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2605.07344 2026-05-11 gr-qc hep-th

DESI and Dynamical Dark Energy from Extended Pre-geometric Gravity

Andrea Addazi, Yermek Aldabergenov, Daulet Berkimbayev, Yifu Cai, Salvatore Capozziello, Giuseppe Meluccio

AI总结 该研究探讨了一种保持拓扑预体积形式对称性的MacDowell-Mansouri前几何引力的简单二次扩展,在对称性破缺后,该理论等价于一种类似于伽利略标量-张量理论的Horndeski理论。通过引力希格斯机制,该模型使高斯-玻恩耦合与真空宇宙学常数成反比,并使引力θ角成为动态的引力轴子,其有效质量设定了暗能量尺度,从而自然实现了动态暗能量。该模型与DESI的BAO+FS数据拟合良好,且在引力滑移参数上仅与ΛCDM模型略有偏差,为前几何引力与宇宙加速之间建立了可检验的桥梁。

Comments 8 pages, 3 figures

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英文摘要

We consider the simplest quadratic extension of MacDowell-Mansouri pre-geometric gravity preserving the topological pre-volume form symmetry. After symmetry breaking, it becomes $(\mathrm{Lovelock})^2$ gravity, dual to a Galileon-like Horndeski scalar-tensor theory. The gravitational Higgs mechanism forces the Gauss-Bonnet coupling to be inversely proportional to the bare cosmological constant. The quadratic correction renders the gravitational $θ$-angle dynamical in the form of a gravi-axion, whose effective mass sets the dark energy scale, thus naturally realizing a dynamical dark energy. The model fits DESI's BAO+FS data exceptionally well ($χ^2_{\rm red} = 1.394$), deviating from $Λ\mathrm{CDM}$ by only a few percent in the gravitational slip parameter $γ(z)$ with stable tensor perturbations. This analysis establishes a concrete, testable bridge between pre-geometric gravity and cosmic acceleration.

2605.07343 2026-05-11 physics.ins-det

Review of germanium-silicon single-photon avalanche diodes

Neil Na, Erik Chen, Gerald S. Bullerb, Robert H. Hadfield, Richard A. Sorefd

AI总结 本文综述了锗硅(GeSi)单光子雪崩二极管(SPAD)在短波红外(SWIR)单光子探测(SPD)领域的研究进展,从最初的低温工作演示到近期的常温运行实现。文章总结了GeSi材料在高速光通信和主动光学传感成像中的应用扩展,并探讨了其未来潜在的应用方向。

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Journal ref
Proc. of SPIE Vol. 13448, 1344808 (2025)
英文摘要

While it took about a decade for a germanium (Ge) thin film grown on a silicon (Si) substrate to be successfully applied as a detector material for high-speed optical fiber communication application, it took about another decade to further expand its usage as a sensor material for active optical sensing and imaging applications. In this paper, we shall review the progress of a shortwave infrared (SWIR) single-photon detection (SPD) with germanium-silicon (GeSi) single-photon avalanche diode (SPAD), ranging from the first demonstration at cryogenic temperature (Z. Lu et al., 2011) to the recent demonstration at room temperature (N. Na et al, 2024). Potential new applications will also be discussed.

2605.07341 2026-05-11 math.PR

A Scaling Limit of Random Walks in the Rational Adeles

Rahul Rajkumar

AI总结 本文研究了有理阿代尔数上的随机游动在尺度极限下的收敛性,证明了其收敛于一个阿代尔Lévy过程。通过在$p$-进数上构造随机游动,并利用生存时间分析,作者展示了这些随机游动几乎处处在所有时间上都具有阿代尔性质。研究还表明,阿代尔随机游动是对有限乘积路径空间上过程的小扰动,并在$J_1$ Skorokhod拓扑下建立了弱收敛性。

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英文摘要

This paper shows the convergence of adele-valued random walks to an adelic Lévy process under scaling limits. We use random walks on the $p$-adic numbers to construct random walks initially on the infinite product space, and use survival time analysis to prove that the random walks are almost surely adelic for all time. The adelic random walks are shown to be small perturbations of processes that are supported on a finite product of path spaces. Weak convergence to an adelic Lévy process is established in the $J_1$ Skorokhod topology.

2605.07340 2026-05-11 cs.CR

A Unified Open-Set Framework for Scalable PUF-Based Authentication of Heterogeneous IoT Devices

Xin Wang, Peichun Hua, Chip Hong Chang, Wenye Liu, Yue Zheng

AI总结 随着异构物联网设备数量的增加,如何有效防止假冒和伪造成为关键安全挑战。本文提出了一种统一的开集框架,用于实现对多种物理不可克隆函数(PUF)类型物联网设备的可扩展身份认证,该方法无需辅助数据,利用基于OpenGAN的分类器处理不同PUF类型的原始响应,将其编码为统一的图像表示,从而实现高效、鲁棒的单次分类与冒充者拒绝。实验表明,该框架在多种噪声PUF数据集上实现了100%的闭集准确率和接近零的开集错误率,且认证速度显著优于现有方法。

Comments 8 pages, 3 figures, 5 tables, submitted for conference

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英文摘要

As modern cyber systems scale to include large populations of heterogeneous IoT devices, securing them against impersonation and forgery is a critical cybersecurity challenge. Physical Unclonable Functions (PUFs) offer a lightweight, hardware-rooted trust anchor for IoT security. However, different PUF architectures possess distinct challenge-response spaces and raw response reliabilities, making existing authentication protocols PUF-type specific. To bridge this interoperability bottleneck, this paper proposes a scalable, helper-data-free, open-set PUF authentication framework that leverages an OpenGAN-based classifier to manage heterogeneous fleets of IoT devices. Our method addresses the limitations of traditional database-centric and digital-twin modeling methods by encoding raw responses from diverse PUF types, including strong, weak and hybrid PUFs, into a unified image representation. This enables robust, single-pass classification and impostor rejection. We integrate the classifier into a generic protocol employing hybrid encryption and Bloom filter-based replay detection. Evaluated across four different types of noisy PUF data (Arbiter, SRAM, DRAM, and heterogeneous PUFs), our framework achieves 100% closed-set accuracy and near-zero open-set error rates with up to 45 devices, a significant improvement over the 3 to 5 devices in prior classification-based approaches. Prototyped on a Raspberry Pi, our framework completes one authentication cycle within 0.67 s, approximately 30x faster than the state-of-the-art open-set baselines.

