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2602.17644 2026-02-20 astro-ph.CO gr-qc

Cosmic voids evolution in modified gravity via hydrodynamics

Tommaso Moretti, Noemi Frusciante, Giovanni Verza, Francesco Pace

Comments 30 pages, 13 figures

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英文摘要

We present a hydrodynamical description of spherical void evolution in modified gravity (MG), extending the standard General Relativity (GR) and dynamical dark energy treatment by encoding gravity modifications into effective couplings that enter the Euler and Poisson equations. This yields a compact non-linear evolution equation for the Eulerian density contrast, controlled by a time- and density-dependent effective gravitational strength, and provides a direct map between model functions and void observables. We apply the framework to the luminal Galileon class of models, where derivative self-interactions generate Vainshtein screening and might lead to a breakdown of the physical branch in sufficiently underdense regions. Exploiting this feature, we apply the void-informed viability requirement that translates into bounds on the theory parameter space and, equivalently, on the minimum attainable void depth as a function of redshift. For viable parameters of a concrete model, we quantify the impact of MG on isolated void evolution, the Lagrangian to Eulerian mapping, and the shell-crossing threshold. Relative to GR, we find a clear hierarchy of MG effects, with ${\cal O}(10\%)$ modifications in the gravitational couplings, percent-level shifts in the void density evolution, and sub-percent deviations in both the mapping and the shell-crossing thresholds. Moreover, within the adopted parametrization, we show analytically that voids always lie in an unscreened regime on the physical branch. Overall, the formalism provides a self-consistent route to predict void dynamics and consistency constraints in a broad class of MG models.

2602.17638 2026-02-20 cond-mat.str-el cond-mat.stat-mech hep-th

Planckian bound on the local equilibration time

Marvin Qi, Alexey Milekhin, Luca Delacrétaz

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The local equilibration time $τ_{\rm eq}$ of quantum many-body systems is conjectured to be bounded below by the Planckian time $\hbar /T$. We formalize this conjecture by defining $τ_{\rm eq}$ as the time scale at which a hydrodynamic description emerges for conserved densities. Drawing on analytic properties of real time thermal correlators, we establish a rigorous lower bound $τ_{\rm eq} \geq α\hbar /T$ on the onset of hydrodynamic behavior in a `regulated' thermal two-point function. The dimensionless coefficient $α$ depends only on dimensionality and the type of hydrodynamic or diffusive behavior that emerges, and is independent of the thermalization mechanism or other microscopic details. This bound applies universally to local quantum many-body systems, with or without a quasiparticle description, including in the presence of inelastic scattering.

2602.17637 2026-02-20 math.CO cs.DM

On Sets of Monochromatic Objects in Bicolored Point Sets

Sujoy Bhore, Konrad Swanepoel

Comments 19 pages, 7 figures

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Let $P$ be a set of $n$ points in the plane, not all on a line, each colored \emph{red} or \emph{blue}. The classical Motzkin--Rabin theorem guarantees the existence of a \emph{monochromatic} line. Motivated by the seminal work of Green and Tao (2013) on the Sylvester-Gallai theorem, we investigate the quantitative and structural properties of monochromatic geometric objects, such as lines, circles, and conics. We first show that if no line contains more than three points, then for all sufficiently large $n$ there are at least $n^{2}/24 - O(1)$ monochromatic lines. We then show a converse of a theorem of Jamison (1986): Given $n\ge 6$ blue points and $n$ red points, if the blue points lie on a conic and every line through two blue points contains a red point, then all red points are collinear. We also settle the smallest nontrivial case of a conjecture of Milićević (2018) by showing that if we have $5$ blue points with no three collinear and $5$ red points, if the blue points lie on a conic and every line through two blue points contains a red point, then all $10$ points lie on a cubic curve. Further, we analyze the random setting and show that, for any non-collinear set of $n\ge 10$ points independently colored red or blue, the expected number of monochromatic lines is minimized by the \emph{near-pencil} configuration. Finally, we examine monochromatic circles and conics, and exhibit several natural families in which no such monochromatic objects exist.

2602.17631 2026-02-20 quant-ph math.DS math.OC

The Hidden Nature of Non-Markovianity

Jihong Cai, Advith Govindarajan, Marius Junge

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The theory of open quantum systems served as a tool to prepare entanglement at the beginning stage of quantum technology and more recently provides an important tool for state preparation. Dynamics given by time dependent Lindbladians are Markovian and lead to decoherence, decay of correlation and convergence to equilibrium. In contrast Non-Markovian evolutions can outperform their Markovian counterparts by enhancing memory. In this letter we compare the trajectories of Markovian and Non-Markovian evolutions starting from a fixed initial value. It turns out that under mild assumptions every trajectory can be obtained from a family of time dependent Lindbladians. Hence Non-Markovianity is invisible if single trajectories are concerned.

2602.17629 2026-02-20 math.DG math.AP

Distance Functions, Curvature and Topology

Carlo Mantegazza, Francesca Oronzio

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We discuss some properties of the distance functions on Riemannian manifolds and we relate their behavior to the geometry of the manifolds. This leads to alternative proofs of some "classical" theorems connecting curvature and topology.

2602.17627 2026-02-20 math.FA

Towards direct $L^2$-bounds for maximal partial sums of Walsh--Fourier series: The case of dyadic partial sums

Joseph D. Lakey

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We outline an approach to obtain direct $L^2$ estimates not requiring interpolation for so-called linearized partial sums operators associated with expansions in Walsh functions. We focus specifically on a simpler case of dyadic partial sums but also outline a second approach to proving bounds on general linearized partial sums.

2602.17626 2026-02-20 astro-ph.EP

New Kreutz Sungrazer C/2026 A1 (MAPS): Third Time's the Charm?

