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We consider Monte Carlo algorithms for the simulation of charged lattice gases with purely local dynamics. We study the mobility of particles as a function of temperature and show that the poor mobility of particles at low temperatures is…

Statistical Mechanics · Physics 2007-05-23 L. Levrel , A. C. Maggs

An exact analytical method for determining the Lagrangian velocity correlation and the diffusion coefficient for particles moving in a stochastic velocity field is derived. It applies to divergence-free 2-dimensional Gaussian stochastic…

Plasma Physics · Physics 2007-05-23 M. Vlad , F. Spineanu , J. H. Misguich , R. Balescu

The explicit semi-Lagrangian method method for solution of Lagrangian transport equations as developed in [Natarajan and Jacobs, Computer and Fluids, 2020] is adopted for the solution of stochastic differential equations that is consistent…

Computational Physics · Physics 2021-07-07 H. Natarajan , P. P. Popov , G. B. Jacobs

Numerical methods for solving the ideal magnetohydrodynamic (MHD) equations in more than one space dimension must confront the challenge of controlling errors in the discrete divergence of the magnetic field. One approach that has been…

Numerical Analysis · Mathematics 2012-10-16 Christiane Helzel , James A. Rossmanith , Bertram Taetz

Optimal transport has gained significant attention in recent years due to its effectiveness in deep learning and computer vision. Its descendant metric, the Wasserstein distance, has been particularly successful in measuring distribution…

Optimization and Control · Mathematics 2025-02-18 Kaiwen Shi

A new, very fast method for 3D radiative transfer on fully threaded grids with arbitrarily high angular resolution is presented. The method uses completely cell-based discretization, and is ideally suited for problems with diffuse…

Astrophysics · Physics 2009-11-11 A. O. Razoumov , C. Y. Cardall

The theory and numerical modelling of radiation processes and radiative transfer play a key role in astrophysics: they provide the link between the physical properties of an object and the radiation it emits. In the modern era of…

Instrumentation and Methods for Astrophysics · Physics 2019-07-24 Ulrich M. Noebauer , Stuart A. Sim

We propose a new design heuristic to tackle combinatorial optimisation problems, inspired by Hamiltonians for optimal state-transfer. The result is a rapid approximate optimisation algorithm. We provide numerical evidence of the success of…

Quantum Physics · Physics 2024-02-14 Robert J. Banks , Dan E. Browne , P. A. Warburton

The transport coefficients of the Anderson model are calculated by extending Wilson's NRG method to finite temperature Green's functions. Accurate results for the frequency and temperature dependence of the single--particle spectral…

Condensed Matter · Physics 2009-10-22 T. A. Costi , A. C. Hewson , V. Zlatic

We present the latest version of Pinocchio, a code that generates catalogues of DM haloes in an approximate but fast way with respect to an N-body simulation. This code version extends the computation of particle and halo displacements up…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-11 Emiliano Munari , Pierluigi Monaco , Emiliano Sefusatti , Emanuele Castorina , Faizan G. Mohammad , Stefano Anselmi , Stefano Borgani

We present Arepo-MCRT, a novel Monte Carlo radiative transfer (MCRT) radiation-hydrodynamics (RHD) solver for the unstructured moving-mesh code Arepo. Our method is designed for general multiple scattering problems in both optically thin…

Astrophysics of Galaxies · Physics 2020-12-16 Aaron Smith , Rahul Kannan , Benny T. -H. Tsang , Mark Vogelsberger , Ruediger Pakmor

We present an efficient numerical approach for treating ballistic quantum transport across devices described by tight binding (TB) Hamiltonians designated to systems with localized potential defects. The method is based on the wave function…

Mesoscale and Nanoscale Physics · Physics 2016-09-08 K. Kolasiński , A. Mreńca-Kolasińska , B. Szafran

The purpose of this paper is to propose a time-step-robust cell-to-cell integration of particle trajectories in 3-D unstructured meshes in particle/mesh Lagrangian stochastic methods. The main idea is to dynamically update the mean fields…

Computation · Statistics 2023-04-19 Guilhem Balvet , Jean-Pierre Minier , Christophe Henry , Yelva Roustan , Martin Ferrand

This work originates from a heart's images tracking which is to generate an apparent continuous motion, observable through intensity variation from one starting image to an ending one both supposed segmented. Given two images p0 and p1, we…

Classical Analysis and ODEs · Mathematics 2010-09-20 Olivier Besson , Martine Picq , Jérôme Pousin

Out-of-time ordered (OTO) correlation functions describe scrambling of information in correlated quantum matter. They are of particular interest in incoherent quantum systems lacking well defined quasi-particles. Thus far, it is largely…

Quantum Gases · Physics 2017-06-06 A. Bohrdt , C. B. Mendl , M. Endres , M. Knap

We work out the non-equilibrium steady state properties of a harmonic lattice which is connected to heat reservoirs at different temperatures. The heat reservoirs are themselves modeled as harmonic systems. Our approach is to write quantum…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Abhishek Dhar , Dibyendu Roy

A great deal of research has been conducted in the consideration of meta-heuristic optimisation methods that are able to find global optima in settings that gradient based optimisers have traditionally struggled. Of these, so-called…

Neural and Evolutionary Computing · Computer Science 2023-05-01 Max D. Champneys , Timothy J. Rogers

We propose a real-time time-dependent ab__initio approach within a configuration-interaction-singles ansatz to decompose the high-harmonic generation (HHG) signal of molecules in terms of individual molecular-orbital (MO) contributions.…

Chemical Physics · Physics 2025-12-11 Marco Marchetta , Chiara Morassut , Julien Toulouse , Emanuele Coccia , Eleonora Luppi

In this paper, we introduce a neural network-based method to address the high-dimensional dynamic unbalanced optimal transport (UOT) problem. Dynamic UOT focuses on the optimal transportation between two densities with unequal total mass,…

Optimization and Control · Mathematics 2024-09-23 Wei Wan , Jiangong Pan , Yuejin Zhang , Chenglong Bao , Zuoqiang Shi

We calculate the two loop hard correction to the photon self-energy in an electron-positron plasma (EPP) for arbitrary soft momenta. This provides the only missing ingredient to obtain the Hard Thermal Loop (HTL) effective Lagrangian at…

High Energy Physics - Phenomenology · Physics 2020-01-09 Stefano Carignano , Margaret E. Carrington , Joan Soto