2605.07337 2026-05-11 cond-mat.mtrl-sci physics.chem-ph

Water adsorption on a model silicate surface: wollastonite (100)

Luca Lezuo, Andrea Conti, Alexander Hoheneder, Elena Vaníčková, Domitilla Alessandra Aloi, Rainer Abart, Florian Mittendorfer, Michael Schmid, Ulrike Diebold, Giada Franceschi

AI总结 本研究探讨了水分子在典型硅酸盐矿物——透辉石(CaSiO₃)最低能量(100)表面上的吸附行为,旨在揭示其与矿物表面相互作用的微观机制。通过结合非接触原子力显微镜(nc-AFM)实验与密度泛函理论(DFT)计算,研究发现水分子在低覆盖率时主要通过与表面的相互作用形成有序结构,而随着覆盖率增加,水分子间的氢键作用逐渐主导,形成复杂的共存结构。研究为理解水与钙硅酸盐表面的相互作用提供了原子尺度的理论框架。

Comments 18 pages, 5 figures

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英文摘要

Water adsorption on silicate surfaces is a critical yet poorly understood process relevant to, e.g., mineral weathering and cement hydration. This study investigates the structure of water overlayers on a model calcium silicate, the lowest-energy (100) surface of wollastonite (CaSiO3). It combines atomically resolved non-contact atomic force microscopy (nc-AFM), acquired with qPlus sensors and functionalized tips in ultrahigh vacuum (UHV), with density functional theory (DFT) calculations employing the metaGGA r2SCAN+rVV10 functional. Adding incremental doses of water to the sample at cryogenic temperatures produces distinct structures governed by the competition between water-surface and water-water interactions. With two water molecules per surface unit cell, water-surface interactions dominate: In line with previous theoretical predictions, adsorbates follow the surface lattice. As the coverage increases, intermolecular hydrogen bonding competes with bonding to the surface, leading to the emergence of complex, coexisting patterns. While their small energy differences prevent an unambiguous identification of the most stable structure by DFT, the experimentally observed symmetries help constrain plausible structural models. Above a critical density of four water molecules per unit cell, water-water interactions prevail, and water clusters are formed. The results provide an atomic-scale framework for understanding water interactions with calcium silicate surfaces.

2605.07336 2026-05-11 cond-mat.supr-con

Breaking the Trade-off: Bulk 2D Ising Superconductivity with High Tc and Giant Interlayer Spacing via a Unique Chain Intercalation in (BaS)1/3TaS2

Ziyi Zhu, Leiming Chen, Xiangqi Liu, Haonan Wang, Chen Xu, Ze Yan, Zhengyang Li, Wei Xia, Jiawei Luo, Na Yu, Xia Wang, Ke Qu, Zhenzhong Yang, Yanfeng Guo

AI总结 该研究通过一种独特的链式插层策略,成功合成了一种新型二维超导材料(BaS)₁/₃TaS₂,打破了传统插层体系中高超导转变温度(Tc)与大层间距之间的权衡关系。该材料在TaS₂双层之间插入了Ba-S-S-Ba链结构,显著增大了层间距至12.75 Å,同时保持了高Tc,实现了二维伊辛超导性的稳定实现。这一成果为设计具有大层间距和高超导性能的体块二维伊辛超导体提供了新思路。

Comments Mian Text 26 pages, 6 figures abd SI 6 pages, 1 figure, 3 tables

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Journal ref
Journal of The American Chemical of Society, 2026
英文摘要

Two-dimensional (2D) transition metal dichalcogenides (TMDs) are promising platforms for low dimensional superconductivity. However, in conventional intercalated systems, achieving a high superconducting transition temperature (Tc) often comes at the expense of reduced interlayer spacing and weakened 2D character. Here, we overcome this long-standing compromise through a unique chain-like intercalation strategy. We report the synthesis and properties of a new polymorph, (BaS)1/3TaS2, in which a distinctive Ba-S-S-Ba chain structure is inserted between TaS2 bilayers. This unique configuration breaks the bulk c axis mirror symmetry while achieving exceptional interlayer decoupling, with an inter-bilayer spacing of 12.75 Å-more than three times that of pristine 2H-TaS2. By suppressing interlayer electronic coupling, this structural evolution allows local inversion symmetry breaking within individual TaS2 layers to dominate. This prevents compensation of the Ising spin-orbit fields typical of centrosymmetric bulk phases, enabling robust 2D Ising superconductivity. Remarkably, the compound exhibits an enhanced Tc without sacrificing its large interlayer spacing, thereby breaking the conventional trade-off between large spacing/high anisotropy and high Tc. Comprehensive transport, magnetic, and thermodynamic measurements confirm its robust superconducting state. Our work establishes a versatile intercalation framework for designing bulk-like 2D Ising superconductors, providing a new route to reconcile competing material demands and expanding the scope of Ising superconductivity research.

2605.07332 2026-05-11 quant-ph

Towards second-long electron spin coherence of a telecom quantum emitter in naturally abundant CeO$_2$

Basanta Mistri, Vishal Ranjan, Siddharth Dhomkar

AI总结 该研究探讨了在天然丰度的氧化铈(CeO₂)中掺杂铒(Er³⁺)离子的电子自旋量子比特的相干特性,旨在实现适用于量子技术的电信波段量子发射体。通过半经典模拟和簇关联展开计算,研究系统分析了磁场强度、脉冲序列、铒浓度和自旋温度等因素对自旋退相干的影响,发现低掺杂浓度和亚开尔文温度下,自旋浴退相干可显著抑制,使得哈恩回波相干时间接近秒级。研究还表明,即使在液氦温度下,相干时间也可达到约10毫秒,并可通过动态解耦脉冲进一步提升,为基于Er³⁺:CeO₂的量子比特、量子存储器和集成量子网络提供了重要基础。

Comments 11 pages, 7 figures

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英文摘要

Rare-earth-ion-doped crystals has emerged as a promising platform for quantum technologies, owing to their narrow telecom-band optical emission, long spin memory, and compatibility with silicon integrated photonic architectures. However, the realization of scalable quantum devices requires host materials with intrinsically dilute spin environments to suppress decoherence. In this context, erbium (Er$^{3+}$) doped cerium oxide (CeO$_2$) is an attractive candidate due to the ultra-low concentration of nuclear spins in the host matrix and its compatibility with silicon-based technologies. Here we perform a comprehensive investigation of the coherence properties of Er$^{3+}$ electron spin qubit in CeO$_2$ via semiclassical as well as detailed cluster correlation expansion simulations. By systematically exploring magnetic field strength, pulse sequences, erbium concentration, and spin temperature, we identify regimes where decoherence from the spin bath is strongly suppressed. Our investigations illustrate that at dilute doping concentration (of the order of 10 ppb) and sub-Kelvin temperatures, operation near clock transitions enables Hahn-echo coherence times to approach the second timescale even at natural isotopic abundance. Importantly, from a practical standpoint, coherence times on the order of $\sim 10$ ms are expected even at liquid helium temperature (about 2 K) for similar concentrations. Moreover, we demonstrate that an additional enhancement can be obtained with conventional multi-$π$-pulse dynamical decoupling protocols. Thus, our findings establish Er$^{3+}$ doped CeO$_2$ as a front-runner for realizing spin qubits, quantum memories, and integrated quantum networks.

