Event № 91

We study the distribution of eigenvalues of operators which are compact perturbations of bounded operators , obtaining bounds on thenumber of eigenvalues in regions of the complex plane which are separated from the essential spectrum. Our results can be understood as quantitative versions of some well-known qualitative results of spectral theory.Our methods include a finite-dimensional reduction procedure and employingcomplex analysis. The talk will present some background and related results,our main results and methods, and some questions that remain open.

Joint work with: Michael Demuth, Franz Hanauska and Marcel Hansmann.