equilibrium reconstruction code \cite{liuqe1} for the TCV tokamak at EPFL, achieving inference times below 100~$\bmμ$s and enabling 10~kHz shape control. The model is trained on around 10,000 TCV discharges spanning the full operational range of plasma shapes. Its modular branch/trunk architecture decouples magnetic measurement encoding from spatial coordinate processing, enabling physics-informed regularization via automatic differentiation of the predicted flux map. The surrogate has been compiled and deployed on the TCV real-time control system, and validated both offline and in real time against the models \texttt{liuqe-rt} and \texttt{lih}, showing comparable accuracy. Closed-loop performance assessed with the real-time software in-the-loop \texttt{fge} \cite{fge1} demonstrates control-equivalent behavior across multiple control strategies.