2605.07328 2026-05-11 cs.NI

Unconsented Sensing: A Sociotechnical Governance Framework for 6G ISAC

Anass Sedrati

AI总结 随着6G集成感知与通信(ISAC)技术的发展,蜂窝基础设施将转变为持续的环境与生物特征感知网络。现有标准化工作虽重视隐私与可信性,但其技术手段仍以加密匿名化为主,忽视了感知数据下游机器学习模型所带来的社会技术与法律复杂性。本文提出了一种以“用途限定感知激活、公民透明机制和算法责任”为核心的治理框架,旨在弥合ISAC持续监控与全球数字权利法规之间的法律冲突,为6G感知基础设施的合法部署提供监管路径。

Comments 6 pages, 1 figure, ICT2026 Conference

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英文摘要

The forthcoming deployment of 6G Integrated Sensing and Communication (ISAC) will transform cellular infrastructure into pervasive, continuous environmental and biometric sensing grids. While current telecom standardization efforts (e.g., 3GPP, ETSI) have formally recognized privacy and trustworthiness as critical pillars for 6G, their proposed mitigations remain overwhelmingly technocentric, relying on cryptographic anonymization and physical layer security. This approach critically underestimates the sociotechnical and legal complexities of the downstream machine learning (ML) models required to interpret raw sensing data, creating a profound collision with existing digital rights legislation. This position paper argues that technical security is insufficient. ISAC trustworthiness must be redefined as mandatory regulatory and sociotechnical compliance. We identify the specific legal friction points between continuous ISAC surveillance and the mandates of emerging global digital rights regimes, using the stringent requirements of the EU AI Act and GDPR as our primary regulatory baselines. To bridge this gap, we propose a governance framework centered on three pillars: Purpose-bound sensing activation, citizen transparency mechanisms, and algorithmic accountability for ISAC-driven ML models. Ultimately, this paper provides a regulatory roadmap to prevent the illegal deployment of 6G sensing infrastructures and ensure they remain viable before physical deployment.

2605.07322 2026-05-11 math.CO

New results on the odd- and unique-Ramsey numbers

Shagnik Das, Ying-Sian Wu

AI总结 本文研究了奇数-Ramsey数和唯一-Ramsey数的相关问题,提出了针对完全图和二分图的下界估计,并分析了在超Dirac图中哈密顿圈的奇数-Ramsey数的非平凡性。此外,作者还证明了唯一-Ramsey数在环图上的下界,揭示了奇数-Ramsey数与唯一-Ramsey数之间的多项式差距。这些结果深化了对图的Ramsey性质的理解。

Comments 22 pages

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英文摘要

The odd-Ramsey number $r_{\text{odd}}(n,H)$ of a graph $H$ is the minimum number of colors needed to edge-color $K_n$ so that in every copy of $H$ some color occurs an odd number of times, and the unique-Ramsey number $r_{\text{u}}(n,H)$ is the corresponding notion in which some color is required to occur not only an odd number of times but exactly once. In this paper, we address three questions from previous papers. We show $r_{\text{odd}}(n,K_{s,t})> n^{1/\left(\frac s2+\frac 1{2\lfloor t/8 \rfloor}\right)}$ when $s\leq t$ and $s$ is odd and $t$ is even, which is log-asymptotically tight when $s$ is fixed and $t\to\infty$. Next, we consider the odd-Ramsey number when the host graph to be edge-colored is a super-Dirac graph, and show that in any host graph with minimum degree at least $n/2+2$, the odd-Ramsey number of Hamilton cycles is non-trivial. Finally, we show that $r_\text{u}(n,C_n)> n/4$, which leads to a polynomial gap between $r_\text{odd}(n,C_n)$ and $r_\text{u}(n,C_n)$.

2605.07321 2026-05-11 cs.AR cs.DC cs.NA eess.IV math.NA

TREA: Low-precision Time-Multiplexed, Resource-Efficient Edge Accelerator for Object Detection and Classification

Vijay Pratap Sharma, Mukul Lokhande, Ratko Pilipovic, Omkar Kokane, Santosh Kumar Vishvakarma

AI总结 本文提出了一种名为 TREA 的低精度时分复用、资源高效的边缘人工智能加速器,专门用于目标检测和分类任务,旨在满足边缘视觉平台对面积、功耗和延迟的严格约束。TREA 采用基于最高有效位优先的移位加法计算的双精度(4/8位)SIMD乘加单元(DQ-MAC),结合运行时位截断技术,有效降低硬件开销并提升吞吐量。同时,其配合结构化硬件感知剪枝策略(SHARP),在保持MAC单元充分利用的同时实现近50%的结构稀疏性,显著提升了计算效率和能效。

Comments TVLSI (Under Review)

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英文摘要

This work presents TREA, a low-precision time-multiplexed and resource-efficient edge-AI accelerator for object detection and classification, targeting stringent area-power-latency constraints of edge vision platforms. The proposed architecture integrates a dual-precision (4/8-bit) SIMD multiply-accumulate (DQ-MAC) unit based on most-significant-digit-first (MSDF) shift-and-add computation with run-time bit truncation, eliminating conventional multiplier overhead and reducing accumulator bit-width. The DQ-MAC supports 4x FxP4 or 1x FxP8 operations per cycle, achieving up to 4x throughput improvement without hardware duplication. A structured hardware-aware reductive pruning (SHARP) strategy is co-designed with the SIMD datapath, enabling near 50% structured sparsity while maintaining full MAC utilization. This allows a 3x3 convolution kernel to be computed in 1 cycle in FxP4 mode compared to 9 cycles in FxP8, and a 5x5 kernel in 3 cycles versus 25 cycles, yielding up to 9x latency reduction at the kernel level. The accelerator further incorporates a reconfigurable CORDIC-based nonlinear activation function (RQ-NAF) core with a 9-stage pipeline, supporting Sigmoid, Tanh, and ReLU at one output per cycle after pipeline fill, while enabling (N-1) hardware reuse through time-multiplexing. The complete TREA architecture employs a 1D array of 100 SIMD DQ-MAC units with layer-wise hardware reuse, significantly reducing area and control complexity. Experimental results demonstrate substantial improvements in latency, hardware utilization, and energy efficiency compared to conventional fixed-precision and non-reconfigurable accelerators, validating TREA as an effective solution for real-time edge vision workloads.

2605.07320 2026-05-11 cs.HC

Splitting User Stories Into Tasks with AI -- A Foe or an Ally?

Luka Pavlič, Reinhard Bernsteiner, Stephan Schlögl, Christian Ploder

AI总结 在敏捷软件开发中,将用户故事拆解为具体任务是一项关键但耗时的工作。本文探讨了生成式AI工具在任务拆分中的应用潜力,通过GitLab Duo进行对照实验,发现当前AI工具虽无法完全取代开发者,但能生成更细致的任务列表并帮助避免遗漏重要任务。研究建议采用AI与传统方法结合的混合方式,以在保持规划准确性的同时提升效率。

Comments 12 pages, 2 figures, 4 tables

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英文摘要

In agile software development, breaking down user stories into actionable tasks is a critical yet time-consuming process. This paper investigates the potential of Generative AI tools to assist in task splitting, aiming to enhance planning efficiency. We conducted a controlled experiment comparing traditional task-splitting methods with AI-assisted approaches using GitLab Duo. Our findings indicate that while current AI tools are not yet mature enough to replace developers, they can aid in generating more granular task lists and ensuring no important tasks are overlooked. Participants favored a hybrid approach, combining AI tools with conventional methods to maintain high accuracy in planning. This study highlights the potential benefits and limitations of integrating Generative AI into agile development processes, suggesting that AI tools can serve as valuable aids in task splitting, provided there is human oversight to filter out irrelevant tasks.

