ON THE VELOCITY OF LIGHT IN UNIFORMLY MOVING DIELECTRICS

A wave equation for the electromagnetic four-potential Aα=(Φ/c, A) in a moving isotropic and non-dispersive (in its proper frame) dielectric is obtained. By using a dispersion relation which results from the wave equation in the absence of sources, the phase and group velocities of the light waves are obtained. Also, when temporal dispersion in the proper frame of the dielectric is taken into account, a relativistic derivation of the three-dimensional Fresnel dragging coefficient for the phase velocity is discussed to first order in the relative velocity. © 1990 Taylor & Francis Ltd.