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2605.08027 2026-05-11 stat.ME stat.AP

Randomization Tests for Distributions of Individual Treatment Effects via Combined Rank Statistics

David Kim, Yongchang Su, Jake Bowers, Xinran Li

AI总结 本文研究如何在随机实验中推断个体处理效应的分布,如受益比例、中位效应等。作者提出了一种自适应结合多个秩统计量的检验方法,在不依赖先验知识的情况下保持有限样本有效性,并针对分层实验设计了有效聚合不同层信息的加权方案。该方法在实际应用中表现出比单一检验更高的功效,例如在教师培训项目的评估中,综合检验显示约一半受训教师受益,而单一检验可能仅显示少数受益。

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英文摘要

What proportion of treated units actually benefited from an experimental intervention? What is the median or the largest individual treatment effect? This paper develops methods for answering such questions about the distribution of individual causal effects in randomized experiments. Existing approaches require the analyst to select a rank-based test statistic before observing the data. A poor choice can substantially reduce power, while searching over multiple test statistics and adjusting for multiplicity using Bonferroni correction also incurs power loss. We propose inference procedures that adaptively combine multiple rank-based statistics while maintaining finite-sample validity. For stratified experiments, we further develop weighting schemes that effectively aggregate evidence across strata of heterogeneous sizes. The resulting combined test achieves power comparable to, or exceeding, that of the best individual test, without requiring prior knowledge of the optimal statistic. When applied to a randomized experiment evaluating a teacher training program, the combined test suggests that roughly half of treated teachers benefited, whereas a single rank-based test may indicate only a small minority. Thus, the choice of test determined whether the program appears broadly successful or narrowly effective.

2605.08026 2026-05-11 math.OC

Approximate directional stationarity and associated qualification conditions

Isabella Käming, Patrick Mehlitz

AI总结 本文研究了近似方向平稳性及其相关的资格条件,旨在将近似平稳性和方向平稳性相结合,提出一种新的优化必要性条件——近似方向平稳性。该条件适用于带有非光滑几何约束的优化问题,能够更精确地刻画局部最优解的性质。此外,作者还提出了一种基于近似方向平稳点的资格条件,通过验证一个特定序列和简单的Mangasarian–Fromovitz型条件,可推导出方向平稳性,从而为优化理论提供了新的分析工具。

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英文摘要

Approximate stationarity conditions provide necessary optimality conditions without requiring additional assumptions by demanding that a perturbed stationarity system possesses solutions as the involved perturbations tend to zero. Together with associated approximate constraint qualifications, which are typically rather mild, they raised much interest in the optimization community during the last decade. In parallel, directional stationarity conditions became quite popular as they sharpen standard stationarity conditions by incorporating data associated with underlying critical directions. The purpose of this paper is twofold. First, we melt the aforementioned concepts of approximate and directional stationarity to formulate and study so-called approximate directional stationarity. For the underlying model problem, an optimization problem with nonsmooth geometric constraints is chosen, which covers diverse practically relevant applications. The role of approximate directional stationarity as a necessary optimality condition is investigated in much detail, complementing results from the literature. Second, we formulate a qualification condition which, based on an approximately directionally stationary point, can be exploited to infer its directional stationarity. The latter condition depends on one particular sequence verifying approximate directional stationarity and merely requires to check a simple condition of Mangasarian--Fromovitz type stated in terms of the directional tools of limiting variational analysis. This contrasts standard approximate constraint qualifications that typically demand a certain stable behavior of all sequences validating approximate stationarity. Throughout, various approaches to verify directional stationarity of local minimizers are established, and illustrative examples are presented to make the theoretical results more accessible.

2605.08023 2026-05-11 math.DG math.AG math.CV

Asymptotics of small eigenvalues on degenerations of Kähler manifolds

Junyu Cao

AI总结 本文研究了紧凯勒流形在单参数退化情形下拉普拉斯算子小特征值的渐近行为,给出了其精确的渐近速率。通过结合Li的统一Skoda不等式与辅助Monge-Ampère方程方法,推广了Dai和Yoshikawa在高维空间中的结果。作为应用,文章还得到了具有可约奇纤维的凯勒流形退化情形下的估计结果。

Comments 37 pages; comments are welcome!

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英文摘要

We derive the exact asymptotic rates of the small eigenvalues of the Laplacian on one-parameter degenerations of compact Kähler manifolds equipped with induced background metrics. This generalizes a recent result of Dai and Yoshikawa to higher dimensions. To achieve this, we combine Li's uniform Skoda inequality with the method of auxiliary Monge-Ampère equations, introduced by Guo--Phong--Song--Sturm--Tong and adapted by Guedj--Tô. As an application, we establish estimates for degenerations of compact Kähler manifolds with reducible singular fibers.

2605.08021 2026-05-11 quant-ph

Generalized master equation for driven quantum oscillators: microscopic origin of nonlinear dissipation and asymmetric resonances

Jakob Wagner, Jeff Maki, Oded Zilberberg, Kilian Seibold

AI总结 本文研究了受驱动的非线性量子振子的耗散动力学问题,提出了一个推广的Caldeira-Leggett主方程,能够保留系统的非线性和时间依赖性。该方法揭示了非线性耗散和不对称共振的微观起源,通过动态调整系统-环境耦合,产生了超越传统固定耗散模型的非线性耗散通道。研究结果表明,这种新的耗散机制能够抑制大振幅激发和相空间涨落,并在驱动Kerr振子中表现出抑制双稳态、不对称共振响应等新现象,为理解驱动开放量子系统的耗散行为提供了微观理论框架。

Comments 14 pages, 6 figures, comments are welcome

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英文摘要

Driven nonlinear quantum oscillators are a central platform for quantum technologies, yet their dissipative dynamics are typically described using Lindblad or Caldeira-Leggett master equations derived under assumptions that exclude nonlinearities and driving. Here, we derive a generalized Caldeira-Leggett master equation for driven nonlinear oscillators by retaining the full nonlinear and time-dependent system dynamics in the construction of the dissipator. For position- and momentum-dependent system-bath coupling, the dissipator itself becomes dynamically dressed, generating nonlinear and drive-dependent dissipative channels beyond conventional fixed-dissipator approaches. This produces nonlinear damping together with dissipation-induced corrections to the effective drive. The resulting dissipative dynamics suppress large-amplitude excitations and reduce phase-space fluctuations. For a driven Kerr oscillator, this leads to the suppression of bistability, asymmetric resonance responses, and strongly modified fluctuation distributions. More broadly, our results establish a microscopic framework in which nonlinear dynamics and driving directly reshape the dissipative sector of driven open quantum systems.

