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Related papers: Mean-field dynamos: the old concept and some recen…

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We study mean field dynamo action in renovating flows with finite and non zero correlation time ($\tau$) in the presence of shear. Previous results obtained when shear was absent are generalized to the case with shear. The question of…

Astrophysics of Galaxies · Physics 2015-06-04 Sanved Kolekar , Kandaswamy Subramanian , S. Sridhar

A theory of thermohydrodynamics in two-dimensional electron systems in quantizing magnetic fields is developed including a nonlinear transport regime. Spatio-temporal variations of the electron temperature and the chemical potential in the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Hiroshi Akera , Hidekatsu Suzuura

We show that the initial-value problem for the non-relativistic magnetic dynamo equation turns out to be ill-posed when the electromotive force depends linearly on the magnetic field. This result implies that the increasing of magnetic…

High Energy Astrophysical Phenomena · Physics 2021-11-29 Marcelo E. Rubio , Federico A. Stasyszyn

Using mean-field theory, we compute the evolution of the magnetic field in a cylinder with outer perfectly conducting boundaries, an imposed axial magnetic and electric field. The thus injected magnetic helicity in the system can be…

Plasma Physics · Physics 2012-03-27 Koen Kemel , Axel Brandenburg , Hantao Ji

Ferrofluids belong to an important class of highly functional soft matter, benefiting from their magnetically controllable physical properties. Therefore, it is of central importance to quantitatively predict the dynamic magnetic response…

Soft Condensed Matter · Physics 2020-11-17 Angbo Fang

Strongly stratified hydromagnetic turbulence has previously been found to produce magnetic flux concentrations if the domain is large enough compared with the size of turbulent eddies. Mean-field simulations (MFS) using parameterizations of…

Solar and Stellar Astrophysics · Physics 2014-02-06 A. Brandenburg , O. Gressel , S. Jabbari , N. Kleeorin , I. Rogachevskii

The prevailing theory for the origin of cosmic magnetic fields is that they have been amplified to their present values by the turbulent dynamo inductive action in the protogalactic and galactic medium. Up to now, in calculation of the…

Astrophysics · Physics 2007-05-23 Leonid Malyshkin

We combine simulations with new analyses that overcome previous pitfalls to explicate how nonhelical mean-field dynamos grow and saturate in unstratified, magnetorotationally driven turbulence. Shear of the mean radial magnetic field…

Plasma Physics · Physics 2025-11-20 Tushar Mondal , Pallavi Bhat , Fatima Ebrahimi , Eric G. Blackman

We introduce an effective action for non-dissipative magnetohydrodynamics. A crucial guiding principle is the generalized global symmetry of electrodynamics, which naturally leads to introducing a "dual photon" as the degree of freedom…

High Energy Physics - Theory · Physics 2018-11-13 Paolo Glorioso , Dam Thanh Son

We study the magneto-rotational instability (MRI) driven dynamo in a geometrically thin disc ($H/R\ll 1$) using stratified zero net flux (ZNF) shearing box simulations. We find that mean fields and EMFs oscillate with a primary frequency…

High Energy Astrophysical Phenomena · Physics 2024-07-22 Prasun Dhang , Abhijit Bendre , Kandaswamy Subramanian

In an experiment in the Institute of Continuous Media Mechanics in Perm (Russia) an non--stationary screw dynamo is intended to be realized with a helical flow of liquid sodium in a torus. The flow is necessarily turbulent, that is, may be…

Fluid Dynamics · Physics 2009-11-11 K. -H. Raedler , R. Stepanov

We introduce on/off intermittency into a mean field dynamo model by imposing stochastic fluctuations in either the alpha effect or through the inclusion of a fluctuating electromotive force. Sufficiently strong small scale fluctuations with…

Astrophysics · Physics 2008-03-27 A. Brandenburg , E. A. Spiegel

The magnetic field in Hall plasmas is frozen in the electron component and is advected not only with the plasma motion but also with the electrical current flow. Its coupling with the plasma may be not as strong as characteristic of the MHD…

Astrophysics · Physics 2009-11-06 L. I. Rudakov

Recently, Feigel has predicted a new effect in magnetoelectric media. The theoretical evaluation of this effect requires a careful analysis of a dynamics of the moving magnetoelectric medium and, in particular, the derivation of the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yuri N. Obukhov , Friedrich W. Hehl

A generalized mean magnetic field induction equation for differential rotators is derived, including a compressibility, and the anisotropy induced on the turbulent quantities from the mean magnetic field itself and a mean velocity shear.…

Astrophysics · Physics 2009-10-31 Eric G. Blackman

(abridged) Aims: To study turbulent transport coefficients that describe the evolution of large-scale magnetic fields in turbulent convection. Methods: We use the test field method together with 3D numerical simulations of turbulent…

Astrophysics · Physics 2009-07-29 P. J. Käpylä , M. J. Korpi , A. Brandenburg

We consider the behavior of an Ising ferromagnet obeying the Glauber dynamics under the influence of a fast switching, random external field. In Part I, we introduced a general formalism for describing such systems and presented the mean…

Statistical Mechanics · Physics 2009-10-31 J. Hausmann , P. Rujan

We address magnetic-field generation by dynamo action in systems with inhomogeneous electrical conductivity and magnetic permeability. More specifically, we first show that the Taylor-Couette kinematic dynamo undergoes a drastic reduction…

Fluid Dynamics · Physics 2021-12-29 Florence Marcotte , Basile Gallet , Francois Pétrélis , Christophe Gissinger

In analogy with the load and the metage in hydrodynamics, we define magnetohydrodynamic load and magnetohydrodynamic metage in the case of magnetofluids. They can be used to write the magnetic field in MHD in Clebsch's form. We show how…

Plasma Physics · Physics 2015-05-13 Sagar Chakraborty , Partha Guha

We consider the linear stability of two-dimensional nonlinear magnetohydrodynamic basic states to long-wavelength three-dimensional perturbations. Following Hughes & Proctor (2009a), the 2D basic states are obtained from a specific forcing…

Solar and Stellar Astrophysics · Physics 2009-12-31 A. Courvoisier , D. W. Hughes , M. R. E. Proctor
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