Charged multifluids in general relativity

TL;DR

This paper derives gauge-invariant dynamical equations for multi-component plasmas in general relativity, revealing high-frequency plasma oscillations alongside standard gravitational instabilities in cosmological models.

Contribution

It presents a comprehensive set of covariant fluid and Maxwell equations suitable for analyzing linear perturbations in relativistic plasmas, including new high-frequency mode insights.

Findings

Identification of high-frequency plasma oscillation mode

Extension of perturbation analysis to multi-component relativistic plasmas

Framework applicable to gauge-invariant cosmological perturbations

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.