arXivDaily arXiv每日学术速递 周一至周五更新
重置
全部学科分类 2077
2505.18544 2026-05-11 quant-ph

Coherence as a resource for phase estimation

Felix Ahnefeld, Thomas Theurer, Martin B. Plenio

AI总结 本文研究了量子相位估计中量子相干性作为资源的作用,建立了不能生成相干性的量子网络的资源理论,并将其与相位估计的性能联系起来。通过使用固定相干态和多个未知相位的单位ary副本,作者提出了一种通用的成本函数来评估估计质量,并推导出最优协议及最小平均成本。研究证明了每一份相干性都能提升相位估计的精度,确立了相干性作为衡量相位估计性能的资源。

Comments 7+28 pages. This version matches the published version

详情
Journal ref
Phys. Rev. Lett. 136, 180201 (2026)
英文摘要

Quantum phase estimation is a core task in quantum technologies ranging from metrology to quantum computing, where it appears as a key subroutine in various algorithms. Here, we quantitatively connect the performance of phase estimation protocols with quantum coherence. To achieve this, we construct and characterize resource theories of quantum networks that cannot generate coherence. Given multiple copies of a unitary encoding an unknown phase and access to a fixed coherent state, we estimate the phase using such networks. For a unified and general approach, we assess the quality of the estimate using a generic cost function that penalizes deviations from the true value. We determine the minimal average cost that can be achieved in this manner and explicitly derive optimal protocols. From this, we construct a family of coherence measures that directly connect a state's coherence with its value for phase estimation, demonstrating that every bit of coherence helps. This establishes coherence as a resource that quantifies the performance of phase estimation, and, thus, of any quantum technology relying on it as a subroutine.

2505.16545 2026-05-11 quant-ph hep-th

$\mathcal{PT-}$Symmetric Two-Level Open Quantum Systems: Information Theoretic Facets

Baibhab Bose, Devvrat Tiwari, Subhashish Banerjee

AI总结 本文研究了具有$\mathcal{PT}$对称性的两能级开放量子系统,扩展了η-厄米哈密顿量的理论并引入了适用于此类系统的广义Lindblad主方程。通过一个简单的光与物质相互作用模型,计算了非马尔可夫性指标和保真度等信息论量,并与传统两能级厄米系统进行了对比。此外,还分析了两个$\mathcal{PT}$对称与厄米开放量子系统之间的纠缠特性,揭示了它们之间的显著差异。

Comments 14 pages, 6 figures

详情
Journal ref
Physica Scripta 101, 185103 (2026)
英文摘要

The theory of a two-level $η$-Hermitian Hamiltonian with $\mathcal{PT}$ symmetry is reviewed and extended to include open system dynamics. A first-principles derivation of the generalized Gorini-Kossakowski-Sudarshan-Lindblad master equation appropriate for a $\mathcal{PT}-$symmetric Hamiltonian is presented. Inspired by a simple light matter interaction open system model, information theoretic quantities like a non-Markovian witness and fidelity are calculated for the $\mathcal{PT-}$symmetric Hamiltonian, and the results are compared with their corresponding two-level Hermitian counterparts. The nature of entanglement between two $\mathcal{PT-}$symmetric and Hermitian open quantum systems is calculated, and the contrast observed.

2505.08989 2026-05-11 math.OC math.PR

Agency Problems and Adversarial Bilevel Optimization under Uncertainty and Cyber Threats

Thibaut Mastrolia, Haoze Yan

AI总结 本文研究了在不确定性和网络威胁环境下,委托人与代理人之间的代理问题,将其建模为一个具有跳跃的二阶倒向随机微分方程和积分偏微分HJBI方程的极大极小双层随机控制问题。通过扩展随机Perron方法,得到了委托人问题的粘性次解和上解,并在满足一定比较原理的条件下,证明了其唯一粘性解的存在性。研究还引入了基于SIR模型的网络风险框架,展示了激励机制如何在网络威胁下提升项目质量。

详情
英文摘要

We study an agency problem between a leader (the principal) seeking to design an optimal incentive scheme to a follower (the agent) to increase the value of a risky project subjected to accidents and volatility uncertainty. The agency problem is formulated as a max-min bilevel stochastic control problem with accidents and ambiguity. We show that the problem of the follower is reduced to solve a second order BSDE with jumps, reducing the problem of the leader to solve an integro-partial Hamilton-Jacobi-Bellman-Isaacs (HJBI) equation. By extending stochastic Perron's method to our setting, we obtain viscosity sub- and supersolution envelopes for the Principal's integro-HJBI equation. Under an additional comparison principle in a suitable polynomial growth class, these envelopes coincide and the Principal's value is identified with the unique viscosity solution. The holding company seeks to design an optimal incentive scheme to mitigate these losses. In response, the subsidiary selects an optimal cybersecurity investment strategy, modeled through a stochastic epidemiological SIR (Susceptible-Infected-Recovered) framework. The cyber threat landscape is captured through an L-hop risk framework with two primary sources of risk, internal risk propagation via the contagion parameters in the SIR model, and external cyberattacks from a malicious external hacker. The uncertainty and adversarial nature of the hacking lead to consider a robust stochastic control approach that allows for increased volatility and ambiguity induced by cyber incidents. We illustrate our results with numerical simulations showing how the contracting mechanism enhances the quality of a cluster under cyber threats.

2505.07957 2026-05-11 cond-mat.other quant-ph

Experimental Observation of Short-Range Magnetic Correlations in Amorphous Nb$_2$O$_5$ and Ta$_2$O$_5$ Thin Films

Y. V. Krasnikova, A. A. Murthy, D. Bafia, F. Crisa, A. Clairmont, Z. Sung, J. Lee, A. Cano, M. Shinde, D. M. T. van Zanten, M. Bal, A. Romanenko, A. Grassellino, R. Dhundhwal, D. Fuchs, T. Reisinger, I. M. Pop, A. Suter, T. Prokscha, Z. Salman

AI总结 本研究利用缪子自旋旋转(μSR)技术,探究了铌氧化物(Nb₂O₅)和钽氧化物(Ta₂O₅)薄膜的磁性特性。实验发现,在2.8 K的低温下,两种氧化物均表现出磁响应,但其磁性行为存在显著差异:低结晶度的热氧化Ta₂O₅磁性被抑制,而全非晶态的Ta₂O₅则表现出局部静态磁性;相比之下,非晶态Nb₂O₅则以磁性涨落为主,磁序更加无序。这些磁性差异可能解释了钽和铌氧化物在超导量子比特和谐振腔中的性能限制。

Comments 15 pages, 15 figures

详情
Journal ref
Phys. Rev. B 113, 134446 (2026)
英文摘要

We use muon spin rotation/relaxation/resonance ($μ$SR) to investigate the magnetic properties of niobium pentoxide (Nb$_2$O$_5$) and tantalum pentoxide (Ta$_2$O$_5$) thin films. In both oxides, we observe a magnetic response at the lowest available temperature of 2.8 K. This response appears to be structurally dependent: thermally oxidized Ta$_2$O$_5$ with low crystallinity demonstrates suppressed magnetism, while fully amorphous Ta$_2$O$_5$ demonstrates local static magnetism. In contrast, amorphous Nb$_2$O$_5$ is dominated by magnetic fluctuations and is strongly magnetically disordered compared to Ta$_2$O$_5$. Our results suggest that these fundamental differences in the magnetism of Ta and Nb oxides could explain the performance limitations in superconducting qubits and resonators.

