O Laboratório de Combinatória e Computação Científica convida a todos para o seminário "Geometry of matrix polynomial spaces", de Andrii Dmytryshyn (Örebro University and Umeå University, Sweden. Será no Anfiteatro Maria Irene, dia 3 de julho de 2019, às 15h, no NCE.

Speaker: Andrii Dmytryshyn (Örebro University and Umeå University, Sweden)

Title: Geometry of matrix polynomial spaces

Abstract:
We study how small perturbations of matrix polynomials may change their elementary divisors and minimal indices by constructing the closure hierarchy graphs (stratifications) of orbits and bundles of matrix polynomial Fiedler linearizations. We show that the stratification graphs do not depend on the choice of Fiedler linearization which means that all the spaces of the matrix polynomial Fiedler linearizations have the same geometry (topology). We also develop the theory for structure preserving stratification of skew-symmetric matrix polynomials. The results are illustrated by examples using the software tool Stratigraphy. This is a joint work with Stefan Johansson (Umeå University), Bo Kågström (Umeå University), and Paul Van Dooren (Université catholique de Louvain).