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2507.09171 2026-05-01 hep-th cond-mat.str-el

Connecting boundary entropy and effective central charge at holographic interfaces

Evangelos Afxonidis, Ignacio Carreño Bolla, Carlos Hoyos, Andreas Karch

Comments 30 pages, 11 figures, v2: section 6.2 removed, finite contribution at infinity corrected

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英文摘要

The entanglement entropy of intervals in $1+1$ interface CFTs is modified in two ways compared to a CFT without interface: there is a finite boundary entropy contribution, and, for an interval with an endpoint at the interface, the coefficient of the logarithmically divergent contribution -- which is usually proportional to the central charge of the CFT -- is modified to an effective central charge. We show that the latter modification can be understood as a limit of the former using holographic duals of interface CFTs. Furthermore, we show that a finite contribution also appears in intervals that do not cross the interface and it is needed to ensure strong subbaditivity of the entanglement entropy.

2507.08813 2026-05-01 physics.pop-ph quant-ph

Quantum Listenings -- Amateur Sonification of Vacuum and other Noises

Carsten Henkel

Comments version after review, 10 pages, to appear in Eur. Phys. J. Web Conf. (2026) proceedings of conference "Complexity and Disorder" (Paris, Jan 2025)

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Journal ref
Eur. Phys. J. Web of Conf. 366 (2025) 01003
英文摘要

The sensory perceptions of vision and sound may be considered as complementary doorways towards interpreting and understanding physical phenomena. We provide a few selected samples where scientific data of systems usually not directly accessible to humans may be listened to. The examples are chosen close to the regime where quantum mechanics is applicable. Visual and auditory renderings are compared with some connections to music, illustrating in particular a kind of fractal complexity along the time axis.

2507.04253 2026-05-01 quant-ph

Optimizing Quantum Chemistry Simulations with a Hybrid Quantization Scheme

Calvin Ku, Yu-Cheng Chen, Alice Hu, Min-Hsiu Hsieh

Comments 21 pages, 14 figures, reordered and rewritten applications, added numerical estimations

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Journal ref
Commun Phys 9, 148 (2026)
英文摘要

Complex quantum simulation workflows are often hindered by incompatible wavefunction representations adopted across different algorithmic frameworks. In particular, the mismatch between the first- and second-quantization formalisms prevents algorithms specialized for their respective quantizations from being integrated within a single circuit, thereby forcing practitioners to rely on suboptimal methods simply to maintain a consistent representation. To address this challenge, we propose a hybrid quantization scheme that employs a conversion circuit to switch between the two, requiring $\mathcal{O}(N\log N\log M)$ gates for a system of N electrons and M orbitals. This capability is critical for constructing complex quantum simulation workflows, allowing us to use the most efficient quantization for each individual step. We discuss its applications to bring polynomial improvements in the characterization of ground-state, ab-initio molecular dynamics, and characterization of spectroscopic properties. Quantitative estimations of such applications found up to three orders of magnitude fewer ground-state preparations when measuring the 2-reduced density matrix of molecular systems.

2507.03247 2026-05-01 astro-ph.EP

Optical and Near-Infrared Spectroscopy of the Outbursting Comet 12P/Pons-Brooks

Ruining Zhao, Bin Yang, Michael S. P. Kelley, Silvia Protopapa, Aigen Li, Yang Huang, Jifeng Liu

Comments 18 pages, 4 figures, 1 table, accepted for publication in ApJ

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英文摘要

We present optical and near-infrared (NIR) observations of the outbursting, Halley-type comet 12P/Pons-Brooks. Three NIR spectra were obtained during two outbursts in October and November 2023, with the 3-meter Infrared Telescope Facility and the Palomar 200-inch Telescope, respectively. The NIR spectra exhibited absorption features at 1.5 and 2.0 $μ$m, consistent with the diagnostic absorption bands of water ice, superimposed on a red dust-scattering continuum. We find that the absorption bands and the red continuum can be well explained by micrometer-sized crystalline ice at 140--170 K, along with sub-micrometer-sized refractory grains (e.g., amorphous carbon). In addition, an optical spectrum was obtained with the Lijiang 2.4-meter Telescope during the November 2023 outburst, which exhibited the emission bands of gaseous CN, C$_3$, C$_2$ and NH$_2$. The C$_3$/CN and C$_2$/CN ratios suggest that 12P/Pons-Brooks was ''typical'' in C$_3$ abundance but somewhat depleted in C$_2$. The specific kinetic energy of the 2023 November outburst is estimated to be $\sim8\times10^3$ J kg$^{-1}$, suggesting a likely triggering mechanism similar to 332P/Ikeya--Murakami and 17P/Holmes, i.e., the crystallization of amorphous water ice. A refractory-to-ice ratio of $\sim$1.7--3.2 is derived from the total mass loss of dust and gas, aligning with the lower-end estimates for 67P/Churyumov-Gerasimenko and 1P/Halley. This suggests either a less evolved nucleus or an outburst region enriched in icy materials relative to the bulk nucleus.

