Spectral problems in boundary value problems constitute a fundamental area of applied mathematics and mathematical physics, where the focus lies on determining eigenvalues and corresponding ...

Boundary value problems (BVPs) and spectral analysis constitute fundamental areas in the study of differential equations. These topics not only underpin theoretical advances in mathematical analysis ...

We use a classical result of Hildebrandt to establish simple conditions for the absence of eigenvalues of non-selfadjoint discrete and continuous Schrödinger operators on the boundary of their ...

We introduce the notion of the L-core of a graph what enables a simple description of some properties of the eigenspace of the eigenvalue — 2 in generalized line graphs and an elegant formulation of ...