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Related papers: Small-scale magnetohydrodynamic dynamos: from dete…

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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 small-scale turbulent dynamo is a key mechanism for amplifying galactic magnetic fields, yet the resulting field morphology remains poorly understood. Using 3D driven turbulence simulations across a range of compressibilities,…

Astrophysics of Galaxies · Physics 2026-03-25 Sasi M. Behara , Amit Seta

Two-dimensional magnetohydrodynamics (2D MHD), forced at (a) large length scales or (b) small length scales, displays turbulent, but statistically steady, states with widely different statistical properties. We present a systematic,…

Fluid Dynamics · Physics 2019-06-27 Debarghya Banerjee , Rahul Pandit

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

We analyze probe data obtained from a toroidal magnetized plasma configuration suitable for studies of low-frequency gradient-driven instabilities. These instabilities give rise to field-aligned convection rolls analogous to Rayleigh-Benard…

Plasma Physics · Physics 2009-11-13 Tatjana Zivkovic , Kristoffer Rypdal

Observations reveal the presence of supermassive black holes (SMBH) as early as ~700 million years after the Big Bang. Their formation path is still subject to current debate. We explore the influence of magnetic fields, which are strongly…

Astrophysics of Galaxies · Physics 2019-06-12 Philipp Grete , Muhammad A. Latif , Dominik R. G. Schleicher , Wolfram Schmidt

We investigate properties of solar wind-like plasma turbulence using direct numerical simulations. We analyze the transition from large, magnetohydrodynamic (MHD) scales to the ion characteristic ones using two-dimensional hybrid (fluid…

Solar and Stellar Astrophysics · Physics 2022-05-18 Petr Hellinger , Victor Montagud-Camps , Luca Franci , Lorenzo Matteini , Emanuele Papini , Andrea Verdini , Simone Landi

Magnetohydrodynamic (MHD) turbulence in the majority of natural systems, including the interstellar medium, the solar corona, and the solar wind, has Reynolds numbers far exceeding the Reynolds numbers achievable in numerical experiments.…

Solar and Stellar Astrophysics · Physics 2015-06-22 J. C. Perez , J. Mason , S. Boldyrev , F. Cattaneo

We test a new technique of studying magnetohydrodynamic (MHD) turbulence suggested by Lazarian \& Pogosyan, using synthetic synchrotron polarization observations. This paper focuses on a one-point statistics, which is termed the…

High Energy Astrophysical Phenomena · Physics 2016-07-20 Jian-Fu Zhang , Alex Lazarian , Hyeseung Lee , Jungyeon Cho

We present a new theoretical picture of magnetically dominated, decaying turbulence in the absence of a mean magnetic field. We demonstrate that such turbulence is governed by the reconnection of magnetic structures, and not by ideal…

Fluid Dynamics · Physics 2021-10-13 David N. Hosking , Alexander A. Schekochihin

In the presence of magnetic helicity, inverse transfer from small to large scales is well known in magnetohydrodynamic (MHD) turbulence and has applications in astrophysics, cosmology, and fusion plasmas. Using high resolution direct…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-23 Axel Brandenburg , Tina Kahniashvili , Alexander G. Tevzadze

We study a simple magnetohydrodynamical approach in which hydrodynamics and MHD turbulence are coupled in a shell model, with given dynamo constrains in the large scales. We consider the case of a low Prandtl number fluid for which the…

Earth and Planetary Astrophysics · Physics 2015-05-13 Roberto Benzi , Jean-Francois Pinton

Relativistic astrophysical phenomena such as gamma-ray bursts (GRBs) and active galactic nuclei often require long-lived strong magnetic field. Here, we report on three-dimensional special-relativistic magnetohydrodynamic (MHD) simulations…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Tsuyoshi Inoue , Katsuaki Asano , Kunihito Ioka

The energy spectrum and the nolinear cascade rates of MHD turbulence is not clearly understood. We have addressed this problem using direct numerical simulation and analytical calculations. Our numerical simulations indicate that…

chao-dyn · Physics 2007-05-23 Mahendra K. Verma , Gaurav Dar

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

A quantum field model of helical MHD stochastically forced by gaussian hydrodynamic, magnetic and mixed noices is investigated. These helical noises lead to an exponential increase of magnetic fluctuations in the large scale range.…

Chaotic Dynamics · Physics 2007-05-23 M. Hnatic , M. Jurcisin , M. Stehlik

The ideal invariants present in the formalism of magnetohydrodynamics (MHD), i.e. global quantities that are conserved in the absence of sources and dissipative effects, play an important role in various theoretical and numerical studies of…

Fluid Dynamics · Physics 2011-08-15 B. Teaca , C. C. Lalescu , B. Knaepen , D. Carati

The multiplicity of routes from deterministic chaos to turbulence caused by the spontaneous breaking of the local reflectional symmetry in the flows induced by Rayleigh-Taylor instability has been studied using the notion of distributed…

Fluid Dynamics · Physics 2023-02-23 A. Bershadskii

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

We introduce the concept of intermittency dimension for the magnetohydrodynamics (MHD) to quantify the intermittency effect. With dependence on the intermittency dimension, we derive phenomenological laws for intermittent MHD turbulence…

Analysis of PDEs · Mathematics 2020-12-22 Mimi Dai