English
Related papers

Related papers: Power-Law NLED-Based Magnetic Universe Can Mimic P…

200 papers

The Friedmann equations for a brane with induced gravity are analyzed and compared with the standard general relativity and Randall-Sundrum cases. Randall-Sundrum gravity modified the early universe dynamics, whereas induced gravity changes…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Burin Gumjudpai

A novel nonlinear electrodynamics (NLE) model with two dimensionful parameters is introduced and investigated. Our model obeys the Maxwellian limit and exhibits behaviour similar to the Born-Infeld Lagrangian in the weak field limit. It is…

General Relativity and Quantum Cosmology · Physics 2024-12-09 Anjan Kar

This work revises the Brane World Theory known as Randall-Sundrum with the modification of an exponential, redshift-dependent brane tension. This model is studied in a scenario assuming no dark energy, with the aim of determining whether it…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-27 Kyra Jacobo , Dorian Araya

We study cosmological consequences of non-constant brane world moduli in five dimensional brane world models with bulk scalars and two boundary branes. We focus on the case where the brane tension is an exponential function of the bulk…

High Energy Physics - Theory · Physics 2008-11-26 Ph. Brax , C. van de Bruck , A. -C. Davis , C. S. Rhodes

It is well-known that the application of Newtonian dynamics to an expanding spherical region leads to the correct relativistic expression (the Friedmann equation) for the evolution of the cosmic scale factor. Here, the cosmological…

Astrophysics · Physics 2009-10-30 R. H. Sanders

In the 5-dimensional braneworld cosmology, the Friedmann equation of our 4-dimensional universe on a brane is modified at high temperatures while the standard Big Bang cosmology is reproduced at low temperatures. Based on two well-known…

High Energy Physics - Phenomenology · Physics 2019-11-14 Victor Baules , Nobuchika Okada , Satomi Okada

In this paper we analyze the cosmological dynamics of phantom field in a variety of potentials unbounded from above. We demonstrate that the nature of future evolution generically depends upon the steepness of the phantom potential and…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. Sami , Alexey Toporensky

Cosmological magnetic fields are being observed with ever increasing correlation lengths, possibly reaching the size of superclusters, therefore disfavouring the conventional picture of generation through primordial seeds later amplified by…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-23 Federico R. Urban , Ariel R. Zhitnitsky

Magnetic fields are widely observed in the Universe in virtually all astrophysical objects, from individual stars to entire galaxies, even in the intergalactic medium, but their specific generation has long been debated. Due to the…

Astrophysics of Galaxies · Physics 2017-11-08 Michael Rieder , Romain Teyssier

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

Electromagnetism appears to have the potential to alter the fate of relativistic gravitational implosion. Coulomb forces, for example, can in principle prevent the ultimate collapse of charged matter to a singularity. Also, half a century…

General Relativity and Quantum Cosmology · Physics 2021-09-22 Christos G. Tsagas , Panagiotis Mavrogiannis

We make the observation that a brane universe accelerates through its bulk spacetime, and so may be interpreted as an Unruh observer. The bulk vacuum is perceived to be a thermal bath that heats matter fields on the brane. It is shown that,…

High Energy Physics - Theory · Physics 2007-05-23 David Jennings

We investigate the cosmological consequences of a brane-world theory which incorporates time variations in the gravitational coupling G and the cosmological term Lambda. We analyze in detail the model where (dG/dt)/G ~ H and Lambda ~ H^2,…

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. Ponce de Leon

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

A primordial magnetic field may be generated during an inflationary period if conformal invariance is broken. We reexamine and generalize previous results about the magnetic field produced by couplings of the form $R^n…

Astrophysics · Physics 2009-10-28 F. D. Mazzitelli , F. M. Spedalieri

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

In this paper, we investigate the dynamics of the universe on the background of f-essence when a non-minimal coupling with gravity. Field equations are obtained and using the Noether theorem, explicit forms of the coupling function and the…

General Physics · Physics 2017-05-26 Tolkynay Myrzakul , Ertan Gudekli , Shynaray Myrzakul , Ratbay Myrzakulov

The dynamics in QED in a strong constant magnetic field and its connection with the noncommutative QED are studied. It is shown that in the regime with the lowest Landau level (LLL) dominance the U(1) gauge symmetry in the fermion…

High Energy Physics - Theory · Physics 2009-11-11 E. V. Gorbar , Michio Hashimoto , V. A. Miransky

The evolution and viscous damping of cosmic magnetic fields in the early universe, is analysed. Using the fact that the fluid, electromagnetic, and shear viscous energy-momentum tensors are all conformally invariant, the evolution is…

Astrophysics · Physics 2011-09-29 Kandaswamy Subramanian , John D. Barrow

Despite impressive phenomenological successes, cosmological models are incomplete without an understanding of what happened at the big bang singularity. Maxwell electrodynamics, considered as a source of the classical Einstein field…

General Relativity and Quantum Cosmology · Physics 2017-02-17 A. Övgün