2506.21299 2026-05-01 quant-ph cond-mat.quant-gas

Meson spectroscopy of exotic symmetries of Ising criticality in Rydberg atom arrays

Joseph Vovrosh, Julius de Hond, Sergi Julià-Farré, Johannes Knolle, Alexandre Dauphin

Comments 7+3 pages, 3+2 figures

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英文摘要

The Ising model serves as a canonical platform for exploring emergent symmetry in quantum critical systems. The critical point of the 1D Ising chain is described by a conformal Ising field theory, which remains integrable in the presence of a magnetic perturbation, leading to massive particles associated with the exceptional Lie algebra $E_8$. Weakly coupling two Ising chains into a ladder breaks this integrability and is predicted to confine the elementary excitations of each chain into a richer spectrum of bound states organized by a $\mathcal{D}^{(1)}_8$ symmetry. Experimental signatures of $E_8$ excitations have arguably been observed in scattering studies of the spin chain material CoNb$_2$O$_6$, but direct evidence of confinement driven by inter-chain coupling has remained elusive. Here, we probe these emergent symmetries in a Rydberg atom quantum processing unit, leveraging its tunable geometry to realize both chain and ladder configurations. We identify mass spectra consistent with $E_8$ at the single-chain critical point and, in the weakly coupled ladder, report the first signatures of confinement of Ising excitations into the bound-state spectrum predicted by $\mathcal{D}^{(1)}_8$ symmetry. Our results demonstrate the power of Rydberg platforms for investigating symmetry emergence in quantum many-body systems and provide a direct window into the interplay of confinement, geometry, and criticality.

2506.21149 2026-05-01 cs.LO

Pebble Games and Algebraic Proof Systems

Lisa-Marie Jaser, Jacobo Toran

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英文摘要

Analyzing refutations of the well known 0pebbling formulas Peb$(G)$ we prove some new strong connections between pebble games and algebraic proof system, showing that there is a parallelism between the reversible, black and black-white pebbling games on one side, and the three algebraic proof systems Nullstellensatz, Monomial Calculus and Polynomial Calculus on the other side. In particular we prove that for any DAG $G$ with a single sink, if there is a Monomial Calculus refutation for Peb$(G)$ having simultaneously degree $s$ and size $t$ then there is a black pebbling strategy on $G$ with space $s$ and time $t+s$. Also if there is a black pebbling strategy for $G$ with space $s$ and time $t$ it is possible to extract from it a MC refutation for Peb$(G)$ having simultaneously degree $s$ and size $ts$. These results are analogous to those proven in {deRezende et al.21} for the case of reversible pebbling and Nullstellensatz. Using them we prove degree separations between NS, MC and PC, as well as strong degree-size tradeoffs for MC. We also notice that for any directed acyclic graph $G$ the space needed in a pebbling strategy on $G$, for the three versions of the game, reversible, black and black-white, exactly matches the variable space complexity of a refutation of the corresponding pebbling formula Peb$(G)$ in each of the algebraic proof systems NS, MC and PC. Using known pebbling bounds on graphs, this connection implies separations between the corresponding variable space measures.

2506.19091 2026-05-01 quant-ph

Pulsed laser attack at 1061 nm potentially compromises quantum key distribution

Anastasiya Ponosova, Irina Zhluktova, Daria Ruzhitskaya, Daniil Trefilov, Anqi Huang, Alexey Wolf, Vladimir Kamynin, Vladimir Tsvetkov, Vadim Makarov

Comments 7 pages, 4 figures, 1 table

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Journal ref
Appl. Phys. Lett. 127, 194002 (2025)
英文摘要

Quantum key distribution systems offer cryptographic security, provided that all their components are thoroughly characterised. However, certain components might be vulnerable to a laser-damage attack, particularly when attacked at previously untested laser parameters. Here, we show that exposing 1550-nm fiber-optic isolators to 1061-nm sub-nanosecond pulsed illumination with 1.16 W average power permanently degrades their isolation at 1550 nm, while their forward transparency is less affected. One experimental sample was exposed to 17-mW average power picosecond attacking pulses that temporarily reduced its isolation below the specified guaranteed minimum value. This indicates a potential security threat in these attacking laser regimes that need to be addressed by improving security analysis for various light-injection attacks.

