Non-relativistic Scattering: Pulsating Interfaces

Scattering by pulsating objects is discussed. In the case of the pulsating cylinder, its surface vibrates time-harmonically in the radial direction. The formalism is based on first-order / v c relativistic approximations, and on the assumption that the ambient media are not affected by the mechanical motion of the interface. This is conducive to simpler and amenable approximations. The cases analyzed display the modulation effect due to the mechanical motion at frequency Ω , creating new spectral components in the scattered wave, peaking at the sideband frequencies ex n ω ± Ω around the excitation frequency. To put such phenomena in a quasi-relativistic and electromagnetic context, and account for the boundary-condition problem and the representation of the scattered wave is the subject of the present investigation. Such effects can be used to remotely sense the properties of the scatterer, especially its motion.