장소: 129동 310호 / zoom: 946 805 8300

We prove that groups acting properly on 2-dimensional CAT(0) complexes with a bound on the orders of cell stabilisers satisfy the Tits Alternative, that is, their finitely generated subgroups are either virtually free abelian or contain a (non-abelian) free subgroup. This is joint work with Piotr Przytycki (McGill).