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Related papers: The dynamo effect in decaying helical turbulence

200 papers

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

The small-scale turbulent dynamo is an important process contributing to the cosmic magnetization. In partially ionized astrophysical plasmas, the dynamo growth of magnetic energy strongly depends on the coupling state between ions and…

Astrophysics of Galaxies · Physics 2019-02-20 Siyao Xu , Sudip K. Garain , Dinshaw S. Balsara , A. Lazarian

The free decay of MHD turbulence at large Reynolds numbers is studied numerically using a shell model. We study the statistical properties based on representative sample of realisations (128 realisations for each type of initial conditions)…

Fluid Dynamics · Physics 2010-09-23 Peter Frick , Rodion Stepanov

The ohmic decay of magnetic fields in the crusts of neutron stars is generally believed to be governed by Hall drift which leads to what is known as a Hall cascade. Here we show that helical and fractionally helical magnetic fields undergo…

High Energy Astrophysical Phenomena · Physics 2020-09-18 Axel Brandenburg

Analytical solution of ${\alpha}$-dynamo equation representing strongly torsioned helical dynamo is obtained in the thin twisted Riemannian flux tubes approximation. The $\alpha$ factor possesses a fundamental contribution from torsion…

Astrophysics · Physics 2007-12-27 Garcia de Andrade

The excitation and further sustenance of large-scale magnetic fields in rotating astrophysical systems, including planets, stars and galaxies, is generally thought to involve a fluid magnetic dynamo effect driven by helical…

Fluid Dynamics · Physics 2021-12-10 F. Rincon

The presence of large scale magnetic fields in nature is often attributed to the inverse cascade of magnetic helicity driven by turbulent helical dynamos. In this work we show that in turbulent helical dynamos, the inverse flux of magnetic…

Fluid Dynamics · Physics 2022-11-23 Guillaume Bermudez , Alexandros Alexakis

We use three-dimensional direct numerical simulations of the helically forced magnetohydrodynamic equations in spherical shell segments in order to study the effects of changes in the geometrical shape and size of the domain on the growth…

Astrophysics · Physics 2010-01-15 Dhrubaditya Mitra , Reza Tavakol , Axel Brandenburg , David Moss

We have studied the large scale dynamo process forced with helical magnetic energy. The magnetically driven dynamo is not so well studied as kinetically forced dynamo. It has been thought to represent the amplification of magnetic field in…

Plasma Physics · Physics 2021-09-21 Kiwan Park , Myung-Ki Cheoun

The kinematic regime of the magnetic dynamo neglects the backreaction of the magnetic field on the flow. For small magnetic diffusivity, in the early stage of evolution, there is an ideal phase where dissipative effects can also be…

Chaotic Dynamics · Physics 2009-11-07 Jean-Luc Thiffeault , Allen H. Boozer

We study the evolution of primordial magnetic fields in an expanding cosmic plasma. For this purpose we present a comprehensive theoretical model to consider the evolution of MHD turbulence that can be used over a wide range of physical…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-12 Tina Kahniashvili , Axel Brandenburg , Alexander G. Tevzadze

Recent MHD dynamo simulations for magnetic Prandtl number $>1$ demonstrate that when MHD turbulence is forced with sufficient kinetic helicity, the saturated magnetic energy spectrum evolves from having a single peak below the forcing scale…

Astrophysics · Physics 2009-11-07 Eric G. Blackman

We study the evolution of QCD phase transition-generated magnetic fields in freely decaying MHD turbulence of the expanding Universe. We consider a magnetic field generation model that starts from basic non-perturbative QCD theory and…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-18 Alexander G. Tevzadze , Leonard Kisslinger , Axel Brandenburg , Tina Kahniashvili

Magnetic helicity is a fundamental constraint in both ideal and resistive magnetohydrodynamics. Measurements of magnetic helicity density on the Sun and other stars are used to interpret the internal behaviour of the dynamo generating the…

Solar and Stellar Astrophysics · Physics 2022-11-03 Parag Gupta , Radostin D. Simitev , David MacTaggart

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

We consider the evolution of primordial magnetic fields generated during cosmological, electroweak or QCD, phase transitions. We assume that the magnetic field generation can be described as an injection of magnetic energy to cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-24 Tina Kahniashvili , Alexander G. Tevzadze , Axel Brandenburg , Andrii Neronov

The evolution of the magnetic helicity tensor for a nonzero mean magnetic field and for large magnetic Reynolds numbers in an anisotropic turbulence is studied. It is shown that the isotropic and anisotropic parts of the magnetic helicity…

Astrophysics · Physics 2008-11-26 N. Kleeorin , I. Rogachevskii

It has been recently shown numerically that there exists an inverse transfer of magnetic energy in decaying, nonhelical, magnetically dominated, magnetohydrodynamic turbulence in 3-dimensions (3D). We suggest that magnetic reconnection is…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-23 Pallavi Bhat , Muni Zhou , Nuno F. Loureiro

Isotropic homogeneous hydromagnetic turbulence is studied using numerical simulations at resolutions of up to 1024^3 meshpoints. It is argued that, in contrast to the kinematic regime, the nonlinear regime is characterized by a spectral…

Astrophysics · Physics 2007-05-23 A. Brandenburg , N. E. L. Haugen , W. Dobler

Understanding large scale magnetic field growth in turbulent plasmas in the magnetohydrodynamic limit is a goal of magnetic dynamo theory. In particular, assessing how well large scale helical field growth and saturation in simulations…

Plasma Physics · Physics 2015-06-15 Kiwan Park , Eric G. Blackman , Kandaswamy Subramanian