Resistive relativistic magnetohydrodynamics from a charged multi-fluids perspective

TL;DR

This paper develops a comprehensive relativistic magnetohydrodynamics model from a charged multi-fluid perspective, incorporating resistivity, entropy, and causality considerations, with applications to astrophysical plasmas.

Contribution

It introduces a variational approach to resistive relativistic MHD with two charged fluids, including hot plasma effects and entropy dynamics, expanding existing models.

Findings

Complete resistive relativistic MHD model for cold plasmas

Novel hot plasma analysis with causality-preserving relaxation times

Explicit coupling between heat and charge fluxes in hot systems

Abstract

We consider general relativistic magnetohydrodynamics from a charged multifluids point-of-view, taking a variational approach as our starting point. We develop the case of two charged components in detail, accounting for a phenomenological resistivity, providing specific examples for pair plasmas and proton-electron systems. We discuss both cold, low velocity, plasmas and hot systems where we account for a dynamical entropy component. The results for the cold case (which accord with recent work in the literature) provide a complete model for resistive relativistic magnetohydrodynamics, clarifying the assumptions that lead to various models that have been used in astrophysical applications. The analysis of the hot case is (as far as we are aware) novel, accounting for the relaxation times that are required to ensure causality and demonstrating the explicit coupling between fluxes of heat and charge.