Séminaire d'arithmétique à Lyon

A Tannakian formalism for Bruhat-Tits buildings

par Paul Ziegler (Technische Universität München)

Europe/Paris
M7.411 (ENS Lyon, UMPA)

M7.411

ENS Lyon, UMPA

Description

In the theory of reductive groups over local fields, Bruhat-Tits buildings are the analogues of symmetric spaces in the theory of Lie groups.
By Goldman-Iwahori, the Bruhat-Tits building of the general
linear group GL_n over a local field k can be described as the set of non-archimedean norms on the vector space k^n.
I will explain how via a Tannakian formalism this can be generalized to a concrete description of the Bruhat-Tits building of an arbitrary reductive group.
This also gives a description of the functor of points of Bruhat-Tits group schemes.