2505.06617 2026-05-11 cs.NE

Adversarial Coevolutionary Illumination with Generational Adversarial MAP-Elites

Timothée Anne, Noah Syrkis, Meriem Elhosni, Florian Turati, Franck Legendre, Alain Jaquier, Sebastian Risi

AI总结 本文提出了一种名为 Generational Adversarial MAP-Elites (GAME) 的协同进化质量-多样性算法,用于解决对抗性问题。该方法通过交替进化对抗双方,结合视觉嵌入模型,无需依赖特定领域的行为描述符,直接基于视频进行演化。实验表明,GAME 在多个对抗场景中表现出色,能够发现比单方面优化方法更优的解,并揭示了包括“军备竞赛”动态、进化新颖性提升等演化现象,展示了其广泛适用性及未来研究方向。

Comments This is the extended version (published in IEEE Transactions on Evolutionary Computation) of our conference paper presented at ALIFE 2025

详情
英文摘要

Quality-Diversity (QD) algorithms seek to discover diverse, high-performing solutions across a behavior space, in contrast to conventional optimization methods that target a single optimum. Adversarial problems present unique challenges for QD approaches, as the competing nature of opposing sides creates interdependencies that complicate the evolution process. Existing QD methods applied to such scenarios typically fix one side, constraining the open-endedness. We present Generational Adversarial MAP-Elites (GAME), a coevolutionary QD algorithm that evolves both sides by alternating which side is evolved at each generation. By integrating a vision embedding model (VEM), our approach eliminates the need for domain-specific behavior descriptors and instead operates on video. We validate GAME across three distinct adversarial domains: a multi-agent battle game, a soft-robot wrestling environment, and a deck building game. We validate that all its components are necessary, that the VEM is effective in two different domains, and that GAME finds better solutions than one-sided QD baselines. Our experiments reveal several evolutionary phenomena, including arms race-like dynamics, enhanced novelty through generational extinction, and the preservation of neutral mutations as crucial stepping stones toward the highest performance. While GAME successfully illuminates all three adversarial problems, its capacity for truly open-ended discovery remains constrained by the nature of the search spaces used in this paper. These findings show GAME's broad applicability and highlight opportunities for future research into open-ended adversarial coevolution. Code and videos are available at: https://github.com/Timothee-ANNE/GAME

2504.17440 2026-05-11 eess.AS

Generating Localized Audible Zones Using a Single-Channel Parametric Loudspeaker

Tao Zhuang, Shaozhe Li, Feng Niu, Jia-Xin Zhong, Jing Lu

AI总结 本文提出了一种基于多载波参数扬声器的单通道声区控制方法,突破了传统多通道扬声器阵列的限制。该方法通过将不同音频信号调制到不同频率的超声载波上,并合成单一复合信号进行发射,利用空气中的非线性解调效应,实现多通道声场的虚拟生成。该技术为应用现有的多通道声区控制算法提供了单扬声器解决方案,为简化高对比度声区控制系统提供了新途径。

详情
英文摘要

Advanced sound zone control (SZC) techniques typically rely on massive multi-channel loudspeaker arrays to create high-contrast personal sound zones, making single-loudspeaker SZC seem impossible. In this Letter, we challenge this paradigm by introducing the multi-carrier parametric loudspeaker (MCPL), which enables SZC using only a single loudspeaker. In our approach, distinct audio signals are modulated onto separate ultrasonic carrier waves at different frequencies and combined into a single composite signal. This signal is emitted by a single-channel ultrasonic transducer, and through nonlinear demodulation in air, the audio signals interact to virtually form multi-channel outputs. This novel capability allows the application of existing SZC algorithms originally designed for multi-channel loudspeaker arrays. Simulations validate the effectiveness of our proposed single-channel MCPL, demonstrating its potential as a promising alternative to traditional multi-loudspeaker systems for achieving high-contrast SZC. Our work opens new avenues for simplifying SZC systems without compromising performance.

2504.16119 2026-05-11 eess.SP physics.optics

Microring Perceptron Sensing for Low-Power Radio-Frequency Detection with Quantum-Compatible Photonic Preprocessing

Bo-Han Wu, Shi-Yuan Ma, Mahmoud Jalali Mehrabad, Mingran Jia, Sri Krishna Vadlamani, Hyeongrak Choi, Dirk Englund

AI总结 本文提出了一种基于微环感知器(MiRP)的低功耗射频检测方法,通过微环谐振器中的光频转换实现射频信号到光学特征信号的预检测处理,从而提升在低信噪比条件下的检测性能。该方法结合可编程光学泵浦实现三波混频,与后端数字神经网络共同优化,实现了端到端的联合训练,有效保留任务相关的信息。实验表明,MiRP在低射频输入功率下显著优于传统处理方法,为射频传感提供了新的改进方向。

Comments 14 pages, 5 figures

详情
英文摘要

Radio-frequency (RF) sensing underpins applications ranging from radar and wireless communication to biomedical and quantum measurement, where detection sensitivity at low signal-to-noise ratio (SNR) directly limits the achievable range, resolution, and information capacity. Machine learning has been widely applied to enhance sensing performance, but predominantly as post-detection analysis of already-acquired data. At low SNR, however, the information missing from acquired data cannot be recovered downstream, making pre-detection processing essential. Here we introduce microring perceptron (MiRP) sensing, a framework that exploits RF-photonic transduction in a microring resonator, where a programmable optical pump performs three-wave mixing to implement a learned mapping from the incoming RF signal to optical feature signals prior to detection. The transducer front end and digital neural-network back end are jointly optimized within a single end-to-end training pipeline, allowing the sensing system to learn an encoding that preserves task-relevant information through detection. Across benchmark tasks, MiRP sensing achieves substantially higher task performance than conventional processing at low input RF power levels where detection noise dominates. The algorithmic gain reported here offers an orthogonal axis of improvement that composes with, and amplifies the impact of, existing and future advances along complementary dimensions, including hardware efficiency and quantum-enhanced optical sensing.

