arXivDaily arXiv每日学术速递 周一至周五更新
重置
全部学科分类 1717
2604.00996 2026-04-02 hep-ph nucl-th

Pions reloaded

M. N. Ferreira, A. S. Miramontes, J. M. Morgado, J. Papavassiliou, J. M. Pawlowski

Comments 6 pages, 4 figures. Submitted to the proceedings of the Excited QCD Workshop 2026

详情
英文摘要

We present a novel version of the pion Bethe-Salpeter equation in the chiral limit, solved using as ingredients state-of-the-art QCD correlation functions. The constraints imposed by the axial Ward-Takahashi identities are exactly fulfilled, both formally and numerically.

2604.00995 2026-04-02 eess.SP

Robust Multidimensional Chinese Remainder Theorem (MD-CRT) with Non-Diagonal Moduli and Multi-Stage Framework

Guangpu Guo, Xiang-Gen Xia

详情
英文摘要

The Chinese remainder theorem (CRT) provides an efficient way to reconstruct an integer from its remainders modulo several integer moduli, and has been widely applied in signal processing and information theory. Its multidimensional extension (MD-CRT) generalizes this principle to integer vectors and integer matrix moduli, enabling reconstruction in multidimensional signal processing scenarios. However, since matrices are generally non-commutative, the multidimensional extension introduces new theoretical and algorithmic challenges. When all matrix moduli are diagonal, the system is equivalent to applying the one-dimensional CRT independently along each dimension. This work first investigates whether non-diagonal (non-separable) moduli offer fundamental advantages over traditional diagonal ones. We show that under the same determinant constraint, non-diagonal matrices do not increase the dynamic range but yield more balanced and better-conditioned sampling patterns. More importantly, they generate lattices with longer shortest vectors, leading to higher robustness to vector remainder errors, compared to diagonal ones. To further improve the robustness, we develop a multi-stage robust MD-CRT framework that improves the robustness level without reducing the dynamic range. Due to the multidimensional nature and modulo matrix forms, it is challenging and not straightforward to extend the existing one-dimensional multi-stage robust CRT. In this paper, we obtain a new condition for matrix moduli, which can be easily checked, such that a multi-stage robust MD-CRT can be implemented. Both theoretical analysis and simulation results demonstrate that the proposed multi-stage robust MD-CRT achieves stronger error tolerance and more reliable reconstruction under erroneous vector remainders than that of single-stage robust MD-CRT.

2604.00992 2026-04-02 eess.SY cs.SY

Tube-Based Safety for Anticipative Tracking in Multi-Agent Systems

Armel Koulong, Ali Pakniyat

Comments This work has been submitted to the 65th IEEE Conference on Decision and Control for possible publication

详情
英文摘要

A tube-based safety framework is presented for robust anticipative tracking in nonlinear Brunovsky multi-agent systems subject to bounded disturbances. The architecture establishes robust safety certificates for a feedforward-augmented ancillary control policy. By rendering the state-deviation dynamics independent of the agents' internal nonlinearities, the formulation strictly circumvents the restrictive Lipschitz-bound feasibility conditions otherwise required for robust stabilization. Consequently, this structure admits an explicit, closed-form robust positively invariant (RPI) tube radius that systematically attenuates the exponential control barrier function (eCBF) tightening margins, thereby mitigating constraint conservatism while preserving formal forward invariance. Within the distributed model predictive control (MPC) layer, mapping the local tube radii through the communication graph yields a closed-form global formation error bound formulated via the minimum singular value of the augmented Laplacian. Robust inter-agent safety is enforced with minimal communication overhead, requiring only a single scalar broadcast per neighbor at initialization. Numerical simulations confirm the framework's efficacy in safely navigating heterogeneous formations through cluttered environments.

2604.00990 2026-04-02 hep-ph hep-th

Quantum effects on neutrino parameters from a flavored gauge boson

Alejandro Ibarra, Lukas Treuer

Comments 16 pages, 7 figures

详情
英文摘要

We calculate the one-loop renormalization group equations of the neutrino mass matrix when the Standard Model particle content is extended with a massive gauge boson which has family-dependent couplings to the left-handed leptons. We show that quantum effects induced by the extra gauge boson increase the rank of the neutrino mass matrix at the one-loop level, in contrast to the well-known result that Standard Model fields can only increase the rank at the two-loop level. We also discuss the possibility of generating dynamically the measured mass differences and mixing angles between the active neutrinos in scenarios with normal and inverted mass ordering.

