English
Related papers

Related papers: Evolution of magnetic fields through cosmological …

200 papers

We extend some previous attempts to explain the origin and evolution of primordial magnetic fields during inflation induced from a 5D vacuum. We show that the usual quantum fluctuations of a generalized 5D electromagnetic field cannot…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Federico Agustín Membiela , Mauricio Bellini

The origin of the seeds of galactic magnetic fields is a subject that remains under debate. Here we will explore a simple source based on tiny charge asymmetries in slowly rotating protogalaxies. We use current knowledge of galaxy formation…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-31 Nelson D. Padilla , Juan Racker , Ignacio J. Araya , Federico Stasyszyn

We investigate the cosmological evolution of large- and small-scale magnetic fields in galaxies at high redshifts. Results from simulations of hierarchical structure formation cosmology provide a tool to develop an evolutionary model of…

Astrophysics · Physics 2009-11-13 Tigran G. Arshakian , Rainer Beck , Marita Krause , Dmitry Sokoloff

A cosmic scalar field evolving very slowly in time can account for the observed dark energy of the Universe. Unlike a cosmological constant, an evolving scalar field also has local spatial gradients due to gravity. If the scalar field has a…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-01 Michael V. Romalis , Robert R. Caldwell

Galactic magnetic fields are observed of order $\sim 10^{-6}G$, but their origin is not definitely known yet. In this paper we consider the primordial magnetic fields generated in the early universe and analyse their effects on the density…

Astrophysics · Physics 2016-08-30 Seoktae Koh , Chul H. Lee

Magnetic fields are ubiquitous in the Universe. Extragalactic disks, halos and clusters have consistently been shown, via diffuse radio-synchrotron emission and Faraday rotation measurements, to exhibit magnetic field strengths ranging from…

Magnetic fields appear to be a generic feature of the early universe and are a natural source of secondary CMB non-Gaussianity. In recent years the statistical nature of the stresses of a primordial magnetic field has been well studied. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Iain A. Brown

We study the amplification of magnetic fields during the formation of primordial halos. The turbulence generated by gravitational infall motions during the formation of the first stars and galaxies can amplify magnetic fields very…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Jennifer Schober , Dominik Schleicher , Christoph Federrath , Simon Glover , Ralf Klessen , Robi Banerjee

We study the symmetries of the post-recombination cosmological magnetohydrodynamical equations which describe the evolution of dark matter, baryons and magnetic fields in a self-consistent way. This is done both at the level of fluid…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 P. Berger , A. Kehagias , A. Riotto

Sufficiently large seeds for generating the observed (inter)galactic magnetic fields emerge naturally in string cosmology from the amplification of electromagnetic vacuum fluctuations due to a dynamical dilaton background. The success of…

High Energy Physics - Theory · Physics 2009-10-28 M. GasperinI , M. Giovannini , G. Veneziano

Magnetic fields correlated on several kiloparsec scales are seen in spiral galaxies. Their origin could be due to amplification of a small seed field by a turbulent galactic dynamo. We critically review the current status of the galactic…

Astrophysics · Physics 2007-05-23 Kandaswamy Subramanian

Cosmic magnetic fields may be generated during early cosmic phase transition, such as the QCD- or electroweak- transitions. The magnitude of the remainder of such fields at the present epoch crucially depends on the exponent $n$ of their…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-02 Karsten Jedamzik , Guenter Sigl

The existence of a weak galactic magnetic field has been repeatedly confirmed by observational data. The origin of this field has not as yet been explained in a fully satisfactory way and represents one of the main challenges of the…

Astrophysics · Physics 2009-11-06 Alexander Schekochihin , Stanislav Boldyrev , Russell Kulsrud

The origin of interstellar and intergalactic magnetic fields remains largely unknown. One possibility is that they are related to the primordial magnetic fields (PMFs) produced by, for instance, the phase transitions of the early Universe.…

High Energy Astrophysical Phenomena · Physics 2024-03-05 Yao-Yu Li , Chi Zhang , Ziwei Wang , Ming-Yang Cui , Yue-Lin Sming Tsai , Qiang Yuan , Yi-Zhong Fan

Observationally, magnetic fields reach equipartition with thermal energy and cosmic rays in the interstellar medium of disk galaxies such as the Milky Way. However, thus far cosmological simulations of the formation and evolution of…

Astrophysics of Galaxies · Physics 2015-06-18 R. Pakmor , F. Marinacci , V. Springel

Possible origins of the magnetic fields of neutron stars include inheritance from the main sequence progenitor and dynamo action at some stage of evolution of progenitor. Inheritance is not sufficient to explain the fields of magnetars.…

Astrophysics · Physics 2009-06-23 H. C. Spruit

Cosmological hydrodynamical simulations of primordial star formation suggest that the gas within the first star-forming halos is turbulent. This has strong implications on the subsequent evolution, in particular on the generation of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Sharanya Sur , Dominik R. G. Schleicher , Robi Banerjee , Christoph Federrath , Ralf S. Klessen

The inflationary production of magnetic field seeds for galaxies is discussed. The analysis is carried out by writing the wave equation of the electromagnetic field in curved spacetimes. The conformal invariance is broken by taking into…

General Relativity and Quantum Cosmology · Physics 2009-11-10 G. Lambiase , A. R. Prasanna

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

Different mechanisms which may possibly explain existence of magnetic fields on astronomically large scales are described. A recently suggested model of magnetic fields generation slightly before hydrogen recombination is discussed in more…

Astrophysics · Physics 2007-05-23 A. D. Dolgov
‹ Prev 1 4 5 6 7 8 10 Next ›