The Riesz basis property of an indefinite Sturm-Liouville problem with non-separated boundary conditions

Branko Ćurgus, Andreas Fleige, Aleksey Kostenko

We consider a regular indefinite Sturm-Liouville eigenvalue problem \{$-f"+qf=\lambda rf$} on $[a,b]$ subject to general self-adjoint boundary conditions and with a weight function…