Special Session 164: Periodic and Ergodic Schrodinger Operators

Measure estimates coming from periodic approximations
Lior Tenenbaum
Bar-Ilan university
Israel
Co-Author(s):    
Abstract:
In studying spectra of complex operators, it is often helpful to work with simpler approximations. In this talk, I will describe a method for estimating the measure of a spectrum that is approximated, in the Hausdorff sense, by spectra of periodic operators. The idea is to consider suitable ``fattenings`` of these spectra and show that their measures converge to that of the limiting spectrum. I will then illustrate this method with an application to aperiodic Schr\odinger operators, whose underlying structures can be approximated by periodic ones.