2605.08018 2026-05-11 stat.ME

BAMIFun: Bayesian Multiple Imputation for Functional Data

Ziren Jiang, Lei Xuan, Eric F. Lock, Erjia Cui

AI总结 本文提出了一种用于函数型数据的贝叶斯多重插补方法BAMIFun,旨在解决现代函数型数据中轨迹观测稀疏或不规则导致的缺失值问题。该方法基于贝叶斯低秩模型和惩罚样条表示,有效提升了插补的平滑性和推断可靠性,并通过Gibbs采样算法实现后验计算。此外,研究还扩展了该框架以处理多维函数型数据,通过低秩函数张量奇异值分解(FTSVD)模型实现了现有方法无法支持的场景下的多重插补。实验表明,BAMIFun在插补精度和下游推断的置信度方面均优于现有方法。

Comments 2 Tables, 3 Figures

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英文摘要

Missing data are pervasive in modern functional datasets, where trajectories are often sparsely or irregularly observed. Although Functional Principal Component Analysis (FPCA) is widely used to reconstruct incomplete curves, existing FPCA-based approaches typically employ single imputation, leading to overly optimistic inferences in downstream analyses. To address these challenges, we develop a novel Bayesian multiple imputation framework for functional data (BAMIFun). For single-level functional data, we impose a Bayesian low-rank model that incorporates penalized spline representations to enforce smoothness of eigenfunctions and derive an efficient Gibbs sampler algorithm for posterior computation. In addition, we demonstrate and validate how to properly account for the estimation uncertainties in downstream analysis. Furthermore, we extend the framework to multiway functional data using a low-rank Functional Tensor Singular Value Decomposition (FTSVD) model, enabling Bayesian multiple imputation in settings not supported by existing methods. Simulation studies show that, compared to existing methods, BAMIFun achieves accurate imputation while providing substantially improved coverage and more reliable downstream inference. Case studies using a physical activity dataset and an infant gut microbiome dataset further demonstrate the practical advantages of our proposed methods under severe missingness. Code for our algorithms is available at https://github.com/ZirenJiang/BAMIFun.

2605.08016 2026-05-11 cs.DS cs.CC cs.DM

Planarizing Gadgets for (k, l)-tight Graphs Do Not Exist

Archit Chauhan, Rohit Gurjar, Kilian Rothmund, Thomas Thierauf

AI总结 本文研究了识别 $(k, l)$-tight 图的问题,该问题与图刚性等经典问题密切相关。尽管对于平面图已有确定性 NC 算法,但一般图上仍无相应结果。本文的主要贡献是证明,无条件地,用于将一般图问题转化为平面图问题的“平面化装置”在 $(k, l)$-tight 图识别问题中并不存在。

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英文摘要

The problem of recognizing (k, l)-tight graphs is a fundamental problem that has close connections to well studied problems like graph rigidity. The problem is better understood for planar graphs as compared to general graphs. For example, deterministic NC-algorithms for the problem are known for planar graphs, but no such algorithm is known for general graphs. A common approach to reduce a graph problem to the planar case is to use planarizing gadgets. Our main contribution is to show that, unconditionally, planarizing gadgets for the problem of recognizing (k, l)-tight graphs do not exist.

2605.08015 2026-05-11 eess.SY cs.SY

Entropic Value-at-Risk for Inter-Vehicle Collision in Platoons: Network- and Delay-Induced Bounds on Risk Due to Extreme Events

Vivek Pandey, Nader Motee

AI总结 本文研究了在随机扰动和时延动态影响下,车联网车队中车辆间碰撞风险的量化问题。作者提出了一种基于熵值风险价值(EVaR)的严格风险评估框架,用于衡量极端事件引起的碰撞风险,并分析了通信网络结构和时延对风险的约束影响。研究发现,网络代数连通性决定了最大EVaR,而拉普拉斯矩阵的最大特征值则影响网络结构带来的最小固有风险,为车联网车队的安全设计提供了理论依据和实践指导。

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英文摘要

Safe operation of connected vehicle platoons under stochastic disturbances and time-delayed dynamics requires accurate quantification of rare but dangerous events, such as inter-vehicle collisions. We propose a rigorous framework for quantifying the risk of inter-vehicle collisions in connected vehicle platoons subject to time-delayed stochastic dynamics. We adopt the \emph{entropic value-at-risk} (EVaR) as a conservative metric to capture \emph{risk due to extreme events}, highlighting its advantages over conventional Value-at-Risk (VaR) and Conditional Value-at-Risk (CVaR). By expressing the inter-vehicle distance covariance in terms of the Laplacian eigenvalues of the communication network, we derive \emph{network-and time-delay-induced bounds} on both the minimum inherent risk and the worst-case risk. Specifically, the algebraic connectivity dictates the maximum EVaR, while the largest Laplacian eigenvalue determines the minimum risk inherently induced by the network structure. Numerical simulations illustrate how network topology and time delay shape collision risk, offering actionable insights for the safe design of vehicle platoons operating under stochastic disturbances.

2605.08014 2026-05-11 q-bio.NC math.DS

Dynamical mechanisms of flexible phase-locking in cortical theta oscillators

Yangyang Wang, Benjamin R. Pittman-Polletta

AI总结 本研究探讨了大脑皮层θ振荡器如何实现对不同时间尺度输入信号的灵活相位锁定机制。通过动力系统理论分析,研究发现多时间尺度的内在抑制电流相互作用,能够产生延迟Hopf分岔现象,从而显著扩展振荡器的同步频率范围。实验表明,θ频段和δ频段的抑制电流协同作用,形成了三时间尺度结构,使皮层振荡器在外部输入下具备更强的相位锁定能力,为语音分割等认知功能提供了潜在的神经机制基础。

Comments 30 pages, 15 figures

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英文摘要

Oscillatory activity in auditory cortex is thought to play a central role in auditory and speech processing by synchronizing neural rhythms to external acoustic features of the speech stream. To support this function, cortical oscillators must flexibly phase-lock to inputs spanning a wide range of timescales, including rhythms substantially slower than their intrinsic frequency. Here we identify a general dynamical mechanism by which intrinsic inhibitory currents operating on multiple timescales enable such flexible phase-locking. Using tools from dynamical systems theory, we show that interactions between slow and superslow inhibitory processes generate prolonged post-input recovery delays through delayed Hopf phenomena, thereby substantially expanding the frequency range over which entrainment can occur. We demonstrate this mechanisms in a biophysically grounded cortical theta oscillator model for speech segmentation. Specifically, we show that both a theta-timescale (4-8 Hz) inhibitory current $I_m$ and a slower delta-timescale (1-4 Hz) inhibitory potassium current $I_{\rm K_{SS}}$ are crucial for entrainment flexibility. Their interaction creates a three-timescale structure that gives rise to pronounced delay phenomena associated with a delayed Hopf bifurcation (DHB). Interestingly, the superslow $I_{\rm K_{SS}}$ and the associated DHB play little role in the unforced oscillatory dynamics, but are recruited to support phase locking under external forcing. Moreover, the intermediate-timescale current $I_m$, rather than being redundant, further expands the phase-locking range by prolonging delayed recovery along the superslow manifold. Together, these results suggest that coordination among intrinsic inhibitory currents operating on multiple timescales may represent a key mechanism supporting flexible phase locking to rhythmic inputs in the brain.

