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Related papers: On Simplified Numerical Turbulence Models in Test-…

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We explore the influence of turbulence on the transport of energetic particles by using test-particle simulations. We compute parallel and perpendicular diffusion coefficients for two-component turbulence, isotropic turbulence, a model…

Solar and Stellar Astrophysics · Physics 2015-08-06 Mohammad Hussein , Robert Tautz , Andreas Shalchi

We use direct numerical simulations to study the evolution, or relaxation, of magnetic configurations to an equilibrium state. We use the full single-fluid equations of motion for a magnetized, non-resistive, but viscous fluid; and a…

Astrophysics · Physics 2009-10-31 S. I. Vainshtein , Z. Mikić , R. Rosner , J. A. Linker

Drift effects play a significant role in the transport of charged particles in the heliosphere. A turbulent magnetic field is also known to reduce the effects of particle drifts. The exact nature of this reduction, however, is not clear.…

Space Physics · Physics 2017-05-26 Eugene Engelbrecht , Du Toit Strauss , Kobus le Roux , Adri Burger

The microturbulent approximation of turbulent motions is widely used in radiative transfer calculations. Mainly motivated by its simple computational application it is probably in many cases an oversimplified treatment of the dynamical…

Astrophysics · Physics 2009-11-07 R. Boeger , W. H. Kegel , M. Hegmann

The turbulent diffusion tensor describing the evolution of the mean concentration of a passive scalar is investigated for non-helically forced turbulence in the presence of rotation or a magnetic field. With rotation, the Coriolis force…

Solar and Stellar Astrophysics · Physics 2009-05-09 Axel Brandenburg , Andreas Svedin , Geoffrey M. Vasil

This research was motivated by the recent observations indicating very strong magnetic fields at some supernova remnant shocks, which suggests in-situ generation of magnetic turbulence. The dissertation presents a numerical model of…

High Energy Astrophysical Phenomena · Physics 2009-04-27 Andrey Vladimirov

We introduce a Monte Carlo model of nonlinear diffusive shock acceleration allowing for the generation of large-amplitude magnetic turbulence. The model is the first to include strong wave generation, efficient particle acceleration to…

Astrophysics · Physics 2008-11-26 Andrey Vladimirov , Donald C. Ellison , Andrei Bykov

Fluid discontinuities, such as shock fronts and vortex sheets, can reflect waves and become unstable to corrugation. Analytical calculations of these phenomena are tractable in the simplest cases only, while their numerical simulations are…

Plasma Physics · Physics 2023-08-16 William Béthune

We present the results of a numerical investigation of charged-particle transport across a synthesized magnetic configuration composed of a constant homogeneous background field and a multiscale perturbation component simulating an effect…

Statistical Mechanics · Physics 2007-05-23 Francesco Chiaravalloti , Alexander V. Milovanov , Gaetano Zimbardo

The scattering of electromagnetic waves by an obstacle is analyzed through a set of partial differential equations combining the Maxwell's model with the mechanics of fluids. Solitary type EM waves, having compact support, may easily be…

Computational Physics · Physics 2018-03-28 Daniele Funaro , Eugene Kashdan

In weakly collisional extragalactic plasmas such as the intracluster medium, viscous stress and the rate of change of the magnetic-field strength are proportional to the local pressure anisotropy, so subject to constraints imposed by the…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-26 Federico Mogavero , Alexander A. Schekochihin

This article introduces a physically realistic model for explaining how electromagnetic waves can be internally generated, propagate and interact in strongly magnetized plasmas or in nuclear magnetic resonance experiments. It studies high…

Analysis of PDEs · Mathematics 2020-09-04 Remi Carles , Christophe Cheverry

We analyze a suite of thin sheet magnetohydrodynamical simulations based on the formulation of Basu, Ciolek, Dapp & Wurster. These simulations allow us to examine the observational consequences to a star-forming region of varying the input…

Solar and Stellar Astrophysics · Physics 2009-07-22 Helen Kirk , Doug Johnstone , Shantanu Basu

Vacuum instability of the strong electromagnetic field has been discussed since long time ago. The instability of the strong electric field due to creation of electron pairs is one of the examples, which is known as Schwinger process. What…

High Energy Physics - Phenomenology · Physics 2016-10-19 Hyun Kyu Lee

In general, Maxwell's equations require that a wave of magnetic field be accompanied by a wave of electric field, and vice versa. In magnetic media it is possible to have waves of magnetization with negligible electric field. We discuss an…

Classical Physics · Physics 2007-05-23 Kirk T. McDonald

We present the results of our detailed pseudospectral direct numerical simulation (DNS) studies, with up to $1024^3$ collocation points, of incompressible, magnetohydrodynamic (MHD) turbulence in three dimensions, without a mean magnetic…

Chaotic Dynamics · Physics 2011-01-31 Ganapati Sahoo , Prasad Perlekar , Rahul Pandit

The behavior of the one-dimensional random-force-driven Burgers equation is investigated in the path integral formalism on a discrete space-time lattice. We show that by means of Monte Carlo methods one may evaluate observables, such as…

High Energy Physics - Lattice · Physics 2010-11-05 P. Düben , D. Homeier , K. Jansen , D. Mesterhazy , G. Münster

The stability and dynamics of a free magnetic polaron are studied by Monte Carlo simulation of a classical two-dimensional Heisenberg model coupled to a single electron. We compare our results to the earlier mean-field analysis of the…

Strongly Correlated Electrons · Physics 2009-10-31 M. J. Calderon , L. Brey , P. B. Littlewood

We report on the experimental observation of a transition from a dispersive wave turbulence regime to a nondispersive regime involving shock waves on the surface of a fluid. We use a magnetic fluid in a canal subjected to an external…

Fluid Dynamics · Physics 2023-02-01 Guillaume Ricard , Eric Falcon

Spin-wave computing, a potential successor to CMOS-based technologies, relies on the efficient manipulation of spin waves for information processing. While basic logic devices like magnon transistors, gates, and adders have been…

Mesoscale and Nanoscale Physics · Physics 2023-11-29 Jan Klíma , Ondřej Wojewoda , Václav Roučka , Tomáš Molnár , Jakub Holobrádek , Michal Urbánek
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