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Related papers: Mean-field dynamo as a quantumlike modulational in…

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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

Observations in polarized emission reveal the existence of large-scale coherent magnetic fields in a wide range of spiral galaxies. Radio-polarization data show that these fields are strongly inclined towards the radial direction, with…

Astrophysics · Physics 2009-11-13 Oliver Gressel , Udo Ziegler , Detlef Elstner , Günther Rüdiger

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

This is a brief review of the main results of our recent studies of the nonlinear evolution of the small-scale MHD dynamo in the high-Prandtl-number regime and of the structure of the resulting saturated state of the isotropic homogeneous…

Astrophysics · Physics 2007-05-23 A. A. Schekochihin , S. C. Cowley , G. W. Hammett , J. L. Maron , J. C. McWilliams

We generalize the mean field magnetic dynamo to include local evolution of the mean vorticity in addition to the mean magnetic field. The coupled equations exhibit a general mean field dynamo instability that enables the transfer of…

Astrophysics · Physics 2009-10-30 Eric G. Blackman , Tom Chou

Turbulence is typically not in equilibrium, i.e. mean quantities such as the mean energy and helicity are typically time-dependent. The effect of non-stationarity on the turbulent hydromagnetic dynamo process is studied here with the use of…

Fluid Dynamics · Physics 2023-08-10 Krzysztof A. Mizerski , Nobumitsu Yokoi , Axel Brandenburg

Structure formation in turbulence is effectively an instability of "plasma" formed by fluctuations serving as particles. These "particles" are quantumlike; namely, their wavelengths are non-negligible compared to the sizes of background…

Plasma Physics · Physics 2020-05-20 Vasileios Tsiolis , Yao Zhou , Ilya Y. Dodin

The dynamo effect is a class of macroscopic phenomena responsible for generation and maintaining magnetic fields in astrophysical bodies. It hinges on hydrodynamic three-dimensional motion of conducting gases and plasmas that achieve high…

Strongly Correlated Electrons · Physics 2018-10-31 Victor Galitski , Mehdi Kargarian , Sergey Syzranov

The standard magnetohydrodynamic (MHD) description of the plasma in the hot, magnetized gas of the intra-cluster (ICM) medium is not adequate because it is weakly collisional. In such collisionless magnetized gas, the microscopic velocity…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 R. Santos-Lima , E. M. de Gouveia Dal Pino , A. Lazarian , G. Kowal , D. Falceta-Gonçalves

We use ensemble machine learning algorithms to study the evolution of magnetic fields in magnetohydrodynamic (MHD) turbulence that is helically forced. We perform direct numerical simulations of helically forced turbulence using mean field…

Solar and Stellar Astrophysics · Physics 2019-09-11 Farrukh Nauman , Joonas Nättilä

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

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

Weak turbulence of magnetohydrodynamic (MHD) waves in strongly magnetized plasma is studied when the thermal pressure is less than the magnetic field pressure. In this situation the main nonlinear mechanism is the resonance scattering of…

Plasma Physics · Physics 2009-11-07 Evgenii A. Kuznetsov

We study the phenomenon of turbulence from the point of view of statistical physics. We discuss what makes the turbulent states different from the thermodynamic equilibrium and give the turbulent analog of the partition function. Then,…

High Energy Physics - Theory · Physics 2016-09-06 V. Gurarie

The influence of fluctuating conductivity on the coefficients known from the mean-field electrodynamics is considered. If the conductivity fluctuations are assumed as uncorrelated with the turbulent velocity field then only the effective…

Plasma Physics · Physics 2020-07-15 G. Rüdiger , M. Küker , P. J. Käpylä

Turbulence is the most common state of astrophysical flows. In typical astrophysical fluids, turbulence is accompanied by strong magnetic fields, which has a large impact on the dynamics of the turbulent cascade. Recently, there has been a…

Astrophysics · Physics 2011-05-10 Jungyeon Cho , A. Lazarian , Ethan Vishniac

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

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

The role of turbulence in astrophysical environments and its interplay with magnetic fields is still highly debated. In this lecture, we will discuss this issue in the framework of dynamo processes. We will first present a very brief…

Solar and Stellar Astrophysics · Physics 2015-06-12 E. M. de Gouveia Dal Pino , R. Santos-Lima , G. Kowal , D. Falceta-Gonçalves

We construct the low-frequency formulation of the turbulence characterizing the plasma in a Tokamak edge. Under rather natural assumptions we demonstrate that, even in the presence of poloidal magnetic fluctuations, it is possible to deal…

Plasma Physics · Physics 2024-07-02 Giovanni Montani , Fabio Moretti