2605.08009 2026-05-11 quant-ph

Error Correction of Beamsplitter-Generated Entangled GKP States

Moritz Fontboté-Schmidt, Jeremy Metzner, Florence Berterottière, Ivan Rojkov, Alexander Ferk, Martin Stadler, Bahadir Dönmez, Ralf Berner, Stephan Welte, Daniel Kienzler, Jonathan P. Home

AI总结 本文研究了利用光束分束器生成的GKP纠缠态的纠错问题,提出了一种基于囚禁离子的两运动模式实现GKP量子比特纠缠态生成的方法。通过将两个无逻辑信息的qunaught态在光束分束器上干涉,成功生成了所有四个贝尔态,平均保真度达到69%,并展示了通过量子纠错延长纠缠态寿命的实验结果。该成果为基于GKP码的量子计算提供了关键的高斯操作,推动了多模玻色编码和信息通道基础测试的研究。

Comments 6 pages, 4 figures

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英文摘要

To be useful, quantum computers will be required to successfully correct errors occurring at the hardware level. Bosonic codes provide a hardware-efficient option for error correction, but fault-tolerance further requires that the available gate interactions be compatible with the code. A promising bosonic code is the Gottesman-Kitaev-Preskill (GKP) code, for which a linear beamsplitter-like coupling between two bosonic modes is fault-tolerant, making this a key primitive for building larger systems. Here, using two motional modes of a trapped ion, we demonstrate the generation of entangled states of GKP qubits by interfering two qunaught states, which have a grid structure but carry no logical information, on a beamsplitter. We generate all four Bell states with an average fidelity of 69%, and subsequently demonstrate an extension of the entangled state lifetime through the use of quantum error correction. These results complete the set of Gaussian operations required for quantum computing with GKP codes and enable explorations of multi-mode bosonic encodings as well as fundamental tests of information channels.

2605.08002 2026-05-11 stat.ME math.ST stat.TH

Cellwise and Casewise Robust Multivariate Regression with Inference

Fabio Centofanti, Mia Hubert, Peter J. Rousseeuw

AI总结 本文研究了在存在案例型和单元型异常值、缺失数据及高维特征情况下的多元线性回归问题,提出了一个鲁棒的多元回归估计方法——单元多元回归(cellMR),该方法结合了单元鲁棒协方差估计和岭正则化,能够同时处理多种数据污染问题。此外,作者还提出了一种基于自助法的推断方法cellBoot,能够在存在异常值的情况下提供渐近有效的置信区间,并通过模拟和基因组实际应用验证了方法的有效性。

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Multivariate linear regression is a fundamental statistical task, but classical estimators such as ordinary least squares are highly sensitive to outliers. These may occur as casewise outliers that affect entire observations, or as outlying cells, that are individual contaminated entries in the predictor and/or response matrix. Moreover, modern datasets frequently contain missing values and are high-dimensional. To address these challenges we propose the cellwise multivariate regression (cellMR) estimator, a robust regression method that simultaneously accommodates casewise and cellwise outliers, missing data, and high dimensionality. The approach builds on a cellwise robust covariance estimator and uses ridge regularization for numerical stability. We further introduce cellBoot, a novel bootstrap-based inference procedure tailored to the cellMR framework. Relying on indirect inference, cellBoot provides asymptotically valid confidence intervals that are robust to casewise and cellwise contamination. We derive influence functions of the regression estimator and prove the asymptotic validity of the cellBoot confidence intervals. Simulations and a real genomics application illustrate the strong finite-sample performance of the proposed methods.

2605.08001 2026-05-11 math.ST stat.ME stat.TH

Scale selection for geometric medians on product manifolds

Kisung You

AI总结 本文研究了在乘积流形上几何中位数的尺度选择问题,指出直接联合优化位置和尺度会导致尺度退化到边界,从而使问题退化为边缘中位数,丢失一个因子的信息。为此,作者提出了三种改进方法,分别从敏感性路径、鲁棒尺度校准和平衡方程等角度出发,确保尺度估计的稳定性、一致性及单位不变性,并通过仿真验证了方法在欧几里得和Bures-Wasserstein空间中的有效性。

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Geometric medians on product manifolds are sensitive to the relative scaling of factor metrics because the median objective couples the factors rather than separating them. We study this scale-selection problem and first prove that naive joint minimization over location and scale is degenerate: the scale is driven to the boundary and the problem collapses to a marginal median, effectively discarding one factor. Thus relative scale is not identifiable from the raw median loss alone. We develop three alternatives to mitigate this issue. The first treats scale as indexing a sensitivity path and establishes uniform consistency, a functional central limit theorem, and a derivative-based sensitivity measure. The second constructs a robust scale-calibrated median using marginal radial median scales, yielding unit invariance, consistency, a two-step central limit theorem, and bounded influence. The third introduces a bounded balance equation for direct scale estimation, with monotonicity, uniqueness, joint asymptotic normality, and bounded influence. Simulations illustrate boundary collapse, sensitivity, unit invariance, and balanced estimation in Euclidean and Bures-Wasserstein settings.

2605.07998 2026-05-11 astro-ph.GA

The Spitzer Spectroscopic Data Fusion -- Merged Spectroscopic Redshift Catalogs in Spitzer Fields

Mattia Vaccari

AI总结 本文介绍了“斯皮策光谱数据融合”项目,整合了涵盖十四个别样星系巡天区域的多份光谱红移目录,通过1角秒匹配半径合并各目录数据,为每个天体提供最佳红移值及相关来源和重叠标识。该数据集旨在为光谱红移训练、光谱能量分布拟合及多波段交叉识别研究提供社区共享的校准资源,并定期更新以包含新发布的光谱巡天数据。

Comments Accepted for publication by RNAAS on 8 May 2026

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I present the Spitzer Spectroscopic Data Fusion, a collection of merged spectroscopic redshift catalogs covering fourteen of the most widely studied extragalactic survey fields. Building on the Spitzer Data Fusion multi-wavelength photometric database, the collection merges several publicly available spectroscopic redshift catalogs within each field using a 1 arcsec matching radius, delivers a single best redshift per source together with provenance and overlap flags, and is available on Zenodo at https://zenodo.org/doi/10.5281/zenodo.6368347 The dataset is regularly updated as new spectroscopic surveys are published. It is intended as a community calibration resource for photometric redshift training, SED fitting, and multi-wavelength cross-identification studies.