2506.17463 2026-05-01 math.ST stat.ME stat.TH

Testing Separability of High-Dimensional Covariance Matrices

Bongjung Sung, Peter D. Hoff

Comments 85 pages, 32 pages in the main text, new theoretical results, including the convergence of the Kronecker MLE under the partial-isotropy core, with more sophisticated results on the asymptotic distributions and consistency, are added

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英文摘要

Due to their parsimony, separable covariance models have been popular in modeling matrix-variate data. However, the inference from such a model may be misleading if the population covariance matrix $Σ$ is actually non-separable, motivating the use of statistical tests of separability. The existing separability tests suffer mainly from two issues: 1) test statistics that are not well-defined in high-dimensional settings, 2) low power for small sample sizes and null distributions that depend on unknown parameters, preventing exact error rate control. To address these issues, we propose novel invariant tests using the core covariance matrix, a complementary notion to a separable covariance matrix. We show that testing separability of $Σ$ is equivalent to testing sphericity of its core component. With this insight, we construct test statistics that are well-defined in high-dimensional settings and have distributions that are invariant under the null hypothesis of separability, allowing for exact simulation of null distributions. We establish the asymptotic properties of some test statistics by proving the asymptotic spectral equivalence between the sample covariance matrix and its core in a $p/n\rightarrowγ\in(0,\infty)$ regime. The large power of our proposed tests relative to existing procedures is demonstrated numerically.

2506.12768 2026-05-01 math.OC

A bang-bang solution with infinitely many switching points for a parabolic boundary control problem with terminal observation

Constantin Christof

Comments Minor revision, to appear in Mathematical Control and Related Fields

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英文摘要

We study a parabolic boundary control problem with one spatial dimension, control constraints of box type, and an objective function that measures the $L^2$-distance to a desired terminal state. It is shown that, for a certain choice of the desired state, the considered problem possesses an optimal control that is chattering, i.e., of bang-bang type with infinitely many switching points and a positive objective function value. Whether such a solution is possible has been an open question in the literature. We are able to answer this question in the affirmative by means of Fourier analysis and an auxiliary result on the existence of power series with a certain structure and sign-changing behavior. The latter may also be of independent interest.

2506.07208 2026-05-01 nlin.SI math-ph math.MP

Revisiting Bäcklund-Darboux transformations for KP and BKP integrable hierarchies

A. Zabrodin

Comments 58 pages, 1 figure

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英文摘要

We consider Bäcklund-Darboux transformations for integrable hierarchies of nonlinear equations such as KP, BKP and their close relatives referred to as modified KP and Schwarzian KP. We work in the framework of the bilinear formalism based on the bilinear equations for the tau-function. This approach allows one to extend the theory to fully difference (or discrete) versions of the integrable equations and their hierarchies in a natural way. We also show how to construct the Bäcklund-Darboux transformations in the operator approach developed by the Kyoto school, in which the tau-functions are represented as vacuum expectation values of certain operators made of free fermionic fields (charged for KP and neutral for BKP).

2506.06753 2026-05-01 cs.DL

Influential scientists shape knowledge flows between science and IGO policy

Kimitaka Asatani, Yurie Iwata, Yuta Tomokiyo, Basil Mahfouz, Masaru Yarime, Ichiro Sakata

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Journal ref
Proc. Natl. Acad. Sci. U.S.A. 123(17), e2514861123 (2026)
英文摘要

Intergovernmental organizations (IGOs) increasingly rely on scientific evidence, yet the pathways through which scientific research enters policy remain opaque. By linking 230,737 scientific papers cited in IGO policy documents (2015-2023) to their authors and collaboration networks, we identify a small group of policy-influential scientists (PI-Sci) who dominate this knowledge flow. These scientists form tightly interconnected, internationally spanning co-authorship networks and achieve policy citations shortly after publication, a distinctive feature of cumulative advantage at the science-policy interface. The concentration of influence varies by field: tightly clustered in established domains like climate modeling, and more dispersed in emerging areas like AI governance. Many PI-Sci serve on high-level advisory bodies (e.g., IPCC), and major IGOs frequently co-cite the same PI-Sci papers, indicating synchronized knowledge diffusion through shared expert networks. These findings reveal how network structure and elite brokerage shape the translation of research into global policy, highlighting opportunities to broaden the scope of knowledge that informs policy.