2604.00989 2026-04-02 math.AG

Perverse Schober Structures for Conifold Degenerations

Abdul Rahman

详情
英文摘要

We study a one parameter degeneration of Calabi Yau threefolds whose central fiber contains a single ordinary double point. Using the nearby and vanishing cycle formalism, we construct a canonical perverse object on the singular fiber from the variation morphism between vanishing and nearby cycles. We show that this object restricts to the constant perverse sheaf on the smooth locus and differs from the intersection complex by a single rank one contribution supported at the node. Thus the object isolates the vanishing cycle contribution associated with the conifold degeneration in a canonical sheaf theoretic form. We also explain how this construction aligns with the rank-one Picard Lefschetz phenomenon that appears categorically through spherical monodromy, making it a natural comparison object for the decategorified effect of spherical twists in the ordinary double point case.

2604.00984 2026-04-02 nucl-th hep-th math-ph math.MP

Exact interpolation between Fick and Cattaneo diffusion in relativistic kinetic theory

Lorenzo Gavassino

Comments 10 pages, 4 figures, comments welcome!

详情
英文摘要

We construct a family of exactly solvable relativistic kinetic theories in $1+1$ dimensions whose hydrodynamic sector continuously interpolates between Fick's and Cattaneo's laws of diffusion. The interpolation is controlled by a single parameter $a\in[0,1]$, which tunes the microscopic scattering dynamics from infinitely soft but infinitely frequent scatterings ($a=0$), reproducing standard diffusion, to maximally hard but finite-rate scatterings ($a=1$), yielding hyperbolic Cattaneo-type transport. For intermediate values of $a$, the dynamics combines frequent weak scatterings with rare strong randomizing events, providing a concrete microscopic realization of mixed diffusive-telegraphic behavior. Remarkably, the full quasinormal mode spectrum can be obtained analytically for all $a$. This allows us to track explicitly how purely diffusive modes continuously deform into damped propagating modes as the collision structure is varied.

2604.00982 2026-04-02 eess.AS

VisG AV-HuBERT: Viseme-Guided AV-HuBERT

Aristeidis Papadopoulos, Rishabh Jain, Naomi Harte

Comments Includes Supplementary Material. Accepted for Publication at International Conference on Pattern Recognition 2026 - ICPR 2026. Code is available at https://github.com/aristosp/visg_avhubert

详情
英文摘要

Audio-Visual Speech Recognition (AVSR) systems nowadays integrate Large Language Model (LLM) decoders with transformer-based encoders, achieving state-of-the-art results. However, the relative contributions of improved language modelling versus enhanced audiovisual encoding remain unclear. We propose Viseme-Guided AV-HuBERT (VisG AV-HuBERT), a multi-task fine-tuning framework that incorporates auxiliary viseme classification to strengthen the model's reliance on visual articulatory features. By extending AV-HuBERT with a lightweight viseme prediction sub-network, this method explicitly guides the encoder to preserve visual speech information. Evaluated on LRS3, VisG AV-HuBERT achieves comparable or improved performance over the baseline AV-HuBERT, with notable gains under heavy noise conditions. WER reduces from 13.59% to 6.60% (51.4% relative improvement) at -10 dB Signal-to-Noise Ratio (SNR) for Speech noise. Deeper analysis reveals substantial reductions in substitution errors across noise types, demonstrating improved speech unit discrimination. Evaluation on LRS2 confirms generalization capability. Our results demonstrate that explicit viseme modelling enhances encoder representations, and provides a foundation for enhancing noise-robust AVSR through encoder-level improvements.

2604.00981 2026-04-02 astro-ph.SR

High-Precision Near-Infrared Abundances of Solar Analogs in the YJ Bands

Noriyuki Matsunaga, Takuji Tsujimoto, Daisuke Taniguchi, Hiroaki Sameshima, Shogo Otsubo, Tomomi Takeuchi, Yuki Sarugaku, Ilaria Petralia, Scarlet Elgueta, Matilde Coello-Guzman, Kei Fukue, Yuji Ikeda, Hideyo Kawakita, Valentina D'Orazi, Giuseppe Bono

