Bücher von Kurt O. Friedrichs

In the summer of 1941 Brown University undertook a Program of Advanced Instruction and Research in Mechanics. Indeed in certain instances only in the last few years has the -field caught up with the ideas developed in the course of these lectures.

The present lectures intend to provide an introduction to the spectral analysis of self-adjoint operators within the framework of Hilbert space theory. Next, simple differential operators are treated as operators in Hilbert space, and the final chapter deals with the perturbation of discrete and continuous spectra.