2506.05374 2026-05-01 cs.CR cs.IT math.IT

A New Representation of Binary Sequences by means of Boolean Functions

S. D. Cardell, A. Fúster-Sabater, V. Requena, M. Beltrá

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英文摘要

Boolean functions and binary sequences are main tools used in cryptography. In this work, we introduce a new bijection between the set of Boolean functions and the set of binary sequences with period a power of two. We establish a connection between them which allows us to study some properties of Boolean functions through binary sequences and vice versa. Then, we define a new representation of sequences, based on Boolean functions and derived from the algebraic normal form, named reverse-ANF. Next, we study the relation between such a representation and other representations of Boolean functions as well as between such a representation and the binary sequences. Finally, we analyse the generalized self-shrinking sequences in terms of Boolean functions and some of their properties using the different representations.

2506.01906 2026-05-01 cond-mat.supr-con physics.app-ph physics.ins-det quant-ph

Flux-trapping characterization for superconducting electronics using a cryogenic widefield N-$V$ diamond microscope

Rohan T. Kapur, Pauli Kehayias, Sergey K. Tolpygo, Adam A. Libson, George Haldeman, Collin N. Muniz, Alex Wynn, Nathaniel J. O'Connor, Neel A. Parmar, Ryan Johnson, Andrew C. Maccabe, John Cummings, Justin L. Mallek, Danielle A. Braje, Jennifer M. Schloss

Comments 9 pages main text (5 figures), 7 pages supplementary information (5 figures)

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Journal ref
Phys. Rev. Applied 25, 044073 (2026)
英文摘要

Magnetic flux trapping is a significant hurdle limiting the reliability and scalability of superconducting electronics, yet tools for imaging flux vortices remain slow or insensitive. We present a cryogenic widefield NV-diamond magnetic microscope capable of rapid, micrometer-scale imaging of flux trapping in superconducting devices. Using this technique, we measure vortex expulsion fields in Nb thin films and patterned strips, revealing a crossover in expulsion behavior between $10$ and $20~μ$m strip widths. The observed scaling agrees with theoretical models and suggests the influence of film defects on vortex expulsion dynamics. This instrument enables high-throughput magnetic characterization of superconducting materials and circuits, providing new insight for flux mitigation strategies in scalable superconducting electronics.

2505.20183 2026-05-01 cs.SE cs.CR

Exposing Go's Hidden Bugs: A Novel Concolic Framework

Karolina Gorna, Nicolas Iooss, Yannick Seurin, Rida Khatoun

Comments Accepted in the 23rd IEEE/ACIS International Conference on Software Engineering, Management and Applications (SERA 2025)

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Journal ref
2025 IEEE/ACIS 23rd International Conference on Software Engineering Research, Management and Applications (SERA)
英文摘要

The widespread adoption of the Go programming language in infrastructure backends and blockchain projects has heightened the need for improved security measures. Established techniques such as unit testing, static analysis, and program fuzzing provide foundational protection mechanisms. Although symbolic execution tools have made significant contributions, opportunities remain to address the complexities of Go's runtime and concurrency model. In this work, we present Zorya, a novel methodology leveraging concrete and symbolic (concolic) execution to evaluate Go programs comprehensively. By systematically exploring execution paths to uncover vulnerabilities beyond conventional testing, symbolic execution offers distinct advantages, and coupling it with concrete execution mitigates the path explosion problem. Our solution employs Ghidra's P-Code as an intermediate representation (IR). This implementation detects runtime panics in the TinyGo compiler and supports both generic and custom invariants. Furthermore, P-Code's generic IR nature enables analysis of programs written in other languages such as C. Future enhancements may include intelligent classification of concolic execution logs to identify vulnerability patterns.

2505.14982 2026-05-01 eess.SY cs.SY

Generating Sustainability-Targeting Attacks For Cyber-Physical Systems

Faysal Ahamed, Tanushree Roy

Comments 10 pages, 3 figures

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英文摘要

Sustainability-targeting attacks (STA) are a growing threat to cyber-physical system (CPS)-based infrastructure, as sustainability goals become an integral part of CPS objectives. STA can be especially disruptive if it impacts the long-term sustainability cost of CPS, while its performance goals remain within acceptable parameters. Thus, in this work, we propose a general mathematical framework for modeling such stealthy STA and derive the feasibility conditions for generating a minimum-effort maximum-impact STA on a linear CPS using a max-min formulation. A gradient ascent descent algorithm is used to construct this attack policy with an added constraint on stealthiness. An illustrative example has been simulated to demonstrate the impact of the generated attack on the sustainability cost of the CPS.