Comments 24 pages, 8 figures, accepted for publication in ApJS

详情
英文摘要

We present a near-infrared abundance analysis of 46 solar analogs with known ages, observed with the WINERED WIDE-mode spectrograph at a resolution of $λ/Δλ= 28,000$. Using an empirically calibrated, line-by-line approach in the $YJ$ bands (0.976--1.089 and 1.182--1.319~{$μ$}m), we derive abundances for 16 elements. Despite the intrinsic weakness of near-infrared phosphorus diagnostics, the combination of five P\,{\sc i} lines yields a typical uncertainty half-width of $\sim$0.04~dex, providing an estimate of the internal precision over the solar-analog sample. For other elements, the internal precision ranges from $\sim$0.01~dex for Fe and Si to over 0.05--0.14~dex for elements with only a couple of lines available. The resulting per-object abundances for various elements are consistent with previous measurements using high-precision optical spectra with residuals of 0.03--0.2~dex depending on the element. The inferred age--[X/Fe] relations reproduce known trends for the thin disk, while extending them to elements difficult to access in the optical, including P and K. We find the slope of the age--[P/Fe] relation is steeper than that for $α$ elements, which provides an empirical constraint for future modeling of Galactic phosphorus evolution. In addition, we publish a high signal-to-noise (S/N 500--1000) reference spectrum constructed by combining solar-analog spectra, together with the spectra of individual stars, and an empirically calibrated line list with per-line zero-point corrections, for future near-infrared spectroscopic studies.

2604.00980 2026-04-02 astro-ph.GA

A subgrid model for chemical enrichment in cosmological simulations

Camila A. Correa, Joop Schaye, Matthieu Schaller, James W. Trayford, Evgenii Chaikin, Alejandro Benitez-Llambay, Carlos S. Frenk, Sylvia Ploeckinger, Alexander J. Richings

Comments Accepted for publication in MNRAS

详情
英文摘要

We present the modules for stellar nucleosynthesis, stellar mass loss, and turbulent diffusion of the new COLIBRE subgrid model for cosmological hydrodynamical simulations of galaxy formation. COLIBRE models the thermal evolution of the multi-phase interstellar medium, dust grains, star formation, and stellar and AGN feedback. This work focuses on the model for chemical enrichment. We track the evolution of 12 chemical elements produced by a broad range of nucleosynthetic channels, including core-collapse supernovae and stellar winds, Type Ia supernovae, and asymptotic giant branch (AGB) stars. Enrichment from $s$- and $r$-process elements is modelled via contributions from AGB stars, neutron star mergers, common envelope supernovae, and collapsars. We present an updated compilation of stellar yields taken from the literature, which we release alongside this work. Small-scale element mixing is implemented through a turbulent diffusion process. While diffusion has only a minimal impact on basic integrated galaxy properties, it does reduce the slope of the gas-phase metallicity-mass relation compared with simulations that do not include it. The distribution of element ratios of individual stellar particles is sensitive to diffusion, but only at low metallicities ($Z \lesssim 10^{-1}\,\rm{Z}_\odot$). The model is tested using redshift $z=0$ results from a set of cosmological simulations, mostly of (25 Mpc)$^3$ volumes, demonstrating generally good agreement with Milky Way stellar abundance trends from the APOGEE survey. The model also reproduces the alpha-element enhancement relations observed in galaxies from SDSS, ATLAS-3D, and the Local Group.

2604.00976 2026-04-02 math.SP math.AP

On the Effectless Cut Method for Laplacian Eigenvalues in any dimensions

Vincenzo Amato, Nunzia Gavitone, Francesca de Giovanni

详情
英文摘要

In this paper, we study the optimization of the first Laplacian eigenvalue on axisymmetric doubly connected domains under positive Robin boundary conditions. Under additional geometric constraints, we prove that spherical shells maximize this eigenvalue. Our approach combines known isoperimetric inequalities for mixed Laplacian eigenvalues with a higher-dimensional extension of the effectless cut technique introduced by Hersch to study multiply connected membranes of given area fixed along their boundaries.

2604.00975 2026-04-02 hep-ph

How uncertain are model predictions for the muon content of extensive air showers

Sergey Ostapchenko

Comments Contribution to the 2026 Very High Energy Phenomena in the Universe session of the 60th Rencontres de Moriond

详情
英文摘要

The relation of model predictions for muon content of extensive air showers (EAS) to particular properties of hadron-air interactions is discussed. Further, using a new Monte Carlo generator of cosmic ray interactions, QGSb, the relevance of particular interaction mechanisms to the predicted EAS muon number is studied in some detail. The corresponding constraints imposed by accelerator measurements are discussed as well.