2605.07997 2026-05-11 hep-ph

Symmetry-Breaking Effects on Form Factors and Observables in $B \to K_0^*(1430)μ^+μ^-$ Decay

Saba Ayub, Saba Shafaq, Arslan Sikandar, M. Jamil Aslam

AI总结 本文研究了在 $B \to K_0^*(1430)μ^+μ^-$ 衰变过程中对称性破缺效应对形式因子和可观测量的影响。通过引入顶夸克和大能量极限下的对称性关系,并结合顶点重整化和光锥分布振幅方法,系统计算了形式因子的微扰修正。研究发现,这些修正对分支比和轻子极化不对称性等物理量产生约3%的影响,若实验观测到显著偏差,可能指示新物理效应的存在。

Comments 18 pages, 7 figures

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In the heavy-quark and large-energy limits, symmetry relations reduce the number of independent form factors governing heavy-to-light $B$-meson decays. Exploiting these relations, the form factors can be parametrized while systematically incorporating symmetry-breaking corrections from perturbative QCD. Using vertex renormalization together with light-cone distribution amplitudes, we compute the vertex and hard-spectator contributions for the $B \to K_0^*(1430)$ transition. We then analyze the impact of these form factors on physical observables, including the branching ratio and lepton polarization asymmetries $(P_L, P_N)$, in $B \to K_0^*(1430)μ^+μ^-$. Our results indicate that perturbative corrections induce modest shifts of $\sim 3\%$ in both the branching ratio and the normal lepton polarization asymmetry. Consequently, any significant deviation observed experimentally from these predictions would provide a clear signal of potential New Physics effects.

2605.07996 2026-05-11 cs.GT cs.MA econ.GN q-fin.EC

Nash without Numbers: A Social Choice Approach to Mixed Equilibria in Context-Ordinal Games

Ian Gemp, Crystal Qian, Marc Lanctot, Kate Larson

AI总结 本文提出了一种无需精确效用值的纳什均衡新方法,适用于仅能提供行动序位信息的博弈场景。研究通过引入社会选择理论,重新定义了最佳响应概念,从而在偏好序位的基础上建立了“情境序位纳什均衡”的新框架。该方法在弱化效用假设的前提下保证了均衡的存在性,并探讨了其计算复杂性与学习规则,为基于人类偏好数据的博弈分析提供了新工具。

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Nash equilibrium serves as a fundamental mathematical tool in economics and game theory. However, it classically assumes knowledge of player utilities, whereas economics generally regards preferences as more fundamental. To leverage equilibrium analysis in strategic scenarios, one must first elicit numerical utilities consistent with player preferences, a delicate and time-consuming process. In this work, we forgo precise utilities and generalize the Nash equilibrium to a setting where we only assume a player is capable of providing an ordinal ranking of their actions within the context of other players' joint actions. The key technical challenge is to rethink the definition of a best-response. While the classical definition identifies actions maximizing expected payoff, we naturally look towards social choice theory for how to aggregate preferences to identify the most preferred actions. We define this generalized notion of a context-ordinal Nash equilibrium, establish its existence under mild conditions on aggregation methods, introduce notions of regularization, approximation, and regret, explore complexity for simple settings, and develop learning rules for computing such equilibria. In doing so, we provide a generalization of Nash equilibrium and demonstrate its direct applicability to elicited preferences in human experiments.

2605.07995 2026-05-11 astro-ph.GA physics.atom-ph

Space as a spectroscopic laboratory: High-resolution spectroscopy of the [$^{13}$C II] hyperfine structure with SOFIA/upGREAT

S. Kabanovic, V. Ossenkopf-Okada, S. Schlemmer, J. Stutzki, N. Schneider, U. U. Graf, O. Asvany, D. A. Riechers, C. Guevara, R. Higgins, R. Simon, Y. Okada, M. Mertens, L. Schneider, R. Güsten, A. G. G. M. Tielens

AI总结 本文利用SOFIA/upGREAT望远镜的高分辨率观测,首次精确测量了[$^{13}$C II]的超精细结构跃迁频率,确定了其磁偶极超精细常数。通过对比[$^{12}$C II]的谱线,还提高了[$^{13}$C II]的中心频率精度。研究展示了天文观测在原子物理参数测定中的潜力,为缺乏实验室数据的其他原子和分子跃迁提供了新方法。

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The [$^{12}$C II] emission at 158 $μ$m is a key cooling line of the interstellar medium and traces gas kinematics in spectrally resolved observations. Its spectral profile is often modified by optical depth effects. The intrinsic line shape can be reconstructed by comparison with emission from the less abundant $^{13}$C isotope. Due to the additional neutron spin, [$^{13}$C II] emission splits into three hyperfine structure (hfs) transitions. Laboratory measurements have provided the centroid frequency and the strongest component ($F=2-1$); the two weaker components ($F=1-0$ and $F=1-1$) have been inferred only from quantum-mechanical calculations. The magnetic-dipole hfs constants, from which the transition frequencies follow, have not been measured experimentally. The high spectral resolution of observations with the upgraded German Receiver for Astronomy at Terahertz Frequencies (upGREAT) on board SOFIA enabled simultaneous detection of all three hfs transitions. From these astronomical data we determine, for the first time, the magnetic-dipole hfs constants $A_{1/2}^{\rm hf} = 810.71(11)$ MHz and $A_{3/2}^{\rm hf} = 162.18(5)$ MHz of the [$^{13}$C II] $2s^2\,2p\,{}^2P^\circ$ ground term. Combined with the laboratory centroid frequency, this yields the rest frequencies of all three hfs lines. Using [$^{12}$C II] as a reference, we also improve the precision of the [$^{13}$C II] centroid frequency. This work shows that spectrally resolved astronomical observations can constrain fundamental atomic properties, with hfs precision rivaling laboratory measurements. The approach extends to other atomic and molecular transitions where laboratory data are difficult to obtain.

2605.07994 2026-05-11 cs.IT math.IT

Semantic Smoothing for Language Models via Distribution Estimation and Embeddings

Haricharan Balasundaram, Swathi Shree Narashiman, Pranay Mathur, Andrew Thangaraj

AI总结 本文提出了一种基于语义平滑的语言模型平滑方法,通过嵌入表示在语义相似的上下文中共享统计信息。该方法从对数困惑度的分解出发,将平滑问题转化为在Kullback-Leibler损失下的分布估计问题,并利用嵌入空间中上下文的接近性来推导出词分布的KL散度接近性。实验表明,该方法在多种嵌入模型和语言模型上有效降低了测试困惑度,具有较好的泛化能力。

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英文摘要

We propose semantic smoothing, a smoothing method for language models that uses embeddings to share statistical observations across semantically similar contexts. The starting point is a decomposition of log-perplexity that motivates smoothing as a collection of distribution-estimation problems under Kullback-Leibler (KL) loss. We then show that, under a Lipschitz-logit model for embedding-based language generation, proximity of context embeddings implies proximity of the corresponding next-word distributions in KL divergence. Combining these observations, we formulate semantic smoothing as distribution estimation in KL loss with KL-proximity side information. For $n$ samples on a $d$-symbol alphabet with a side-information distribution at KL distance $Δ$, we give an interpolation estimator with worst-case KL risk $O(\min\{Δ,d/n\})$, and prove a matching-order lower bound for uniform side information. We extend the estimator to multiple and empirically estimated synonymous distributions. Experiments on synthetic Markov data and WikiText-103 bigram models using Word2Vec, GloVe, and GPT-2 embeddings show that semantic smoothing consistently reduces test perplexity when applied to add-constant and Kneser-Ney estimates.

