Charged multifluids in general relativity

Abstract

The exact 1+3 covariant dynamical fluid equations for a multi-component plasma, together with Maxwell's equations are presented in such a way as to make them suitable for a gauge-invariant analysis of linear density and velocity perturbations of the Friedmann-Robertson-Walker model. In the case where the matter is described by a two component plasma where thermal effects are neglected, a mode representing high-frequency plasma oscillations is found in addition to the standard growing and decaying gravitational instability picture. Further applications of these equations are also discussed.

Gravitational, shear and matter waves in Kantowski-Sachs cosmologies

“…In this way, a set of gauge-invariant perturbation variables can be easily identified as the ones that vanish on the chosen background [38][39][40][41][42][43][44]50]. This feature of the covariant approach makes it a very versatile method for studying perturbations on a variety of backgrounds and physical situations and relating the results obtained in a unified way [45][46][47][48][49] In this paper we present for the first time a general treatment of the vorticity-free perturbations of Kantowski-Sachs cosmologies with positive cosmological constant, extending earlier work [51], which focused only on the scalar perturbation sector. Here we present for the first time an analysis of a full scalar, vectorial and tensorial perturbations, focusing on gravitational and matter wave evolutions.…”

Natural generation and amplification of magnetic seed fields

“…These fields are facilitated by currents that arise from local charge separation generated by vortical velocity fields prevalent in the early plasma (cf. also [7,8]). …”

Lorentz-violating inflationary magnetogenesis

“…Accordingly, the evolution in vacuum of electromagnetic fields described by the Lorentz-violating electromagnetic Lagrangian density (34) is formally equivalent to the evolution of electromagnetic fields described by the standard Maxwell theory in a continuous medium with ε and μ given by Eqs. (31) and (32). Continuing with the analogy of continuous media, the quantity n defined below Eq.…”