Zdenek Sekanina

Comments 8 pages, 3 figures, 2 tables

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This paper describes progress achieved in early investigations of the orbital motion and light curve of comet C/2026 A1 (MAPS), the third ground-based discovery of a Kreutz sungrazer in the 21st century. The highly unusual trait of the comet that has so far been ascertained is its extraordinarily long orbital period. The most recent orbital computations make it increasingly likely that the object is a fragment of one of the comets observed by Ammianus Marcellinus in AD 363, thereby strengthening evidence in support of the contact-binary hypothesis of the Kreutz system. In this context, the comet is the only second-generation fragment of Aristotle's comet that we are aware of to appear after the 12th century. It does not look like a major fragment, but rather like an outlying fragment of a much larger sungrazer. In 363 it apparently separated from a parent different from the lineage of comet Pereyra. The light curve of comet MAPS has so far been fairly smooth, without outbursts. To reach the brightness of comet Ikeya-Seki, the comet would have to follow an r^(-17) law in the coming weeks, which is unlikely.

2602.17622 2026-02-20 cs.CR cs.SE

What Makes a Good LLM Agent for Real-world Penetration Testing?

Gelei Deng, Yi Liu, Yuekang Li, Ruozhao Yang, Xiaofei Xie, Jie Zhang, Han Qiu, Tianwei Zhang

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LLM-based agents show promise for automating penetration testing, yet reported performance varies widely across systems and benchmarks. We analyze 28 LLM-based penetration testing systems and evaluate five representative implementations across three benchmarks of increasing complexity. Our analysis reveals two distinct failure modes: Type A failures stem from capability gaps (missing tools, inadequate prompts) that engineering readily addresses, while Type B failures persist regardless of tooling due to planning and state management limitations. We show that Type B failures share a root cause that is largely invariant to the underlying LLM: agents lack real-time task difficulty estimation. As a result, agents misallocate effort, over-commit to low-value branches, and exhaust context before completing attack chains. Based on this insight, we present Excalibur, a penetration testing agent that couples strong tooling with difficulty-aware planning. A Tool and Skill Layer eliminates Type A failures through typed interfaces and retrieval-augmented knowledge. A Task Difficulty Assessment (TDA) mechanism addresses Type B failures by estimating tractability through four measurable dimensions (horizon estimation, evidence confidence, context load, and historical success) and uses these estimates to guide exploration-exploitation decisions within an Evidence-Guided Attack Tree Search (EGATS) framework. Excalibur achieves up to 91% task completion on CTF benchmarks with frontier models (39 to 49% relative improvement over baselines) and compromises 4 of 5 hosts on the GOAD Active Directory environment versus 2 by prior systems. These results show that difficulty-aware planning yields consistent end-to-end gains across models and addresses a limitation that model scaling alone does not eliminate.

2602.17621 2026-02-20 eess.SY cs.SY

Method to Compute Pointing Displacement, Smear, and Jitter Covariances for Optical Payloads

Peter Seiler, Mark E. Pittelkau, Felix Biertümpfel

Comments Final accepted manuscript (AAM) for AIAA Journal of Guidance, Control and Dynamics

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This paper presents a method to assess the pointing and image motion performance of optical payloads in the presence of image displacement (shift), smear, and jitter. The method assumes the motion is a stationary random process over an image exposure interval. Displacement, smear, and jitter covariances are computed from the solution to a Lyapunov differential equation. These covariances parameterize statistical image motion modulation transfer functions (MTFs), and they can be used to verify pointing and image motion MTF requirements. The method in the present paper extends a previous method to include smear, as well as displacement, and hence jitter. The approach in the present paper also leads, as a special case, to a more efficient method to compute the displacement covariance than the previous method. Numerical examples illustrate the proposed method.

2602.17619 2026-02-20 cs.NI

EDRP: Enhanced Dynamic Relay Point Protocol for Data Dissemination in Multi-hop Wireless IoT Networks

Jothi Prasanna Shanmuga Sundaram, Magzhan Gabidolla, Luis Fujarte, Shawn Duong, Jianlin Guo, Toshiaki Koike-Akino, Pu, Wang, Kieran Parsons, Philip V. Orlik, Takenori Sumi, Yukimasa Nagai, Miguel A. Carreira-Perpinan, Alberto E. Cerpa

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Emerging IoT applications are transitioning from battery-powered to grid-powered nodes. DRP, a contention-based data dissemination protocol, was developed for these applications. Traditional contention-based protocols resolve collisions through control packet exchanges, significantly reducing goodput. DRP mitigates this issue by employing a distributed delay timer mechanism that assigns transmission-start delays based on the average link quality between a sender and its children, prioritizing highly connected nodes for early transmission. However, our in-field experiments reveal that DRP is unable to accommodate real-world link quality fluctuations, leading to overlapping transmissions from multiple senders. This overlap triggers CSMA's random back-off delays, ultimately degrading the goodput performance. To address these shortcomings, we first conduct a theoretical analysis that characterizes the design requirements induced by real-world link quality fluctuations and DRP's passive acknowledgments. Guided by this analysis, we design EDRP, which integrates two novel components: (i) Link-Quality Aware CSMA (LQ-CSMA) and (ii) a Machine Learning-based Block Size Selection (ML-BSS) algorithm for rateless codes. LQ-CSMA dynamically restricts the back-off delay range based on real-time link quality estimates, ensuring that nodes with stronger connectivity experience shorter delays. ML-BSS algorithm predicts future link quality conditions and optimally adjusts the block size for rateless coding, reducing overhead and enhancing goodput. In-field evaluations of EDRP demonstrate an average goodput improvement of 39.43\% than the competing protocols.

