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A possible explanation for the origin of the magnetic fields observed today in matter structures is that they were generated in the primordial universe. After briefly revising the model of a primordial stochastic magnetic field and…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Chiara Caprini

Large-scale magnetic fields are observed today to be coherent on galactic scales. While there exists an explanation for their amplification and their specific configuration in spiral galaxies -- the dynamo mechanism -- a satisfying…

High Energy Physics - Theory · Physics 2009-12-04 Rhiannon Gwyn , Stephon Alexander , Robert H. Brandenberger , Keshav Dasgupta

Anisotropy of kinetic coefficients in presence of a magnetic field is represented by Hall currents, which appear in a collisional medium due to action of the Lorentz force on the charged particles between collisions. We derive equations,…

Plasma Physics · Physics 2026-04-28 G. S. Bisnovatyi-Kogan , M. V. Glushikhina

Following Prendergast we study the relativistically expanding electromagnetic fields generated by an axisymmetric explosion of magnetic energy in a small volume. The magnetic field expands uniformly either within a cone or in all directions…

Astrophysics · Physics 2009-11-13 K. N. Gourgouliatos , D. Lynden-Bell

We propose a new mechanism for turbulent mean-field dynamo in which the magnetic fluctuations resulting from a small-scale dynamo drive the generation of large-scale magnetic fields. This is in stark contrast to the common idea that…

Solar and Stellar Astrophysics · Physics 2015-11-23 Jonathan Squire , Amitava Bhattacharjee

Inflation has the potential to seed the galactic magnetic fields observed today. However, there is an obstacle to the amplification of the quantum fluctuations of the electromagnetic field during inflation: namely the conformal invariance…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Amjad Ashoorioon , Robert B. Mann

In this letter we compute energy transfer rates from velocity field to magnetic field in MHD turbulence using field-theoretic method. The striking result of our field theoretic calculation is that there is a large energy transfer rate from…

Chaotic Dynamics · Physics 2007-05-23 Mahendra K. Verma

We use non-linear gauge-invariant perturbation theory to study the interaction of an inflation produced seed magnetic field with density and gravitational wave perturbations in an almost Friedmann-Lema\^itre-Robertson-Walker (FLRW)…

General Relativity and Quantum Cosmology · Physics 2012-10-23 Bishop Mongwane , Peter K. S. Dunsby , Bob Osano

Magnetic fields correlated on several kiloparsec scales are seen in spiral galaxies. Their origin could be due to the winding up of a primordial cosmological field or due to amplification of a small seed field by a turbulent galactic…

Astrophysics · Physics 2007-05-23 K. Subramanian

Magnetohydrodynamic simulations of fully convective, rotating spheres with volume heating near the center and cooling at the surface are presented. The dynamo-generated magnetic field saturates at equipartition field strength near the…

Astrophysics · Physics 2007-05-23 W. Dobler , M. Stix , A. Brandenburg

We investigate primordial magnetogenesis and the evolution of the electromagnetic field through a quantum bounce, in a model that starts in the far past from a contracting phase where only dust is present and the electromagnetic field is in…

General Relativity and Quantum Cosmology · Physics 2020-05-11 E. Frion , N. Pinto-Neto , S. D. P. Vitenti , S. E. Perez Bergliaffa

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

The current understanding of astrophysical magnetic fields is reviewed, focusing on their generation and maintenance by turbulence. In the astrophysical context this generation is usually explained by a self-excited dynamo, which involves…

Astrophysics · Physics 2008-11-26 Axel Brandenburg , Kandaswamy Subramanian

Magnetism is one of the four fundamental forces. However, the origin of magnetic fields in stars, galaxies and clusters is an open problem in astrophysics and fundamental physics. When and how were the first fields generated? Are…

Astrophysics · Physics 2009-11-10 B. M. Gaensler , R. Beck , L. Feretti

Large scale primordial magnetic fields (PMFs) threading the intergalactic medium are observed ubiquitously in the Universe playing a key role in the cosmic evolution. Their origin is still debated constituting a very active field of…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-14 Theodoros Papanikolaou , Konstantinos N. Gourgouliatos

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

Relativistic charged particles (CR for cosmic-rays) produced by Supernova explosion of the first generation of massive stars that are responsible for the re-ionization of the universe escape into the intergalactic medium, carrying an…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Francesco Miniati , A. R. Bell

There is a reformulation of magnetohydrodynamics in which the fundamental dynamical quantities are the positions and velocities of the lines of magnetic flux in the plasma, which turn out to obey equations of motion very much like ideal…

Astrophysics · Physics 2009-10-31 Mattias Christensson , Mark Hindmarsh

We present a new magnetic field generation mechanism in underdense plasmas driven by the beating of two, co-propagating, Laguerre-Gaussian (LG) orbital angular momentum (OAM) laser pulses with different frequencies and also different twist…

Plasma Physics · Physics 2018-10-10 Y. Shi , J. Vieira , R. M. G. M. Trines , R. Bingham , B. F. Shen , R. J. Kingham

Several lines of evidence suggest that protogalactic and galactic environments manage to grow magnetic field very rapidly. This makes the theoretical problem of achieving rapid growth of magnetic fields in such environments difficult.…

Astrophysics · Physics 2009-11-10 D. S. Balsara , J. S. Kim , M. M. Mac Low , G. Mathews