Speaker
Sabine Boegli, Durham
Abstract
The essential numerical range is a useful concept to describe spectral pollution when approximating a linear operator by projection or domain truncation methods. In this talk I will first give an introduction to the topic and then present some new results for differential operators for which a modified definition gives tighter bounds on the set of spectral pollution. This is joint work with Marco Marletta (Cardiff) and Christiane Tretter (Bern).