English
Related papers

Related papers: Potential Vorticity Mixing in a Tangled Magnetic F…

200 papers

Accretion disks are likely threaded by external vertical magnetic flux, which enhances the level of turbulence via the magnetorotational instability (MRI). Using shearing-box simulations, we find that such external magnetic flux also…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Xue-Ning Bai , James M. Stone

We identify velocity channel map intensities as a new way to trace magnetic fields in turbulent media. This work makes use of both of the modern theory of MHD turbulence predicting that the magnetic eddies are aligned with the local…

Astrophysics of Galaxies · Physics 2018-02-07 A. Lazarian , Ka Ho Yuen

The effect of a magnetic field on the linear phase of the advective-acoustic instability is investigated, as a first step toward a magnetohydrodynamic (MHD) theory of the stationary accretion shock instability taking place during stellar…

Solar and Stellar Astrophysics · Physics 2014-11-20 Jerome Guilet , Thierry Foglizzo

Planetary and stellar dynamos likely result from turbulent motions in magnetofluids with kinematic viscosities that are small compared to their magnetic diffusivities. Laboratory experiments are in progress to produce similar dynamos in…

Astrophysics · Physics 2009-11-11 P. D. Mininni

We analyze the development and influence of turbulence in three-dimensional particle-in-cell simulations of guide-field magnetic reconnection at the magnetopause with parameters based on observations of an electron diffusion region by the…

Space Physics · Physics 2020-05-06 L. Price , M Swisdak , J. F. Drake , D. B. Graham

The physics of a twisted magnetic flux tube rising in a stratified medium is studied using a numerical MHD code. The problem considered is fully compressible (no Boussinesq approximation), includes ohmic resistivity, and is two dimensional,…

Astrophysics · Physics 2009-10-30 T. Emonet , F. Moreno-Insertis

In this work, we study the transport of vorticity on curved dynamical two-dimensional magnetic membranes. We find that topological transport can be controlled by geometrically reducing symmetries, enabling processes absent from flat…

Mesoscale and Nanoscale Physics · Physics 2025-05-27 Chau Dao , Ji Zou , Eric Kleinherbers , Yaroslav Tserkovnyak

(Abridged) We here investigate, by means of fully 3-D Smoothed Particle Magnetohydrodynamic numerical simulations, the effects of magnetic fields on overdense, radiatively cooling, pulsed jets, using different initial magnetic field…

Astrophysics · Physics 2009-11-06 Adriano H. Cerqueira , Elisabete M. de Gouveia Dal Pino

A mean-field Fokker-Planck equation approach to the dynamics of ferrofluids in the presence of a magnetic field and velocity gradients is proposed that incorporates magnetic dipole-dipole interactions of the colloidal particles. The model…

Soft Condensed Matter · Physics 2015-06-24 Patrick Ilg , Siegfried Hess

Magnetohydrodynamic turbulence affects both terrestrial and astrophysical plasmas. The properties of magnetized turbulence must be better understood to more accurately characterize these systems. This work presents ideal MHD simulations of…

Fluid Dynamics · Physics 2021-04-28 Forrest W. Glines , Philipp Grete , Brian W. O'Shea

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 develop a mean-field model to examine the stability of a `quasi-2D suspension' of elongated particles embedded within a viscous membrane. This geometry represents several biological and synthetic settings, and we reveal mechanisms by…

Fluid Dynamics · Physics 2024-05-22 Harishankar Manikantan

Observations of pressure-gravity mixed modes, combined with a theoretical framework for understanding mode formation, can yield a wealth of information about deep stellar interiors. In this paper, we seek to develop a formalism for treating…

Solar and Stellar Astrophysics · Physics 2020-01-08 Shyeh Tjing Loi , John C. B. Papaloizou

Magnetic field fluctuations in MHD turbulence can be viewed as current sheets that are progressively more anisotropic at smaller scales. As suggested by Loureiro & Boldyrev (2017) and Mallet et al (2017), below a certain critical thickness…

Plasma Physics · Physics 2017-08-09 Stanislav Boldyrev , Nuno F. Loureiro

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

We investigate the mean electromotive force in the kinematic framework, that is, ignoring the back-reaction of the magnetic field on the fluid velocity, under the assumption of axisymmetric turbulence determined by the presence of either…

Solar and Stellar Astrophysics · Physics 2012-02-23 A. Brandenburg , K. -H. Rädler , K. Kemel

Motivated by the empirical finding that the known hemispheric rules for the current helicity at the solar surface are not strict, the excitation of small-scale current helicity by the influence of a large-scale helical magnetic background…

Solar and Stellar Astrophysics · Physics 2016-08-03 Guenther Ruediger , Manfred Kueker

There are observational evidences for the existence of twisted magnetic field in the solar corona. This inspires us to investigate the effect of a twisted magnetic field on the evolution of magnetohydrodynamic (MHD) kink waves in coronal…

Solar and Stellar Astrophysics · Physics 2017-08-29 Zanyar Ebrahimi , Kayoomars Karami , Roberto Soler

Evolving magnetic fields are frequently embedded in plasmas that are turbulent. When the primary interest is in effects that are on a large scale compared to that of the turbulence, it is desirable to average over the turbulence to obtain…

Plasma Physics · Physics 2025-04-08 Allen H Boozer

(Abridged) We report results of three dimensional MHD simulations of global accretion disks threaded with weak vertical magnetic fields. We perform the simulations in the spherical coordinates with different temperature profiles and…

Earth and Planetary Astrophysics · Physics 2015-06-17 Takeru K. Suzuki , Shu-ichiro Inutsuka