Théorie spectrale de la propagation des ondes acoustiques dans un milieu stratifié perturbe

Abstract

Abstract In this article the spectral analysis of the self adjoint operator governing the propagation acoustic waves in a perturbed stratified medium is given. Both a medium whose sound speed is a short range perturbation of that of a stratified medium and a stratified medium exterior to a compact set are considered. The basic tool is a division theorem for the self adjoint operator governing the propagation of acoustic waves in a pure stratified medium.