2605.07318 2026-05-11 eess.SY cs.SY

Stability-Certified Koopman Observer Design for Nonlinear Systems via Generalized Persidskii Dynamics

Syed Pouladi

AI总结 本文研究了基于Koopman算子提升的非线性系统状态估计问题,针对模型失配和测量噪声下观测器收敛性的认证难题,提出了一个稳定性保证的Koopman观测器设计方法。通过建立Koopman隐空间观测器误差动态与广义Persidskii系统之间的结构对应关系,设计了一个非线性修正项,并利用线性矩阵不等式(LMI)同时保证估计误差对提升残差和外部扰动的输入到状态稳定性(ISS)。数值实验表明,该观测器在估计精度和鲁棒性方面显著优于扩展卡尔曼滤波器和线性Koopman观测器。

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英文摘要

This paper addresses the problem of nonlinear state estimation for dynamical systems whose governing equations are approximated through Koopman operator liftings. While Koopman-based predictors have demonstrated broad approximation capability for nonlinear dynamics, certifying observer convergence under model mismatch and measurement noise has remained a largely open problem. To resolve this, we establish a structural correspondence between the error dynamics of a Koopman latent-space observer and the class of generalized Persidskii systems, which admits diagonal Lyapunov functions and incremental sector characterizations. Exploiting this connection, we design a nonlinear correction term whose gain is computed via a linear matrix inequality (LMI) that simultaneously certifies input-to-state stability (ISS) of the estimation error with respect to both lifting residuals and external disturbances. Exponential convergence in the nominal case and ultimate boundedness under bounded perturbations are established analytically. Numerical validation on the Van~der~Pol oscillator and a nonlinear robotic arm with friction uncertainty demonstrates that the proposed observer substantially outperforms both the Extended Kalman Filter and a linear Koopman observer in terms of estimation accuracy and robustness, achieving up to a 42\% reduction in steady-state RMSE under lifting mismatch.

2605.07312 2026-05-11 stat.ME

Incorporating Missing Data Considerations into Sample Size Calculations for Developing Clinical Prediction Models

Glen P. Martin, Sian Bladon, Rebecca Whittle, Molly Wells, Gary S. Collins, Richard D. Riley

AI总结 临床预测模型的开发需要足够大的数据集以减少过拟合并确保预测性能的稳健性。现有样本量计算方法假设所有纳入参与者的所有预测变量数据完整,但实际中缺失值普遍存在,可能影响模型性能并增加所需样本量。本研究通过模拟实验和实际案例,探讨了缺失预测变量对模型校准和过拟合的影响,并提出了一种将缺失数据假设和处理策略纳入后验抽样样本量计算框架的方法,为在存在缺失数据的情况下合理确定最小样本量提供了实用的解决方案。

Comments 35 pages, 5 figures (8 supplementary figures), 1 table (1 supplementary table)

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英文摘要

Clinical prediction models must be developed using sufficiently large datasets to minimise overfitting and ensure robust predictive performance. Existing sample size calculations assume complete predictor data for all included participants, yet missing values are common and may increase required sample sizes. This study aimed to quantify how missing predictor data and different imputation methods affect overfitting and model degradation, within datasets that adhere to current sample size criteria. We also aimed to explore how a general sample size framework based on anticipated posterior (sampling) distributions can be adapted to incorporate missing data assumptions and handling strategies. Using a simulation study, we found that in development data meeting current minimum sample size requirements, missing data reduced predictive performance, with expected calibration slopes frequently falling below the targeted value of 0.9. Increasing the required sample size to account for missing data reduced overfitting concerns, but the necessary inflation factor was context specific. In some scenarios, up to twice the minimum sample size was needed to achieve performance comparable to models developed using fully observed data. Expected value of perfect information calculations allowed quantification of the expected loss due to finite samples and missingness. Through two applied examples, we illustrate how embedding missing data assumptions and handling within the posterior sampling approach provides a principled way to determine required minimum sample sizes under missing data. Overall, missing predictor data increases minimum sample size requirements to develop stable and well-calibrated models. Our adaptations to recent posterior (sampling) sample size calculations offer a practical approach for incorporating missing data directly into sample size calculations.

2605.07311 2026-05-11 eess.SP

A Microfabricated PCM-Switched Reconfigurable Intelligent Surface for Wideband Millimeter-Wave Beam Steering

Afsaneh Hojjati-Firoozabadi, Raafat Mansour

AI总结 本文提出了一种基于微加工技术的可重构智能表面(RIS),利用电控的氧化钒(VO₂)开关实现毫米波波束成形。该RIS通过多层微制造工艺在氧化铝基板上实现,每个单元尺寸远小于波长,集成数百个亚微米级VO₂开关,实现了对表面阻抗的可控调制。实验表明,该RIS可在33 GHz中心频率、18%带宽内实现高达60度的波束偏转,并提升远场增益10-20 dB,为高频可重构表面提供了可行的实现方案。

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英文摘要

This paper presents the design, fabrication, and experimental validation of a reconfigurable intelligent surface (RIS) employing electrically actuated vanadium dioxide (VO2) switches for millimeter wave beam steering. The proposed RIS is realized using a multilayer microfabrication process on an alumina substrate, enabling monolithic integration of hundreds of sub-4 micrometer VO2 switching elements within deeply subwavelength unit cells, approximately one-fifth of the wavelength. The switching-induced modulation of surface impedance is analyzed through full-wave simulations, and the resulting phase and amplitude responses are experimentally characterized using a custom WR-28 waveguide measurement setup. Based on the validated unit-cell design, a 10 x 20 RIS array integrating 200 VO2 switches is fabricated. The switches within each column are serially biased using integrated routing lines, allowing programmable control of the spatial phase distribution across the surface. Synthesized phase profiles enable dynamic beam steering, resulting in measured far-field gain enhancement of 10-20 dB over an 18 percent fractional bandwidth centered at 33 GHz, with steering angles up to 60 degrees. The measured radiation patterns are in good agreement with semi-numerical channel modeling predictions. By combining thin-film PCM switching with an integration-aware unit-cell design, this work demonstrates a scalable RIS architecture that mitigates packaging parasitics and footprint limitations inherent to conventional semiconductor-based implementations, providing a practical pathway toward higher-frequency reconfigurable surfaces.

