Linear causality and stability constraints on relativistic second-order magnetohydrodynamics
The work develops a theoretical framework for relativistic second-order magnetohydrodynamics using entropy current analysis to study linear causality and stability. By linearizing the theory around equilibrium, it identifies coupled magneto-sonic, Alfvén, and charge-diffusion sectors. The analysis shows that causality constraints depend on propagation direction and anisotropic transport coefficients.