2604.00970 2026-04-02 math.NT hep-th

One-loop $p$-adic string theory and the Néron local height function

An Huang, Christian Jepsen

Comments 12 pages, 1 figure

详情
英文摘要

The $p$-adic string worldsheet action on the quotient of the Bruhat-Tits tree of $PGL(2,\mathbb{Q}_p)$ by a genus 1 Schottky group has a dual description on the asymptotic boundary, the Tate curve $\mathbb{Q}_p^\ast/q^\mathbb{Z}$. We show that the two point function of the dual action coincides with the Néron-Tate local height function of the Tate curve.

2604.00968 2026-04-02 cs.HC

FlexAI: A Multi-modal Solution for Delivering Personalized and Adaptive Fitness Interventions

Shivangi Agarwal, Zoya Ghoshal, Bharat Jain, Siddharth Siddharth

详情
英文摘要

Personalization of exercise routines is a crucial factor in helping people achieve their fitness goals. Despite this, many contemporary solutions fail to offer real-time, adaptive feedback tailored to an individual's physiological states. Contemporary fitness solutions often rely only on static plans and do not adjust to factors such as a user's pain thresholds, fatigue levels, or form during a workout routine. This work introduces FlexAI, a multi-modal system that integrates computer vision, physiological sensors (heart rate and voice), and the reasoning capabilities of Large Language Models (LLMs) to deliver real-time, personalized workout guidance. FlexAI continuously monitors a user's physical form and level of exertion, among other parameters, to provide dynamic interventions focused on exercise intensity, rest periods, and motivation. To validate our system, we performed a technical evaluation confirming our models' accuracy and quantifying pipeline latency, alongside an expert review where certified trainers validated the correctness of the LLM's interventions. Furthermore, in a controlled study with 25 participants, FlexAI demonstrated significant improvements over a static, non-adaptive control system. With FlexAI, users reported significantly greater enjoyment, a stronger sense of achievement, and significantly lower levels of boredom and frustration. These results indicate that by integrating multi-modal sensing with LLM-driven reasoning, adaptive systems like FlexAI can create a more engaging and effective workout experience. Our work provides a blueprint for integrating multi-modal sensing with LLM-driven reasoning, demonstrating that it is possible to create adaptive coaching systems that are not only more engaging but also demonstrably reliable.

2604.00967 2026-04-02 cs.LO

The Varieties of Ought-Implies-Can and Deontic STIT Logic

Kees van Berkel, Tim S. Lyon

Comments Published at Deontic Logic and Normative Systems - 15th International Conference, DEON 2020/21, Munich, Germany [virtual], July 21-24, 2021. URL to Published Version: https://www.collegepublications.co.uk/DEON/Van%20Berkel%20%26%20Lyon_DEON2020.pdf

详情
英文摘要

STIT logic is a prominent framework for the analysis of multi-agent choice-making. In the available deontic extensions of STIT, the principle of Ought-implies-Can (OiC) fulfills a central role. However, in the philosophical literature a variety of alternative OiC interpretations have been proposed and discussed. This paper provides a modular framework for deontic STIT that accounts for a multitude of OiC readings. In particular, we discuss, compare, and formalize ten such readings. We provide sound and complete sequent-style calculi for all of the various STIT logics accommodating these OiC principles. We formally analyze the resulting logics and discuss how the different OiC principles are logically related. In particular, we propose an endorsement principle describing which OiC readings logically commit one to other OiC readings.

2604.00965 2026-04-02 math.NA cs.NA

Understanding Transformers and Attention Mechanisms: An Introduction for Applied Mathematicians

Michel Fabrice Serret

Comments 13 pages, 9 figures

详情
英文摘要

This document provides a brief introduction to the attention mechanism used in modern language models based on the Transformer architecture. We first illustrate how text is encoded as vectors and how the attention mechanism processes these vectors to encode semantic information. We then describe Multi-Headed Attention, examine how the Transformer architecture is built and look at some of its variants. Finally, we provide a glimpse at modern methods to reduce the computational and memory cost of attention, namely KV caching, Grouped Query attention and Latent Attention. This material is aimed at the applied mathematics community and was written as introductory presentation in the context of the IPAM Research Collaboration Workshop entitled "Randomized Numerical Linear Algebra" (RNLA), for the project: "Randomization in Transformer models".