2605.07310 2026-05-11 math.AP

Lifespan estimate for one dimensional wave equation with semilinear terms of spatial derivative

Ning-An Lai, Cui Ren, Takiko Sasaki, Hiroyuki Takamura

AI总结 本文研究了一维带有非自治半线性项(包含未知函数空间导数)的波动方程初值问题的经典解的寿命上下界。相较于时间导数型半线性项的研究,该问题在处理空间依赖权重的迭代过程中更具挑战性,尤其在证明寿命上界时更为复杂。研究发现部分结果与Li和Zhou提出的经典阻尼波动方程的常微分不等式一致,并给出了更一般情形下爆破结果的简洁证明。

Comments 30 pages

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英文摘要

This paper studies the upper and lower bounds of the lifespan for the classical solutions to the initial value problems of one dimensional wave equations with non-autonomous semilinear terms including the space-derivative of the unknown function.This is a non-trivial business comparing to the analogous results with time-derivative type semilinear terms, especially for the proof to obtain the sharp upper bound of the lifespan as we have to deal with space dependent weights among iteration procedures of the weighted functional of the solution. Also it is surprising that a part of them reaches to the same ordinary differential inequality for classical semilinear damped wave equations introduced by Li and Zhou (Discrete Contin. Dynam. Systems, 1995, 1(4): 503-520), and we show a simple proof for blow up result from this ordinary differential inequality by iteration argument and slicing method in more general situation.

2605.07309 2026-05-11 eess.SY cs.SY stat.AP

Variational PMB filter via coordinate descent Kullback-Leibler divergence minimisation

Ángel F. García-Fernández, Yuxuan Xia

AI总结 本文提出了一种新的变分泊松多伯努利(V-PMB)滤波器推导方法,用于多目标估计。该方法通过引入包含目标状态及其轨迹索引的扩展空间,并结合全局假设变量,将V-PMB投影解释为在该空间上进行坐标下降的Kullback-Leibler散度最小化过程,以拟合最佳的PMB密度到PMBM后验分布。研究还表明该方法能够保持后验的概率假设密度,并通过与其他PMB滤波器变体的对比,展示了V-PMB滤波器在目标近距离接近后分离场景中的优势。

Comments Accepted in Proceedings of the 29th International Conference on Information Fusion, 2026. Matlab code available at https://github.com/Agarciafernandez/MTT

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英文摘要

This paper presents a new derivation of the variational Poisson multi-Bernoulli (V-PMB) filter for multi-target estimation proposed in [#Williams15]. The proposed derivation is based on considering an augmented space that includes the set of target states with their track indices and the global hypothesis variable. Then, we show that the V-PMB projection performs a coordinate descent Kullback-Leibler divergence (KLD) minimisation on this augmented space to fit the best possible PMB density to the Poisson multi-Bernoulli mixture (PMBM) posterior. We also show that this V-PMB projection keeps the probability hypothesis density of the posterior. The paper also includes a comparison with the PMBM filter and other PMB filter variants, including a track-oriented Murty-based implementation, a track-oriented loopy belief propagation implementation and a global nearest neighbour implementation, showing the benefits of the V-PMB filter compared to the other PMB filters when targets get in close proximity and then separate.

2605.07303 2026-05-11 hep-ph hep-ex

LHC Mono-$W/Z$ Signatures as a Probe for Dark Matter Explanations of Astrophysical Excesses

Yu-Chen Guo, Ying-Xin Li, Chih-Ting Lu

AI总结 本文研究了惰性双希格斯二重态模型(IDM)中暗物质(DM)解释天体物理异常(如银河中心伽马射线过剩和AMS-02反质子异常)的可能性,并聚焦于DM质量在70-75 GeV范围、通过$SS\to WW^{\ast}$湮灭主导的参数区间。研究提出了一种在LHC上分离带电和中性质量劈裂信号的方法,利用单$W/Z$信号对这一参数空间进行验证,结果表明高亮度LHC能够有效测试该模型,且从不同信号通道获得了对质量劈裂参数的显著排除限制。

Comments 11 pages, 11 figures, 3 tables. Comments are welcome

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英文摘要

The inert two-Higgs doublet model (IDM) is a compelling framework for weakly interacting massive particles (WIMPs) linked to electroweak symmetry breaking. It can account for both the Galactic Center gamma-ray excess (GCE) and the AMS-02 antiproton anomaly while also satisfying relic density and direct detection constraints for dark matter (DM) masses in the $55-75$ GeV range. Three specific DM annihilation channels can be identified: Higgs resonance, $SA$ co-annihilation, and $SS\to WW^{\ast}$ annihilation. Among these, the DM mass range of $70-75$ GeV with dominant $SS\to WW^{\ast}$ annihilation has received less attention in collider searches. To validate this parameter space, we combine LHC searches for mono-$W/Z$ signatures. In particular, we develop a channel-separation strategy to disentangle the contributions of charged mass splitting ($Δ^{\pm}$) and neutral mass splitting ($Δ^0$) in the inert scalar sector at the LHC. Our results indicate that most of the parameter space consistent with these astrophysical anomalies in the $SS\to WW^{\ast}$ annihilation regime will be testable at the High-Luminosity LHC. Specifically, from the leptonic channel we obtain a $2σ$ exclusion limit of $80 \lesssim Δ^0 \lesssim 260$ GeV, while the hadronic channel yields $30 \lesssim Δ^0 \lesssim 150$ GeV and $70 \lesssim Δ^{\pm} \lesssim 230$ GeV for $m_S = 70$ GeV.

2605.07300 2026-05-11 stat.ME stat.AP

A Beta-GAM Hidden Markov Model for Proportion Time Series

Andrea Nigri, Han Lin Shang, Marco Bonetti

AI总结 本文提出了一种用于单位比例时间序列的隐马尔可夫模型,该模型通过贝塔分布描述观测值,并利用广义可加模型(GAM)将贝塔均值与协变量联系起来,同时允许每个隐状态具有特定的精度参数,从而灵活建模非线性协变量效应和状态依赖的变异性。通过带罚项的期望最大化算法进行估计,并结合信息准则进行隐状态数量和光滑惩罚的选择,最终通过参数自举方法量化不确定性。该模型在模拟和俄罗斯特定年龄死亡率数据上的应用表明其在捕捉状态转换动态、识别潜在结构变化方面具有良好的表现。

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英文摘要

We propose a hidden Markov model for univariate proportion time series taking values in (0,1), where regime switching captures latent structural changes and the emission distribution belongs to the Beta family. In each latent state, the Beta mean is linked to covariates through a generalized additive model (GAM) with spline-based smooth functions, while the Beta precision is state-specific, enabling flexible modeling of both nonlinear covariate effects and regime-dependent variability. Estimation is carried out via a penalized expectation--maximization algorithm, combining smoothing with numerical maximization of the penalized emission likelihood. To select the number of latent states and the smoothing penalty, we implement a grid search guided by standard information criteria (Akaike Information Criterion/Bayesian Information Criterion/Integrated Completed Likelihood) with a diagnostic filter that removes degenerate solutions characterized by explosive precision estimates. Uncertainty is quantified through a parametric bootstrap procedure for transition probabilities and state-dependent parameters. Simulation results demonstrate accurate recovery of transition dynamics, state precisions, and latent-state decoding. A motivating application to Russian age-specific mortality data (1960--2014, ages 0--40) illustrates how the proposed model summarizes smooth age patterns in female-to-total mortality ratios while identifying two persistent latent regimes that admit a substantive demographic interpretation in light of the country's well-documented mortality shocks that occurred over the second half of the twentieth century.