2505.12487 2026-05-01 stat.CO stat.ME stat.ML

Stereographic Multiple-Try Metropolis

Zhihao Wang, Jun Yang

Comments 53 pages, 12 figures

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英文摘要

Multiple-proposal MCMC algorithms have recently gained attention for their potential to improve performance, especially through parallel implementation on modern hardware. We introduce Stereographic Multiple-Try Metropolis (SMTM), a novel family of gradient-free algorithms designed for sampling high-dimensional distributions. By integrating multiple-try Metropolis (MTM) with the stereographic MCMC framework, SMTM overcomes the traditional limitations of MTM, particularly its pathological convergence behavior often observed in high dimensions. For both light-tailed and heavy-tailed targets, SMTM not only outperforms classical MTM and the existing stereographic random-walk Metropolis but also demonstrates strong robustness to tuning. These advantages are supported by high-dimensional scaling analysis and validated through extensive simulation studies.

2505.12087 2026-05-01 math.AT math.CT

Non-Hausdorff manifolds over locally ordered spaces via sheaf theory

Yorgo Chamoun, Emmanuel Haucourt

Comments 39 pages

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英文摘要

Locally ordered spaces can be used as topological models of concurrent programs: the local order models the irreversibility of time during execution. Under certain conditions, one can even work with locally ordered manifolds. In this paper, we build the universal euclidean local order over every locally ordered space; in categorical terms, the subcategory of euclidean local orders is coreflective in the category of locally ordered spaces. Our construction is based on a well-known correspondance between sheaves and étale bundles. This is a far reaching generalization of a result about realizations of graph products. We particularize the construction to locally ordered realization of precubical sets, and show that it admits a purely combinatorial description. With the same proof techniques, we show that, unlike for the topological realization, there is a unique (up to symmetry) precubical set whose locally ordered realization is isomorphic to $\mathbb{R}^n$.

2505.09839 2026-05-01 math.PR

Density Frankl-Rödl on the Sphere

Venkatesan Guruswami, Shilun Li

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英文摘要

We establish a density variant of the Frankl-Rödl theorem on the sphere $\mathbb{S}^{n-1}$, which concerns avoiding pairs of vectors with a specific distance, or equivalently, a prescribed inner product. In particular, we establish lower bounds on the probability that a randomly chosen pair of such vectors lies entirely within a measurable subset $A \subseteq \mathbb{S}^{n-1}$ of sufficiently large measure. Additionally, we prove a density version of spherical avoidance problems, which generalize from pairwise avoidance to broader configurations with prescribed pairwise inner products. Our framework encompasses a class of configurations we call inductive configurations, which include simplices with any prescribed inner product $-1 < r < 1$. As a consequence of our density statement, we show that all inductive configurations are sphere Ramsey.

2505.05388 2026-05-01 eess.SP

On Multiangle Discrete Fractional Periodic Transforms

Christian Oswald, Franz Pernkopf

Comments Python code available at https://github.com/OsChri, 5 pages, 1 figure

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Journal ref
2026 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2026)
英文摘要

The efficient multiangle centered discrete fractional Fourier transform (MA-CDFRFT) [1] has proven to be a useful tool for time-frequency analysis; in this paper, we generalize the MA-CDFRFT to general M -periodic transforms, which, among others, include the standard discrete Fourier, discrete sine, discrete cosine, Hadamard and discrete Hartley transform. Furthermore, we exploit the symmetries inherent to the MA-CDFRFT and our novel multiangle standard discrete fractional Fourier transform (MA-DFRFT) to halve the number of FFTs needed to compute these transforms, which paves the way for applications in resource-constrained environments.

2505.00424 2026-05-01 math.LO

Monotone infinitary operations on ordinals (extended version)

Paolo Lipparini

Comments v2 is an extended version of "A Monotone Infinitary Operation on Ordinals" appeared in print on MLQ, shortened in the published version owing to space constraints. In Appendix I we recast some results in terms of combinatorial game theory. Numberings of theorems, equations etc. are consistent with numberings in the published version (not so for numbered items in the reference list)

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Mathematical Logic Quarterly 72 (2026) 1-13
英文摘要

We define and study an $ ω$-ary operation on the class of the ordinals, which is strictly monotone in many significant cases (by an elementary argument, there is no fully strictly monotone infinitary operation on ordinals). We compare the operation with the finitary Hessenberg natural sum, which is the smallest finitary strictly monotone operation on each argument. We also compare it with other infinitary generalizations of Hessenberg sum. We provide order-theoretical characterizations of our operation, both as the rank of sequences in an appropriate well-founded order, and as a mixed (or shuffled) sum of the ordinals in the sequence. The latter means that such an infinitary sum is the largest realization as an order-preserving disjoint union of copies of the summands, under some boundedness restriction. The former characterization can be recast in terms of combinatorial games, leading to the problem whether the operation can be extended to the class of Conway surreal numbers.

