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We present numerical simulations of driven magnetohydrodynamic (MHD) turbulence with weak/moderate imposed magnetic fields. The main goal is to clarify dynamics of magnetic field growth. We also investigate the effects of the imposed…

Astrophysics · Physics 2011-02-11 J. Cho , E. Vishniac , A. Beresnyak , A. Lazarian , D. Ryu

Previous theoretical work has speculated about the existence of double-diffusive magnetic buoyancy instabilities of a dynamically evolving horizontal magnetic layer generated by the interaction of forced vertically sheared velocity and a…

Solar and Stellar Astrophysics · Physics 2009-08-17 Lara J. Silvers , Geoffrey M. Vasil , Nicholas H. Brummell , Michael R. E. Proctor

The mean plane-of-sky magnetic field strength is traditionally obtained from the combination of polarization and spectroscopic data using the Davis-Chandrasekhar-Fermi (DCF) technique. However, we identify the major problem of the DCF to be…

Astrophysics of Galaxies · Physics 2022-08-31 A. Lazarian , Ka Ho Yuen , Dmitri Pogosyan

Isotropic homogeneous hydromagnetic turbulence is studied using numerical simulations at resolutions of up to 1024^3 meshpoints. It is argued that, in contrast to the kinematic regime, the nonlinear regime is characterized by a spectral…

Astrophysics · Physics 2007-05-23 A. Brandenburg , N. E. L. Haugen , W. Dobler

In the present study we investigate electrostatic stabilization mechanisms acting on stratified fluids. Electric fields have been shown to control and even suppress the Rayleigh-Taylor instability when a heavy fluid lies above lighter…

Fluid Dynamics · Physics 2013-10-15 Radu Cimpeanu , Demetrios T. Papageorgiou

We present a new mechanism for generation of large-scale magnetic field by thermal convection which does not involve the alpha-effect. We consider weakly nonlinear perturbations of space-periodic steady convective magnetic dynamos in a…

Fluid Dynamics · Physics 2015-12-01 Roman Chertovskih , Vladislav Zheligovsky

Disorder-induced spectral correlations of mesoscopic quantum systems in the non-diffusive regime and their effect on the magnetic susceptibility are studied. We perform impurity averaging for non-translational invariant systems by combining…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Edward McCann , Klaus Richter

Some recent results and open issues in magnetic dynamo theory are addressed. The distinction between small-scale and mean-field dynamo (MFD) action in forced turbulent flows is emphasized. Though useful, the MFD has been controversial. This…

Astrophysics · Physics 2007-05-23 Eric G. Blackman

We study the linear stability of weakly magnetized differentially rotating plasmas in both collisionless kinetic theory and Braginskii's theory of collisional, magnetized plasmas. We focus on the very weakly magnetized limit that is…

Astrophysics of Galaxies · Physics 2015-06-23 Eliot Quataert , Tobias Heinemann , Anatoly Spitkovsky

This study considers advective and diffusive transport of passive scalar fields by spatially-varying incompressible flows. Prior studies have shown that the eddy diffusivities governing the mean field transport in such systems can generally…

Fluid Dynamics · Physics 2023-06-30 Jessie Liu , Hannah Williams , Ali Mani

We present the first demonstration of the negative effective magnetic pressure instability in direct numerical simulations of stably stratified, externally forced, isothermal hydromagnetic turbulence in the regime of large plasma beta. By…

Solar and Stellar Astrophysics · Physics 2011-10-05 Axel Brandenburg , Koen Kemel , Nathan Kleeorin , Dhrubaditya Mitra , Igor Rogachevskii

We study the stability of a type of stratified flows of the two dimensional inviscid incompressible MHD equations with velocity damping. The exponential stability for the perturbation near certain stratified flow is investigated in a…

Analysis of PDEs · Mathematics 2019-10-24 Yi Du , Wang Yang , Yi Zhou

We present a hydrodynamic theory for electron-hole magnetotransport in graphene incorporating carrier-population imbalance, energy, and momentum relaxation processes. We focus on the electric response and find that the carrier and energy…

Mesoscale and Nanoscale Physics · Physics 2019-01-30 Hong-Yi Xie , Alex Levchenko

3-D extended-MHD simulations of the magnetized ablative Rayleigh-Taylor instability are presented for the first time. Previous 2-D simulations claiming perturbation suppression by magnetic tension are shown to be misleading, as they do not…

Plasma Physics · Physics 2022-03-14 Christopher A. Walsh

The potential of the nonaxisymmetric magnetic instability to transport angular momentum and to mix chemicals is probed considering the stability of a nearly uniform toroidal field between conducting cylinders with different rotation rates.…

Solar and Stellar Astrophysics · Physics 2015-05-13 G. Ruediger , M. Gellert , M. Schultz

We present a mesoscopic approach to analyze the dynamics of a single magnetic dipole under the influence of an oscillating magnetic field, based on the formulation of a Fokker-Planck equation. The dissipated power and the viscosity of a…

Condensed Matter · Physics 2016-09-07 A. Perez Madrid , T. Alarcon , J. M. G. Vilar , J. M. Rubi

Pointwise zero velocity helicity density is shown not to prevent steady flows from acting as kinematic dynamos. We present numerical evidences that such flows can generate both small-scale magnetic fields as well as, by the magnetic…

Fluid Dynamics · Physics 2019-03-27 Alexander Andrievsky , Roman Chertovskih , Vladislav Zheligovsky

We establish a variational framework for nonlinear instabilities in a setting of the ideal magnetohydrodynamic (MHD) equations. We apply a variational method to various kind of smooth steady states which are shown to be nonlinearly unstable…

Analysis of PDEs · Mathematics 2007-05-23 Hyung Ju Hwang

The linear stability analysis of the Faraday instability on a viscous ferrofluid in a horizontal magnetic field is performed. Strong dipole-dipole interactions lead to the formation of chains elongated in the field direction. The formation…

Fluid Dynamics · Physics 2007-05-23 V. V. Mekhonoshin , Adrian Lange

We have tested the ability of driven turbulence to generate magnetic field structure from a weak uniform field using three dimensional numerical simulations of incompressible turbulence. We used a pseudo-spectral code with a numerical…

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