Sturm-Liouville differential operators in direct sum spaces
Sturm-Liouville problems with coefficients which have a singularity in the interior of the interval under consideration are of interest in applied mathematics and mathematical physics. This singular point may be viewed as a left end point of one interval and a right end point of another. Motivated in part by the occurrence of this kind of problem, the authors study more general situations: Sturm-Liouville boundary value problems on two intervals in the setting of the direct sum of the \(L^ 2\) spaces of functions defined on each of the separate intervals, providing an operator theoretic framework for the study of two differential operators together.
self-adjoint operators in direct sum spaces
scientific article; zbMATH DE number 4013061