2605.07298 2026-05-11 math.CO

On the Number of Zero Forcing Minimal Forts on Trees

Nguyen Hoang Dat, Franklin H. J. Kenter

AI总结 本文解决了 Becker 等人提出的关于树结构中零强制最小堡垒数量的猜想,证明了任意 $n$ 顶点树的最大最小堡垒数不超过路径图相应数量的 $\binom{n}{2}$ 倍。研究结合了计算与理论方法,提出了一种高效算法用于计算小树的最小堡垒数,并建立了适用于所有森林的递归关系,从而完成归纳证明,为相关问题提供了重要的理论支持。

Comments 20 pages

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英文摘要

We solve a conjecture by Becker et al. (arXiv:2404.05963) on the topic of zero forcing regarding the number of minimal forts of a tree. They conjectured and we prove $\mathcal{F}_{T_n} \le \binom{n}{2} \mathcal{F}_{P_n}$ where $\mathcal{F}_{T_n}$ is the maximum number of minimal forts on a tree on $n$ vertices and $\mathcal{F}_{P_n}$ is the number of minimal forts of the path graph on $n$ vertices. Our solution relies on both a computational and theoretical approach. Computationally, we introduce and implement an efficient algorithm to compute the exact number of minimal forts for small trees; this is used to establish the large base case required for our strong induction. Theoretically, we provide an adaptation of the recursion relation that defines $\mathcal{F}_{P_n}$ that applies for all forests; this is used in the induction step to establish the result.

2605.07296 2026-05-11 cs.IR

PRISM: Refracting the Entangled User Behavior Space for E-Commerce Search

Haoqian Zhang, Ziyuan Yang, Yi Zhang

AI总结 电商搜索系统通常依赖于用户行为建模来估计物品的相关性和用户偏好,但实际中用户行为受到曝光机制、反馈循环和语义匹配等多重因素影响,导致行为信号高度纠缠且动态变化。为了解决这一问题,本文提出PRISM框架,通过显式建模用户偏好与物品相关性的交互关系,而非将其视为独立成分,从而提升模型的鲁棒性与语义一致性。PRISM引入了偏好修正模块和语义锚定机制,结合多源行为信号进行自适应聚合,有效缓解了行为混淆和语义偏差问题,在两个公开电商数据集上取得了优于现有方法的实验结果。

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E-commerce search systems rely on modeling user behavior to estimate item relevance and user preference, which are typically assumed to be stable and independently learnable signals. However, in practice, user interactions are jointly shaped by exposure mechanisms, feedback loops, and semantic matching, leading to entangled and dynamically drifting behavioral signals. As a result, both preference estimation and relevance modeling suffer from confounding effects and semantic misalignment, which limits the robustness of downstream ranking models. To address this issue, we propose PRISM, a Preference-Relevance Interaction Semantic Modeling framework for e-commerce search behavior prediction. PRISM explicitly models the interaction between user preference and item relevance rather than treating them as independent components. Specifically, it introduces a preference rectification module to iteratively refine user preference under relevance-aware constraints, improving robustness against behavioral confounding. To ensure semantic consistency, we further incorporate a large language model (LLM)-driven semantic anchoring mechanism that leverages positive and negative prototypes to calibrate relevance representations. Finally, a preference-conditioned evidence routing module adaptively aggregates multi-source behavioral signals, enabling context-aware and preference-aligned relevance estimation. Extensive experiments on two public e-commerce benchmarks demonstrate that PRISM consistently outperforms strong baselines, validating the effectiveness of explicitly modeling preference-relevance interaction for robust and semantically grounded search behavior modeling.

2605.07295 2026-05-11 quant-ph

A Distributed Switching Protocol for Quantum Networks

Aman Yacob Tekleab, Yifeng Shen, Yoshii Yutaro, Amin Taherkhani, Rodney Van Meter, Shota Nagayama

AI总结 随着基于纠缠的量子网络建设与部署的推进,如何高效利用网络资源将成为实现系统可扩展性的关键挑战。本文提出了一种适用于无缓冲、多分支量子网络的分布式交换协议,通过共享贝尔态分析器(BSA)在交换网络中建立端节点间的连接,并采用双路径预留机制实现分布式资源分配。仿真结果表明,该协议在不同网络负载条件下均能保持较高的链路建立成功率和稳定的性能,为构建大规模、可管理的自动化量子网络提供了重要基础。

Comments 7 pages, 5 figures

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With the advent of the construction and deployment of entanglement-based quantum networks, the efficient use of network resources will become a critical challenge for the scalable operation of such a system. Recently, architectures that incorporate memoryless optical switches have gained attention for forwarding entangled photons. By leveraging these architectures, costly resources such as high efficiency Bell State Analyzers (BSAs) can be shared across the network. Nevertheless, the introduction of switching substantially complicates the process of multiplexing and resource allocation compared to an individual link. In this work, we propose a switching protocol for unbuffered, multidrop quantum networks in a photonic synchronization domain that establishes a link between two end nodes using a shared BSA in the switched network. To achieve this, two end nodes cooperatively select the target BSA node with the lowest path cost and independently reserve each path within the network. Bi-path reservations are performed to allocate resources in a distributed manner. The proposed protocol is evaluated through simulation on Q-Fly network topologies under varying traffic conditions. The results demonstrate high link establishment success with stable performance even under increased network load. These capabilities which are driven by our proposed protocol are an essential way to realize large-scale, managed, and automated quantum networks.

2605.07293 2026-05-11 cs.CR

When the Ruler is Broken: Parsing-Induced Suppression in LLM-Based Security Log Evaluation

Chaitanya Vilas Garware, Sharif Noor Zisad

AI总结 本文研究了基于大语言模型(LLM)的安全运营中心(SOC)日志分类器在评估过程中因正则表达式解析器引入的系统性误差问题。作者提出了一种称为“解析诱导抑制”的现象,即由于严格的字段解析规则导致模型性能被严重低估。通过实验证明,使用模糊解析方法后,同一模型的威胁检测准确率从0%提升至76%,表明评估方法对结果有显著影响。为此,作者提出了SOC-Bench v0基准框架,旨在通过标准化分类体系和模糊解析规范,提升未来SOC LLM研究的评估准确性。

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LLM-based SOC log classifiers are commonly evaluated using regular-expression pipelines that extract structured fields from free-form model output. We demonstrate that this practice introduces a class of silent, systematic evaluation errors, which we term parsing-induced suppression that can cause a fully functional model to appear completely non-functional. Using OpenSOC-AI, a LoRA fine-tuned TinyLlama-1.1B system for security log threat classification, as a reproducible case study, we show that a strict regex parser reported 0% threat accuracy while a corrected fuzzy parser recovered 76% threat accuracy on the same model outputs and the same evaluation set. A gap of 76 percentage points attributable entirely to evaluation methodology. Severity accuracy remained constant at 58% under both parsers, providing a built-in control that isolates field name format mismatch as the causal mechanism rather than model degradation. For external reference, Claude Sonnet evaluated zero-shot on the same 50 example set achieved 88% threat accuracy and 58% severity accuracy under the same fuzzy protocol. Residual errors under fuzzy evaluation concentrate in three categories including reconnaissance, brute force, and credential stuffing, each contributing all 4 misclassifications, a pattern that reflects class-boundary difficulty among behaviorally adjacent log types rather than global model failure. We propose SOC-Bench v0, a benchmark framework comprising a standardized 13 category threat taxonomy, minimum statistical power requirements, fuzzy field extraction specification, and a public scoring script intended to prevent parser specific accuracy distortion in future SOC LLM research.

