English
Related papers

Related papers: Nonlinear diffusion equations for anisotropic MHD …

200 papers

We experimentally study linear and nonlinear waves on the surface of a fluid covered by an elastic sheet where both tension and flexural waves take place. An optical method is used to obtain the full space-time wave field, and the…

Fluid Dynamics · Physics 2014-02-10 Luc Deike , Jean-Claude Bacri , Eric Falcon

The multiple scattering of scalar waves in diffusive media is investigated by means of the radiative transfer equation. This approach amounts to a resummation of the ladder diagrams of the Born series; it does not rely on the diffusion…

Condensed Matter · Physics 2007-05-23 E. Amic , J. M. Luck , Th. M. Nieuwenhuizen

We consider the Allen-Cahn equation with nonlinear anisotropic diffusion and derive anisotropic direction-dependent curvature flow under the sharp interface limit. The anisotropic curvature flow was already studied, but its derivation is…

Analysis of PDEs · Mathematics 2024-03-05 Tadahisa Funaki , Hyunjoon Park

We perform direct 3-dimensional numerical simulations for magnetohydrodynamic (MHD) turbulence in a periodic box of size $2\pi$ threaded by strong uniform magnetic fields. We use a pseudo-spectral code with hyperviscosity and…

Astrophysics · Physics 2009-10-31 Jungyeon Cho , Ethan T. Vishniac

We report on three-dimensional direct numerical simulation of wave turbulence on the free surface of a magnetic fluid subjected to an external horizontal magnetic field. A transition from capillarywave turbulence to anisotropic…

Plasma Physics · Physics 2023-09-29 Evgeny Kochurin , Guillaume Ricard , Nikolay Zubarev , Eric Falcon

Turbulence in the magnetized plasma is well understood to be the consequence of wave interactions. When the Hall effect is added to the minimum magnetohydrodynamics (MHD), the MHD waves become dispersive and different nonlinear interactions…

Plasma Physics · Physics 2026-02-19 Erik C. Hansen , Prerana Sharma , Swadesh M. Mahajan

A nonlinear description for perpendicular particle diffusion in strong electromagnetic fluctuations is developed by using the fundamental Newton-Lorentz equation. Although not based on the same approach, the recently presented nonlinear…

Astrophysics · Physics 2009-11-10 O. Stawicki

For a plasma in a stationary homogeneous turbulence, the Fokker-Planck equation is derived from the nonlinear Vlasov equation by introducing the entropy principle. The ensemble average in evaluating the kinetic diffusion tensor, whose…

Plasma Physics · Physics 2016-03-23 Shaojie Wang

Galactic transport models for cosmic rays involve the diffusive motion of these particles in the interstellar medium. Due to the large-scale structured galactic magnetic field this diffusion is anisotropic with respect to the local field…

High Energy Astrophysical Phenomena · Physics 2013-06-07 Frederic Effenberger , Horst Fichtner , Klaus Scherer , Ingo Büsching

Anisotropic diffusion is imperative in understanding cosmic ray diffusion across the Galaxy, the heliosphere, and the interplay of cosmic rays with the Galactic magnetic field. This diffusion term contributes to the highly stiff nature of…

High Energy Astrophysical Phenomena · Physics 2023-08-09 Pranab J. Deka , Ralf Kissmann , Lukas Einkemmer

We interpret the forward Maxwell equation with up to third order induced polarizations and get so called nonlinear wave equation in frequency domain (NWEF), which is based on Maxwell wave equation and using slowly varying spectral amplitude…

Optics · Physics 2013-01-09 Hairun Guo , Xianglong Zeng , Morten Bache

A recently introduced nonlinear Fokker-Planck equation, derived directly from a master equation, comes out as a very general tool to describe phenomenologically systems presenting complex behavior, like anomalous diffusion, in the presence…

Statistical Mechanics · Physics 2009-11-13 Veit Schwammle , Evaldo M. F. Curado , Fernando D. Nobre

Nonlinear interactions involving electrostatic upper-hybrid (UH), ion-cyclotron (IC), lower-hybrid (LH), and Alfven waves in quantum magnetoplasmas are considered. For this purpose, the quantum hydrodynamical equations are used to derive…

Plasma Physics · Physics 2008-11-26 P. K. Shukla , S. Ali , L. Stenflo , M. Marklund

We develop a two dimensional, self-consistent, compressible fluid model to study evolution of Alfvenic modes in partially ionized astrophysical and space plasmas. The partially ionized plasma consists mainly of electrons, ions and…

Space Physics · Physics 2015-05-14 Dastgeer Shaikh

We expand the off-resonant scattering theory for particle diffusion in magnetized current filaments that can be typically compared to astrophysical jets, including active galactic nucleus jets. In a high plasma beta region where the…

Astrophysics · Physics 2009-11-13 Mitsuru Honda , Yasuko S. Honda

We derive diffusive macroscopic equations for the particle and energy density of a system whose time evolution is described by a kinetic equation for the one particle position and velocity function f(r,v,t) that consists of a part that…

Statistical Mechanics · Physics 2018-11-14 Pedro L. Garrido , Joel L. Lebowitz

We found universal anizopropic spectra of acoustic turbulence with the linear dispersion law \bbox{$\omega (k) =ck$} within the framework of generalized kinetic equation which takes into account the finite time of three-wave interactions.…

chao-dyn · Physics 2009-10-31 V. S L'vov , Yu. V. L'vov , A. Pomyalov

Alfv\'enic-type turbulence in strongly magnetized, low-beta pair plasmas is investigated. A coupled set of equations for the evolution of the magnetic and flow potentials are derived, covering both fluid and kinetic scales. In the fluid…

Plasma Physics · Physics 2018-10-31 N. F. Loureiro , S. Boldyrev

The multiple scattering of scalar waves in diffusive media is investigated by means of the radiative transfer equation. This approach, which does not rely on the diffusion approximation, becomes asymptotically exact in the regime of most…

Condensed Matter · Physics 2009-10-28 E. Amic , J. M. Luck , Th. M. Nieuwenhuizen

The silo discharge process is studied by molecular dynamics simulations. The development of the velocity profile and the probability density function for the displacements in the horizontal and vertical axis are obtained. The PDFs obtained…

Statistical Mechanics · Physics 2009-11-11 R. Arevalo , A. Garcimartin , D. Maza