2605.07992 2026-05-11 gr-qc

Uncertainty Principles and Maximum Entropic Force

Jonas Mureika, Elias C. Vagenas

AI总结 本文研究了由多种引力不确定性原理引起的量子引力对最大熵力的修正,包括广义不确定性原理(GUP)、扩展不确定性原理(EUP)及其组合形式。研究发现,修正后的熵力依赖于这些不确定性原理中的无量纲参数,从而反映了不同量子引力理论的影响。此外,修正后的熵力还与构成“EUP面积”的普朗克面积数量有关,揭示了量子引力效应对宏观引力作用的潜在影响。

Comments 10 pages, LaTeX, no figures, to appear in Eur.Phys.J. C

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英文摘要

We consider quantum gravity corrections to the maximum entropic force that arise from several gravitational uncertainty principles. These include the Generalized Uncertainty Principle (GUP), the Extended Uncertainty Principle (EUP), the Generalized Extended Uncertainty Principle (GEUP), and the Linear-Quadratic GUP (LQGUP). We find that the modified entropic force depends on the dimensionless parameters of the uncertainty principles and, thus, on the underlying quantum gravity theory. Furthermore, the entropic force, which is quantum gravity corrected in the framework of the extended uncertainty principles, also depends on the number of Planck areas that made the ``EUP area".

2605.07991 2026-05-11 math.AG

On Bands and Limit Theorems in Tropical Geometry

Arne Kuhrs, Alejandro Martínez Méndez, Pedro Souza

AI总结 本文综述了Baker-Jin-Lorscheid提出的带(bands)与带概形(band schemes)的基本理论,这是一个用于热带化、分析化及$\mathbb{F}_1$-几何的代数框架。对于非阿基米德赋值域上的仿射概形$X$,文章证明$X$可以视为其在带概形范畴中所有仿射嵌入所对应带概形的极限,从而在概形理论层面推广了Payne的极限定理。该结果从带概形的角度重新诠释了Payne关于仿射热带化的定理,并在实热带情形中得到了类似结论。

Comments 13 pages

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英文摘要

We review the basic theory of bands and band schemes introduced by Baker-Jin-Lorscheid, which is an algebraic framework for tropicalization, analytification, and $\mathbb{F}_1$-geometry. For an affine scheme $X$ over a non-Archimedean valued field $k$, one can associate to every affine embedding $ι$ of $X$ a naturally defined affine band scheme $Y_ι$ whose rational points over the tropical band $\mathbb{T}$ recover the tropicalization $Trop(X,ι)$. We prove that $X$ is the limit of the $Y_ι$ in the category of band schemes, thereby obtaining a scheme-theoretic enhancement of Payne's limit theorem. By taking $\mathbb{T}$-rational points, this recovers Payne's theorem for affine tropicalizations from the perspective of band scheme theory and the same method provides an analogous result in the real tropical setting.

2605.07989 2026-05-11 eess.SY cs.SY

Allocation of Dynamic Operating Envelopes in Radial Distribution Networks

Wilhiam de Carvalho, Florin Capitanescu, Cyril Rasic, Jean-François Toubeau, François Vallée

AI总结 本文深入分析了动态运行包络(DOE)不同构成方面对配电网容量计算与分配的影响,揭示了潮流模型、约束类型及计算场景对DOE结果的显著影响。研究提出了一种新型DOE算法LACE,具有透明且可扩展的计算特性,适用于更大规模网络或与其他优化引擎协同工作。通过多种测试馈线的数值仿真,包括使用比利时真实数据的低压馈线,为配电系统运营商及相关研究者提供了重要的理论支持与实用工具。

Comments Conference paper

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英文摘要

This paper provides an in-depth analysis on how different aspects of the dynamic operating envelope (DOE) formulation impact the computation and allocation of network capacity. We show that the envelopes are significantly affected by the power flow model (non-linear or linear), binding network constraint (thermal or voltage) and by the calculation case (import or export envelope). We also propose a novel DOE algorithm (LACE) that presents transparent and scalable computation that is useful for larger networks or to act in tandem with other optimization engines. We run numerical simulations with different test feeders, including a realistic low-voltage feeder with real-world data from Belgium. This paper provides crucial insights and tools to distribution system operators (DSOs), stakeholders and academics alike to make sure DOE calculation achieves desirable and efficient outcome.

2605.07983 2026-05-11 quant-ph

Price and Payoff: Non-Determinism in Fault Tolerant Quantum Computation

Aditi Awasthi, Sayam Sethi, Sahil Khan, Gokul Subramanian Ravi, Jonathan Mark Baker

AI总结 本文研究了容错量子计算中魔法态非确定性生成对资源分配的影响,提出了一种结合电路调度与不同随机生成模型的仿真框架,揭示了非确定性对执行时间与资源需求的双重影响:一方面增加总执行时间,另一方面降低峰值资源需求。研究发现,针对基于蒸馏的架构,采用随机感知的资源分配策略可减少多达27%的时空体积,并减少最多30%的工厂数量,为容错量子计算的资源规划提供了更精确的方法。

Comments 11 pages, 12 figures

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A promising approach to achieving scalable fault-tolerant quantum computation is the use of quantum error correction (QEC) codes augmented with magic states i.e. resource states produced via distillation, cultivation, or $R_z$ synthesis and teleported into the circuit as needed. Because magic-state production dominates the space-time volume of fault-tolerant programs, system architects must decide how many production units to allocate. Current approaches rely on deterministic analysis that either provisions for worst-case peak demand (wasting valuable qubit resources on factories that are never simultaneously utilized) or assumes average demand, which increases execution time. In this work, we build a simulation framework that couples circuit scheduling with different stochastic magic state production models, and use it to quantify the impact of non-determinism on circuit execution. We show that non-determinism has a dual effect that deterministic models cannot capture: it inflates total execution time (the price), while deflating peak per-cycle resource demand (the payoff). For distillation-based architectures, this demand smoothing shifts the space-time-optimal provisioning point: fewer factories are needed to minimize space-time volume than deterministic analysis predicts. Across benchmarks, stochastic-aware provisioning reduces space-time volume by up to 27% compared to the deterministic optimum for distillation, while requiring up to 30% fewer factories. We characterize these effects across each preparation mechanism, map the resulting design-space tradeoffs, and demonstrate that static resource estimation systematically mis-characterizes the cost of fault-tolerant execution. Our results establish that stochastic-aware analysis is necessary for right-sizing the factory allocations and should replace deterministic heuristics as the standard methodology for FTQC resource planning.