2602.17617 2026-02-20 math.AG

Generically log smooth families via generators and relations

Simon Felten

Comments 57 pages, 2 figures

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Let $f\colon X \to \mathbb{A}^1_t$ be an affine flat morphism of finite type, and let $V = f^{-1}(0)$. Then, we obtain a morphism of log schemes $f\colon (X|V) \to (\mathbb{A}^1_t|0)$. In this article, we develop algorithmic tools to study the log-geometric properties of $f$ by means of a presentation \[Γ(X,\mathcal{O}_X) = \Bbbk[t,x_1,\ldots,x_n]/(f_1,\ldots,f_r).\] We obtain similar tools for projective flat morphisms when the homogeneous coordinate ring is given by generators and relations. We provide an implementation of our algorithms in Macaulay2. In a slightly different direction, we give some results on the sheaf $\mathcal{LS}_V$ of log smooth structures on a toroidal crossing scheme $(V,\mathcal{P},\barρ)$.

2602.17615 2026-02-20 quant-ph

A Shadow Enhanced Greedy Quantum Eigensolver

Jona Erle, Balint Koczor

Comments 16 pages, 6 figures

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While ground-state preparation is expected to be a primary application of quantum computers, it is also an essential subroutine for many fault-tolerant algorithms. In early fault-tolerant regimes, logical measurements remain costly, motivating adaptive, shot-frugal state-preparation strategies that efficiently utilize each measurement. We introduce the Shadow Enhanced Greedy Quantum Eigensolver (SEGQE) as a greedy, shadow-assisted framework for measurement-efficient ground-state preparation. SEGQE uses classical shadows to evaluate, in parallel and entirely in classical post-processing, the energy reduction induced by large collections of local candidate gates, greedily selecting at each step the gate with the largest estimated energy decrease. We derive rigorous worst-case per-iteration sample-complexity bounds for SEGQE, exhibiting logarithmic dependence on the number of candidate gates. Numerical benchmarks on finite transverse-field Ising models and ensembles of random local Hamiltonians demonstrate convergence in a number of iterations that scales approximately linearly with system size, while maintaining high-fidelity ground-state approximations and competitive energy estimates. Together, our empirical scaling laws and rigorous per-iteration guarantees establish SEGQE as a measurement-efficient state-preparation primitive well suited to early fault-tolerant quantum computing architectures.

2602.17613 2026-02-20 math.CA

Power weight inequalities for spherical maximal functions

Marco Fraccaroli, Joris Roos, Andreas Seeger

Comments 17 pages, 1 figure

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This paper is about spherical maximal functions with general dilation sets acting on functions in weighted $L^p(|x|^α)$ spaces. Aside from endpoint cases, a complete description of the allowable ranges of $p$, $α$ is given in terms of the Legendre--Assouad function of the dilation set. This settles, up to endpoints, an open problem of Duoandikoetxea and Seijo.

2602.17612 2026-02-20 quant-ph

Scalable, self-verifying variational quantum eigensolver using adiabatic warm starts

Bojan Žunkovič, Marco Ballarin, Lewis Wright, Michael Lubasch

Comments 6 pages, 1 figure + 33 pages

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We study an adiabatic variant of the variational quantum eigensolver (VQE) in which VQE is performed iteratively for a sequence of Hamiltonians along an adiabatic path. We derive the conditions under which gradient-based optimization successfully prepares the adiabatic ground states. These conditions show that the barren plateau problem and local optima can be avoided. Additionally, we propose using energy-standard-deviation measurements at runtime to certify eigenstate accuracy and verify convergence to the global optimum.

2602.17610 2026-02-20 cs.DC cs.DB

Exploring Novel Data Storage Approaches for Large-Scale Numerical Weather Prediction

Nicolau Manubens Gil

Comments PhD. thesis successfully defended at The University of Edinburgh on the 16th October 2025

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Driven by scientific and industry ambition, HPC and AI applications such as operational Numerical Weather Prediction (NWP) require processing and storing ever-increasing data volumes as fast as possible. Whilst POSIX distributed file systems and NVMe SSDs are currently a common HPC storage configuration providing I/O to applications, new storage solutions have proliferated or gained traction over the last decade with potential to address performance limitations POSIX file systems manifest at scale for certain I/O workloads. This work has primarily aimed to assess the suitability and performance of two object storage systems -namely DAOS and Ceph- for the ECMWF's operational NWP as well as for HPC and AI applications in general. New software-level adapters have been developed which enable the ECMWF's NWP to leverage these systems, and extensive I/O benchmarking has been conducted on a few computer systems, comparing the performance delivered by the evaluated object stores to that of equivalent Lustre file system deployments on the same hardware. Challenges of porting to object storage and its benefits with respect to the traditional POSIX I/O approach have been discussed and, where possible, domain-agnostic performance analysis has been conducted, leading to insight also of relevance to I/O practitioners and the broader HPC community. DAOS and Ceph have both demonstrated excellent performance, but DAOS stood out relative to Ceph and Lustre, providing superior scalability and flexibility for applications to perform I/O at scale as desired. This sets a promising outlook for DAOS and object storage, which might see greater adoption at HPC centres in the years to come, although not necessarily implying a shift away from POSIX-like I/O.

