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Related papers: Gauge-covariant stochastic neural fields: Stabilit…

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A class of high-order canonical symplectic structure-preserving geometric algorithms are developed for high-quality simulations of the quantized Dirac-Maxwell theory based strong-field quantum electrodynamics (SFQED) and relativistic…

Quantum Physics · Physics 2021-02-18 Qiang Chen , Jianyuan Xiao , Peifeng Fan

Using the covariant approach and conformal transformations, we present a gauge-invariant formalism for cosmological perturbations in generalized Einstein theories (GETs), including the Brans-Dicke theory, theories with a non-minimally…

Astrophysics · Physics 2010-11-01 Toshinari Hirai , Kei-ichi Maeda

Covariant stochastic partial differential equations are studied in any dimension. A special class of such equations is selected and it is proven that the solutions can be analytically continued to Minkowski space-time yielding tempered…

funct-an · Mathematics 2008-02-03 C. Becker , R. Gielerak , P. Ługiewicz

Real-world learning tasks often encounter uncertainty due to covariate shift and noisy or inconsistent labels. However, existing robust learning methods merge these effects into a single distributional uncertainty set. In this work, we…

Methodology · Statistics 2026-03-17 Varun Venkatesh , Eyke Hüllermeier , Bernd Bischl , Mina Rezaei

Scalar perturbations of Friedmann-Lemaitre cosmologies can be analyzed in a variety of ways using Einstein's field equations, the Ricci and Bianchi identities, or the conservation equations for the stress-energy tensor, and possibly…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Claes Uggla , John Wainwright

We derive a set of equations monitoring the evolution of covariant and gauge-invariant linear scalar perturbations of Friedman-Lema\^itre-Robertson-Walker models with multiple interacting non-linear scalar fields. We use a dynamical…

General Relativity and Quantum Cosmology · Physics 2014-08-06 Artur Alho , Filipe C. Mena

The hyperspherical adiabatic method is used to derive stability criteria for Bose-Einstein condensates in deformed external fields. An analytical approximation is obtained. For constant volume the highest stability is found for spherical…

Soft Condensed Matter · Physics 2009-11-10 O. Sørensen , D. V. Fedorov , A. S. Jensen

We analyze the emergent regimes and the stimulus-response relationship of a population of noisy map neurons by means of a mean-field model, derived within the framework of cumulant approach complemented by the Gaussian closure hypothesis.…

Chaotic Dynamics · Physics 2017-09-13 Igor Franovic , Oleg V. Maslennikov , Iva Bacic , Vladimir I. Nekorkin

Recent theoretical and numerical developments show analogies between quantum chromodynamics (QCD) and disordered systems in condensed matter physics. We study the spectral fluctuations of a Dirac particle propagating in a finite four…

High Energy Physics - Theory · Physics 2009-10-31 T. Guhr , T. Wilke , H. A. Weidenmueller

It has been shown that by using a Lagrange multiplier field to ensure that the classical equations of motion are satisfied, radiative effects beyond one-loop order are eliminated. It has also been shown that through the contribution of some…

High Energy Physics - Theory · Physics 2024-04-18 D. G. C. McKeon , F. T. Brandt , S. Martins-Filho

Biological neural networks are notoriously hard to model due to their stochastic behavior and high dimensionality. We tackle this problem by constructing a dynamical model of both the expectations and covariances of the fractions of active…

Neurons and Cognition · Quantitative Biology 2025-02-25 Vincent Painchaud , Patrick Desrosiers , Nicolas Doyon

Stochastic partial differential equations can be used to model second order thermodynamical phase transitions, as well as a number of critical out-of-equilibrium phenomena. In (2+1) dimensions, many of these systems are conjectured (and…

Statistical Mechanics · Physics 2013-05-29 L. Moriconi , M. Moriconi

This paper studies large deviation principles and weak convergence, both at the level of finite-dimensional distributions and in functional form, for a class of continuous, isotropic, centered Gaussian random fields defined on the unit…

Probability · Mathematics 2026-01-09 Simmaco Di Lillo , Claudio Macci , Barbara Pacchiarotti

We introduce a stochastic model to analyze in quantitative detail the effect of the high frequency components of the residual accelerations onboard spacecraft (often called g-jitter) on fluid motion. The residual acceleration field is…

Condensed Matter · Physics 2007-05-23 Jaume Casademunt , Wenbin Zhang , Jorge Vinals , R. F. Sekerka

We present a theoretical investigation of a three-level $\Lambda$-type atom driven by a strong coherent laser and a weak stochastic field exhibiting amplitude and phase fluctuations. The stochastic field is modeled as a complex…

Quantum Physics · Physics 2025-12-29 Sajad Ahmadi , Mohsen Akbari , Shahpoor Saeidian , Ali Motazedifard

Generating large-scale samples of stationary random fields is of great importance in the fields such as geomaterial modeling and uncertainty quantification. Traditional methodologies based on covariance matrix decomposition have the…

Methodology · Statistics 2022-08-23 Bin Zhu , Jiahao Liu , Zhengshou Lai , Tao Qian

The question of gauge-covariance in the non-Abelian gauge-field formulation of two space-dimensional systems with spin-orbit coupling relevant to spintronics is investigated. Although, these are generally gauge-fixed models, it is found…

Mesoscale and Nanoscale Physics · Physics 2016-01-27 M. S. Shikakhwa , S. Turgut , N. K. pak

We examine the weak coupling limit of Euclidean SU(n) gauge theory in covariant gauges. Following an earlier suggestion, an equivariant BRST-construction is used to define the continuum theory on a finite torus. The equivariant gauge fixing…

High Energy Physics - Theory · Physics 2008-11-26 Martin Schaden , Alexander Rozenberg

Gauge theories have been a cornerstone of the description of the world at the level of the fundamental particles. The Lagrangian or the action describing the corresponding interactions is invariant under certain gauge transformations. This…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Bashir , A. Raya

We study the relationship between the equations of first order Lagrangian field theory on fiber bundles and the covariant Hamilton equations on the finite-dimensional polysymplectic phase space of covariant Hamiltonian field theory. The…

High Energy Physics - Theory · Physics 2009-10-31 G. Giachetta , L. Mangiarotti , G. Sardanashvily