On a Weyl–Titchmarsh theory for discrete symplectic systems on a half line

Abstract

Recently, Bohner and Sun [9] introduced basic elements of a Weyl–Titchmarsh theory into the study of discrete symplectic systems. We extend this development through the introduction of Weyl–Titchmarsh functions together with a preliminary study of their properties. A limit point criterion is described and characterized. Green’s function for the half-line is introduced as a limit of such functions in the regular case and half-line solutions obtained are seen to satisfy λ-dependent boundary conditions at infinity.