On the discrete spectrum of complex banded matrices

Abstract

The discrete spectrum of complex banded matrices which are compact perturbations of the standard banded matrix of order $p$ is under consideration. The rate of stabilization for the matrix entries sharp in the sense of order which provides finiteness of the discrete spectrum is found. The $p$-banded matrix with the discrete spectrum having exactly $p$ preassigned points on the interval $(-2,2)$ is constructed. The results are applied to the study of the discrete spectrum of asymptotically periodic complex Jacobi matrices.