Seminar on Combinatorics, Lie Theory, and Topology

The affine Grassmannian as a presheaf quotient

Name: The affine Grassmannian as a presheaf quotient
Start: 2024-06-13T15:00:00+02:00
End: 2024-06-13T16:00:00+02:00
Location: No location set

by Kestutis Cesnavicius (Université de Paris-Saclay)

Thursday 13 Jun 2024, 15:00 → 16:00 Europe/Rome

Aula Magna di Scienze (Area Pontecorvo)Kestutis CesnaviciusKestutis CesnaviciusKestutis Cesnavicius

Description

The affine Grassmannian of a reductive group $G$ is usually defined as the étale sheafification of the quotient of the loop group $LG$ by the positive loop subgroup. I will discuss various triviality results for $G$-torsors which imply that this sheafification is often not necessary.