Bounds for distance between eigenvalues of boundary value problems with retarded argument

Abstract

In this study we are concerned with spectrum of boundary value problems with retarded argument with discontinuous weight function, two supplementary transmission conditions at the point of discontinuity, spectral and physical parameters in the boundary condition and we obtain bounds for the distance between eigenvalues. We extend and generalize some approaches and results of the classical regular and discontinuous Sturm-Liouville problems. In the special case that ? (x) = 1, the transmission coefficients ?1 = ?1, ?2 = ?2 and retarded argument ? = 0 in the results obtained in this work coincide with corresponding results in the classical Sturm-Liouville operator. © 2019 Mathematical Institute Slovak Academy of Sciences 2019.