First-order spin magnetohydrodynamics

TL;DR

This paper develops a first-order relativistic spin magnetohydrodynamics framework incorporating antisymmetric spin currents and analyzes anisotropic linear wave behavior near equilibrium, revealing a critical angle affecting wave modes.

Contribution

It introduces a novel formulation of relativistic spin MHD with antisymmetric spin currents and studies the anisotropic wave properties, highlighting critical angle phenomena.

Findings

Identification of a critical angle where wave modes transition from propagating to diffusive.

Linear wave solutions exhibit angle-dependent behavior not fully described by polynomial solutions.

Analysis of anisotropic wave properties near equilibrium in relativistic spin MHD.

Abstract

Based on recent papers, we discuss the formulation of the first-order relativistic spin magnetohydrodynamics (MHD) with the totally antisymmetric spin current and properties of the anisotropic linear waves awaken near an equilibrium configuration. We show that there appears a critical angle in the momentum direction of the linear waves, where a pair of propagating modes turns into purely diffusive modes. Due to this critical behavior, polynomial solutions do not fully capture the angle dependence of the linear waves.