International Journal of Mathematics and Mathematical Sciences 
Volume 2005 (2005), Issue 9, Pages 1481-1495
doi:10.1155/IJMMS.2005.1481

Boundary value problems with regular singularities and singular boundary conditions

G. Freiling1 and V. Yurko2

 1Fachbereich Mathematik, Universität Duisburg-Essen, Duisburg 47048, Germany
2Department of Mathematics and Mechanics, Saratov State University, Astrakhanskaya 83, Saratov 410026, Russia
Received 14 May 2004

Abstract

Singular boundary conditions are formulated for nonselfadjoint Sturm-Liouville operators with singularities and turning points. For boundary value problems with singular boundary conditions, properties of the spectrum are studied and the completeness of the system of root functions is proved.