Weak integrality of finitely presented groups

Seminar series

Arithmetic Geometry Seminar

Date

Wed, 12 Feb 2025
16:00

Location

Lecture Room 4

Speaker

Hélène Esnault

Organisation

Freie Universität Berlin

This is a notion we defined with Johan de Jong. If a finitely presented group is the topological fundamental group of a smooth quasi-projective complex variety, then we prove that it is weakly integral. To this aim we use the Langlands program (both arithmetic to produce companions and geometric to use de Jong’s conjecture). On the other hand there are finitely presented groups which are not weakly integral (Breuillard). So this notion is an obstruction.