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Spatiotemporal correlation of magnetic field fluctuations is investigated using the Magnetospheric Multiscale mission in the terrestrial magnetosheath. The first observation of the turbulence propagator in space emerges through analysis of…

Magnetized turbulence is ubiquitous in many astrophysical and terrestrial plasmas but no universal theory exists. Even the detailed energy dynamics in magnetohydrodynamic (MHD) turbulence are still not well understood. We present a suite of…

Astrophysics of Galaxies · Physics 2023-02-06 Philipp Grete , Brian W. O'Shea , Kris Beckwith

We investigate test-particle diffusion in dynamical turbulence based on a numerical approach presented before. For the turbulence we employ the nonlinear anisotropic dynamical turbulence model which takes into account wave propagation…

High Energy Astrophysical Phenomena · Physics 2016-09-28 Martin Heusen , Andreas Shalchi

A gauge invariant and hence physically meaningful definition of magnetic helicity density for random fields is proposed, using the Gauss linking formula, as the density of correlated field line linkages. This definition is applied to the…

Astrophysics · Physics 2011-02-11 Kandaswamy Subramanian , Axel Brandenburg

The problem of determining the effective conductivity tensor of a magnetoactive turbulent plasma is considered in the approximation of isolated particles. Additional gyrotropicterms are shown to appear in the conductivity tensor in the…

Plasma Physics · Physics 2009-11-10 Otto G. Chkhetiani

The stability problem of MHD Taylor-Couette flows with toroidal magnetic fields is considered in dependence on the magnetic Prandtl number. Only the most uniform (but not current-free) field with B\_in = B\_out has been considered. For high…

Astrophysics · Physics 2008-09-22 M. Gellert , G. Ruediger

In a density-stratified turbulent medium the cross helicity <u'.B'> is considered as a result of the interaction of the velocity fluctuations and a large-scale magnetic field. By means of a quasilinear theory and by numerical simulations we…

Solar and Stellar Astrophysics · Physics 2011-10-05 G. Rüdiger , L. L. Kitchatinov , A. Brandenburg

Natural dynamos such as planets and stars generate global scale magnetic field despite the inferred presence of small scale turbulence. Such systems are known as large scale dynamos and are typically driven by convection and influenced by…

Fluid Dynamics · Physics 2022-02-24 Ming Yan , Michael A. Calkins

We study the effect of an imposed vertical magnetic field on the turbulent mass diffusion properties of magnetorotational turbulence in protoplanetary discs. It is well-known that the effective viscosity generated by the turbulence depends…

Astrophysics · Physics 2009-11-11 Anders Johansen , Hubert Klahr , Antony J. Mee

The feasibility of a mean-field dynamo in nonhelical turbulence with superimposed linear shear is studied numerically in elongated shearing boxes. Exponential growth of magnetic field at scales much larger than the outer scale of the…

In mean-field magnetohydrodynamics the mean electromotive force due to velocity and magnetic field fluctuations plays a crucial role. In general it consists of two parts, one independent of and another one proportional to the mean magnetic…

Solar and Stellar Astrophysics · Physics 2010-01-03 K. -H. Rädler , A. Brandenburg

On the basis of a non-local Lagrangian for Maxwell equations in a dispersive medium, the energy-momentum tensor of the field is derived. We obtain the Field equations through variational methods and an extension of Noether theorem for a…

Classical Physics · Physics 2021-05-12 Carlos Heredia , Josep Llosa

We study the asymptotic properties of a stochastic model for the induction equations of the magnetic field in a three dimensional periodic domain. The turbulent velocity field driving the electromotive force on the magnetic field is modeled…

Probability · Mathematics 2025-06-04 Federico Butori , Eliseo Luongo

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

We investigate dynamo action in global compressible solar-like convective dynamos in the framework of mean-field theory. We simulate a solar-type star in a wedge-shaped spherical shell, where the interplay between convection and rotation…

Solar and Stellar Astrophysics · Physics 2018-01-17 Jörn Warnecke , Matthias Rheinhardt , S. Tuomisto , Petri J. Käpylä , Maarit J. Käpylä , Axel Brandenburg

Mechanisms of nonhelical large-scale dynamos (shear-current dynamo and effect of homogeneous kinetic helicity fluctuations with zero mean) in a homogeneous turbulence with large-scale shear are discussed. We have found that the…

Astrophysics · Physics 2009-11-13 I. Rogachevskii , N. Kleeorin

The behavior of magnetic field lines in a turbulent plasma is a key property of the medium, with important consequences for plasma dynamics and charged-particle transport. We study the diffusion properties of magnetic field lines in…

High Energy Astrophysical Phenomena · Physics 2026-05-22 Matthieu Bouchet , Yoann Génolini , Silvio S. Cerri , Alexandre Marcowith , Philipp Mertsch

We study the linear evolution of small perturbations in self-gravitating fluid systems with magnetic fields. We consider wave-like perturbations to nonuniform filamentary and sheet-like hydrostatic equilibria in the presence of a uniform…

Astrophysics · Physics 2015-06-24 Curtis S. Gehman , Fred C. Adams , Richard Watkins

The degree of intermittency of the magnetic field of a large-scale dynamo is considered. Based on simulations it is argued that there is a tendency for the field to become more diffuse and non-intermittent as the dynamo saturates. The…

Solar and Stellar Astrophysics · Physics 2011-07-14 Axel Brandenburg

Local shearing box simulations of stratified magneto rotational turbulence invariably exhibit cyclic field patterns which propagate away from the disc midplane. A common explanation for this is magnetic buoyancy. The recent analysis by Shi…

Earth and Planetary Astrophysics · Physics 2015-05-18 Oliver Gressel
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