Non-relativestic scattering by time-varying bodies and media

Abstract

We are interested in first order v/c velocity effects in scattering problems involving motion of media and scatterers. Previously constant velocities have been considered for scattering by cylindrical and spherical configurations. Presently time-varying motion - specifically harmonic oscillation - is investigated. A firstorder quasi-Lorentz transformation is introduced heuristically, in order to establish relations to existing exact Special-Relativistic results. We then consider simple problems of plane interfaces, normal incidence, and uniform motion, in order to introduce the model: Starting with an interface moving with respect to the medium in which the excitation wave is introduced, then considering the problem of an interface at rest and a moving medium contained in a half space. The latter corresponds to a Fizeau experiment configuration. Afterwards these configurations are considered for harmonic motion. This provides the method for dealing with the corresponding problems of scattering by a circular cylinder, involving harmonic motion. The present formalism provides a systematic approach for solving scattering problems in the presence of time-varying media and boundaries.