Spectral analysis of discrete elliptic operators and applications in control theory

Abstract

In this paper we propose an analysis of discrete spectral properties for a finite difference discretization of quite general 1D second-order self-adjoint elliptic operators. We particularly investigate some (uniform in the discretization parameter) qualitative behavior of eigenfunctions and eigenvalues. With those estimates we manage to obtain new results for the construction of bounded families of controls for semi-discrete parabolic PDEs, in particular for boundary controls of a coupled parabolic system with fewer controls than equations.