Colloquium University of Texas at Arlington - Department of Mathematics Proudly Presents Dr. Alejandro Uribe Professor of Mathematics University of Michigan Friday, February 19, 2016 3:00 p.m. 311 Pickard Hall “Spectral, pseudo-spectral, and numerical range asymptotics for matrices and Schrödinger operators: An overview of old and new results” Abstract: I will begin by a review of the concepts of spectrum, pseudospectrum and numerical range of matrices, that is, in the context of linear algebra. Although these objects are closely related for hermitian matrices, in the non-hermitian case they are remarkably different, which I will illustrate with examples. I will then discuss asymptotic results of these objects, for certain sequences of matrices (generalized Toeplitz matrices), and for certain Schrödinger operators with complex potentials. I will end with a conjecture that is strongly supported by numerical evidence, but that, to my knowledge, has not been settled. Refreshments before the talk and socializing following the talk http://www.uta.edu/math/pages/main/seminar.htm