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The vector nature of magnetic fields and the geometrical interpretation of gravity introduced by general relativity, guarantee a special coupling between magnetism and spacetime curvature. This magneto-geometrical interaction effectively…

Astrophysics · Physics 2009-10-31 Christos G. Tsagas

We discuss how the vector nature of magnetic fields, and the geometrical interpretation of gravity introduced by general relativity, lead to a special coupling between magnetism and spacetime curvature. This magneto-geometrical interaction…

General Relativity and Quantum Cosmology · Physics 2017-01-25 Christos G Tsagas

We present the formalism for the covariant treatment of gravitational radiation in a magnetized environment and discuss the implications of the field for gravity waves in the cosmological context. Our geometrical approach brings to the fore…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Christos G. Tsagas

Plane symmetric cosmological models are investigated with or without any dark energy components in the field equations. Keeping an eye on the recent observational constraints concerning the accelerating phase of expansion of the universe,…

General Relativity and Quantum Cosmology · Physics 2015-02-24 S. K. Tripathy , K. L. Mahanta

We review spacetime dynamics in the presence of large-scale electromagnetic fields and then consider the effects of the magnetic component on perturbations to a spatially homogeneous and isotropic universe. Using covariant techniques, we…

Astrophysics · Physics 2008-11-26 J. D. Barrow , R. Maartens , C. G. Tsagas

We deal with a dynamical mechanism in which a large cosmological constant, as suggested by inflationary scenarios, decays due to expansion of the universe. This mechanism has its origin in the gravitational coupling of the vacuum density.…

General Relativity and Quantum Cosmology · Physics 2018-06-05 Yousef Bisabr

We analyze the properties of the electric and magnetic fields in different reference frames within a cosmological background space-time. First, we investigate the conformal properties of the electromagnetic fields and charge currents,…

General Relativity and Quantum Cosmology · Physics 2019-03-27 Luciano Combi , Gustavo E. Romero

We show that the difference between the theoretically expected and measured by WMAP amplitude of the quadrupole fluctuations of CMB can be related to the impact of the anisotropic curvature of the homogeneous universe dominated by the dark…

Astrophysics · Physics 2008-11-26 M. Demiański , A. G. Doroshkevich

We study the amplification of large-scale magnetic fields during preheating and inflation in several different models. Preheating can resonantly amplify seed fields on cosmological scales. In the presence of conductivity, however, the…

Astrophysics · Physics 2009-10-31 Bruce A. Bassett , Giuseppe Pollifrone , Shinji Tsujikawa , Fermin Viniegra

A large-scale cosmic magnetic field affects not only the growth of density perturbations, but also rotational instabilities and anisotropic deformation in the density distribution. We give a fully relativistic treatment of all these…

Astrophysics · Physics 2008-11-26 Christos Tsagas , Roy Maartens

The gravitational collapse of a magnetised medium is investigated by studying qualitatively the convergence of a timelike family of non-geodesic worldlines in the presence of a magnetic field. Focusing on the field's tension we illustrate…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Christos G. Tsagas

We review recent literature on the connection between quantum entanglement and cosmology, with an emphasis on the context of expanding universes. We discuss recent theoretical results reporting on the production of entanglement in quantum…

General Relativity and Quantum Cosmology · Physics 2015-03-20 Eduardo Martin-Martinez , Nicolas C. Menicucci

The evolution of the magnetic field in an accreting neutron star is investigated using a fully general relativistic treatment and assuming that initially the currents supporting the field are completely confined to the crust. We find that…

Astrophysics · Physics 2009-10-31 Sushan Konar

Magnetic fields interact with gravitational waves in various ways. We consider the coupling between the Weyl and the Maxwell fields in cosmology and study the effects of the former on the latter. The approach is fully analytical and the…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-06 Christos G. Tsagas

We study the evolution of magnetic fields in turbulent hot plasma of the early Universe accounting for the chiral magnetic effect. The magnetohydrodynamic turbulence is modeled by replacing the matter velocity in the advection term in the…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-17 Maxim Dvornikov

As evidenced by a great number of works, it is common practice to assume that the Universe is flat. However, the majority of studies which make use of observational data to constrain the curvature density parameter are premised on the…

General Relativity and Quantum Cosmology · Physics 2019-07-18 Christine R. Farrugia , Joseph Sultana

In this work, one examines how the presence of a non-minimal coupling between the spacetime curvature and matter affects the evolution of cosmological perturbations around a homogeneous and isotropic Universe and hence the formation of…

General Relativity and Quantum Cosmology · Physics 2013-05-27 Orfeu Bertolami , Pedro Frazão , Jorge Páramos

We derive the amplification of the cosmological magnetic field associated with forming gravitational structure. The self-similar solutions of magnetohydrodynamic equations are computed both in linear and nonlinear regimes. We find that the…

Astrophysics · Physics 2009-11-10 G. Siemieniec-Ozieblo , Z. Golda

It is shown that gravitating magnetic fields affect the evolution of curvature perturbations in a way that is reminiscent of a pristine non-adiabatic pressure fluctuation. The gauge-invariant evolution of curvature perturbations is used to…

Astrophysics · Physics 2008-11-26 Massimo Giovannini

In the presence of cosmic chiral asymmetry, chiral-vorticity and chiral-magnetic effects can play an important role in the generation and evolution of magnetic fields in the early universe. We include these chiral effects in the magnetic…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Hiroyuki Tashiro , Tanmay Vachaspati , Alexander Vilenkin
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