2605.07981 2026-05-11 physics.optics physics.ao-ph

Learning from Translation: Seasonal Errors and Feature Importance of the ERA5 Turbulence Predictions

Arial Tolentino, Markus Petters, Luat T. Vuong

AI总结 该研究探讨了利用ERA5再分析数据预测近地表光学湍流强度 $C_n^2$ 的机器学习模型,分析了其在不同季节和地理区域的表现。研究发现,尽管天气和地形条件各异,模型在不同年份间表现出一致的性能和季节性变化,夏季预测精度更高。研究还指出,太阳辐射是影响湍流预测的最主要因素,表明辐射能量传递在驱动大气湍流中起核心作用,并强调了结合物理知识的机器学习方法在提升模型泛化能力中的潜力。

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Turbulence is a phenomena that is {\it locally} and statistically characterized by measurements, but it is caused by {\it nonlocal} energy cascades associated with the environment. The presence of turbulence coincides with fluctuations in the refractive index, which impact optical sensing, imaging, and signaling applications. Here, we study the machine learning models that predict near-surface optical turbulence strength $C_n^2$, derived from anemometer-based surface flux measurements through Monin-Obukhov similarity theory, using ERA5 reanalysis data as model inputs. We evaluate the model's ability to perform temporal extrapolation by training on one year of co-located $C_n^2$ observations and ERA5 data, and applying the model to ERA5 data from other years at the same site to reconstruct a multi-year time series. We compare the predictions across Southern California and New York. In spite of varying weather and terrain, the ML models show consistent performance and seasonal behavior across training years. All models show greater correlation, faster convergence, and lower prediction errors in the summer. However, some ERA5 features drive predictions in New York but not California and vice versa, and such feature dependence depends on the season. Seasonal error and feature trends suggest that turbulence is affected by atmospheric composition or other seasonal environmental considerations that are not currently monitored by ERA5. We find, regardless of terrain, the primary feature of importance to turbulence prediction is solar radiation, which underlines the central role of radiative energy transfer in driving atmospheric turbulence. We point toward physics-informed ML translation and feature selection as tools for improving the generalizability of data-driven models.

2605.07976 2026-05-11 astro-ph.GA

Testing the BH$^*$ Model: a UV-to-Optical Spectral Fitting of The Cliff

Rosa M. Mérida, Marcin Sawicki, Gaia Gaspar, Chris J. Willott, Kartheik G. Iyer

AI总结 本文研究了黑洞恒星(BH*)模型,该模型认为大红矮星(LRDs)的“V”形光谱能量分布(SED)由一个吸积黑洞及其周围的中性气体包层产生。通过分析The Cliff(红移$z_{spec}=3.55$)的JWST/NIRSpec全波段光谱,研究发现其宿主星系具有低质量、低金属丰度、星暴特性,并受到一定尘埃消光影响,同时黑洞与宿主质量比超出传统比例关系,可能暗示黑洞与宿主演化不同步或参数估计存在偏差。

Comments 15 pages, 7 figures, 2 tables. Submitted for publication in A&A

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英文摘要

In the black hole star (BH*) model, the characteristic "V"-shaped SED of LRDs is produced by an accreting BH embedded in a dense neutral-gas envelope with a near-unity covering factor. This envelope reprocesses radiation and emits as a ~5,000K blackbody, producing the optical continuum. Meanwhile, the UV is powered by a low-mass, dust-free, metal-poor host. The BH* scenario is promising, but it has yet to undergo detailed testing; conducting a self-consistent UV-to-optical spectral-fitting analysis of LRDs would provide a robust assessment of the model. In this work, we test the BH* scenario by fitting the full JWST/NIRSpec PRISM spectrum of The Cliff ($z_{spec}=3.55$), an LRD that played a pivotal role in the development of this model. A Bagpipes fit that allows stellar, nebular, AGN, and blackbody components naturally yields a BH*-like solution for The Cliff, even with broad priors. Our method allows us to characterize its host, despite remaining unresolved in JWST imaging. From the continuum, we infer the host to be low-mass (log $M_\star/M_\odot$~7.7), star-forming, metal-poor, affected by non-negligible dust attenuation ($A_V$~0.5 mag) acting on both stellar and nebular components. Larger $M_\star$ (up to log $M_\star/M_\odot$~8.1) and attenuations (up to $A_V$~1 mag) are obtained depending on the assumed dust attenuation law. Modest AGN UV leakage is consistently allowed by the code, but remains weak and not robustly constrained, with both AGN+host and host-dominated UV scenarios yielding equivalent fits. The star formation history of the host is relatively smooth, with the galaxy already assembling log $M_\star/M_\odot$~7 about 200 Myr before $z_{spec}=3.55$. The BH-to-$M_\star$ ratio exceeds the values expected from BH-host scaling relations, especially at recent times. This tension may indicate either inaccurate estimates of the BH properties or non-coeval BH-host evolution.

2605.07974 2026-05-11 math.AG math.AC

Tensor product surfaces and graded syzygies

Matthew Weaver

AI总结 本文研究由双齐次多项式基定义的有理映射所对应的张量积曲面在三维射影空间中的隐式方程问题。作者通过扩展前人关于分级系综的研究,提出了一种在理想具有单分级系综的情况下求解隐式方程的方法,为几何建模中广泛存在的此类曲面提供了更高效的计算工具。

Comments 24 pages. Comments welcome

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英文摘要

Let $U\subseteq H^0(\mathcal{O}_{\mathbb{P}^1\times \mathbb{P}^1}(a,b))$ be a four-dimensional vector space and consider the rational map $ϕ_U:\,\mathbb{P}^1\times \mathbb{P}^1 \dashrightarrow \mathbb{P}^3$ defined by its basis of bihomogeneous polynomials. The tensor product surface $X_U\subseteq \mathbb{P}^3$ is the closed image of $ϕ_U$, and a fundamental problem in this setting is to determine its implicit equation. As these surfaces are ubiquitous within the field of geometric modeling and design, knowledge of their implicit equations is particularly advantageous, allowing for more effective and efficient computations. In this article, we expand upon work of Duarte-Schenck and work of the present author to solve this implicitization problem when the bigraded ideal $I_U$ admits a singly graded syzygy.