2602.17609 2026-02-20 eess.SP cs.ET

Device-Centric ISAC for Exposure Control via Opportunistic Virtual Aperture Sensing

Marouan Mizmizi, Zhibin Yu, Guanglong Du, Umberto Spagnolini

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Regulatory limits on Maximum Permissible Exposure (MPE) require handheld devices to reduce transmit power when operated near the user's body. Current proximity sensors provide only binary detection, triggering conservative power back-off that degrades link quality. If the device could measure its distance from the body, transmit power could be adjusted proportionally, improving throughput while maintaining compliance. This paper develops a device-centric integrated sensing and communication (ISAC) method for the device to measure this distance. The uplink communication waveform is exploited for sensing, and the natural motion of the user's hand creates a virtual aperture that provides the angular resolution necessary for localization. Virtual aperture processing requires precise knowledge of the device trajectory, which in this scenario is opportunistic and unknown. One can exploit onboard inertial sensors to estimate the device trajectory; however, the inertial sensors accuracy is not sufficient. To address this, we develop an autofocus algorithm based on extended Kalman filtering that jointly tracks the trajectory and compensates residual errors using phase observations from strong scatterers. The Bayesian Cramér-Rao bound for localization is derived under correlated inertial errors. Numerical results at 28GHz demonstrate centimeter-level accuracy with realistic sensor parameters.

2602.17604 2026-02-20 quant-ph

Phase-sensitive representation of Majorana stabilizer states

Tomislav Begušić, Garnet Kin-Lic Chan

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Stabilizer states hold a special place in quantum information science due to their connection with quantum error correction and quantum circuit simulation. In the context of classical simulations of many-body physics, they are an example of states that can be both highly entangled and efficiently represented and transformed under Clifford operators. Recently, Clifford operators have been discussed in the context of fermionic quantum computation through their extension, the Majorana Clifford group. Here, we document the phase-sensitive form of the corresponding Majorana stabilizer states, as well as the algorithms for computing their amplitudes, their inner products, and update rules for transforming Majorana stabilizer states under Majorana Clifford gates.

2602.17603 2026-02-20 stat.ML stat.AP

SOLVAR: Fast covariance-based heterogeneity analysis with pose refinement for cryo-EM

Roey Yadgar, Roy R. Lederman, Yoel Shkolnisky

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Cryo-electron microscopy (cryo-EM) has emerged as a powerful technique for resolving the three-dimensional structures of macromolecules. A key challenge in cryo-EM is characterizing continuous heterogeneity, where molecules adopt a continuum of conformational states. Covariance-based methods offer a principled approach to modeling structural variability. However, estimating the covariance matrix efficiently remains a challenging computational task. In this paper, we present SOLVAR (Stochastic Optimization for Low-rank Variability Analysis), which leverages a low-rank assumption on the covariance matrix to provide a tractable estimator for its principal components, despite the apparently prohibitive large size of the covariance matrix. Under this low-rank assumption, our estimator can be formulated as an optimization problem that can be solved quickly and accurately. Moreover, our framework enables refinement of the poses of the input particle images, a capability absent from most heterogeneity-analysis methods, and all covariance-based methods. Numerical experiments on both synthetic and experimental datasets demonstrate that the algorithm accurately captures dominant components of variability while maintaining computational efficiency. SOLVAR achieves state-of-the-art performance across multiple datasets in a recent heterogeneity benchmark. The code of the algorithm is freely available at https://github.com/RoeyYadgar/SOLVAR.

2602.17600 2026-02-20 cond-mat.quant-gas cond-mat.str-el quant-ph

Measuring spectral functions of doped magnets with Rydberg tweezer arrays

Romain Martin, Mu Qiao, Ivan Morera, Lukas Homeier, Bastien Gély, Lukas Klein, Yuki Torii Chew, Daniel Barredo, Thierry Lahaye, Eugene Demler, Antoine Browaeys

Comments 7 + 8 pages, 4 + 2 figures

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Spectroscopic measurements of single-particle spectral functions provide crucial insight into strongly correlated quantum matter by resolving the energy and spatial structure of elementary excitations. Here we introduce a spectroscopic protocol for single-charge injection with simultaneous spatial and energy resolution in a Rydberg tweezer array, effectively emulating scanning tunneling microscopy. By combining this protocol with single-atom-resolved imaging, we go beyond conventional spectroscopy by not only measuring the single-particle spectral function but also directly imaging the microscopic structure of the excitations underlying spectral resonances in frustrated $tJ$ Hamiltonians. We reveal resonances associated with the formation of bound magnetic polarons -- composite quasiparticles consisting of a mobile hole bound to a magnon -- and directly extract their binding energy, spatial extent, and spin character. Finally, by exploiting the spatial tunability of our platform, we measure the local density of states across different lattice geometries. Our work establishes Rydberg tweezer arrays as a powerful platform for spectroscopic studies of strongly correlated models, offering microscopic control and direct real-space access to emergent quasiparticles in engineered quantum matter.

2602.17597 2026-02-20 hep-ph astro-ph.CO

Stochastic galactic supernova flux of semi-relativistic particles

David Alonso-González, David Cerdeño, Marina Cermeño, Andres D. Perez

Comments 19 pages, 8 figures

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New exotic particles with MeV masses, such as axion-like particles or light dark matter, can be emitted from core-collapse supernovae (SNe) with semi-relativistic velocities. Due to their speed dispersion, they would arrive at Earth as an extended packet with a time spread that can be as large as tens of millennia for typical detectors. It has been argued in the literature that the superposition of packets from all galactic SNe would give rise to a smooth and stationary diffuse flux that could be observable on terrestrial experiments. In this article, we critically examine this hypothesis by carrying out a numerical simulation of the galactic history of SN explosions. We show that, although the particle packets do overlap, due to the short observational time window, each of them only contributes with a very narrow range of energies and with an intensity that depends on the SN distance. As a consequence, the energy dependence of the resulting flux is extremely sensitive to the stochastic nature of the SN population and far from smooth. This has profound implications for the expected signature in terrestrial experiments, which displays a spectral shape that is not properly described by the smooth approximation. We develop a numerical tool to compute this stochastic galactic flux for generic semi-relativistic particles, which also allows us to explore sub-MeV particles, where the smooth diffuse flux approach does not hold. To test this framework, we revisit existing bounds on axion-like particles and fermionic dark matter, finding weaker constraints than previously reported.