2504.08292 2026-05-11 physics.optics

Study of polarization-dependent band inversions and edge states from two-dimensional square lattice plasmonic crystals

T. H. Chan, Y. H. Guan, C. Liu, H. C. Ong

AI总结 本研究探讨了二维方晶格等离激元晶体中极化依赖的能带反转及边缘态现象。通过分析布里渊区高对称点处本征模的远场特性,揭示了在Γ和X点处存在不同于传统紧束缚模型的极化依赖能带反转,从而引发能带拓扑的细微变化。研究进一步通过调控系统几何实现了具有不同场对称性的极化选择性零维和一维边缘态,并通过角分辨和极化分辨的衍射光谱实验验证了理论结果,展示了远场技术在诊断电磁及声学晶格系统能带拓扑中的可行性。

详情
英文摘要

When two topologically trivial and nontrivial systems are brought together, a localized energy state is formed at the interface. For crystalline quantum and classical systems, their topology can be determined by studying the eigenmode symmetries at high symmetry points (HSPs) in the Brillouin zone. As electromagnetic systems are usually leaky, their radiations retain the eigenmode information, thus providing a means for probing the band topology. Here, we formulate the far-field characteristics of the eigenmodes at HSPs in 2D square lattice plasmonic systems and reveals, unlike the conventional tight-binding model, several polarization-dependent band inversions occur at theΓand X points, rendering subtle changes in their band topology. In particular, by carefully tuning the system geometry to facilitate trivial and non-trivial phases, polarization selective 0D and 1D edge states that possess distinct field symmetries are realized. The evolution of 0D or 1D edge state depends on the degree of bulk-edge overlapping. We perform angle- and polarization-resolved diffraction spectroscopy on 2D Au plasmonic nanohole arrays to verify the theory and observe such states. Our study demonstrates the applicability of simple far-field technique for diagnosing the band topology of various crystalline classical systems in electromagnetics and acoustics.

2504.06588 2026-05-11 eess.SY cs.SY

Synchrophasors and Synchrowaveforms for the Distribution Grid: The SoCal 28-Bus Dataset

Yiheng Xie, Lucien Werner, Kaibo Chen, Thuy-Linh Le, Christine Ortega, Steven Low

AI总结 本文介绍了一个真实配电网络的开放数据集,包含同步相量和波形测量单元(PMUs/WMUs)的测量数据,涵盖多种发电资源、负荷类型及网络拓扑变化。该数据集通过密集部署的PMU传感器网络,实现了对所有非零功率注入节点的测量,支持状态估计、系统辨识、潮流优化等多种应用,并提供了用于分析谐波、暂态事件和电网稳定性的同步波形数据。数据集还包含电路拓扑和参数,为研究者在真实系统上开发和测试算法提供了宝贵资源。

详情
英文摘要

We provide an open-access dataset of phasor & waveform measurement units (PMUs/WMUs) of a real-world electrical distribution network. The network consists of diverse sets of generation resources (including solar panels, fuel cells, natural gas generators, and utility interconnections), loads (including large-scale electric vehicle charging, data centers, central cooling, offices), topology changes (such as line outages and load transfers), as well as a mixture of single- and three-phase networks. We describe a densely deployed PMU sensor network in a distribution grid, in which all buses with non-zero power injections are measured. This approach enables a range of applications such as state estimation, system identification, power flow optimization, and feedback control, several of which are discussed in this paper. Additionally, we provide a synchronized waveform dataset which allows the analysis of harmonics, transient events, dynamic grid impedance, and stability. Data collection started in 2023 while new data is generated continuously and made available online. A characterization of measurement error is provided. Finally, we provide circuit topology and parameters as a part of the dataset. Together, the circuit and timeseries data offer an opportunity for researchers to develop and test algorithms on a real-world system.

2503.19924 2026-05-11 q-bio.NC nlin.AO

Human brain state classification via permutation entropy of EEG phase dynamics across consciousness levels and inattentive-type ADHD

Athokpam Langlen Chanu, Youngjai Park, Jaesung Choi, Younghwa Cha, UnCheol Lee, Joon-Young Moon, Jong-Min Park

AI总结 该研究通过分析脑电图(EEG)信号的排列熵,探讨不同人类脑状态是否能够根据EEG动态的无序性进行区分。研究聚焦于EEG相位动态的主要模式,反映前后脑信息流,并利用排列熵量化无序程度,应用于全身麻醉和静息状态下的EEG数据集。结果表明,排列熵分布对脑状态具有明显依赖性,尤其在清醒、注意力缺陷多动障碍(ADHD)及闭眼状态下表现出更低的均值和更大的标准差,但其在区分ADHD患者与健康对照组方面效果有限,提示原始时间序列信息可能在ADHD检测中更为关键。

Comments 18 pages, Accepted for publication in Chaos, Solitons and Fractals

详情
英文摘要

We analyze electroencephalography (EEG) signals using the ordinal pattern framework to investigate whether different human brain states can be distinguished based on the disorder of EEG dynamics. Rather than analyzing raw EEG signals, we focus on the principal mode of EEG phase dynamics, reflecting anterior-posterior information flow, and quantify disorder using permutation entropy. We apply this to two datasets: (i) EEG recordings from a general anesthesia protocol, and (ii) EEG recordings acquired in the resting state from healthy control subjects and individuals with inattentive-type attention deficit hyperactivity disorder (ADHD), including eyes-open and eyes-closed conditions. We find that the permutation entropy distributions exhibit a clear dependence on brain state. In particular, conscious, inattentive-type ADHD, and eyes closed conditions show lower mean values and larger standard deviations of permutation entropy. To evaluate the discriminative power of permutation entropy, we train classification models using permutation entropy as an input feature. The results show that the distinction between conscious and unconscious states can be reliably captured in the general-anesthesia dataset. In the resting-state dataset, eyes-open and eyes-closed conditions are distinguishable, whereas classification between control and inattentive-type ADHD groups does not show clear separability. This indicates that information not captured in ordinal patterns, such as the original time-series values, may play a more crucial role in detecting inattentive-type ADHD. Our findings demonstrate that permutation entropy derived from EEG phase dynamics provides an effective indicator of brain states, particularly in relation to consciousness, while also highlighting its limitations for identifying individuals with inattentive-type ADHD.

