Nonsmooth eigenfunctions in problems of mathematical physics

摘要

We study whether V.A. Il’in’s method for proving the uniqueness of the solution of a mixed problem for a hyperbolic equation applies to a problem with transmission conditions in the interior of the interval. We show that the system of eigenfunctions corresponding to this problem is complete in the space L 2(0, l) and is a Riesz basis in this space.