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Earlier Bamba et al [JCAP (2012)] have obtained cosmological magnetic fields in teleparallel torsion theories of gravity that are not compatible with galactic dynamos. This result agrees with previous ones obtained by the author which shows…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-02 Luiz Carlos Garcia de Andrade

Earlier Bassett et al [Phys Rev D 63 (2001) 023506] investigated the amplification of large scale magnetic fields during preheating and inflation in several different models. They argued that in the presence of conductivity resonance effect…

Astrophysics of Galaxies · Physics 2014-12-30 L C Garcia de Andrade

Recently Barrow, and Tsagas [Phys Rev D 77: 107302, (2008)] have shown that slow decay of cosmological magnetic slowly decay in FRW universes on curvature scales as $B\sim{a^{-1}}$ in the context of general relativity (GR). This helps…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-27 L C Garcia de Andrade

Cosmological magnetic helicity has been thought to be a fundamental agent for magnetic field amplification in the universe. More recently Semikoz and Sokoloff [Phys Rev Lett 92 (2004): 131.301.] showed that the weakness of the seed fields…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-17 L Garcia de Andrade

Recently much controversy has been shed on BICEP 2 experiments for the concerning this validity or not and a possible set of new experiments to detect primordial inflation and gravitational waves. Since gravitational waves imply the…

General Relativity and Quantum Cosmology · Physics 2015-01-13 L. C. G. Andrade

Earlier de Sabbata and Gasperini have shown that neutrinos oscillation which gives them a mass can be induced by torsion. More recently Enqvist et al have shown that it is possible to use massive neutrinos BBN magnetic fields to seed…

General Relativity and Quantum Cosmology · Physics 2016-04-06 Garcia de Andrade

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

Dynamo action is shown to be induced from homogeneous non-minimal photon-torsion axial coupling in the quantum electrodynamics (QED) framework in Riemann flat spacetime contortion decays. The geometrical optics in Riemann-Cartan spacetime…

General Relativity and Quantum Cosmology · Physics 2010-07-13 Garcia de Andrade

We discuss how a cosmological magnetic field could affect the expansion of the universe, through its interaction with the spacetime geometry. The tension of the field lines means that the magneto-curvature coupling tends to accelerate…

Astrophysics · Physics 2009-10-31 D. R. Matravers , C. G. Tsagas

The origin and maintenance of coherent magnetic fields in the Universe is reviewed with an emphasis on the possible challenges that arise in their theoretical understanding. We begin with the interesting possibility that magnetic fields…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-12 Kandaswamy Subramanian

Using cosmological MHD simulations of the magnetic field in galaxy clusters and filaments we evaluate the possibility to infer the magnetic field strength in filaments by measuring cross-correlation functions between Faraday Rotation…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 F. Stasyszyn , S. E. Nuza , K. Dolag , R. Beck , J. Donnert

We consider the Lagrangian density for a free Maxwell field, in which the electromagnetic field tensor minimally couples to the affine connection, in the Einstein-Cartan-Sciama-Kibble theory of gravity. We derive the formulae for the…

General Relativity and Quantum Cosmology · Physics 2011-10-06 Nikodem J. Poplawski

Magnetic configurations, stable on the long term, appear to exist in various evolutionary phases, from Main-Sequence stars to white dwarfs and neutron stars. The large scale ordered nature of these fields, often approximately dipolar, and…

Solar and Stellar Astrophysics · Physics 2015-06-22 Andre Maeder , Georges Meynet

Turbulence is believed to play important roles in the origin of cosmic magnetism. While it is well known that turbulence can efficiently amplify a uniform or spatially homogeneous seed magnetic field, it is not clear whether or not we can…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Jungyeon Cho

In the recent past there have been many attempts to associate the generation of primordial magnetic seed fields with the inflationary era, but with limited success. We thus take a different approach by using a model for nonsingular bouncing…

General Relativity and Quantum Cosmology · Physics 2017-04-20 Ratna Koley , Sidhartha Samtani

Turbulence dynamo deals with amplification of a seed magnetic field in a turbulent medium and has been studied mostly for uniform or spatially homogeneous seed magnetic fields. However, some astrophysical processes (e.g. jets from active…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Jungyeon Cho , Hyunju Yoo

Low-mass galaxies radio observations show in many cases surprisingly high levels of magnetic field. The mass and kinematics of such objects do not favour the development of effective large-scale dynamo action. We attempted to check if the…

Astrophysics of Galaxies · Physics 2018-03-14 Hubert Siejkowski , Marian Soida , Krzysztof T. Chyzy

In this paper we show that the Universe is already strongly magnetized at very early epochs during cosmic evolution. Our calculations are based on the efficient amplification of weak magnetic seed fields, which are unavoidably present in…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-09 Jacques M. Wagstaff , Robi Banerjee , Dominik Schleicher , Guenter Sigl

The origin of intergalactic magnetic fields is still a mystery and several scenarios have been proposed so far: among them, primordial phase transitions, structure formation shocks and galactic outflows. In this work we investigate how…

Astrophysics · Physics 2009-11-11 Serena Bertone , Corina Vogt , Torsten Ensslin

It is argued that large scale cosmic magnetic field could be generated in the primeval plasma slightly before hydrogen recombination. Non-zero vorticity, necessary for that, might be created by the photon diffusion in the second order in…

Astrophysics · Physics 2016-08-30 Z. Berezhiani , A. D. Dolgov
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