2605.07968 2026-05-11 cs.FL

Measure Many Quantum Finite Automata on Infinite Words

Abhisek Midya, A Baskar

AI总结 本文提出了一种用于处理无限字符串的量子计算模型——测量多次量子布奇自动机(MMQBA),它是测量多次量子有限自动机(MMQFA)在无限字符串场景下的扩展,采用布奇接受条件。研究明确了MMQBA的语言特性,证明其语言形式可表示为MMQFA在某个阈值下的极限语言,并展示了其在并集运算下封闭但在交集和补集运算下不封闭。此外,文章还分析了MMQBA的可判定性问题,指出空语言问题为半可判定,而普遍性、包含性、等价性和成员性问题均为不可判定。

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We define a quantum computational model over infinite words, called Measure-Many Quantum Büchi Automata (MMQBA), which extends Measure-many Quantum Finite automata (MMQFA) to the infinite word setting with Büchi acceptance condition. In MMQBA, the quantum state evolves through unitary transformations followed by repeated projective measurements. An infinite word is accearaq2ppted with respect to a cutpoint p is in (0, 1] if (i) the run visits accepting states infinitely often, (ii) the limiting cumulative acceptance probability is at least p, and (iii) the limiting cumulative rejection lprobability is strictly less than p. We formalize the semantics of MMQBA, establish a language-theoretic characterization showing that MMQBA languages are precisely of the form lim(L(M, p)) for MMQFA M , and develop a decomposition of the non-halting subspace. We prove that MMQBA is closed under union but not under intersection or complementation. On the algorithmic side, we show that the emptiness problem is semi-decidable, while universality, inclusion, equivalence, and membership remain undecidable.

2605.07967 2026-05-11 math.ST stat.TH

Density Estimation Using the Sinc Kernel

Ingrid Kristine Glad, Nils Lid Hjort, Nikolai G. Ushakov

AI总结 本文研究了一种基于sinc核(或傅里叶积分核)的密度估计方法,该核函数为 $K(x)=(πx)^{-1}\sin x$。通过详细分析该估计器的渐近性质和有限样本性质,研究发现与普遍看法相反,sinc核密度估计器在多个方面优于其他估计器,包括样本量适中时的精度更高、在非光滑密度情况下的渐近性能更优,以及带宽选择更为方便等。

Comments 20 pages, no figures. Preprint, Department of Mathematical Statistics, Norwegian University of Science and Technology, Trondheim, no. 2, 2007; arXiv'd for broader visibility and for direct use in a forthcoming paper

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This paper deals with the kernel density estimator based on the so-called sinc (or Fourier integral) kernel $K(x)=(πx)^{-1}\sin x$. We study in detail both asymptotic and finite sample properties of this estimator. It is shown that, contrary to widespread opinion, the sinc estimator is superior to other estimators in many respects: it is more accurate for quite moderate values of the sample size, has better asymptotics in non-smooth case (the density to be estimated has only first derivative), is more convenient for the bandwidth selection, etc.

2605.07966 2026-05-11 physics.flu-dyn physics.med-ph

Bubble jetting in acoustic microdroplet vaporization

Anunay Prasanna, Samuele Fiorini, Gazendra Shakya, Outi Supponen

AI总结 本研究探讨了声学微滴汽化过程中由气泡塌缩引发的高速液态微射流现象。通过微尺度高速成像实验,揭示了在声波驱动下微滴内气泡对的形成与喷射机制,并分析了多气泡核化与声波持续作用导致的复杂压力场对射流行为的影响。研究发现,气泡生长过程中的蒸发不稳定性会抑制射流生成,同时这些微射流具有穿透微滴界面进入周围流体的能力,为利用其进行靶向药物输送和癌症治疗提供了潜在应用前景。

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英文摘要

Acoustic droplet vaporization denotes the phase-change of micron- and sub-micron-sized droplets upon the application of high-amplitude ultrasound. The asymmetric collapse of the incepted vapor bubbles within the droplets can give rise to high-speed liquid microjets. Here, we describe acoustically-driven and bubble-pair jetting arising within the vaporizing droplet, observed experimentally with ultra-high-speed imaging at the microscale. The existence of complex pressure fields due to the continued acoustic wave-droplet interaction and the nucleation of multiple bubbles within the droplet leads to rich dynamics, with the jets presenting behavioral self-similarity to millimetric bubbles under comparable conditions. Evaporative instabilities that develop during bubble growth impede jet formation during bubble collapse. Furthermore, the ability of the jets to pierce the droplet interface and penetrate into the surrounding fluid is discussed. These powerful microjets could be harnessed to induce cell permeabilization for targeted drug delivery and treatment of cancerous tissue.

2605.07965 2026-05-11 astro-ph.GA astro-ph.HE

A Changing-Look Seyfert Discovered by eROSITA Reveals a Two-Component Broad-Line Region

Alex Markowitz, Mirko Krumpe, David Homan, Bożena Czerny, Mariusz Gromazdki, Hartmut Winkler, Joern Wilms, Steven Hämmerich, Georg Lamer, Tathagata Saha, David A. H. Buckley, Malte Schramm, Daniel E. Reichart, Mara Salvato, Pietro Baldini

AI总结 本文报道了通过eROSITA卫星发现的一个变脸 Seyfert 类星体 HE 1237-2252,在18个月内软X射线流量骤降17倍,随后亮度恢复。研究通过多波段观测发现,该天体的宽Hβ发射线轮廓在亮度变化期间发生显著演化,并分解出两个不同尺度的宽线区成分,揭示了吸积盘结构和X射线冕的变化可能驱动了这一现象。研究为理解活动星系核中吸积过程的动态变化提供了新线索。

Comments 29 pages; 10 figures. Accepted for publication in Astronomy & Astrophysics

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英文摘要

Extreme sudden changes in the flow of accreting gas onto SMBHs manifest themselves via large-amplitude continuum variability and changes to broad Balmer emission profiles, driving changing-look AGN. X-ray flux monitoring with SRG/eROSITA revealed that in the Seyfert AGN HE 1237-2252 the soft X-ray flux dipped abruptly, by a factor of 17 within 18 months. We initiated a follow-up campaign that caught the luminosity recovery after the dip, and enabled us to study how the various accretion components responded during this flux recovery. Our campaign included multiband photometry, X-ray spectroscopy, and optical spectroscopy. We tracked as the accretion rate relative to Eddington increased by a factor of 7 in 3 years. Based on broad Hbeta variability, HE 1237-2252 was subtype 1.0-1.2 in 2002, transitioned to subtype 1.8 by the time of the luminosity dip, and then transitioned back to subtype 1.0 within 3 months as luminosity recovered. Both transitions saw broad Hbeta integrated line flux change by factors of 4-6. The broad Balmer profile is decomposed into a broad Gaussian consistent with virialized gas at 27+/-3 lt-dy, plus a double-peaked profile, consistent with a diskline structure at more than roughly 5 lt-dy. The diskline component's relative contribution to the total profile increases as continuum flux rises. The lack of obscuration in the X-ray spectra, as well as the IR continuum dip, point to an intrinsic pause in the accretion rate as opposed to variable line-of-sight obscuration. Candidates for the underlying mechanisms include propagating cold and warm fronts in the accretion disk. The increased prominence of the diskline BLR component's emission could be due to evolution in the physical extent of the X-ray corona, and in the fraction of >13.6 eV photons intercepted by the diskline, as the accretion rate increases.