2604.00964 2026-04-02 astro-ph.SR

On the variability of the reflection nebula Van den Bergh 27 surrounding RY Tau

Harald Strauss, Klaus Bernhard

Comments 9 pages, 9 figures

详情
Journal ref
BAV Journal No. 109, April 2026
英文摘要

We present an analysis of the short- and long-term optical variability in Van den Bergh 27 (vdB 27), the reflection nebula surrounding RY Tau. The observed variations form a light-echo pattern, with apparent propagation speeds varying across different regions of the nebula and reaching up to approximately 3.6 c, consistent with geometric projection effects. The observed variations in nebular surface brightness are consistent with changes in illumination from the central star.

2604.00962 2026-04-02 hep-ph

Mass relations in heavy hadrons from Jensen-like inequalities

Wen-Xuan Zhang, Wen-Nian Liu, Duojie Jia

Comments 5 pages, 1 figure, 4 tables

详情
英文摘要

We demonstrate that mass inequalities for hadrons with one or more heavy quarks arise primarily from the concavity of binding energies in the quark model, reflecting short-range Coulombic interactions and long-range confinement. Empirical two-body bindings $B_{i\bar{j}}$ are extracted from spin-averaged meson masses, ensuring model independence and direct use of experimental data. Fitting these as functions of reduced mass $μ_{ij}$ reveals a critical confinement scale of 1.34~fm where bindings turn positive. The concave $B(1/μ)$ justifies Jensen-like inequalities under flavor permutation, reproducing relations like $m_{x\bar{y}} > \frac{1}{2}(m_{x\bar{x}} + m_{y\bar{y}})$ and baryon analogs, including $m_{xyz} > \frac{1}{3}(m_{xxx} + m_{yyy} + m_{zzz})$. Hadron mass decomposition validates $ΔM_{\textrm{EXP}} \approx ΔB + ΔC$ with $σ\sim 2.07$~MeV for mesons and baryons. Promoting inequalities to equalities, we predict masses for unobserved heavy baryons (e.g., $M(Ω_{b}^{\ast})=6076.6\,$MeV, $M(Ξ_{cc}^{\ast})=3703.6\,$MeV and $M(Ω_{cc}^{\ast})=3802.4\,$MeV) and identify favored quark-exchange scattering channels.

2604.00961 2026-04-02 stat.ME

Bayesian Multi-Group Functional Factor Models with Parameter-Expanded Cumulative Shrinkage Priors

Xuanye Dai, Anna Gottard, Michele Guindani, Marina Vannucci

详情
英文摘要

Functional data consist of trajectories observed over a continuous domain, such as time, space, or wavelength. Here we consider curves observed on different groups of subjects and propose a Bayesian multi-group functional factor analysis framework that jointly models the data via an explicit decomposition into group-specific mean functions and latent components that capture both common and distinct latent structures across the groups. We represent these functional components as linear combinations of a common set of B-spline bases, achieving a low-rank representation of the latent factors. We further impose a parameter-expanded cumulative shrinkage process prior on the factor loadings, which induces increasing shrinkage and automatically selects the number of active shared and group-specific factors. We evaluate the model's performance through simulation studies and show that the model accurately recovers the number of underlying factors and effectively distinguishes variations in functional observations driven by shared versus group-specific complex structures under various scenarios. For real data analysis, we apply the model to EEG data on alcoholic and healthy subjects and identify shared latent factors, that capture canonical characteristic components of the EEG curves, along with group-specific factors that reveal specific neural activity patterns.

2604.00960 2026-04-02 gr-qc astro-ph.CO hep-ph hep-th

Stability analysis and double critical phenomenon in the Einstein-Maxwell-scalar theory

Zi-Qiang Zhao, Mei-Ling Yan, Zhang-Yu Nie, Jing-Fei Zhang, Xin Zhang

Comments 9 pages, 11 figures

详情
英文摘要

We investigate the dynamical stability and phase transition behavior in a holographic superfluid model incorporating higher-order self-interaction terms $λ|ψ|^4$, $τ|ψ|^6$, and a non-minimal coupling $h(ψ)=e^{α|ψ|^2}$. Thermodynamic and dynamical stability analyzes show that the thermodynamic stability and dynamical stability of the system are consistent. Phase diagram analysis reveals rich critical and supercritical phenomena. For fixed $λ<0$ and $α$, increasing $τ$ shrinks the first-order phase transition region to a critical point and then enters the supercritical region. When varying $α$, the system can exhibit no critical point and, most notably, a double critical phenomenon in which, as $α$ increases, the system first enters the supercritical region and then re-enters the first-order phase transition region. This double critical phenomenon driven by a single parameter is reported for the first time in holographic superfluid models, revealing a complex nonmonotonic coupling effect between the non-minimal coupling and higher-order interaction terms.