2504.13809 2026-05-01 math.NA cs.NA

A Fast Direct Solver for Boundary Integral Equations Using Quadrature By Expansion

Alexandru Fikl, Andreas Klöckner

Comments 31 pages, 12 figures; fixed TeX formatting (v2); highlighted contributions in introduction (v3); typos (v4); clarifications and grid convergence (v5)

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英文摘要

We construct and analyze a hierarchical direct solver for linear systems arising from the discretization of boundary integral equations using the Quadrature by Expansion (QBX) method. Our scheme builds on the existing theory of Hierarchical Semi-Separable (HSS) matrix operators that contain low-rank off-diagonal submatrices. We use proxy-based approximations of the far-field interactions and the Interpolative Decomposition (ID) to construct compressed HSS operators that are used as fast direct solvers for the original system. We describe a number of modifications to the standard HSS framework that enable compatibility with the QBX family of discretization methods. We establish an error model for the direct solver that is based on a multipole expansion of the QBX-mediated proxy interactions and standard estimates for the ID. Based on these theoretical results, we develop an automatic approach for setting scheme parameters based on user-provided error tolerances. The resulting solver seamlessly generalizes across two- and tree-dimensional problems and achieves state-of-the-art asymptotic scaling. We conclude with numerical experiments that support the theoretical expectations for the error and computational cost of the direct solver.

2504.08678 2026-05-01 cs.SE cs.HC

The Ultimate Configuration Management Tool? Lessons from a Mixed Methods Study of Ansible's Challenges

Carolina Carreira, Nuno Saavedra, Alexandra Mendes, João F. Ferreira

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英文摘要

Infrastructure as Code (IaC) tools have transformed the way IT infrastructure is automated and managed, but their growing adoption has also exposed numerous challenges for practitioners. In this paper, we investigate these challenges through the lens of Ansible, a popular IaC tool. Using a mixed methods approach, we investigate challenges faced by practitioners. We analyze 59,157 posts from Stack Overflow, Reddit, and the Ansible Forum to identify common pain points, complemented by 20 semi-structured interviews with practitioners of varying expertise levels. Based on our findings, we highlight key directions for improving Ansible, with implications for other IaC technologies, including stronger failure locality to support debugging, clearer separation of language and templating boundaries, targeted documentation, and improved execution backends to address performance issues. By grounding these insights in the real-world struggles of Ansible users, this study provides actionable guidance for tool designers and for the broader IaC community, and contributes to a deeper understanding of the trade-offs inherent in IaC tools.

2504.08556 2026-05-01 cond-mat.mes-hall

Control of atomic reconstruction and quasi-1D excitons in strain-engineered moiré heterostructures

Shen Zhao, Zhijie Li, Zakhar A. Iakovlev, Peirui Ji, Fanrong Lin, Xin Huang, Kenji Watanabe, Takashi Taniguchi, Mikhail M. Glazov, Anvar S. Baimuratov, Alexander Högele

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Journal ref
Phys. Rev. Lett. 136, 176201 (2026)
英文摘要

In two-dimensional nearly commensurate heterostructures, strain plays a critical role in shaping electronic behavior. While previous studies have focused on random strain introduced during fabrication, achieving controlled structural design has remained challenging. Here, we demonstrate the deterministic creation of one-dimensional arrays from initially zero-dimensional triangular moiré patterns in MoSe$_2$-WSe$_2$ heterobilayers. This transformation, driven by the interplay of uniaxial strain and atomic reconstruction, results in one-dimensional confinement of interlayer excitons within domain walls, exhibiting near-unity linearly polarized emission related to the confinement-induced symmetry breaking. The width of the domain walls--and consequently the degree of exciton confinement--can be precisely tuned by the interlayer twist angle. By applying out-of-plane electric field, the confined excitons exhibit energy shifts exceeding 100~meV and changes in the fine-structure splitting by up to a factor of two. Our work demonstrates the potential of strain engineering for constructing designer moiré systems with programmable quantum properties, paving the way for future optoelectronic applications.