2503.12221 2026-05-11 math.OC

Multiple Approximate-Response Agents (MARA): Fast Near-Optimal Primal Recovery for Distributed Optimization

Tetiana Parshakova, Yicheng Bai, Garrett van Ryzin, Stephen Boyd

AI总结 本文提出了一种名为MARA的快速近似原问题恢复方法,用于分布式优化问题中的对偶方法改进。该方法通过让每个智能体在每次价格查询时生成多个具有有限次优性的原问题响应,并利用这些响应构造凸组合以减少原问题不可行性,从而加速原问题的恢复过程。MARA与对偶价格计算方式无关,可广泛应用于提升各类对偶算法的性能,实验表明其能在少量迭代内收敛到可行且近似最优的解。

详情
英文摘要

Dual methods are useful for distributed optimization because they allow agent-level subproblems to be solved in parallel. However, achieving primal feasibility with dual methods is a challenge; it can take many iterations to find prices that recover primal feasibility, and even with optimal dual prices primal feasibility is not guaranteed unless special conditions like strict convexity hold. To address this limitation, we propose a simple primal recovery method, multiple approximate-response agents (MARA), that is able to rapidly reduce primal infeasibility, tolerating some degree of suboptimality. The method is agnostic to how dual prices are computed, so MARA can be applied to enhance any dual algorithm. Rather than returning a single primal response to each price query, MARA requires agents to generate multiple primal responses, each of which has bounded suboptimality. Because these multiple responses can be computed in parallel, there is no increase in the wall-clock time of the underlying dual algorithm. MARA then constructs a convex combination of the multiple responses by minimizing the sum of the primal and complementary slackness residuals to produce a high-quality primal solution. Tests of MARA using both a price localization method and a dual subgradient method show that it typically converges to a feasible, near-optimal solution in a few tens of iterations. Moreover, hyperparameters of MARA can be flexibly tuned to control the trade-off among speed, computational budget, and degree of suboptimality of the feasible solutions.

2503.09983 2026-05-11 math.CO

On tropical knapsack-type problems

I. M. Buchinskiy, M. V. Kotov, A. V. Treier

AI总结 本文研究了在特定热带代数结构下背包问题和子集和问题的计算复杂性。作者考虑了非负entries的max-plus代数中$k \times k$方阵的半群,以及正entries的max-times代数中$k \times k$方阵的半群,并证明了这些结构下的背包问题和子集和问题均为NP-完全问题。同时,文章展示了这些问题存在伪多项式算法,并针对后者半群提出了多项式通用算法。

Comments fixed Acknowledgments, added DOI

详情
英文摘要

In this paper, we investigate the computational complexity of the knapsack problem and subset sum problem for the following tropical algebraic structures. We consider the semigroup of square matrices of size $k \times k$ with non-negative entries over the max-plus algebra and the semigroup square matrices of size $k \times k$ with positive entries over the max-times algebra. We prove that the knapsack problem and subset sum problem for these structures are $\textsf{NP}$-complete. We demonstrate that there are pseudo-polynomial algorithms to solve these problems. Also, we show that for the latter semigroup, there are polynomial generic algorithms to solve the knapsack problem and the subset sum problem.

2503.08197 2026-05-11 quant-ph

Quantum squeezing amplification with a weak Kerr nonlinear oscillator

Yanyan Cai, Xiaowei Deng, Libo Zhang, Zhongchu Ni, Jiasheng Mai, Peihao Huang, Pan Zheng, Ling Hu, Song Liu, Yuan Xu, Dapeng Yu

AI总结 该研究探讨了如何利用弱 Kerr 非线性振子在超导微波腔中生成和放大量子压缩态。通过精心设计的非共振微波驱动,实现了对多个光子数态的量子压缩演化循环动态,并采用 Trotterization 技术实现了确定性的压缩放大,获得了最大 14.6 dB 的压缩度和 0.28 MHz 的压缩速率。该方法为在硬件效率高的条件下生成高压缩量子态提供了新途径,有望在量子传感和量子信息处理中发挥重要作用。

Comments Main text: 8 pages, 4 figures; Supplementary material: 9 pages, 11 figures, 2 tables

详情
Journal ref
Nat. Commun. 17, 970 (2026)
英文摘要

Quantum squeezed states, with reduced quantum noise, have been widely utilized in quantum sensing and quantum error correction applications. However, generating and manipulating these nonclassical states with a large squeezing degree typically requires strong nonlinearity, which inevitably induces additional decoherence that diminishes the overall performance. Here, we demonstrate the generation and amplification of squeezed states in a superconducting microwave cavity with weak Kerr nonlinearity. By subtly engineering an off-resonant microwave drive, we observe cyclic dynamics of the quantum squeezing evolution for various Fock states |N> with N up to 6 in displaced frame of the cavity. Furthermore, we deterministically realize quantum squeezing amplification by alternately displacing the Kerr oscillator using the Trotterization technique, achieving a maximum squeezing degree of 14.6 dB and squeezing rate of 0.28 MHz. Our hardware-efficient displacement-enhanced squeezing operations provide an alternative pathway for generating large squeezed states, promising potential applications in quantum-enhanced sensing and quantum information processing.

2502.12345 2026-05-11 math.NA cs.NA

Uncertainty quantification for stationary and time-dependent PDEs subject to Gevrey regular random domain deformations

Ana Djurdjevac, Vesa Kaarnioja, Claudia Schillings, André-Alexander Zepernick

AI总结 本文研究了在具有Gevrey正则性随机域变形的椭圆和抛物型偏微分方程中的不确定性量化问题。作者采用了一种更通用的随机场参数化方法,避免了传统参数化模型如Karhunen-Loeve展开的限制,并设计了随机移位格点准蒙特卡洛求积规则来计算解的期望值。理论分析表明,该方法在维度无关的情况下具有近似线性的收敛速率,并通过数值实验验证了理论结果的正确性。

Comments 42 pages, 5 figures

详情
英文摘要

We study uncertainty quantification for partial differential equations subject to domain uncertainty. We parameterize the random domain using the model recently considered by Chernov and Le (2024) as well as Harbrecht, Schmidlin, and Schwab (2024) in which the input random field is assumed to belong to a Gevrey smoothness class. This approach has the advantage of being substantially more general than models which assume a particular parametric representation of the input random field such as a Karhunen-Loeve series expansion. We consider both the Poisson equation as well as the heat equation and design randomly shifted lattice quasi-Monte Carlo (QMC) cubature rules for the computation of the expected solution under domain uncertainty. We show that these QMC rules exhibit dimension-independent, essentially linear cubature convergence rates in this framework. In addition, we complete the error analysis by taking into account the approximation errors incurred by dimension truncation of the random input field and finite element discretization. Numerical experiments are presented to confirm the theoretical rates.

2502.09834 2026-05-11 cs.DS

Optimal $k$-Secretary with Logarithmic Memory

Mingda Qiao, Wei Zhang

AI总结 本文研究了在内存受限情况下解决 $k$-秘书问题的算法。作者提出了一种仅需 $O(\log k)$ 内存的算法,其竞争力比率达到最优的 $1 - O(1/\sqrt{k})$,与 Kleinberg 的经典算法相当但显著降低了内存需求。该成果基于将 $k$-秘书问题归约为量化估计问题,并设计了一种具有 $O(\sqrt{k})$ 期望误差的量化估计算法,从而实现了内存效率与性能的平衡。

Comments To appear at ICALP 2026

详情
英文摘要

We study memory-bounded algorithms for the $k$-secretary problem. The algorithm of Kleinberg (SODA 2005) achieves an optimal competitive ratio of $1 - O(1/\sqrt{k})$, yet a straightforward implementation requires $Ω(k)$ memory. Our main result is a $k$-secretary algorithm that matches the optimal competitive ratio using $O(\log k)$ words of memory. We prove this result by establishing a general reduction from $k$-secretary to (random-order) quantile estimation, the problem of finding the $k$-th largest element in a stream. We show that a quantile estimation algorithm with an $O(k^α)$ expected error (in terms of the rank) gives a $(1 - O(1/k^{1-α}))$-competitive $k$-secretary algorithm with $O(1)$ extra words. We then introduce a new quantile estimation algorithm that achieves an $O(\sqrt{k})$ expected error bound using $O(\log k)$ memory. Of independent interest, we give a different algorithm that uses $O(\sqrt{k})$ words and finds the $k$-th largest element exactly with high probability, generalizing a result of Munro and Paterson (1980).

