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Related papers: Gravity-driven magnetogenesis

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The explanation of the observed galactic magnetic fields may require the existence of a primordial magnetic field. Such a field may arise during the early cosmological phase transitions, or because of other particle physics related…

Astrophysics · Physics 2009-10-30 Kari Enqvist

Interstellar magnetic fields in elliptical galaxies are assumed to have their origin in stellar fields that accompany normal mass loss from an evolving population of old stars. The seed fields are amplified by interstellar turbulence driven…

Astrophysics · Physics 2009-10-30 William G. Mathews , Fabrizio Brighenti

Magnetic fields appear to be ubiquitous in astrophysical environments. Their existence in the intracluster medium is established through observations of synchrotron emission and Faraday rotation. On the other hand, the nature of magnetic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Dongsu Ryu , Dominik R. G. Schleicher , Rudolf A. Treumann , Christos G. Tsagas , Lawrence M. Widrow

The electric and the magnetic part of the Weyl tensor, as well as the invariants obtained from them, are calculated for the Bondi vacuum metric. One of the invariants vanishes identically and the other only exhibits contributions from terms…

General Relativity and Quantum Cosmology · Physics 2009-11-11 L. Herrera , N. O. Santos , J. Carot

In a Friedmann-Robertson-Walker (FRW) cosmological model with zero spatial curvature, we consider the interaction of the gravitational waves with the plasma in the presence of a weak magnetic field. Using the relativistic hydromagnetic…

General Relativity and Quantum Cosmology · Physics 2010-04-30 D. B. Papadopoulos

Using a three dimensional relativistic particle-in-cell code we have performed numerical experiments of plasma shells colliding at relativistic velocities. Such scenarios are found in many astrophysical objects e.g. the relativistic outflow…

Astrophysics · Physics 2007-05-23 C. B. Hededal , J. Trier Frederiksen , T. Haugboelle , Å. Nordlund

The $R^2$ term in the Starobinsky inflationary model can be regarded as a leading quantum correction to the gravitational effective action. We assume that parity-preserving and parity-violating (axial) non-minimal couplings between…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-09 Oleg Savchenko , Yuri Shtanov

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

Beyond the Newtonian approximation, gravitational fields in general relativity can be described using a formalism known as gravitoelectromagnetism. In this formalism a vector potential, the gravitomagnetic potential, arises as a result of…

General Relativity and Quantum Cosmology · Physics 2021-09-02 Viktor T. Toth

It was recently discovered that for a boundary system in the presence of a background magnetic field, the quantum fluctuation of the vacuum would create a non-uniform magnetization density for the vacuum and a magnetization current is…

High Energy Physics - Theory · Physics 2021-07-28 Chong-Sun Chu

Natural dynamos such as planets and stars generate global scale magnetic field despite the inferred presence of small scale turbulence. Such systems are known as large scale dynamos and are typically driven by convection and influenced by…

Fluid Dynamics · Physics 2022-02-24 Ming Yan , Michael A. Calkins

We investigate the influence of cosmic magnetic fields on gravitational wave perturbations, and find exact solutions on large scales. We show that a large-scale magnetic field can generate large-scale non-decaying gravitational waves. In…

Astrophysics · Physics 2009-11-06 Roy Maartens , Christos Tsagas , Carlo Ungarelli

The origin of large scale magnetic fields in the Universe is widely thought to be from early Universe processes, like inflation or phase transitions. These magnetic fields evolve via magnetohydrodynamic processes until the epoch of…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-04 Molly Abramson , Emma Clarke , Tina Kahniashvili , Sayan Mandal , Salome Mtchedlidze , Jennifer Schober

Motivated by the significant interaction of convection, rotation and magnetic field in many astrophysical objects, we investigate the interplay between large-scale flows driven by rotating convection and an imposed magnetic field. We…

Solar and Stellar Astrophysics · Physics 2016-11-23 Laura K. Currie

In this paper, we investigate the entropy of the free gravitational field for a given epoch for some well-known isotropic and anisotropic cosmologies. We use the definition of gravitational entropy proposed by Clifton, Ellis, and Tavakol,…

General Relativity and Quantum Cosmology · Physics 2021-06-08 Samarjit Chakraborty , Sarbari Guha , Rituparno Goswami

The activity of magnetars is believed to be powered by colossal magnetic energy reservoirs. We sketch an evolutionary picture in which internal field evolution in magnetars generates a twisted corona, form which energy may be released…

High Energy Astrophysical Phenomena · Physics 2016-06-22 S. K. Lander

Magnetic fields appear everywhere in the universe. From stars and galaxies, all the way to galaxy clusters and remote protogalactic clouds magnetic fields of considerable strength and size have been repeatedly observed. Despite their…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Alejandra Kandus , Kerstin E. Kunze , Christos G. Tsagas

During common envelope evolution, an initially weak magnetic field may undergo amplification by interacting with spiral density waves and turbulence generated in the stellar envelope by the inspiralling companion. Using 3D…

Solar and Stellar Astrophysics · Physics 2024-03-22 Damien Gagnier , Ondrej Pejcha

Under carefully chosen assumptions a single general relativistic scalar field is able to induce MOND-like dynamics in the weak field approximation of the Einstein frame (gauge) and to modify the light cone structure accordingly. This is…

General Relativity and Quantum Cosmology · Physics 2025-12-10 Erhard Scholz

We explore the possibility that matter bulk flows could generate the required vorticity in the electron-proton-photon plasma to source cosmic magnetic fields through the Harrison mechanism. We analyze the coupled set of perturbed Maxwell…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-05 J. A. R. Cembranos , A. L. Maroto , H. Villarrubia-Rojo