Propagation of Electromagnetic Waves in Media Which Vary Slowly With Position and Time


  • Ronald L. Fante


Using WKB methods we have considered the propagation of electromagnetic waves in isotropic lossless media which vary slowly with both position and time. It is found that in such media the meaning of various quantities, such as the group velocity, must be reinterpreted. The theory is applied to study propagation in space-time, varying dielectrics, and plasmas.