REFRACTION THEORY FOR COSMIC MOVING PLASMA
abstract
This thesis deals with formulating a covariant model for studying the electromagnetic response of moving media and in particular the propagation of electromagnetic wave in electron plasma. Based on the fundamental equations of electrodynamics and special relativity, the constitutive relations for the dielectric tensor of permittivity and for the dispersion equations have been derived. The isotropic and anisotropic moving plasmas have been analyzed. In the first part we considered that the plasma is moving slowly compared with the light speed (classical approach) and in the second part the relativistic corrections (relativistic approach) have been incorporated. The obtained dispersion relations, that characterized the propagation of electromagnetic waves in moving medium, are analytical resolved for the simplest situations. For more complex geometrical orientation of the streaming plasma and the external magnetic field, numerical methods have been employed. In the rest frame the electron plasma is considered homogeneous, cold and the particle collisions are neglected. We have study the case of longitudinal and transversal displacement of anisotropic plasma, relatively to the external magnetic field. In this work, we show that when the plasma is slowly moving, the bulk motion of material medium does not affect the conventional dispersion properties of the medium, thus the relations for the propagation of the ordinary and extraordinary electromagnetic modes will maintain unaltered. On the other hand, for highly relativistic plasma, the dispersion properties are modified substantially and new dispersion electromagnetic branches appear in the medium, on which the streaming motion plays an important role. In addition, we have carried out similar calculations for the propagation of the electromagnetic waves in inhomogeneous plasma, taking into account the dependence of the physical parameters at coordinates.