2604.00957 2026-04-02 math.AP

On the equivalence of generalized solution concepts for systems of hyperbolic conservations laws in fluid dynamics

Thomas Eiter, Robert Lasarzik, Emil Wiedemann

详情
英文摘要

We investigate the relation between several generalized solution concepts for nonlinear PDE systems from fluid dynamics. More precisely, we study measure-valued solutions, dissipative weak solutions, and energy-variational solutions. For the incompressible Euler equations, we prove the equivalence of all three concepts, provided that the energy inequality is formulated in the appropriate way. For several important examples of conservation laws arising in fluid dynamics, we establish the equivalence between energy-variational and suitably refined dissipative weak solutions, where the defect measures are controlled sharply by the energy defect. These examples comprise the compressible isentropic Euler system, the Euler--Korteweg system, and the Euler--Poisson system.

2604.00956 2026-04-02 stat.ME stat.AP

Model Assisted Data Integration: An unbiased sampling strategy to use nonprobability data

Martin Hyllienmark, Gustaf Strandell

详情
英文摘要

The aim of survey statistics is to produce estimates with a minimal bias and a corresponding acceptable variance given a specific budget, preferable with a minor response burden for the participants. In recent years, considerable efforts have been made to achieve this through the extended use of found or non-probability data. However, to be able to safely utilize such data, rigorous theoretical foundations is needed, where one main concern is the of lack control due to not having access to the selection mechanism for the data. Several methods have been proposed in the literature to deal with this, though often relying on assumptions that may be difficult or impossible to verify in practice. Extending on the Data Integrated (DI) estimator introduced by Kim and Tam (2021), this paper introduce the Model Assisted Data Integration (MADI) sampling strategy. The proposed sampling strategy includes an estimator that has the desired properties: it is design-unbiased, has a design-unbiased variance estimator and is suitable for the intense production cycle of the statistical agency. The estimator uses nonprobability data combined with a probability sample that has a sampling design which aims to include individuals not captured by the nonprobability data. The estimator can use arbitrary machine learning models to produce unbiased estimates. A main conclusion of the paper is that the proposed sampling strategy can produce estimates with much lower variances compared to traditional survey estimators, and we use real empirical data to illustrate this point.

2604.00954 2026-04-02 cs.DS

Round-efficient Fully-scalable MPC algorithms for k-Means

Shaofeng H. -C. Jiang, Yaonan Jin, Jianing Lou, Weicheng Wang

详情
英文摘要

We study Euclidean $k$-Means under the Massively Parallel Computation (MPC) model, focusing on the \emph{fully-scalable} setting. Our main result is a fully-scalable $O((\log n/\log\log n)^2)$-approximation in $O(1)$ rounds. Previously, fully-scalable algorithms for $k$-Means either run in super-constant $O(\log\log n \cdot \log\log\log n)$ rounds, albeit with a better $O(1)$-approximation [Cohen-Addad et al., SODA'26], or suffer from bicriteria guarantees [Bhaskara and Wijewardena, ICML'18; Czumaj et al., ICALP'24]. Our algorithm also gives an $O(\log n/\log\log n)$-approximation for $k$-Median, which improves a recent $O(\log n)$-approximation [Goranci et al., SODA'26], and this $o(\log n)$ ratio breaks the fundamental barrier of tree embedding methods used therein. Our main technical contribution is a new variant of the MP algorithm [Mettu and Plaxton, SICOMP'03] that works for general metrics, whose new guarantee is the Lagrangian Multiplier Preserving (LMP) property, which, importantly, holds even under arbitrary distance distortions. Allowing distance distortion is crucial for efficient MPC implementations and useful for efficient algorithm design in general, whereas preserving the LMP property under distance distortion is known to be a significant technical challenge. As a byproduct of our techniques, we also obtain an $O(1)$-approximation to the optimal \emph{value} in $O(1)$ rounds, which conceptually suggests that achieving a true $O(1)$-approximation (for the solution) in $O(1)$ rounds may be a sensible goal for future study.

