A note on the spectral singularities of non-selfadjoint matrix-valued difference operators

Let L denote the non-selfadjoint operator generated in ℓ2(N,E)ℓ2(N,E) by the matrix difference expression (ℓy)n=An−1yn−1+Bnyn+Anyn+1(ℓy)n=An−1yn−1+Bnyn+Anyn+1, n∈Nn∈N, and the boundary condition y0=0y0=0. In this paper we investigate the Jost solution, the continuous spectrum, the eigenvalues and the spectral singularities of LL.