Bonn Topology Group - Abstracts
General Information - Members - Activities - Topology Seminar
Talk
November 10th 2020
Jim Davis (Indiana University, Bloomington, USA): Hyperfield Grassmannians
Abstract
The Grassmannian of k-planes in R^n is a classical object, useful in topology, geometry, and combinatorics. The cohomology of the Grassmannian gives all the characteristic classes of vector bundles. A hyperfield is a generalization of a field, but with multivalued addition. The main example for the talk will be the sign hyperfield S = {+,0,-}. Laura Anderson and I define the notion of a topological hyperfield and the Grassmannian of a hyperfield, and give a partial computation of the mod 2 cohomology of the Grassmannian of the sign hyperfield, showing that it contains the ring of Stiefel-Whitney classes. One of the tools organizing these ideas is the up-topology on a finite poset. This talk with give a survey of these topics and an indication of the many open questions surrounding them.
Back to seminar page
News
Jessica Fintzen wins Cole Prize
Dr. Regula Krapf receives university teaching award
Prof. Catharina Stroppel joined the North Rhine-Westphalia Academy for Sciences and Arts
Prof. Daniel Huybrechts receives the Compositio Prize for the periode 2017-2019
Prof. Catharina Stroppel receives Gottfried Wilhelm Leibniz Prize 2023
Grants for Mathematics students from Ukraine
Prof. Jessica Fintzen is awarded a Whitehead Prize of the London Mathematical Society
Prof. Peter Scholze elected as Foreign Member of the Royal Society