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Related papers: Diffusive Shock Acceleration in Oblique MHD Shocks…

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Relativistic collisionless shocks are associated with efficient particle acceleration when propagating into weakly magnetized homogeneous media; as the magnetization increases, particle acceleration becomes suppressed. We demonstrate that…

High Energy Astrophysical Phenomena · Physics 2023-04-26 Camilia Demidem , Joonas Nättilä , Alexandra Veledina

We develop exact Markov chain Monte Carlo methods for discretely-sampled, directly and indirectly observed diffusions. The qualification "exact" refers to the fact that the invariant and limiting distribution of the Markov chains is the…

We present a new antithetic multilevel Monte Carlo (MLMC) method for the estimation of expectations with respect to laws of diffusion processes that can be elliptic or hypo-elliptic. In particular, we consider the case where one has to…

Numerical Analysis · Mathematics 2025-04-29 Yuga Iguchi , Ajay Jasra , Mohamed Maama , Alexandros Beskos

This study investigates the applicability of the semi-implicit particle-in-cell code FLEKS to heliospheric shock simulations. We examine one- and two-dimensional local planar shock simulations, initialized using MHD states with upstream…

Space Physics · Physics 2025-10-31 Hongyang Zhou , Yuxi Chen , Chuanfei Dong , Liang Wang , Ying Zou , Brian Walsh , Gábor Tóth

New hybrid Molecular Dynamics-Monte Carlo methods are proposed to increase the efficiency of constant-pressure simulations. Two variations of the isobaric Molecular Dynamics component of the algorithms are considered. In the first, we use…

Soft Condensed Matter · Physics 2009-11-07 Roland Faller , Juan J. de Pablo

We present a new magnetohydrodynamic (MHD) code for the simulation of wave propagation in the solar atmosphere, under the effects of electrical resistivity, but not dominant, and heat transference in a uniform 3D grid. The code is based on…

Solar and Stellar Astrophysics · Physics 2017-08-02 Anamaría Navarro , F. D. Lora-Clavijo , Guillermo A. González

The dynamics of viscous thin-film particle-laden flows down inclined surfaces are commonly modeled with one of two approaches: a diffusive flux model or a suspension balance model. The diffusive flux model assumes that the particles migrate…

Using the field-particle correlation technique, we examine the particle energization in a 1D-2V continuum Vlasov--Maxwell simulation of a perpendicular magnetized collisionless shock. The combination of the field-particle correlation…

Modelling random dynamical systems in continuous time, diffusion processes are a powerful tool in many areas of science. Model parameters can be estimated from time-discretely observed processes using Markov chain Monte Carlo (MCMC) methods…

Computation · Statistics 2020-10-12 Susanne Pieschner , Christiane Fuchs

We have developed a cosmic ray (CR) shock code in one dimensional spherical geometry with which the particle distribution, the gas flow and their nonlinear interaction can be followed numerically in a frame comoving with an expanding shock.…

Astrophysics · Physics 2009-11-11 Hyesung Kang , T. W. Jones

A kinetic Monte Carlo method was used to simulate the diffusion of reptating polymer chains across the interface. A time-resolved fluorescence technique conjunction with direct energy transfer method was used to measure the extend of…

Soft Condensed Matter · Physics 2007-05-23 Erkan Tuzel , K. Batuhan Kisacikoglu , Onder Pekcan

Recent developments in vortex particle methods for simulating three-dimensional incompressible flows are presented. A lightweight, dynamic Large-Eddy Simulation model is tested, featuring a dynamic procedure that relies solely on Lagrangian…

Fluid Dynamics · Physics 2026-01-13 Flavio A. C. Martins , Alexander van Zuijlen , Carlos J. Simao Ferreira

Statistical inference for discretely observed jump-diffusion processes is a complex problem which motivates new methodological challenges. Thus existing approaches invariably resort to time-discretisations which inevitably lead to…

Methodology · Statistics 2023-03-02 Flávio B. Gonçalves , Krzysztof G. Łatuszyński , Gareth O. Roberts

We use the Direct Simulation Monte Carlo (DSMC) method combined with an n-body code to study the dynamics of the interaction between a gas-rich spiral galaxy and intracluster or intragroup medium, often known as the ram pressure scenario.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Martin D. Weinberg

Using test particle simulations we study particle acceleration at highly perpendicular ($\theta_{Bn}\geq 75^\circ$) shocks under conditions of modeling magnetic turbulence. We adopt a backward-in-time method to solve the Newton-Lorentz…

Space Physics · Physics 2017-08-23 F. -J. Kong , G. Qin , L. -H. Zhang

In this paper, we propose and analyze a new stochastic homogenization method for diffusion equations with random and fast oscillatory coefficients. In the proposed method, the homogenized solutions are sought through a two-stage procedure.…

Numerical Analysis · Mathematics 2022-03-14 Zihao Yang , Jizu Huang , Xiaobing Feng , Xiaofei Guan

In-situ spacecraft observations recently suggested that the transport of energetic particles accelerated at heliospheric shocks can be anomalous, i.e. the mean square displacement can grow non-linearly in time. In particular, a new analysis…

Solar and Stellar Astrophysics · Physics 2015-06-01 Silvia Perri , Gaetano Zimbardo , Frederic Effenberger , Horst Fichtner

Spectroscopic observations of the 2006 outburst of the recurrent nova RS Ophiuchi at both infrared (IR) and X-ray wavelengths have shown that the blast wave has decelerated at a higher rate than predicted by the standard test-particle…

Astrophysics · Physics 2009-11-13 V. Tatischeff , M. Hernanz

In this paper we develop a direct simulation Monte Carlo (DSMC) method for simulating highly nonequilibrium dynamics of nearly degenerate ultra-cold gases. We show that our method can simulate the high-energy collision of two thermal clouds…

Quantum Gases · Physics 2012-10-16 A. C. J. Wade , D. Baillie , P. B. Blakie

The Direct Simulation Monte Carlo (DSMC) method, developed originally to calculate rarefied gas dynamical problems, is applied to continuous flow including shocks assuming that the Knudsen number is sufficiently small. In particular, we…

Astrophysics · Physics 2007-05-23 Takuya Matsuda , Hiromi Mizutani , Henri. M. J. Boffin