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相关论文: Primordial magnetic fields and nonlinear electrody…

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We study the evolution of an inflation-generated magnetic field, due to its coupling to fluid motions, during cosmological phase transitions. We find that the magnetic field stays almost unchanged on large scales, while on small scales the…

宇宙学与河外天体物理 · 物理学 2013-05-30 Tina Kahniashvili , Axel Brandenburg , Leonardo Campanelli , Bharat Ratra , Alexander G. Tevzadze

In this paper, we study the generation of a large scale magnetic field with amplitude of order $\mu$G in an inflationary model which has been introduced in hep-th/0310221. This inflationary model based on existence of a speed limit for…

高能物理 - 理论 · 物理学 2009-11-11 Mohammad A. Ganjali

Among primordial magnetogenesis models, inflation is a prime candidate to explain the current existence of cosmological magnetic fields. Assuming conformal invariance to be restored after inflation, their energy density decreases as…

宇宙学与河外天体物理 · 物理学 2012-05-11 Vittoria Demozzi , Christophe Ringeval

If the conformal invariance of electromagnetism is broken during inflation, then primordial magnetic fields may be produced. If this symmetry breaking is generated by the coupling between electromagnetism and a scalar field---e.g. the…

宇宙学与河外天体物理 · 物理学 2013-05-29 Robert R. Caldwell , Leonardo Motta , Marc Kamionkowski

Spontaneous breaking of Lorentz invariance compatible with observational limits may realistically take place in the context of string theories, possibly endowing the photon with a mass. In this process the conformal symmetry of the…

广义相对论与量子宇宙学 · 物理学 2016-08-31 O. Bertolami , D. F. Mota

The detection of magnetic fields at high redshifts, and in empty intergalactic space, support the idea that cosmic magnetism has a primordial origin. Assuming that Maxwellian electromagnetism and general relativity hold, and without…

广义相对论与量子宇宙学 · 物理学 2015-06-11 J. D. Barrow , C. G. Tsagas , K. Yamamoto

We study the backreaction problem in a mechanism of magnetogenesis from inflation. In usual analysis, it has been assumed that the backreaction due to electromagnetic fields spoils inflation once it becomes important. However, there exists…

宇宙学与河外天体物理 · 物理学 2014-12-09 Sugumi Kanno , Jiro Soda , Masa-aki Watanabe

The universe is magnetized on all scales probed so far. On the largest scales, galaxies and galaxy clusters host magnetic fields at the micro Gauss level coherent on scales up to ten kpc. Recent observational evidence suggests that even the…

宇宙学与河外天体物理 · 物理学 2017-05-26 Kandaswamy Subramanian

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…

广义相对论与量子宇宙学 · 物理学 2009-11-10 G. Lambiase , A. R. Prasanna

We discuss some aspects of Pereira et al. (2018) concerning magnetars described by nonlinear theories of the electromagnetism and make the case for the Born-Infeld Lagrangian. We focus on the increase of toroidal magnetic fields in these…

高能天体物理现象 · 物理学 2019-04-12 Jonas P. Pereira , Jaziel G. Coelho , Rafael C. R. de Lima

The magnetogenesis scenarios triggered by the early variation of the gauge coupling are critically analyzed. In the absence of sources, it is shown that the electric and magnetic power spectra can be explicitly computed by means of…

宇宙学与河外天体物理 · 物理学 2010-04-29 Massimo Giovannini

Large-scale magnetogenesis is analyzed within the Palatini approach when the gravitational action is supplemented by a contribution that is nonlinear in the Einstein-Hilbert term. While the addition of the nonlinear terms does not affect…

高能物理 - 理论 · 物理学 2021-12-08 Massimo Giovannini

There is a reformulation of magnetohydrodynamics in which the fundamental dynamical quantities are the positions and velocities of the lines of magnetic flux in the plasma, which turn out to obey equations of motion very much like ideal…

天体物理学 · 物理学 2009-10-31 Mattias Christensson , Mark Hindmarsh

The Abelian Born-Infeld classical non-linear electrodynamic has been used to investigate the electric and magnetostatic fields generated by a point-like electrical charge at rest in an inertial frame. The results show a rich internal…

高能物理 - 理论 · 物理学 2008-11-26 S. O. Vellozo , Jose A. Helayel-Neto , A. W. Smith , L. P. G. De Assis

We show that the first structures that form in the universe should spontaneously generate magnetic fields. No primordial seed field is required for this "first dynamo". Although the first dynamo starts with kinetic plasma instabilities, we…

宇宙学与河外天体物理 · 物理学 2009-05-08 Andrei Gruzinov

In this paper I examine cosmological models that contain a stochastic background of nonlinear electromagnetic radiation. I show that for Born-Infeld electrodynamics the equation of state parameter, $w=P/\rho$, remains close to 1/3…

广义相对论与量子宇宙学 · 物理学 2008-12-18 Dan N. Vollick

We study limits on a primordial magnetic field arising from cosmological data, including that from big bang nucleosynthesis, cosmic microwave background polarization plane Faraday rotation limits, and large-scale structure formation. We…

宇宙学与河外天体物理 · 物理学 2010-10-27 Tina Kahniashvili , Alexander G. Tevzadze , Shiv K. Sethi , Kanhaiya Pandey , Bharat Ratra

In the standard model there are charges with abelian anomaly only (e.g. right-handed electron number) which are effectively conserved in the early universe until some time shortly before the electroweak scale. A state at finite chemical…

天体物理学 · 物理学 2009-10-30 M. Joyce , M. Shaposhnikov

This review concerns the origin and the possible effects of magnetic fields in the early Universe. We start by providing to the reader with a short overview of the current state of art of observations of cosmic magnetic fields. We then…

天体物理学 · 物理学 2009-07-09 Dario Grasso , H. R. Rubinstein

We present preliminary results on the possible effects that primordial magnetic fields can have for a warm inflation scenario, based on global supersymmetry, with a new-inflation-type potential. This work is motivated by two considerations:…

宇宙学与河外天体物理 · 物理学 2015-06-17 Gabriella Piccinelli , Angel Sanchez , Alejandro Ayala , Ana Julia Mizher