2502.06088 2026-05-11 hep-ph hep-th

Family Unification in $SO(16)$ Grand Unification

Cheng-Wei Chiang, Tianjun Li, Naoki Yamatsu

AI总结 本文提出了一种基于 $SO(16)$ 大统一规范对称性的六维统一模型,将标准模型的三种规范对称性与 $SU(3)$ 家族对称性统一起来。模型中,三代夸克和轻子被统一为六维 $SO(16)$ 规范对称性的旋量表示中的费米子,通过引入矢量对称性消除了六维规范异常,并在固定点引入局域费米子以消除四维规范异常。该模型还表现出 $SO(16)$ 规范耦合常数在高能下趋于减弱的特性。

Comments 16 pages, 3 tables, no figures

详情
Journal ref
PTEP 2026 (2026) 6, 023B05
英文摘要

We propose a unified model for the three Standard Model (SM) gauge symmetries and $SU(3)$ family symmetry based on $SO(16)$ grand unified gauge symmetry on six-dimensional (6D) spacetime. In this model, three chiral generations of quarks and leptons are unified into a 6D Weyl fermion in the spinor representation of $SO(16)$. The 6D $SO(16)$ gauge anomaly is canceled by the vectorlike nature of the model, and the 4D gauge anomalies are canceled by introducing suitable 4D localized fermions at the fixed point. The 4D gauge coupling constant of $SO(16)$ has the property of becoming weaker at high energies.

2501.19226 2026-05-11 math.GN math.CT math.RA

What is Connectivity?

Jean F. Du Plessis, Zurab Janelidze, Bernardus A. Wessels

AI总结 本文探讨了空间类结构中连通性的一套分类体系,灵感来源于分离空间中连通部分的偏序集并研究其在环境空间中的嵌入方式。该分类涵盖了点集与点自由语境下的各种标准连通性概念,包括图与超图的连通性、拓扑中的连通性与路径连通性,以及框架中元素的连通性。研究为不同数学结构中的连通性提供了统一的理论框架,具有重要的理论意义。

Comments 22 pages, 13 figures, v2 fixed some figure referencing

详情
Journal ref
Appl Categor Struct 34, 18 (2026)
英文摘要

In this paper, we explore a taxonomy of connectivity for space-like structures. It is inspired by isolating posets of connected pieces of a space and examining its embedding in the ambient space. The taxonomy includes in its scope all standard notions of connectivity in point-set and point-free contexts, such as connectivity in graphs and hypergraphs (as well as k-connectivity in graphs), connectivity and path-connectivity in topology, and connectivity of elements in a frame.

2501.08554 2026-05-11 physics.ins-det hep-ex nucl-ex

In-situ high voltage generation with Cockcroft-Walton multiplier for xenon gas time projection chamber

Shinichi Akiyama, Junya Hikida, Masashi Yoshida, Kazuhiro Nakamura, Sei Ban, Masanori Hirose, Atsuko K. Ichikawa, Yoshihisa Iwashita, Tatsuya Kikawa, Yasuhiro Nakajima, Kiseki D. Nakamura, Tsuyoshi Nakaya, Shuhei Obara, Ken Sakashita, Hiroyuki Sekiya, Bungo Sugashima, Soki Urano, Sota Hatsumi, Sota Kobayashi, Hayato Sasaki

AI总结 该研究提出了一种用于氙气时间投影室(TPC)的现场高压生成方案,采用考克罗夫特-沃尔顿(Cockcroft-Walton)倍压器替代传统的高压引入装置,从而简化系统结构并提高可靠性。研究将该倍压器集成于AXEL探测器中,用于搜寻氙-136的无中微子双β衰变,实验在6.8 bar高压下连续运行40天,实现了高达0.67%(全宽半高)的能量分辨率,验证了该方法在高精度探测中的可行性。

Comments 27 pages, 24 figures, preprint for PTEP submission, resubmitted

详情
Journal ref
Progress of Theoretical and Experimental Physics, Volume 2025 Issue 5, 053H03
英文摘要

We have newly developed a Cockcroft-Walton (CW) multiplier that can be used in a gas time projection chamber (TPC). A TPC requires a high voltage to form an electric field that drifts ionization electrons. Supplying the high voltage from outside the pressure vessel requires a dedicated high-voltage feedthrough. An alternative approach is to generate the high voltage inside the pressure vessel with a relatively low voltage introduced from outside. A CW multiplier can convert a low AC voltage input to a high DC voltage output, making it suitable for this purpose. We have integrated a CW multiplier into the AXEL (A Xenon ElectroLuminescence detector), a high pressure xenon gas TPC to search for neutrinoless double beta decay of $^{136}$Xe. It uses silicon photomultipliers to detect the ionization electrons through elecrtoluminescence, making it strong against electronic noise. Operation of the CW multiplier was successfully demonstrated; the TPC was operated for 40 days at 6.8 bar, and an energy resolution as high as (0.67 $\pm$ 0.08) % (FWHM) at 2615 keV was obtained.

2501.03660 2026-05-11 math.QA

Involutive (simple) latin solutions of the Yang-Baxter equation and related (left) quasigroups

Marco Bonatto, Marco Castelli

AI总结 本文研究具有正规位移群的 involutive 非退化集合理论 Yang-Baxter 方程解,重点描述了不可缩解的块不可约性与同余关系,并证明这些解属于拉丁解的范畴。文章进一步刻画了具有幂零置换群的简单解,并在位移群为交换且正规的情形下引入第一魏尔代数进行更精确的描述,同时对最小规模为 $p^p$ 的简单解进行了枚举与分类。最后通过实例说明了相关结果。

Comments 22 pages, Theorems 44 and 48 from the first version have been removed and replaced by other results. Some typos have been corrected. The main results of the paper remain unchanged

详情
英文摘要

In this paper, we study involutive non-degenerate set-theoretic solutions of the Yang-Baxter equation with regular displacement group. In particular, we completely describe the blocks of imprimitivity and the congruences of the irretractable ones, that we show belonging to the class of the latin solutions. Among these solutions, we characterise the simple ones having nilpotent permutation group. A more precise description involving the First Weyl Algebra will be provided when the displacement group is abelian and normal in the total permutation group, and we enumerate and classify the simple ones having minimal size $p^p$, for an arbitrary prime number $p$. Finally, we illustrate our results by some examples.

