From arcs in surfaces to algebraic arcs : a mapping class group proof of homological stability for symplectic groups (Nathalie Wahl, Copenhagen)

15.10.2026 13:00 – 14:00

I will explain my joint work with Ismael Sierra, where we define a notion of «algebraic arcs» in R-modules equipped with an alternating form, and use them to improve the known range for homological stability of symplectic groups over quite general rings, by mimicking a proof for mapping class groups of surfaces.

Lieu

Bâtiment: Conseil Général 7-9

Room 1-05, Thursday 15.10.2026, Séminaire "Groupes et géométrie"

entrée libre