Properties of Eigenvalues and Generalized Eigenfunctions for Sturm–Liouville Problem with Eigenparameter-Dependent Boundary Conditions
摘要
This paper investigates the eigenvalues and generalized eigenfunctions of a Sturm–Liouville problem in which the eigenparameter appears in the boundary conditions. By employing operator pencil theory in a Hilbert space, combined with an appropriate integral transformation, we prove that the system of generalized eigenfunctions forms a Riesz basis. Furthermore, we demonstrate that the spectrum consists of a countably infinite set of real, discrete eigenvalues accumulating at infinity and provide a lower bound estimation for the eigenvalues.