2503.24324 2026-05-01 stat.AP econ.GN physics.soc-ph q-fin.EC q-fin.RM

Mitigating Financial Risk from Climate-Induced Agricultural Price Volatility

Sourish Das, Sudeep Shukla, Abbinav Sankar Kailasam, Anish Rai, Sejal Garg, Anirban Chakraborti

Comments 15 pages, 11 figures

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英文摘要

Agricultural price volatility, driven by market dynamics and meteorological factors such as temperature and precipitation, poses challenges for sustainable finance, planning, and policy. This study analyzes the impact of climate on crop price volatility for soybean in Madhya Pradesh (India) and Illinois (US), rice in Assam (India), wheat in North Dakota (US), cotton in Gujarat (India), and corn in Iowa (US). Using CMIP6 climate projections from the Copernicus Climate Change Service, we examine historical climate patterns and evaluate two future scenarios: SSP2-4.5 (moderate) and SSP5-8.5 (severe). We estimate conditional price volatility using the Exponential Generalized Autoregressive Conditional Heteroskedasticity (EGARCH) model, and forecast this volatility with a Seasonal Autoregressive Integrated Moving Average with Exogenous Regressors (SARIMAX) model that incorporates meteorological variables. Finally, we apply the Black-Scholes framework to evaluate the cost of put-option-based insurance, which provides protection to farmers against adverse price drops linked to climate change. Our results highlight the role of meteorological data in improving agricultural risk modelling, enabling better design of insurance mechanisms, price stabilization tools, and sustainable policy interventions under climate uncertainty.

2503.22334 2026-05-01 math.PR

Probabilistic analysis of optimal multi-pivot QuickSort

Cecilia Holmgren, Jasper Ischebeck, Daniel Krenn, Florian Lesny, Ralph Neininger

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英文摘要

We consider a multi-pivot QuickSort algorithm using $K\in\mathbb{N}$ pivot elements to partition a nonsorted list into $K+1$ sublists in order to proceed recursively on these sublists. For the partitioning stage, various strategies are in use. We focus on the strategy that minimizes the expected number of key comparisons in the standard random model, where the list is given as a uniformly permuted list of distinct elements. We derive asymptotic expansions for the expectation and variance of the number of key comparisons as well as a limit law for all $K\in\mathbb{N}$, where the convergence holds for all (exponential) moments. For $K\le 4$ we also bound the rate of convergence within the Wasserstein and Kolmogorov--Smirnov distance. Our analysis of the expectation is based on classical results for random $m$-ary search trees. For the remaining results, combinatorial considerations are used to make the contraction method applicable.

2503.20486 2026-05-01 cond-mat.mes-hall cond-mat.other

Characteristic determinant approach to the spectrum of one-dimensional $\mathcal{P}\mathcal{T}$-symmetric systems

Vladimir Gasparian, Peng Guo, Antonio Pérez Garrido, Esther Jódar

Comments The title is changed to Characteristic determinant approach to the spectrum of one-dimensional $\mathcal{P}\mathcal{T}$-symmetric systems. Some minor changes in the text to match PRR accepted version

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Journal ref
Phys. Rev. Research 7, 033257 (2025)
英文摘要

We obtain a closed form expression for the energy spectrum of $\mathcal{P}\mathcal{T}$-symmetric superlattice systems with complex potentials of periodic sets of two $δ$-potentials in the elementary cell. In the presence of periodic gain and loss we analyzed in detail a diatomic crystal model, varying either the scatterer distances or the potential heights. It is shown that at a certain critical value of the imaginary part of the complex amplitude, topological states depending on the lattice size and the configuration of the unit cell can disappear. This may happened at the $\mathcal{PT}$-symmetry breaking (exceptional) points.

2503.17461 2026-05-01 hep-ex

Electroweak diboson production in association with a high-mass dijet system in semileptonic final states from $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

ATLAS Collaboration

Comments 61 pages in total, author list starting page 44, 14 figures, 5 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2018-27/

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Journal ref
Eur. Phys. J. C 86, 433 (2026)
英文摘要