2605.07291 2026-05-11 eess.AS

Evaluating voice anonymisation using similarity rank disclosure

Shilpa Chandra, Matteo Pettenò, Nicholas Evans, Michele Panariello, Massimiliano Todisco, Tom Bäckström, Dorothea Kolossa, Rainer Martin, Themos Stafylakis, Nicolas Gengembre

AI总结 本文研究了语音匿名化技术的评估问题,指出当前依赖分类器性能指标(如等错误率EER)的方法存在局限性,无法全面反映隐私风险。为此,作者引入了基于信息论的相似度排名泄露(SRD)指标,直接在特征表示层面进行评估,能够更准确地刻画平均和最坏情况下的隐私泄露风险。实验表明,SRD能够发现EER方法遗漏的隐私泄露和系统弱点,展示了其在语音匿名化评估中的灵活性和解释性优势。

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英文摘要

The evaluation of voice anonymisation remains challenging. Current practice relies on automatic speaker verification metrics such as the equal error rate (EER). Performance estimates dependent on the classifier and operating point provide an incomplete or even misleading characterisation of privacy risk. We investigate the use of similarity rank disclosure (SRD), an information-theoretic metric, which operates on feature representations rather than classifier decisions, providing a threshold-independent assessment of privacy and analysis of both average and worst-case disclosure. We report its application to speaker embeddings, fundamental frequency, and phone embeddings using 2024 VoicePrivacy Challenge systems. The SRD reveals privacy leaks and system-specific weaknesses missed by EER-based evaluation. Findings highlight the merit of representation-level metrics and demonstrate the potential of SRD as a flexible and interpretable tool for the evaluation of voice anonymisation.

2605.07290 2026-05-11 math.AP

A revisit via slicing method on a quadratic semilinear wave equation in two space dimensions

Masakazu Kato, Hiroyuki Takamura, Kyouhei Wakasa

AI总结 本文重新研究了二维空间中一个二次半线性波动方程的爆破结果,重点在于通过切片方法给出一个简洁的证明。研究发现,当初始速度的零阶矩不为零时,经典解的寿命估计会出现对数损失,该结果已有接近最优的常数。作者采用迭代论证和点态估计的方法,为数值分析提供了更直接的应用途径。

Comments 15 pages. arXiv admin note: substantial text overlap with arXiv:2512.07119

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英文摘要

In this paper, we are focusing on proofs of a blow-up result for a quadratic semilinear wave equation in two space dimensions. There is a logarithmic loss in estimating the lifespan of a classical solution if the 0th moment of the initial speed does not vanish. This result is already known with almost sharp constants. But in order to have a direct application to the numerical analysis, we show a simple proof by iteration argument for a point-wise estimate of the solution with a slicing technique. Such a research direction can be found in the case of critical nonlinearity.

2605.07283 2026-05-11 math.AP

Dirichlet problem for Lane-Emden type equations with several sublinear terms

Toe Toe Shwe, Kentaro Hirata, Adisak Seesanea

AI总结 本文研究了具有多个次线性项的Lane-Emden型方程的Dirichlet问题,证明了正有界解的存在性、唯一性以及精确的点态双边估计。作者考虑的方程形式为 $ L u = \sum_{i=1}^{m} σ_i u^{q_i} + σ_0 $,其中 $ 0 < q_i < 1 $,且 $ L $ 是一个具有有界系数的均匀椭圆算子。研究还展示了该方法可推广至涉及分数拉普拉斯算子的类似问题,具有重要的理论意义和应用价值。

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英文摘要

We prove the existence, uniqueness, and sharp bilateral pointwise estimates for positive bounded solutions to the Lane--Emden type problem \[ \begin{cases} L u = \sum\limits_{i=1}^{m}σ_{i} u^{q_{i}}+σ_0, \quad u\geq0 & \text{in } Ω, \liminf \limits_{x \rightarrow y} u(x) = f(y), & y \in \partial^\inftyΩ, \end{cases} \] where $0 < q_{i} < 1$. Here $Lu = - \text{div}(A \nabla u)$ is a uniformly elliptic operator with bounded coefficients, $σ_{i}$ is a nonnegative locally finite Borel measure on an $A$-regular domain $Ω\subset \mathbb{R}^n$ which possesses a positive Green function associated with $L$, and $f$ is a nonnegative continuous function on the boundary $\partial^\inftyΩ$. An analogous result for positive continuous solutions to the problem is also illustrated. Our method can be adapted to address related sublinear problems with zero boundary conditions involving the fractional Laplace operator $(-Δ)^α$ for $0< α< n/2$, in place of $L$, in $\mathbb{R}^n$ as well.

2605.07281 2026-05-11 physics.optics quant-ph

Scalable Liquid-Crystal Integrated Silicon Nitride Photonic Circuits for Reconfigurable Quantum Interference

Chunghyun Ahn, Yongjin Hwang, Sangbaek Lee, Jinil Lee, Hyunjin Ko, Sunghyun Moon, Hojoong Jung, Hyun-Yong Yu, Se-Um Kim, Hyounghan Kwon

AI总结 本文研究了基于液晶(LC)集成氮化硅(SiN)光子芯片的可重构量子干涉实现问题,提出了一种新型的低功耗、高可见度量子干涉装置。通过开发基于液晶的马赫-曾德干涉仪(LC-MZI),实现了与CMOS兼容的高性能相位调制,并在双光子干涉实验中获得了高达98.5%的可见度。此外,研究还验证了该方法的可扩展性,为构建可重构、节能的量子光子电路提供了可行的平台。

Comments 22 pages, 5 figures. Final version for submission

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英文摘要

Integrated quantum photonics requires compact, efficient, and low-power phase modulators. While silicon nitride (SiN) is a promising platform, existing modulators suffer from high power consumption, thermal crosstalk, or high driving voltages. Liquid crystal (LC) offers a compelling alternative because of the large index changes and industrial maturity. However, their suitability for supporting various applications in the photonic quantum system has not been experimentally confirmed.Here, we report the first experimental demonstration that LC-based phase modulators integrated on a SiN platform show highly visible quantum interference. We fabricated a liquid-crystal integrated Mach-Zehnder interferometer (LC-MZI) that achieved CMOS-compatible performance with V_pi * L < 1 V-mm. In two-photon interference experiments, the devices exhibited high-visibility quantum interference (~98.5%) with voltage-tunable phase control. Furthermore, we validated the scalability of our approach by demonstrating wafer-scale fabrication using stepper lithography. This work establishes LC-integrated SiN photonics as a scalable, reconfigurable, and energy-efficient platform for quantum photonic circuits.