2602.17595 2026-02-20 cond-mat.mtrl-sci

Discovery of Polymer Electrolytes with Bayesian Optimization and High-Throughput Molecular Dynamics simulations

Antonia S. Kuhn, Jurğis Ruža, KyuJung Jun, Pablo Leon, Rafael Gómez-Bombarelli

Comments 28 pages, 5 figures

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Polymer electrolytes are critical for safe, high-energy-density solid-state batteries, yet discovering candidates that balance high ionic conductivity with high transference numbers remains a significant challenge. In this work, we develop a high-throughput screening platform that utilizes molecular dynamics simulations to navigate a chemical space of 1.7 million hypothetical polymer electrolyte candidates. Data from previous literature is used to warm-start batch Bayesian optimization for iteratively selecting new polymer electrolytes to evaluate. We iteratively identified, evaluated and analyzed 767 homopolymers as potential candidates. Our results reveal several candidates with transport properties exceeding the benchmark polyethylene oxide (PEO)/LiTFSI system. Crucially, our optimization campaigns for ionic conductivity and Li-diffusivity demonstrate that branched architectures and ketone functional groups significantly enhance ion-hopping mechanisms within the polymer matrix. We provide an in-depth mechanistic comparison of Li vs. Na cation transport and offer our open-source framework to accelerate the discovery of liquid, gel, and multi-cation electrolyte systems.

2602.17593 2026-02-20 astro-ph.GA

MUSEQuBES: Probing Anisotropies in Gas and Metal Distributions in the Circumgalactic Medium

Sayak Dutta, Sowgat Muzahid, Joop Schaye, Sean Johnson, Edmund Christian Herenz, Ismael Pessa, Ramona Augustin, Nicolas F. Bouché, Joey Braspenning, Sebastiano Cantalupo, Sourav Das, Martin Wendt

Comments Submitted to ApJ. Comments are welcome

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We investigate the azimuthal dependence of H I and O VI-bearing gas in the circumgalactic medium (CGM) of 113 isolated galaxies in the redshift range 0.12 < z < 0.75, including 91 new measurements from the MUSE Quasar-fields Blind Emitters Survey (MUSEQuBES). The H I covering fraction (k_HI) within the virial radius (Rvir) of low-mass (7 < log10(M*/Msun)< 9) galaxies, for a threshold column density of log10(N(HI)/cm^-2) = 14.5, exhibits an enhancement along both the disk plane (azimuthal angle phi < 20 degree) and in the polar direction (phi > 70 degree). In contrast, such a bimodal distribution is not observed for higher mass galaxies (9 < log10(M*/Msun) < 11.3). Similarly, the O VI covering fraction (k_OVI), for a threshold of log10(N(OVI)/cm^-2) = 14.0, shows a tentative enhancement along both the projected major and minor axes for low-mass galaxies. In contrast, O VI-bearing gas around higher- mass galaxies appears more uniformly distributed, with no significant azimuthal dependence. Finally, using the halo circular-velocity-normalized pixel-velocity two-point correlation function (TPCF), we find that O VI absorbers are kinematically narrower along the disk plane compared to the polar directions of the host galaxies with similar stellar mass distributions. The observed isotropic distribution of O VI in high-mass halos suggests that its spatial distribution is governed by global halo properties; however, the O VI kinematics retain memory of the site of origin.

2602.17592 2026-02-20 stat.ME stat.AP

BMW: Bayesian Model-Assisted Adaptive Phase II Clinical Trial Design for Win Ratio Statistic

Di Zhu, Yong Zang

Comments 32 pages, 2 figures

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The win ratio (WR) statistic is increasingly used to evaluate treatment effects based on prioritized composite endpoints, yet existing Bayesian adaptive designs are not directly applicable because the WR is a summary statistic derived from pairwise comparisons and does not correspond to a unique data-generating mechanism. We propose a Bayesian model-assisted adaptive design for randomized phase II clinical trials based on the WR statistic, referred to as the BMW design. The proposed design uses the joint asymptotic distribution of WR test statistics across interim and final analyses to compute posterior probabilities without specifying the underlying outcome distribution. The BMW design allows flexible interim monitoring with early stopping for futility or superiority and is extended to jointly evaluate efficacy and toxicity using a graphical testing procedure that controls the family-wise error rate (FWER). Simulation studies demonstrate that the BMW design maintains valid type I error and FWER control, achieves power comparable to conventional methods, and substantially reduces expected sample size. An R Shiny application is provided to facilitate practical implementation.

2602.17590 2026-02-20 cs.CR cs.MA

BMC4TimeSec: Verification Of Timed Security Protocols

Agnieszka M. Zbrzezny

Comments To appear in the Proceedings of the 25th International Conference on Autonomous Agents and Multiagent Systems (AAMAS 2026), May 25 - 29, 2026, Paphos, Cyprus

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We present BMC4TimeSec, an end-to-end tool for verifying Timed Security Protocols (TSP) based on SMT-based bounded model checking and multi-agent modelling in the form of Timed Interpreted Systems (TIS) and Timed Interleaved Interpreted Systems (TIIS). In BMC4TimeSec, TSP executions implement the TIS/TIIS environment (join actions, interleaving, delays, lifetimes), and knowledge automata implement the agents (evolution of participant knowledge, including the intruder). The code is publicly available on \href{https://github.com/agazbrzezny/BMC4TimeSec}{GitHub}, as is a \href{https://youtu.be/aNybKz6HwdA}{video} demonstration.