2604.00952 2026-04-02 hep-ph

Renormalization-group-improved constraints on dimension-7 baryon-number-violating operators

Yi Liao, Xiao-Dong Ma, Xiang Zhao

Comments 13 pages, 2 figures

详情
英文摘要

We study constraints on dimension-7 SMEFT baryon-number-violating operators from nucleon decays by incorporating full renormalization group (RG) running effects. At high new physics scales, we demonstrate that RG running effects help set stringent bounds on all 297 Wilson coefficients compared to the tree-level analysis in which only coefficients involving the first and second fermion generations could be constrained. Our findings highlight that the RG running effects through Yukawa mixings are particularly important for indirectly probing operators involving the second and third generation fermions.

2604.00951 2026-04-02 stat.CO

Quantum Statistical Bootstrap

Yongkai Chen, Ping Ma, Wenxuan Zhong

详情
英文摘要

The bootstrap is a foundational tool in statistical inference, but its classical implementation relies on Monte Carlo resampling, introducing approximation error and incurring high computational cost -- especially for large datasets and complex models. We present the Quantum Bootstrap (QBOOT), a quantum algorithm that computes the ideal bootstrap estimate exactly by encoding all possible resamples in quantum superposition, evaluating the target statistic in parallel, and extracting the aggregate via quantum amplitude estimation. Under mild circuit efficiency assumptions, QBOOT achieves a near-quadratic speedup over the classical bootstrap in approximating the ideal estimator, independent of the statistic or underlying distribution. We provide a rigorous theoretical analysis of its statistical error properties -- addressing a gap in the quantum algorithms literature -- and validate our results through experiments on the IBM quantum simulator for the sample mean problem. Our findings demonstrate that QBOOT preserves the asymptotic properties of the ideal bootstrap while substantially improving computational efficiency and precision, establishing a scalable and principled framework for quantum statistical inference.

2604.00950 2026-04-02 eess.SY cs.SY

Mean-Field Control of Adherence in Participation-Coupled Vehicle Rebalancing Systems

Avalpreet Singh Brar, Rong Su, Jaskaranveer Kaur, Gioele Zardini

详情
英文摘要

Human driver participation is a critical source of uncertainty in Mobility-on-Demand (MoD) rebalancing. Drivers follow platform recommendations probabilistically, and their willingness to comply evolves with experienced outcomes. This creates a closed-loop feedback in which stronger recommendations increase participation, participation increases congestion, congestion lowers allocation success, and realized allocations update adherence beliefs. We propose a microscopic stochastic model that couples (i) belief-driven participation, (ii) Poisson demand, (iii) uniform matching, and (iv) Beta--Bernoulli belief updates. Under a large-population closure, we derive a deterministic mean-field recursion for the population adherence state under platform actuation. For i.i.d. Poisson demand and constant recommendation intensity, we prove global well-posedness and invariance of the recursion, establish equilibrium existence, provide uniqueness conditions, and show global convergence in the regime where platform recommendations are no weaker than baseline participation. We then define steady-state adherence and throughput, characterize the induced performance frontier, and show that adherence and throughput cannot, in general, be simultaneously maximized under uniform time-invariant actuation. This yields a throughput-maximization problem with an adherence floor. Exploiting the monotone frontier structure, we show the optimal uniform time-invariant policy is the maximal feasible recommendation intensity and provide an efficient bisection-based algorithm.

2604.00949 2026-04-02 quant-ph physics.comp-ph

Two-Qubit Implementation of QAOA for MAX-CUT on an NV-Center Quantum Processor

Leon E. Röscher, Talía L. M. Lezama, Luca Cimino, Jonah vom Hofe, Riccardo Bassoli, Frank H. P. Fitzek

详情
英文摘要

We report a proof-of-principle implementation of the quantum approximate optimization algorithm (QAOA) for the smallest nontrivial MAX-CUT instance on an NV-center-based quantum processor operating at room temperature. The two-qubit register is encoded in the electron spin and the ${}^{14}\mathrm{N}$ nuclear spin of a single NV$^-$ center. Using a minimization formulation of MAX-CUT, we implement a single-layer QAOA ansatz with native entangling and single-qubit control operations. Because the optical readout of the NV$^-$ center is not projective in the computational basis, we reconstruct computational-basis populations from averaged fluorescence signals and use them to determine the experimental QAOA cost landscape by scanning the variational parameters. These results show that the core elements of QAOA can be realized on this platform and establish a baseline for future improvements in phase tracking, coherence-preserving control, and scaling to larger problem sizes.