2605.07279 2026-05-11 cond-mat.mtrl-sci cond-mat.dis-nn

Physics-informed operator learning for transferable energy-dissipative microstructure dynamics

Jie Xiong, Yue Wu, Xuewei Zhou, Peishuo Zhao, Jiaming Zhu

AI总结 该研究提出了一种基于物理信息的神经算子框架PFNet,用于学习可迁移的能量耗散微结构动力学。PFNet通过学习条件演化算子而非直接关联,结合扩散启发的U-Net结构、熵基状态条件和热力学参数调制,有效捕捉了相场演化的边界一致性、瞬时有序状态及自由能变化。实验表明,PFNet在Cahn-Hilliard粗化和马氏体相变等任务中均能实现高精度预测,展示了其在复杂微结构动力学建模中的广泛适用性。

Comments None

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英文摘要

Phase-field simulations provide mechanistic descriptions of microstructure evolution, but repeated high-fidelity integration over long horizons and broad parameter spaces remains computationally expensive. We present PFNet, a physics-informed neural operator framework that advances microstructural states by learning conditional evolution operators rather than direct correlations. PFNet combines a diffusion-inspired U-Net with periodic padding, entropy-based state conditioning and thermodynamic-parameter modulation to encode boundary consistency, instantaneous ordering state and changes in the free-energy landscape. For Cahn-Hilliard coarsening, PFNet achieves accurate one-step prediction and stable autoregressive rollouts across composition, gradient-energy coefficient, coarsening stage and morphology class, with errors concentrated near diffuse interfaces and topology-changing regions. The same framework extends to a four-channel martensitic-transformation benchmark without martensite-specific redesign. These results indicate that physics-informed operator learning can provide transferable surrogates for phase-field dynamics and broader energy-dissipative dynamical systems.

2605.07272 2026-05-11 math.PR

Small noise asymptotic behaviors for path-dependent multivalued McKean-Vlasov stochastic differential equations

Ying Ma, Huijie Qiao

AI总结 本文研究了受小噪声扰动的路径依赖型多值 McKean-Vlasov 随机微分方程的渐近行为。通过弱收敛方法,在非李普希茨系数条件下建立了该类方程的大偏差原理,并引入辅助方程推导出中偏差原理,最终构造另一辅助方程和极限方程,证明了中心极限定理,为相关随机系统的稳定性分析提供了理论依据。

Comments 45 pages

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英文摘要

This paper investigates the asymptotic behavior of path-dependent multivalued McKean-Vlasov stochastic differential equations perturbed by small noise. Specifically, we first establish a large deviation principle for such equations under non-Lipschitz coefficients by the weak convergence approach. Subsequently, we introduce an auxiliary equation and apply it to derive the moderate deviation principle. Finally, we construct another auxiliary equation and a limit equation, and prove the central limit theorem.

2605.07265 2026-05-11 cs.DS cs.DM math.CO

EPTAS for Hard Graph Cut Problems for Dense Graphs

Kaisei Deguchi, Ken-ichi Kawarabayashi, Hiroaki Mori

AI总结 本文研究了在处处稠密图上若干图割问题的高效近似算法。针对一些经典的最小割问题,如带全局顶点权重约束的最小割、商割和乘积最稀疏割等,作者提出了首个高效多项式时间近似方案(EPTAS),其运行时间为 $f(1/\varepsilon)n^{O(1)}$。该成果的核心技术基于弱正则性引理和抽样估计方法,并通过统一的归约方法推广到其他相关问题,相比以往依赖复杂工具如Lasserre层次或整数规划的方法,更具效率优势。

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英文摘要

Everywhere-$δ$-dense graphs are defined as graphs on $n$ vertices in which every vertex has degree at least $δn$ for some constant $δ> 0$. Approximation schemes are vital for handling NP-hard optimization problems, but for many graph cut problems, existing PTAS algorithms often suffer from running times of $n^{f(1/\varepsilon)}$. In this paper, we bring PTASs down to EPTASs for several fundamental minimization problems on everywhere-$Ω(1)$-dense graphs. Specifically, we present the first Efficient Polynomial-Time Approximation Scheme (EPTAS), running in time $f(1/\varepsilon)n^{O(1)}$, for the ConstrainedMinCut problem under a global constraint on vertex weights, a problem that captures BalancedSeparator and SmallSetExpansion. Moreover, we give the first EPTASs for MinQuotientCut and ProductSparsestCut on everywhere-$δ$-dense graphs with integer-valued dense vertex weights; these problems generalize the four well-known problems UniformSparsestCut, EdgeExpansion, Conductance, and NormalizedCut. Our main technical contribution is an EPTAS for ConstrainedMinCut, based on the weak regularity lemma and sampling and estimation techniques. We then obtain EPTASs for MinQuotientCut and ProductSparsestCut via a unified reduction that invokes this algorithm as a subroutine. In contrast, previous works giving PTASs for these problems on everywhere-$δ$-dense graphs typically rely on powerful tools such as the Lasserre hierarchy or specific integer programming technique, which we avoid.

2605.07262 2026-05-11 hep-lat

Testing machine-learned distributions against Monte Carlo data for the QCD chiral phase transition

Reinhold Kaiser, Frithjof Karsch, Jan Philipp Klinger, Owe Philipsen, Christian Schmidt, Simran Singh

AI总结 该研究探讨了利用条件掩码自回归流(conditional Masked Autoregressive Flows)对格点QCD可观测量进行插值的方法,旨在更高效地研究QCD的手征相变。通过在裸格点参数条件下训练模型,该方法能够在不依赖传统重权计算的情况下,快速生成整个参数空间的样本,从而减少所需的格点系综数量。尽管目前最大似然训练带来的模式覆盖效应仍对临界质量精度造成系统偏差,但该方法在定位相界、确定临界点的普适标度轴等方面已展现出良好的应用前景。

Comments 35 pages, 17 figures and 4 tables

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英文摘要

We demonstrate that conditional Masked Autoregressive Flows constitute a flexible interpolation tool for lattice QCD observables, conditioned on bare lattice parameters. As a benchmark, we use the chiral phase structure of QCD with five degenerate light quark flavours, which on coarse lattices exhibits a region of first-order chiral transitions terminating in a critical quark mass. The method successfully reproduces standard reweighting in the gauge coupling, and naturally extends to interpolation in quark mass and spatial volume, for which reweighting is computationally prohibitive or inapplicable, respectively. Once trained, the model generates samples across the full parameter space in minutes, which can be used to obtain consistent first estimates of the critical quark mass without simulating all intermediate parameter values. This offers a concrete reduction in the number of lattice ensembles required. Precision on the critical mass from learned distributions is so far prohibited by the mode-covering effect inherent to maximum-likelihood-based training, which introduces a systematic bias near first-order transitions. At the current stage, the method is well-suited for a range of practical applications: localising phase boundaries, identifying the universal scaling axes at a critical point, and accelerating informed determinations of parameter values ahead of high-precision Monte Carlo campaigns.