Low-frequency waves in inhomogeneous magnetic fields

Propagation of waves in inhomogeneous, hot, isotropic plasma is described, assuming that the wavelength is much smaller than the scale-length of the plasma. The effect of the magnetic field topology on properties of waves is discussed in some detail. Coupling between the modes of oscillations is always present in an inhomogeneous ‘hot’ plasma. It is particularly strong for magneto- dynamic and sound waves propagating essentially along the fleidlines in the vicinity of a point where the phase velocities of the two modes are equal.