2604.00948 2026-04-02 math.NA cs.NA

Physics-informed neural networks for solving two-phase flow problems with moving interfaces

Qijia Zhai, Pengtao Sun, Xiaoping Xie, Xingwen Zhu, Chen-Song Zhang

详情
英文摘要

In this paper, a meshfree method using physics-informed neural networks (PINNs) is developed for solving two-phase flow problems with moving interfaces, where two immiscible fluids bearing different material properties, are separated by a dynamically evolving interface and interact with each other through interface conditions. Two kinds of distinct scenarios of interface motion are addressed: the prescribed interface motion whose moving velocity is explicitly given, and the solution-driven interface motion whose evolution is determined by the velocity field of two-phase flow. Based upon piecewise deep neural networks and spatiotemporal sampling points/training set in each fluid subdomain, the proposed PINNs framework reformulates the two-phase flow moving interface problem as a least-squares (LS) minimization problem, which involves all residuals of governing equations, interface conditions, boundary conditions and initial conditions. Furthermore, approximation properties of the proposed PINNs approach are analyzed rigorously for the presented two-phase flow model by employing the Reynolds transport theorem in evolving domains, moreover, a comprehensive error estimation is provided to account for additional complexities introduced by the moving interface and the coupling between fluid dynamics and interface evolution. Numerical experiments are carried out to illustrate the effectiveness of the proposed PINNs approach for various configurations of two-phase flow moving interface problems, and to validate the theoretical findings as well. A practical guidance is thus provided for an efficient training set distribution when applying the proposed PINNs approach to two-phase flow moving interface problems in practice.

2604.00945 2026-04-02 cs.CY

A Visionary Look at Vibe Researching

Yebo Feng, Yang Liu

详情
英文摘要

Vibe researching is an emerging paradigm in which human researchers provide high-level direction and critical judgment while LLM-based agents handle the labor-intensive execution of literature review, experimentation, data analysis, and manuscript drafting. Inspired by the "vibe coding" movement in software engineering, it occupies a middle ground between traditional manual research and fully autonomous AI research systems. This paper defines the concept, describes its methodology (multi-agent architectures, memory, tool use, retrieval-augmented generation, and the human's role as orchestrator), identifies seven technical limitations, weighs its positive and negative societal impacts, and maps each problem to a concrete future direction. Our goal is to provide the research community with a clear and honest map of the territory so that the conversation about responsible adoption can start from shared ground.

2604.00943 2026-04-02 physics.soc-ph

Women's mobility networks enable more efficient travel

Sílvia de Sojo, Sune Lehmann, Laura Alessandretti

详情
英文摘要

Our understanding of gender differences in mobility is marked by a clear tension: surveys portray women's movements as more complex than men's, while digital traces suggest less diverse travel. Here, we resolve the contradiction by modeling trajectories as networks of sequential visits, using smartphone traces linked to self-reported gender for 543,155 individuals across 10 countries. We show that the apparent conflict in the literature arises because women's mobility networks are simultaneously more clustered and more home-anchored -- a nuance obscured by aggregate metrics. This pattern arises because women tend to link multiple destinations within single trips, for trips spanning up to 150 km and multiple days. This organization yields systematically higher travel efficiency, measured as distance saved through destination chaining over monthly sequences.

2604.00941 2026-04-02 math.DS

Characterization of Safe Stabilization and Control Lyapunov-Barrier Functions via Zubov Equation Formulation

Yiming Meng, Jun Liu

详情
英文摘要

Design and analysis of stabilizing controllers with safety guarantees for nonlinear systems have received considerable attention in recent years. Control Lyapunov-barrier functions (CLBFs) provide a powerful framework for simultaneously ensuring stability and safety; however, their construction for nonlinear systems remains challenging. To address this issue, we build on recent advances in PDE-based characterizations of control Lyapunov functions and Lyapunov-barrier functions for autonomous systems, and propose a succinct Zubov-HJB PDE formulation for safe stabilization of nonlinear control-affine systems under a common compatibility assumption. We further show that the viscosity solution of this PDE yields a maximal CLBF, enabling (not necessarily continuous) feedback synthesis with stability and safety guarantees. In light of recent advances in neural-network-based methods for solving Zubov-type PDEs, this theoretical framework also provides a natural interface to emerging numerical approaches.