ON THE BASIS PROPERTY OF THE ROOT FUNCTIONS OF STURM-LIOUVILLE OPERATORS WITH GENERAL REGULAR BOUNDARY CONDITIONS

Abstract

We obtain the asymptotic formulas for the eigenyalues and eigenfunctions of the Sturm Liouyille operators with general regular boundary conditions. Using these formulas, we find sufficient conditions on the potential q such that the root functions of these operators do not fbrm a Riesz basis.