2412.20091 2026-05-11 astro-ph.HE

Gamma-Ray Burst Light Curve Reconstruction: A Comparative Machine and Deep Learning Analysis

A. Manchanda, A. Kaushal, M. G. Dainotti, A. Deepu, S. Naqi, J. Felix, N. Indoriya, S. P. Magesh, H. Gupta, K. Gupta, A. Madhan, D. H. Hartmann, A. Pollo, M. Bogdan, J. X. Prochaska, N. Fraija, D. Debnath

AI总结 该研究旨在通过机器学习和深度学习方法重建伽马射线暴(GRB)光变曲线,以提高关键参数的精度,从而增强GRB作为宇宙学工具的应用价值。研究比较了九种模型,包括多层感知机(MLP)、双向LSTM、注意力U-Net等,发现MLP在降低参数不确定性方面表现最佳,而注意力U-Net虽不确定性降低最多,但测试均方误差较高。该成果有助于提升GRB在宇宙学研究中的精确性与可靠性。

Comments 37 pages, 10 figures (105 panels), 5 Tables, Accepted in ApJ

详情
Journal ref
ApJS 281 35 (2025)
英文摘要

Gamma-Ray Bursts (GRBs), observed at high-z, are probes of the evolution of the Universe and can be used as cosmological tools. Thus, we need correlations with small dispersion among key parameters. To reduce such a dispersion, we mitigate gaps in light curves (LCs), including the plateau region, key to building the two-dimensional Dainotti relation between the end time of plateau emission (Ta) and its luminosity (La). We reconstruct LCs using nine models: Multi-Layer Perceptron (MLP), Bi-Mamba, Fourier Transform, Gaussian Process-Random Forest Hybrid (GP-RF), Bidirectional Long Short-Term Memory (Bi-LSTM), Conditional GAN (CGAN), SARIMAX-based Kalman filter, Kolmogorov-Arnold Networks (KANs), and Attention U-Net. These methods are compared to the Willingale model (W07) over a sample of 521 GRBs. MLP and Attention U-Net outperform other methods, with MLP reducing the plateau parameter uncertainties by 37.2% for log Ta, 38.0% for log Fa, and 41.2% for alpha (the post-plateau slope in the W07 model), achieving the lowest 5-fold cross-validation (CV) mean squared error (MSE) of 0.0275. Attention U-Net achieved the lowest uncertainty of parameters, a 37.9% reduction in log Ta, a 38.5% reduction in log Fa and a 41.4% reduction in alpha, but with a higher MSE of 0.134. Although Attention U-Net achieves the largest uncertainty reduction, the MLP attains the lowest test MSE while maintaining comparable uncertainty performance, making it the more reliable model. The other methods yield MSE values ranging from 0.0339 to 0.174. These improvements in parameter precision are needed to use GRBs as standard candles, investigate theoretical models, and predict GRB redshifts through machine learning.

2412.11843 2026-05-11 math.AC

Monomial ideals with minimal generalized Barile-Macchia resolutions

Trung Chau, Huy Tai Ha, Aryaman Maithani

AI总结 本文研究了具有极小广义Barile-Macchia分解的单项理想类,识别出包括泛型单项理想、具有线性商的单项理想以及超树的边理想在内的多个类别。同时,文章还刻画了连通单圈图的边理想在满足桥友好条件时的分解性质,并指出这些理想具有极小的Barile-Macchia分解。Barile-Macchia分解及其广义形式属于细胞分解,是Morse分解的特殊类型。

Comments are welcome! 17 pages

详情
Journal ref
Vietnam Journal of Mathematics, Volume 54, pages 307--324 (2026)
英文摘要

We identify several classes of monomial ideals that possess minimal generalized Barile-Macchia resolutions. These classes of ideals include generic monomial ideals, monomial ideals with linear quotients, and edge ideals of hypertrees. We also characterize connected unicyclic graphs whose edge ideals are bridge-friendly and, in particular, have minimal Barile-Macchia resolutions. Barile-Macchia and generalized Barile-Macchia resolutions are cellular resolutions and special types of Morse resolutions.

2412.00548 2026-05-11 cs.MA

Neural Power-Optimal Magnetorquer Solution for Multi-Agent Formation and Attitude Control

Yuta Takahashi, Shin-ichiro Sakai

AI总结 本文提出了一种基于学习的电流计算模型,用于实现多智能体编队与姿态控制中的功率最优磁场相互作用。研究通过顺序凸规划推导出一种独特、连续且功率最优的电流解,并利用多层感知机对其进行近似。实验和仿真验证了该方法在编队与姿态控制中的有效性。

Comments IEEE Robotics and Automation Letters. Preprint Version. Accepted April, 2026 (DOI: https://doi.org/10.1109/LRA.2026.3692064)

详情
英文摘要

This paper presents a learning-based current calculation model to achieve power-optimal magnetic-field interaction for multi-agent formation and attitude control. In aerospace engineering, electromagnetic coils are referred to as magnetorquer (MTQ) coils and used as satellite attitude actuators in Earth's orbit and for long-term formation and attitude control. This study derives a unique, continuous, and power-optimal current solution via sequential convex programming and approximates it using a multilayer perceptron model. The effectiveness of our strategy was demonstrated through numerical simulations and experimental trials on the formation and attitude control.

2411.13727 2026-05-11 cond-mat.mtrl-sci

Sign of the Gap Temperature Dependence in CsPb(Br,Cl)3 Nanocrystals Determined by Cs-Rattler Mediated Electron-Phonon Coupling

S. Fasahat, N. Fiuza-Maneiro, B. Schäfer, K. Xu, S. Gómez-Graña, M. I. Alonso, L. Polavarapu, A. R. Goñi

AI总结 本研究揭示了CsPb(Br,Cl)3纳米晶体带隙温度依赖性的符号反转现象,发现其源于电子-声子耦合机制的突然变化。通过温度与压力依赖的光致发光实验,研究指出当氯含量超过约40%时,由于晶格畸变引发的同步八面体倾斜和铯离子振动(Cs rattling),导致电子-声子耦合强度与符号发生转变,从而引起带隙温度斜率的反转。这一发现为理解铅卤化物钙钛矿纳米晶体的光电性能提供了关键机制。

Comments 18 pages, 4 figures, 1 table

详情
英文摘要

So far, the striking sign reversal in the near-ambient slope of the gap temperature dependence of colloidal CsPbCl3 perovskite nanocrystals (NCs) compared to its Br counterpart, remains unresolved. Pure bromide NCs exhibit a linear gap increase with increasing temperature, to which thermal expansion and electron-phonon interaction equally contribute. In contrast, the temperature slope for the chlorine compound gap is outspoken negative. By combining temperature and pressure-dependent photoluminescence on a series of CsPb(Br1-xClx)3 NCs, we unravel the origin of such inversion. Responsible is solely the electron-phonon interaction, undergoing a sudden change in sign and magnitude due to activation of an anomalous electron-phonon coupling mechanism linked to vibrational modes characterized by synchronous octahedral tilting and Cs rattling. This takes place in the shrunken orthorhombic NC lattice for Cl concentrations exceeding ca. 40%. We have thus clarified a puzzling result directly impacting the optoelectronic properties of lead halide perovskite NCs.

