Seminario / Bachmann
Giovedì 9 settembre alle 14:30 in aula di rappresentanza
si terrà il seguente seminario
Tom Bachmann (LMU)
"Euler classes of residual intersections"
Abstract: This talk has two parts. In the first, I will review and extend the duality theory of residual intersections in Gorenstein rings, following Artin--Nagata, Ulrich and Eisenbud. In the second I will apply this theory to the computation of Witt valued Euler classes. Specifically I will explain a formula for the Euler class of a vector bundle in terms of the vanishing locus of a (mildly) *degenerate* section. (This is in
contrast with the classical case, where the section should be non-degenerate.)
Everything is joint with Kirsten Wickelgren.