Determination of lower order perturbations of a polyharmonic operator in two dimensions

Abstract

We study an inverse boundary value problem for a polyharmonic operator in two dimensions. We show that the Cauchy data uniquely determine all the anisotropic perturbations of orders at most m - 1 and several perturbations of orders m to 2m - 2 under some restriction. The uniqueness proof relies on the partial derivative-techniques and the method of stationary phase.