2605.07960 2026-05-11 cs.HC

Exploring a Virtual Pet to Provide Context Notifications in a Tourism Recommender System: a Pilot Study

Patrícia Alves, Joana Neto, Ana Barreiro, Jorge Lima, Fausto Alves, Henish Balu, Luís Conceição, Goreti Marreiros

AI总结 本文探讨了一种利用虚拟宠物作为社会中介,在旅游推荐系统中提供情境感知通知的新方法,旨在解决实时通知易造成用户干扰和疲劳的问题。研究提出了一种基于多智能体微服务的推荐框架,结合实时环境数据和用户个性化特征生成推荐,并通过一项针对11名参与者的组内实验,评估了虚拟宠物中介通知方式的可行性与用户接受度。实验结果表明,虚拟宠物能够有效降低系统通知的侵入感,提升用户对安全信息的接受度和通知的实用性。

Comments 30 pages, 7 figures, 7 tables

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While context-aware personalization has been widely explored in modern tourism Recommender Systems (RS), the delivery of real-time notifications remains a significant design challenge due to issues of intrusiveness and user fatigue. This paper presents a proof-of-concept for a tourism recommendation framework that utilizes a virtual pet as a social mediator for delivering context-aware alerts. The system integrates real-time environmental data - including air quality, noise levels, and weather forecasts - and proximity-based notifications with a Multi-Agent Microservice that generates personalized recommendations based on the user's personality traits and preferences. A within-subjects pilot study (n=11) was conducted to evaluate the feasibility and user acceptance of this pet-mediated approach. Participants interacted with two versions of the system - a baseline without contextual alerts and a version featuring pet-mediated notifications - over a four-week period (two weeks per version) in real-world scenarios. Quantitative and qualitative data were collected to assess engagement, perceived naturalness, notification utility, and acceptance. Preliminary results suggest that the virtual pet effectively can "soften" the perceived intrusiveness of system alerts, making safety-critical information feel more welcome and natural. Furthermore, the character-mediated justifications significantly improved the clarity of the notifications, effectively supporting users in their real-time travel decisions. These findings provide a foundation for using virtual pet companions to enhance the transparency and acceptance of context-aware communication in tourism RS.

2605.07958 2026-05-11 physics.acc-ph cond-mat.supr-con

Multilayer model for coatings with arbitrary layers for superconducting radio-frequency applications

Aaron Gobeyn, Wolfgang Ackermann, Herbert De Gersem

AI总结 本文扩展了Kubo等人提出的多层模型,使其适用于任意类型的层序结构,包括超导层、正常导体层和绝缘层,并考虑了所有损耗因素,如欧姆损耗和介电效应。研究分析了$(\text{SI})^n\text{S}$结构的最大适用场强,发现最优配置为$n=1$,但超导层厚度可低于穿透深度且性能损失较小。此外,通过引入虚拟层模拟超导双层间的过渡区域,并发现过渡层增厚会降低最大场强并增大电磁场的有效穿透深度。研究还基于Leontovich边界条件计算了多层结构的表面阻抗,并利用坡印廷定理分析了各层的损耗贡献。

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英文摘要

We extend the multilayer model of \etal{Kubo} for superconductor-insulator-superconductor (SIS) structures in two ways: first, by generalizing it to arbitrary sequences of layers of arbitrary type, i.e. superconducting, normal conducting, and insulating; and second, by accounting for all contributions, including ohmic losses and dielectric effects. We examine the maximum applicable field for $(\text{SI})^n\text{S}$ structures. We find that the optimum configuration corresponds to the $n=1$ case. However, the thickness of the superconducting coating layers can be reduced to below their penetration depth with minor performance penalty. We discuss the ability to model transitions in SS bilayers by introducing a set of virtual layers that represent the transition region through interpolated parameters. We find degradation of the maximum applicable field with thicker transition layers, and a larger effective penetration depth of the electromagnetic fields. Furthermore, the surface impedance of the multilayer structure is calculated using the Leontovich boundary condition, yielding a formulation suitable for integration into finite element simulations. Additionally, the Poynting theorem is used to determine the loss contributions of individual layers.

2605.07957 2026-05-11 cs.SE

Similar Pattern Annotation via Retrieval Knowledge for LLM-Based Test Code Fault Localization

Golnaz Gharachorlu, Mahsa Panahandeh, Lionel C. Briand, Ruifeng Gao, Ruiyuan Wan

AI总结 本文研究了测试代码故障定位(TCFL)问题,即在持续集成环境中定位有缺陷的测试脚本中的错误代码。为了解决传统方法在黑盒条件下定位困难、依赖有限诊断信息的问题,作者提出了SPARK框架,通过检索持续集成环境中积累的调试知识,辅助基于大语言模型的TCFL方法进行故障定位。SPARK通过检索相似的故障标注测试用例,对新出现的失败测试进行有针对性的注释,从而提升定位效果,实验表明其在多个工业数据集上优于现有方法,尤其在处理包含多个故障的复杂测试用例时表现突出。

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英文摘要

Software failures remain a major challenge in modern software development, and identifying the code elements responsible for failures is a time-consuming debugging task. While extensive research has focused on fault localization in the system under test (SUT), failures can also originate from faulty system test scripts. This problem, known as Test Code Fault Localization (TCFL), has received significantly less attention despite its importance in continuous integration (CI) environments where large test suites are executed frequently. TCFL is particularly challenging because it typically operates under black-box conditions, relies on limited diagnostic signals such as error messages and partial logs, and involves large system-level test scripts that expand the fault localization search space. In this paper, we propose SPARK, a framework that integrates accumulated debugging knowledge from continuous integration (CI) environments into Large Language Model (LLM)-based TCFL. Given a newly observed failing test case, SPARK retrieves similar fault-labeled test cases from a debugging knowledge corpus and selectively annotates suspicious lines of the failing test based on their similarity to previously observed fault patterns. These annotations guide the LLM's reasoning while maintaining scalability and avoiding the prompt-length explosion common to naive retrieval-augmented approaches. We evaluate SPARK on three industrial datasets containing real-world faulty Python test cases from different software products. The results show that SPARK consistently improves fault localization effectiveness compared to the existing LLM-based TCFL baseline while maintaining comparable inference cost and token usage. In particular, the approach advances the state of the art by identifying more correct faulty locations in complex test cases containing multiple faults.