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相关论文: Gravitational instability of the primordial plasma…

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Possible existence of the primordial magnetic fields has affected the structure formation of the universe. In this paper it is shown that the initial conditions for density perturbations with magnetic fields derived in previous works are…

宇宙学与河外天体物理 · 物理学 2009-03-20 Kazuhiko Kojima , Kiyotomo Ichiki

In this paper we study a simple model consisting of a dilute fully ionized plasma in the presence of the gravitational and a constant magnetic field to analyze the propagation of hydromagnetic instabilities. In particular we show that the…

天体物理学 · 物理学 2007-05-23 A. Sandoval-Villalbazo , L. S. Garcia-Colin , A. Arrieta

We study the generation and evolution of density perturbations and peculiar velocities due to primordial magnetic fields. We assume that a random magnetic field was present before recombination and follow the field's effect on the baryon…

天体物理学 · 物理学 2009-10-22 Eun-jin Kim , Angela Olinto , Robert Rosner

We study the linear evolution of magnetised cosmological perturbations in the post-recombination epoch. Using full general relativity and adopting the ideal magnetohydrodynamic approximation, we refine and extend the previous treatments.…

宇宙学与河外天体物理 · 物理学 2018-06-13 Dimitra Tseneklidou , Christos G. Tsagas , John D. Barrow

In this paper, we analyze the stability of a homogeneous self-gravitating plasma, having a non-zero resistivity. This study provides a generalization of the Jeans paradigm for determining the critical scale above which gravitational…

高能天体物理现象 · 物理学 2015-03-19 Daniela Pugliese , Nakia Carlevaro , Massimiliano Lattanzi , Giovanni Montani , Riccardo Benini

We study inhomogeneous magnetised cosmologies through the post-recombination era in the framework of Newtonian gravity and the ideal-magnetohydrodynamic limit. The nonlinear kinematic and dynamic equations are derived and linearised around…

宇宙学与河外天体物理 · 物理学 2015-12-02 Hera Vasileiou , Christos G. Tsagas

In weakly collisional extragalactic plasmas such as the intracluster medium, viscous stress and the rate of change of the magnetic-field strength are proportional to the local pressure anisotropy, so subject to constraints imposed by the…

宇宙学与河外天体物理 · 物理学 2015-08-26 Federico Mogavero , Alexander A. Schekochihin

In this work we report a numerical study of the cosmic magnetic field amplification due to collisionless plasma instabilities. The collisionless magnetohydrodynamic equations derived account for the pressure anisotropy that leads, in…

宇宙学与河外天体物理 · 物理学 2015-08-06 D. Falceta-Goncalves , G. Kowal

We consider that no mean magnetic field exists during this epoch, but that there is a mean magnetic energy associated with large-scale magnetic inhomogeneities. We study the evolution of these inhomogeneities and their influence on the…

天体物理学 · 物理学 2009-01-14 E. Battaner , E. Florido , J. Jimenez-Vicente

We study the evolution of primordial magnetic fields in an expanding cosmic plasma. For this purpose we present a comprehensive theoretical model to consider the evolution of MHD turbulence that can be used over a wide range of physical…

宇宙学与河外天体物理 · 物理学 2016-10-12 Tina Kahniashvili , Axel Brandenburg , Alexander G. Tevzadze

The onset and evolution of magnetic fields in laboratory and astrophysical plasmas is determined by several mechanisms, including instabilities, dynamo effects and ultra-high energy particle flows through gas, plasma and interstellar-media.…

等离子体物理 · 物理学 2015-05-20 A. Flacco , J. Vieira , A. Lifschitz , F. Sylla , S. Kahaly , M. Veltcheva , L. O. Silva , V. Malka

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…

天体物理学 · 物理学 2008-11-26 Christos Tsagas , Roy Maartens

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…

天体物理学 · 物理学 2008-11-26 J. D. Barrow , R. Maartens , C. G. Tsagas

Long-range interactions in the dark sector can give rise to collective plasma phenomena that are capable of modifying the evolution of dark matter halos. We present the first study of gravitational collapse in a secluded dark $U(1)_D$ model…

高能物理 - 唯象学 · 物理学 2026-04-03 Pierce Giffin , Andrew Liu , Jeremias Boucsein , Akaxia Cruz , Anirudh Prabhu , Stefano Profumo , M. Grant Roberts

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…

天体物理学 · 物理学 2008-11-26 M. Demiański , A. G. Doroshkevich

Anisotropic stress contributions to the gravitational field can arise from magnetic fields, collisionless relativistic particles, hydrodynamic shear viscosity, gravitational waves, skew axion fields in low-energy string cosmologies, or…

天体物理学 · 物理学 2009-10-30 John Barrow , Roy Maartens

In this paper, we have investigated the density perturbations and cosmological evolution in the FLRW universe in presence of a cosmic magnetic field, which may be assumed to mimic primordial magnetic fields. Such magnetic fields have…

高能物理 - 理论 · 物理学 2025-08-11 Samarjit Chakraborty , Sarbari Guha

We present an analysis of the cosmological evolution of matter sources with small anisotropic pressures. This includes electric and magnetic fields, collisionless relativistic particles, gravitons, antisymmetric axion fields in low-energy…

广义相对论与量子宇宙学 · 物理学 2009-10-30 John D. Barrow

Using second-order gauge-invariant perturbation theory, a self-consistent framework describing the non-linear coupling between gravitational waves and a large-scale homogeneous magnetic field is presented. It is shown how this coupling may…

广义相对论与量子宇宙学 · 物理学 2009-11-11 Gerold Betschart , Caroline Zunckel , Peter Dunsby , Mattias Marklund

We consider anisotropic magnetized cosmologies filled with conductive plasma fluid and study the implications of metric perturbations that propagate parallel to the ambient magnetic field. It is known that in the first order (linear)…

广义相对论与量子宇宙学 · 物理学 2010-10-27 A Kuiroukidis , K Kleidis , D B Papadopoulos
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