A Singular Sturm-Liouville Problem with Limit Circle Endpoints and Eigenparameter Dependent Boundary Conditions

In this paper, we investigate a class of discontinuous singular Sturm-Liouville problems with limit circle endpoints and eigenparameter dependent boundary conditions. Operator formulation is constructed and asymptotic formulas for eigenvalues and fundamental solutions are given. Moreover, the completeness of eigenfunctions is discussed.

On the completeness of eigenfunctions of a discontinuous Dirac operator with an eigenparameter in the boundary condition

This paper deals with a discontinuous Dirac operator with an eigenparameter in the boundary condition. By using Lidskii?s theorem, we investigate the completeness of the system of eigenfunctions of such an operator.