2602.17589 2026-02-20 quant-ph

States that grow linearly in time, exceptional points, and zero norm states in the simple harmonic oscillator

Philip D. Mannheim

Comments 7 pages, revtex 4

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The simple harmonic oscillator has a well-known normalizable, positive energy, bound state spectrum. We show that degenerate with each such positive energy eigenvalue there is a non-normalizable positive energy eigenstate whose eigenfunction is orthogonal to that of the standard energy eigenfunction. This class of states is not built on the vacuum that $a$ annihilates, but is instead built on the vacuum that $a^{\dagger} a$ annihilates. These non-normalizable but nonetheless stationary energy eigenstates are accompanied by yet another set of non-normalizable states, states whose wave functions however are not stationary but instead grow linearly in time. With these states not being energy eigenstates, the eigenbasis of the Hamiltonian is incomplete; with the full Hilbert space containing states that are not energy eigenstates. Thus each energy eigenvalue of the harmonic oscillator is an exceptional point at which the Hamiltonian becomes of non-diagonalizable, and thus manifestly non-Hermitian, Jordan-block form. Such non-Hermitian structures occur for Hamiltonians that have an antilinear $PT$ symmetry. As is characteristic of such systems, one can construct a probability conserving inner product that despite the linear in time growth is nonetheless time independent, and not only that, it leads to states with zero norm. In addition, as is again characteristic of $PT$ symmetry, these non-normalizable states can be made normalizable by a continuation into a so-called Stokes wedge domain in the complex plane. In this domain one has a completely consistent quantum theory, one that lives alongside the standard normalizable energy eigenspectrum sector. This thus not quite so simple harmonic oscillator provides an explicit realization of our general contention that antilinearity is more basic to quantum theory than Hermiticity.

2602.17585 2026-02-20 hep-th

Renormalization Group and String Loops

Arkady A. Tseytlin

Comments 56 pages. Based on lectures at ICTP Trieste School and Workshop on Superstrings, 3-14 April 1989

Journal ref Int. J. Mod. Phys. A 5 (1990) 589-658

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Fixed points of the 2d renormalization group flow are known to correspond to tree level string vacua. We discuss how the renormalization group (or "sigma model") approach can be extended to the string loop level. The central role of the condition of renormalizability of the generating functional for string amplitudes with respect to both "local" and "modular" infinities is emphasized. Several one-loop and two-loop examples of renormalization are considered. It is found that in order to ensure the renormalizability of the generating functional one is to use an "extended" (Schottky-type) parametrization of the moduli space. An approach to resummation of the string perturbative expansion based on operators of insertion of topological fixtures is suggested.

2602.17583 2026-02-20 hep-th hep-ph math-ph math.MP

Non-BPS Monopoles and Dyons via Resurgent Transseries

Gerald V. Dunne, Evan Shinn

Comments 4 figures, 11 pages

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Radially symmetric non-BPS 't Hooft-Polyakov monopoles and dyons are constructed as resurgent transseries: infinite sums of exponentially decaying terms, each multiplied by a factorially divergent fluctuation factor. All higher exponential terms are explicitly expressed in terms of the leading order solutions. In the BPS limit all fluctuation terms truncate.

2602.17582 2026-02-20 hep-ex

Building an AI-native Research Ecosystem for Experimental Particle Physics: A Community Vision

