Propagation of Hydromagnetic Waves in Collisionless Plasma. II. Kinetic Approach

Abstract

The propagation of hydromagnetic waves of small amplitude in a collisionless plasma is considered on the basis of the Vlasov equation. It is found that there exist the Alfvén wave, the fast and the slow magnetoacoustic waves as well as the non-oscillating mode with vanishing real part of the frequency. Under some conditions, the non-oscillating wave causes the mirror instability in the direction nearly perpendicular to a magnetic field. Numerical discussions are carried out in the phase velocity plane as well as in the Friedrichs diagram for each type of waves, and are compared with the corresponding results in the Chew, Coldberger and Low approximation.