2411.10179 2026-05-11 math.CO cs.IT math.IT

Explicit constructions of optimal blocking sets and minimal codes

Anurag Bishnoi, István Tomon

AI总结 本文研究了射影空间中强 $s$-阻塞集的显式构造问题,提出了一种在 $\mathbb{F}_q$ 上 $(k - 1)$ 维射影空间中构造大小为 $O_s(q^s k)$ 的强 $s$-阻塞集的方法,该结果在常数因子意义上是最佳的。该方法还导出了关于仿射阻塞集和 $s$-极小码的最优显式构造,核心思想是在扩展图的基础上构建特定的超图,使得树状结构对应于强 $s$-阻塞集。此外,文章还探讨了该构造与超图规模 Ramsey 数之间的联系。

Comments 19 pages, 4 figures, 1 appendix. This version contains a detailed proof of Lemma 8 and minor corrections

详情
Journal ref
Combinatorica 46, 13 (2026)
英文摘要

A strong $s$-blocking set in a projective space is a set of points that intersects each codimension-$s$ subspace in a spanning set of the subspace. We present an explicit construction of such sets in a $(k - 1)$-dimensional projective space over $\mathbb{F}_q$ of size $O_s(q^s k)$, which is optimal up to the constant factor depending on $s$. This also yields an optimal explicit construction of affine blocking sets in $\mathbb{F}_q^k$ with respect to codimension-$(s+1)$ affine subspaces, and of $s$-minimal codes. Our approach is motivated by a recent construction of Alon, Bishnoi, Das, and Neri of strong $1$-blocking sets, which uses expander graphs with a carefully chosen set of vectors as their vertex set. The main novelty of our work lies in constructing specific hypergraphs on top of these expander graphs, where tree-like configurations correspond to strong $s$-blocking sets. We also discuss some connections to size-Ramsey numbers of hypergraphs, which might be of independent interest.

2411.00008 2026-05-11 physics.soc-ph cs.DL

Women in Science: Measuring Participation in Europe Across Disciplines, Generations and Over Time

Marek Kwiek, Lukasz Szymula

AI总结 本研究通过分析过去三十年的结构化大数据,量化了女性在欧洲科学领域中的参与情况,涵盖14个STEM学科及1990至2023年间的动态变化。研究发现,女性在部分学科中已成为主要研究者,但在数学化程度较高的学科中其贡献相对有限。通过分析科学家的出版记录,研究揭示了科学增长与女性科学家数量增长之间的关联,并突出了不同学科和代际间的显著差异。

Comments 29 pages, 5 figures

详情
英文摘要

In this research, we quantify an inflow of women into science in the past three decades. Structured Big Data allow us to estimate the contribution of women scientists to the growth of science by disciplines (N = STEMM 14 disciplines) and over time (1990-2023). A monolithic segment of STEMM science emerges from this research as divided between the disciplines in which the growth was powerfully driven by women - and the disciplines in which the role of women was marginal. There are four disciplines in which 50% of currently publishing scientists are women; and five disciplines in which more than 50% of currently young scientists are women. But there is also a cluster of four highly mathematized disciplines (MATH, COMP, PHYS, and ENG) in which the growth of science is only marginally driven by women. Digital traces left by scientists in their publications indexed in global datasets open two new dimensions in large-scale academic profession studies: time and gender. The growth of science in Europe was accompanied by growth in the number of women scientists, but with powerful cross-disciplinary and cross-generational differentiations. We examined the share of women scientists coming from ten different age cohorts for 32 European and four comparator countries (the USA, Canada, Australia, and Japan). Our study sample was N = 1,740,985 scientists (including 39.40% women scientists). Three critical methodological challenges of using structured Big Data of the bibliometric type were discussed: gender determination, academic age determination, and discipline determination.

2410.21213 2026-05-11 stat.ME

Spatial causal inference in the presence of preferential sampling to study the impacts of marine protected areas

Dongjae Son, Brian J. Reich, Erin M. Schliep, Shu Yang, David A. Gill

AI总结 本文研究了在存在偏好采样情况下,如何评估海洋保护区(MPAs)对生物多样性的影响。作者提出了一种空间因果推断方法,能够同时考虑采样过程和处理分配中的未测量空间混杂因素,从而更准确地估计因果效应。通过模拟研究和实际数据分析,验证了该方法在识别因果效应方面的有效性,并发现偏好采样对结果估计具有显著影响。

详情
英文摘要

Marine Protected Areas (MPAs) have been established globally to conserve marine resources. Given their maintenance costs and impact on commercial fishing, it is critical to evaluate their effectiveness to support future conservation. In this paper, we use data collected from the Australian coast to estimate the effect of MPAs on biodiversity. Environmental studies such as these are often observational, and processes of interest exhibit spatial dependence, which presents challenges in estimating the causal effects. Spatial data can also be subject to preferential sampling, where the sampling locations are related to the policy and the response variable, further complicating inference and prediction. To address these challenges, we propose a spatial causal inference method that simultaneously accounts for unmeasured spatial confounders in both the sampling process and the treatment allocation. We prove the identifiability of key parameters in the model and the consistency of the posterior distributions of those parameters. We show via simulation studies that the causal effect of interest can be reliably estimated under the proposed model. The proposed method is applied to assess the effect of MPAs on fish biomass. We find evidence of preferential sampling and that properly accounting for this source of bias impacts the estimate of the causal effect.