Thea Klaeboe Aarrestad, Alaa Abdelhamid, Haider Abidi, Jahred Adelman, Jennifer Adelman-McCarthy, Shuchin Aeron, Garvita Agarwal, Usman Ali, Cristiano Alpigiani, Omar Alterkait, Mohamed Aly, Oz Amram, Saeed Ansari Fard, Aram Apyan, John Arrington, Marvin Ascencio-Sosa, Mohammad Atif, Aneesha Avasthi, Muhammad Bilal Azam, Bhim Bam, Joshua Barrow, Rainer Bartoldus, Amit Bashyal, Aashwin Basnet, Ayse Bat, Lothar A. T. Bauerdick, John Beacom, Chris Bee, Michael Begel, Matthew Bellis, Rene Bellwied, Rakitha Beminiwattha, Gabriele Benelli, Douglas Benjamin, Catrin Bernius, Binod Bhandari, Avinay Bhat, Meghna Bhattacharya, Saptaparna Bhattacharya, Prajita Bhattarai, Sudip Bhattarai, Wahid Bhimji, Jianming Bian, Burak Bilki, Mary Bishai, Kevin Black, Kenneth Bloom, Brian Bockelman, Johan Sebastian Bonilla Castro, Tulika Bose, Nilay Bostan, Othmane Bouhali, Dimitri Bourilkov, Dominic Brailsford, Gustaaf Brooijmans, Elizabeth Brost, Maria Brigida Brunetti, Quentin Buat, Brendon Bullard, Jackson Burzynski, Paolo Calafiura, Rodolfo Capdevilla, Fabian Andres Castaño Usuga, Raquel Castillo Fernandez, Fabio Catalano, Viviana Cavaliere, Flavio Cavanna, Giuseppe Cerati, Aidan Chambers, Maria Chamizo-Llatas, Philip Chang, Andrew Chappell, Arghya Chattopadhyay, Sergei Chekanov, Jian-ping Chen, Yi Chen, Zhengyang Chen, J. Taylor Childers, Hector Chinchay, Yuan-Tang Chou, Tasnuva Chowdhury, Neil Christensen, Wonyong Chung, Rafael Coelho Lopes de Sa, Simon Corrodi, Kyle Cranmer, Matteo Cremonesi, Roy Cruz, Mate Csanad, Mariarosaria D'Alfonso, Carlo Dallapiccola, Daine Danielson, Sridhara Dasu, Gavin Davies, Kaushik De, Patrick de Perio, Klaus Dehmelt, Marco Del Tutto, Carlos Ruben Dell'Aquila, Sarah Demers, Paolo Desiati, Bhesha Devkota, Sparshita Dey, Ranjan Dharmapalan, Karri Folan Di Petrillo, Markus Diefenthaler, Jeff Dillon, Zelimir Djurcic, Caterina Doglioni, Francois Drielsma, Edmond Dukes, Irene Dutta, Peter Elmer, Johannes Elmsheuser, Victor Daniel Elvira, Harold Evans, Peter Fackeldey, Cristiano Fanelli, Hao Fang, Mattia Fani, Muhammad Farooq, Matthew Feickert, Ian Fisk, Sam Foreman, Alexander Friedland, Nuwan Chaminda G. W., Louis-Guillaume Gagnon, Massimiliano Galli, Abhijith Gandrakota, Sudeshna Ganguly, Arianna Garcia Caffaro, Rob Gardner, Rocky Bala Garg, Lino Gerlach, Aishik Ghosh, Romulus Godang, Julia Gonski, Loukas Gouskos, Richard Gran, Heather Gray, Andrei Gritsan, Gaia Grosso, Craig Group, Jiawei Guo, Shubham Gupta, Gajendra Gurung, Phillip Gutierrez, Oliver Gutsche, Tyler Hague, Joseph Haley, Eva Halkiadakis, Francis Halzen, Michael Hance, Philip Harris, Harry Hausner, Karsten Heeger, Lukas Heinrich, Alexander Held, Matthew Herndon, Ken Herner, Max Herrmann, David Hertzog, Christian Herwig, Aaron Higuera, Alexander Himmel, Timothy Hobbs, Stefan Hoeche, Tova Holmes, Tae Min Hong, Ben Hooberman, Walter Hopkins, Jessica N. Howard, Shih-Chieh Hsu, Fengping Hu, Patrick Huber, Dirk Hufnagel, Daniel Humphreys, Ia Iashvili, Joseph Incandela, Josh Isaacson, Wasikul Islam, Kirill Ivanov, Wooyoung Jang, Naomi Jarvis, Brij Kishor Jashal, Pratik Jawahar, Dulitha Jayakodige, Torri Jeske, Sergo Jindariani, Jay Hyun Jo, Bhishm Shankar Joshi, Xiangyang Ju, Andreas Jung, Thomas Junk, Michael Kagan, Daisy Kalra, Matthias Kaminski, Edward Karavakis, Stefan Katsarov, Stergios Kazakos, Paul King, Michael Kirby, Max Knobbe, Young Ju Ko, Dmitry Kondratyev, Rostislav Konoplich, Charis Koraka, Scott Kravitz, Lukas Kretschmann, Brandon Kriesten, Georgios K Krintiras, Iason Krommydas, Michelle Kuchera, Audrey Kvam, Martin Kwok, Theodota Lagouri, Sabine Lammers, Eric Lancon, Greg Landsberg, David Lange, Kevin Lannon, Joseph Lau, Luca Lavezzo, Benjamin Lawrence-Sanderson, Duc-Truyen Le, Matt LeBlanc, Sung-Won Lee, Trevin Lee, Charles Leggett, Kayla Leonard DeHolton, James Letts, Hao Li, Haoyang Li, Aklima Khanam Lima, Guilherme Lima, Mia Liu, Qibin Liu, Yinrui Liu, Zhen Liu, Shivani Lomte, Guillermo Loustau de Linares, Lu Lu, Pietro Lugato, Adam Lyon, Yang Ma, Christopher Madrid, Akhtar Mahmood, Kendall Mahn, Devin Mahon, Akshay Malige, Sudhir Malik, Abhishikth Mallampalli, Yurii Maravin, Ralph Marinaro, Pete Markowitz, Matthew Maroun, Kyla Martinez, Verena Ingrid Martinez Outschoorn, Sanjit Masanam, Mario Masciovecchio, Konstantin Matchev, Malek Mazouz, Simone Mazza, Thomas McCauley, Shawn McKee, Karim Mehrabi, Poonam Mehta, Andrew Melo, Mark Messier, Elias Mettner, Christopher Meyer, Jessie Micallef, Sophie Middleton, David W. Miller, Hamlet Mkrtchyan, Abdollah Mohammadi, Abhinav Mohan, Ajit Mohapatra, Farouk Mokhtar, Peter Monaghan, Claudio Silverio Montanari, Michael Mooney, Casey Morean, Eric Moreno, Alexander Moreno Briceño, Stephen Mrenna, Justin Mueller, Daniel Murnane, Benjamin Nachman, Emilio Nanni, Nitish Nayak, Miquel Nebot-Guinot, Orgho Neogi, Chris Neu, Mark Neubauer, Norbert Neumeister, Harvey Newman, Duong Nguyen, Gavin Niendorf, Paul Nilsson, Scarlet Norberg, Andrzej Novak, Sungbin Oh, Isabel Ojalvo, Olaiya Olokunboyo, Yasar Onel, Joseph Osborn, Ianna Osborne, Arantza Oyanguren, Nurcan Ozturk, Paul Padley, Simone Pagan Griso, Pritam Palit, Bishnu Pandey, Vishvas Pandey, Zisis Papandreou, Ganesh Parida, Ki Ryeong Park, Ajib Paudel, Manfred Paulini, Christoph Paus, Gregory Pawloski, Kevin Pedro, Gabriel Perdue, Troels Christian Petersen, Alexey Petrov, Deborah Pinna, Marc-André Pleier, Andrea Pocar, Prafull Purohit, Nived Puthumana Meleppattu, Mateusz Płoskoń, Sitian Qian, Xin Qian, Geting Qin, Aleena Rafique, Srini Rajagopalan, Dylan Rankin, Rebecca Rapp, Salvatore Rappoccio, Rohit Raut, Sagar Regmi, Benedikt Riedel, Andres Rios-Tascon, Stephen Roche, Jenna Roderick, Rimsky Rojas, Dmitry Romanov, Subhojit Roy, Rita Sadek, Dikshant Sagar, Nihar Ranjan Sahoo, Tai Sakuma, Juan Pablo Salas, Mayly Sanchez, Jay Sandesara, Alexander Savin, Ryan Schmitz, Kate Scholberg, Henry Schreiner, Reinhard Schwienhorst, Gabriella Sciolla, Saba Sehrish, Seon-Hee, Seo, Elizabeth Sexton-Kennedy, Oksana Shadura, Bijaya Sharma, Varun Sharma, Suyog Shrestha, Ryan Simeon, Jack Simoni, Siddharth Singh, Kim Siyeon, Louise Skinnari, Jinseop Song, Simone Sottocornola, Alexandre Sousa, Sairam Sri Vatsavai, Giordon Stark, Justin Stevens, Tyler Stokes, Nadja Strobbe, Indara Suarez, Manjukrishna Suresh, Andrew Sutton, Holly Szumila-Vance, Vardan Tadevosyan, Anyes Taffard, Buddhiman Tamang, Hirohisa Tanaka, Erdinch Tatar, Abdel Nasser Tawfik, Vikas Teotia, Kazuhiro Terao, Mitanshu Thakore, Jesse Thaler, Ameya Thete, Inar Timiryasov, Anthony Timmins, Andrew Toler, Dat Tran, Nhan Tran, Patrick Tsang, Ho Fung Tsoi, Vakho Tsulaia, Pham Tuan, Christopher Tully, Shengquan Tuo, Richard Tyson, Darren Upton, Hilary Utaegbulam, Zoya Vallari, Peter van Gemmeren, Vassil Vassilev, Nikhilesh Venkatasubramanian, Renzo Vizarreta, Emmanouil Vourliotis, Ilija Vukotic, Carl Vuosalo, Liv Våge, Tammy Walton, Linyan Wan, Biao Wang, Gensheng Wang, Michael Wang, Yuxuan Wang, Gordon Watts, Yingjie Wei, Derek Weitzel, Shawn Westerdale, Andrew White, Leigh Whitehead, Michael Wilking, Mike Williams, Stephane Willocq, Jeffery Winkler, Frank Winklmeier, Holger Witte, Peter Wittich, Douglas Wright, Yongcheng Wu, Yujun Wu, Wei Xie, Fang Xu, Barbara Yaeggy, Zhen Yan, Liang Yang, Wei Yang, Alejandro Yankelevich, Yiheng Ye, Oguzhan Yer, Efe Yigitbasi, Shin-Shan Yu, Jon Zarling, Chao Zhang, Licheng Zhang, Larry Zhao, Junjie Zhu, Jure Zupan

