Group velocity and causality in standard relativistic resistive magnetohydrodynamics

Abstract

Group velocity of electromagnetic waves in plasmas derived by standard relativistic resistive MHD (resistive RMHD) equations is superluminal. If we assume that the group velocity represents the propagation velocity of a signal, we have to worry about the causality problem. That is, some acausal phenomena may be induced, such that information transportation to the absolute past and spontaneous decrease in the entropy. Here, we tried to find the acausal phenomena using standard resistive RMHD numerical simulations in the suggested situation of the acausal phenomena. The calculation results showed that even in such situations no acausal effect happens. The numerical result with respect to the velocity limit of the information transportation is consistent with a linear theory of wave train propagation. Our results assure that we can use these equations without problems of acausal phenomena.

28 pages, 10 figures

References in corpus (5)

• General Relativistic Magnetohydrodynamic Simulations of Jet Formation and Large-Scale Propagation from Black Hole Accretion Systems
• Two-dimensional MHD simulations of relativistic magnetic reconnection
• Generalized Relativistic Magnetohydrodynamic Equations for Pair and Electron-Ion Plasmas
• Generalized General Relativistic MHD Equations and Distinctive Plasma Dynamics around Rotating Black Holes
• Propagation of Electromagnetic Waves in Resistive Pair Plasma and Causal Relativistic Magnetohydrodynamics

Cited by in corpus (4)

• Thermal-inertial effects on magnetic reconnection in relativistic pair plasmas
• Dispersion relations alone cannot guarantee causality
• Numerical simulation of magnetic reconnection around a black hole
• Relativistic resistive magnetohydrodynamics for a two-component plasma