2410.19566 2026-05-11 math.AP math.PR

A comparison principle based on couplings of partial integro-differential operators

Serena Della Corte, Fabian Fuchs, Richard C. Kraaij, Max Nendel

AI总结 本文研究了一类偏积分微分算子对应的汉密尔顿-雅可比(HJ)、汉密尔顿-贝尔曼(HJB)和汉密尔顿-伊萨克斯(HJI)方程的粘性解比较原理。作者通过重新诠释经典的变量加倍方法,并结合概率耦合的概念,提出了一种适用于微分、差分和积分算子的统一方法,特别适用于与Lévy过程相关的非局部算子。该方法不仅加强了比较原理所导出的上范数收缩性,还使其在严格拓扑下具有连续性,理论结果被应用于多种算子,包括二阶微分算子和空间非均匀Lévy过程的生成算子。

详情
Journal ref
Journal de Mathématiques Pures et Appliquées, Volume 210, June 2026, 103872
英文摘要

This paper is concerned with a comparison principle for viscosity solutions to Hamilton-Jacobi (HJ), -Bellman (HJB), and -Isaacs (HJI) equations for general classes of partial integro-differential operators. Our approach innovates in three ways: (1) We reinterpret the classical doubling-of-variables method in the context of second-order equations by casting the Ishii-Crandall Lemma into a test function framework. This adaptation allows us to effectively handle non-local integral operators, such as those associated with Lévy processes. (2) We translate the key estimate on the difference of Hamiltonians in terms of an adaptation of the probabilistic notion of couplings, providing a unified approach that applies to differential, difference, and integral operators. (3) We strengthen the sup-norm contractivity resulting from the comparison principle to one that encodes continuity in the strict topology. We apply our theory to a variety of examples, in particular, to second-order differential operators and, more generally, generators of spatially inhomogeneous Lévy processes.

2410.18933 2026-05-11 q-bio.NC

Confidence is detection-like in high-dimensional spaces

Wiktoria Kozyra, Kevin O'Neill, Stephen M. Fleming

AI总结 本文研究了高维空间中置信度估计为何常呈现“检测样”特征,即主要受支持决策的正向证据驱动。研究发现,贝叶斯置信度估计在高维信号检测理论框架下也表现出对决策一致证据的高敏感性,这种现象源于对大量未选替代方案进行归一化所引发的非线性效应。研究还指出,当参与者考虑的假设多于实验者设定时,这种“检测样”置信度是合理的,并揭示了类似机制在卷积神经网络中也能引发正向证据偏差,为理解人类与人工智能系统的置信度行为提供了理论联系。

详情
英文摘要

Confidence estimates are often "detection-like" - driven by positive evidence in favour of a decision. This empirical observation has been interpreted as showing that human metacognition is limited by biases or heuristics. Here, we show that Bayesian confidence estimates also exhibit heightened sensitivity to decision-congruent evidence in higher-dimensional signal detection theoretic spaces, leading to detection-like confidence criteria. This effect is due to a nonlinearity induced by normalisation of confidence by a large number of unchosen alternatives. Our analysis suggests that detection-like confidence is rational when participants consider a greater number of hypotheses than assumed by the experimenter. Further, we show that a similar dimensionality-driven mechanism can give rise to and modulate the strength of the positive evidence biases in convolutional neural networks, linking our signal detection theoretic analysis to confidence behaviour in artificial systems.

2410.18707 2026-05-11 cs.LO

Disjoint Projected Enumeration for SAT and SMT without Blocking Clauses

Giuseppe Spallitta, Roberto Sebastiani, Armin Biere

AI总结 本文研究了全解满足性问题(AllSAT)及其理论扩展(AllSMT)的高效求解方法,旨在枚举所有满足给定公式的解,广泛应用于形式验证和人工智能等领域。为解决传统方法中因阻塞子句导致的内存开销大和传播效率低的问题,作者提出两种新型求解器tabularAllSAT和tabularAllSMT,结合冲突驱动子句学习(CDCL)与时间回溯机制,实现高效且互不重叠的解枚举。此外,通过引入一种新的激进隐含式收缩算法,进一步减少部分赋值的数量,提升整体搜索效率,并有效支持投影枚举和SMT公式处理,实验表明该方法在多个场景下优于现有先进求解器。

Comments arXiv admin note: text overlap with arXiv:2306.00461 extended journal version of arXiv:2306.00461

详情
英文摘要

All-Solution Satisfiability (AllSAT) and its extension, All-Solution Satisfiability Modulo Theories (AllSMT), have become more relevant in recent years, mainly in formal verification and artificial intelligence applications. The goal of these problems is the enumeration of all satisfying assignments of a formula (for SAT and SMT problems, respectively), making them useful for test generation, model checking, and probabilistic inference. Nevertheless, traditional AllSAT algorithms face significant computational challenges due to the exponential growth of the search space and inefficiencies caused by blocking clauses, which cause memory blowups and degrade unit propagation performances in the long term. This paper presents two novel solvers: tabularAllSAT, a projected AllSAT solver, and tabularAllSMT, a projected AllSMT solver. Both solvers combine Conflict-Driven Clause Learning (CDCL) with chronological backtracking to improve efficiency while ensuring disjoint enumeration. To retrieve compact partial assignments we propose a novel aggressive implicant shrinking algorithm, compatible with chronological backtracking, to minimize the number of partial assignments, reducing overall search complexity. Furthermore, we extend the solver framework to handle projected enumeration and SMT formulas effectively and efficiently, adapting the baseline framework to integrate theory reasoning and the distinction between important and non-important variables. An extensive experimental evaluation demonstrates the superiority of our approach compared to state-of-the-art solvers, particularly in scenarios requiring projection and SMT-based reasoning.

2409.20372 2026-05-11 math.FA math.CA

Factorization of positive-semidefinite operators with absolutely summable entries

Radu Balan, Fushuai Jiang

AI总结 本文研究了具有绝对可和条目且正半定的无限矩阵是否可以分解为对称秩一形式的问题。作者通过将其转化为测度上的线性规划问题,分析了有限维情况下的优化问题,并推导了其对偶问题,证明了强对偶性。在无限维情况下,作者利用已有结果给出了否定答案,并进一步研究了具有此类分解的算子集合,证明其在适当拓扑下是稠密的,并且在正系数解析维纳子代数作用下保持不变。此外,作者还给出了成功进行秩一分解的充分条件,并精确刻画了何时算子的平方根是2-和算子。

Comments 27 pages, significant update in the infinite-dimensional settings. Abstract update

详情
英文摘要

A problem by Feichtinger, Heil, and Larson asks whether every infinite matrix $A$ with $\sum_{k,l}|A_{kl}| < \infty$ (an equivalent substitute for the Feichtinger algebra) that is positive-semidefinite admits a symmetric rank-one decomposition $A = \sum_k f_k^*\otimes f_k$ with $\sum_k \|f_k\|_{1}^2 < \infty$. In the finite-dimensional setting, we analyze the corresponding quantitative $\ell_1^n$ optimization problem by an exact reformulation as a linear program over measures, derive its dual, and prove strong duality. We then obtain an equivalent adjoint formulation regarding the quality of a convex relaxation. In the infinite-dimensional setting, we first provide a negative answer to this question using a concurrent finite-dimensional result by Bandeira-Mixon-Steinerberger. We further study the collection of operators for which such decomposition exists, showing that they are dense in a suitable topology and invariant under the action of the positive-coefficient analytic Wiener subalgebra. In addition, we give a sufficient condition for successful rank-one decomposition in terms of $2$-summing factorization, and we characterize exactly when $A^{1/2}$ is $2$-summing.