Principal functions of non-selfadjoint discrete Sturm-Liouville equations with quadratic spectral parameter in boundary conditions

Abstract

In this paper, we study the principal functions corresponding to the eigenvalues and the spectral singularities of the boundary value problem (BVP) an-1yn-1 + bnyn + anyn+1 = λyn, n∈ ℕ (γ0 + γ1λ + γ2λ2)y1 + (β0 _ β1λ + β2λ2)yo = 0 where (an) and (bn) n ∈ ℕ are complex sequences, γi βi, ∈ and ℂ is a eigenparameter.