This paper reports the observation of electroweak diboson ($WW/WZ/ZZ$) production in association with a high-mass dijet system, in which final states with one boson decaying leptonically and the other boson decaying hadronically are studied. The hadronically decaying $W/Z$ boson is reconstructed as either two small-radius jets or one large-radius jet with jet substructure requirements. The data analyzed correspond to an integrated luminosity of 140 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV collected with the ATLAS detector during the 2015-2018 data taking at the Large Hadron Collider. The electroweak production of $WW/WZ/ZZ$ in association with two jets is observed in a phase space dominated by vector-boson scattering with a significance of $7.4σ$ (expected $6.1σ$) and the signal strength is determined to be $1.28^{+0.23}_{-0.21}$. The corresponding production cross section in a fiducial phase space is measured in addition. The signal strengths of both electroweak and QCD associated diboson productions are furthermore measured in a two-dimensional fit, the result of which agrees with the Standard Model prediction. The data are interpreted in the context of a dimension-8 effective field theory to probe anomalous quartic gauge couplings resulting in the first set of exclusion limits on the Wilson coefficients in the semileptonic channel reported by the ATLAS Collaboration. The observed limits for the S02, T0 and M0 operators are $(-3.96 < f_{S02} / Λ^4 < 3.96)$ TeV$^{-4}$, $(-0.25 < f_{T0} / Λ^4 < 0.22)$ TeV$^{-4}$, $(-1.26 < f_{M0} / Λ^4 < 1.25)$ TeV$^{-4}$.

2503.09677 2026-05-01 hep-th astro-ph.CO hep-lat hep-ph

Scalar Thermal Field Theory for a Rotating Plasma

Alberto Salvio

Comments 27 pages, 3 figures, for the dataset see https://zenodo.org/records/15012826. v3: accepted for publication in Eur.Phys.J.C

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英文摘要

This paper initiates the systematic study of thermal field theory for generic equilibrium density matrices, which feature arbitrary values not only of temperature and chemical potentials, but also of average angular momentum. The focus here is on scalar fields, although some results also apply to fields with arbitrary spins. A general technique to compute ensemble averages is provided. Moreover, path-integral methods are developed to study thermal Green's functions (with an arbitrary number of points) in generic theories, which cover both the real-time and imaginary-time formalism. It is shown that, while the average angular momentum, like the chemical potentials, does not contribute positively to the Euclidean action, its negative contributions can be compensated by some other contributions that are instead positive, at least in some cases, e.g. when the chemical potentials vanish. As an application of the developed general formalism, it is shown that the production of particles weakly coupled to a rotating plasma can be significantly enhanced compared to the non-rotating case. The Higgs boson production through a portal coupling to a dark sector in the early universe is studied in some detail. The findings of this paper can also be useful, for example, to investigate the physics of rotating stars, ordinary and primordial black holes and more exotic compact objects.

2503.09591 2026-05-01 math.CO

Edge isoperimetry of lattices

Cameron Strachan, Konrad Swanepoel

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英文摘要

We present two results related to an edge-isoperimetric question for Cayley graphs on the integer lattice asked by Ben Barber and Joshua Erde [Isoperimetry of Integer Lattices, Discrete Analysis 7 (2018)]. For any (undirected) graph $G$, the edge boundary of a subset of vertices $S$ is the number of edges between $S$ and its complement in $G$. Barber and Erde asked whether for any Cayley graph on $\mathbb{Z}^d$, there is always an ordering of $\mathbb{Z}^d$ such that for each $n$, the first $n$ terms minimize the edge boundary among all subsets of size $n$. First, we present an example of a Cayley graph $G_d$ on $\mathbb{Z}^d$ (for all $d\geq 2$) for which there is no such ordering. Furthermore, we show that for all $n$ and any optimal $n$-vertex subset $S_n$ of $G_d$, there is no infinite sequence $S_n\subset S_{n+1}\subset S_{n+2}\subset\cdots$ of optimal sets $S_i$, where $|S_i|=i$ for $i\geq n$. This is to be contrasted with the positive result in $\mathbb{Z}^1$ shown by Joseph Briggs and Chris Wells [arXiv:2402.14087]. Our second result is a positive example for the unit-length triangular lattice (which is isomorphic to $\mathbb{Z}^2$) where two vertices are connected by an edge if their distance is $1$ or $\sqrt{3}$. We show that this graph has such an ordering. This is the most complicated example known to us of a two-dimensional Cayley graph for which an ordering exists.

2503.01749 2026-05-01 math.NT

Interpolation of generalized Heegner classes along quaternionic Coleman families

Eris Rocha Walchek

Comments 32 pages

详情
Journal ref
Rend. Sem. Mat. Univ. Padova (2025), published online first
英文摘要

We construct big generalized Heegner classes by interpolating $p$-adically the generalized Heegner classes associated to quaternionic modular forms along a Coleman (finite slope) family, following the approach introduced by Jetchev--Loeffler--Zerbes.