详情
英文摘要

Experimental particle physics seeks to understand the universe by probing its fundamental particles and forces and exploring how they govern the large-scale processes that shape cosmic evolution. This whitepaper presents a vision for how Artificial Intelligence (AI) can accelerate discovery in this field. We outline grand challenges that must be addressed to enable transformative breakthroughs and describe how current and planned experimental facilities can implement this vision to advance our understanding of the vast and complex physical world from the smallest to the largest scales. We show how facilities currently under construction, such as the HL-LHC, DUNE and soon EIC, can both benefit from and serve as proving grounds for this vision, while also enabling a longer-term goal for how future experiments -- like FCC-ee at CERN, IceCube-Gen2, a Muon Collider in the U.S., and smaller to mid-scale projects -- can be fully AI-native. We describe how a truly national-scale collaboration, jointly managed across large funding partners, and involving both DOE laboratories and universities, can make this happen.

2602.17580 2026-02-20 cond-mat.mtrl-sci

The influence of Y content on grain structure evolution in Mg-Y alloys

Qianying Shi, Vaidehi Menon, Liang Qi, John Allison

详情
英文摘要

To advance the understanding of microstructural evolution behavior in Mg-rare earth alloys, the effect of yttrium (Y) addition on static recrystallization and grain growth in Mg alloys was systematically investigated in extruded Mg-1wt.%Y and Mg-7wt.%Y alloys. Y addition was found to significantly retard the microstructural evolution, primarily due to its solute drag effect arising from Y segregation at grain boundaries. The relative intensity of solute drag effects from different alloying elements in Mg alloys was further assessed from both thermodynamic and kinetic perspectives, considering their grain boundary segregation tendencies and diffusivities. Additionally, static recrystallization in Mg-Y alloys was observed to proceed via a two-stage behavior characterized with two distinct JMAK exponents, indicating the heterogeneous nucleation of recrystallized grains. Abnormal grain growth (AGG) behavior was observed in these Mg-Y alloys. Overall, this study highlights the critical role of Y segregation at grain boundaries in controlling recrystallization and grain growth kinetics in Mg-Y alloys. This provides new insights into the design of thermally stable Mg alloys with refined microstructures.

2602.17579 2026-02-20 math.PR math.FA

Non-equilibrium functional inequalities for finite Markov chains

Bastian Hilder, Patrick van Meurs, Upanshu Sharma

Comments 35 pages, 2 figures

详情
英文摘要

Functional inequalities such as the Poincaré and log-Sobolev inequalities quantify convergence to equilibrium in continuous-time Markov chains by linking generator properties to variance and entropy decay. However, many applications, including multiscale and non-reversible dynamics, require analysing probability measures that are not at equilibrium, where the classical theory tied to steady states no longer applies. We introduce generalised versions of these inequalities for arbitrary positive measures on a finite state space, retaining key structural properties of their classical counterparts. In particular, we prove continuity of the associated constants with respect to the reference measure and establish explicit positive lower bounds. As an application, we derive quantitative coarse-graining error estimates for non-reversible Markov chains, both with and without explicit scale separation, and propose a quantitative criterion for assessing the quality of coarse-graining maps.