A note on the spectrum of discrete Klein-Gordon s-wave equation with eigenparameter dependent boundary condition

This paper is concerned with the boundary value problem (BVP) for the discrete Klein-Gordon equation ?(an-1?yn-1)+(vn-?)2 yn = 0; n ? N and the boundary condition (?0+?1?)y1+(?0+?1)y0 = 0 where (an),(vn) are complex sequences, ?i, ?i ? C, i=0,1 and ? is a eigenparameter. The paper presents Jost solution, eigenvalues, spectral singularities and states some theorems concerning quantitative properties of the spectrum of this BVP under the condition ?n?N exp(?n?)(|1-an| + |vn|) < ? for ? > 0 and 1/2 ? ? ? 1. nema