Speaker: Xiaolei Wu (Fudan University)
Time: 10:00-11:00, Apr 9, 2026
Venue: room 1124, Material Science Research Building (Section C)
I will begin by introducing the basic notions of finiteness properties of groups, including finite generation, finite presentability, and their topological and algebraic generalizations. I will then describe the Bestvina–Brady construction, which produces groups with strikingly exotic properties, in particular groups of type FP_2 that are not finitely presented. Finally, I will explain how to construct simple groups exhibiting these exotic finiteness properties. The construction uses Rover–Nekrashevych groups. This is based on joint work with Claudio Llosa Isenrich and Eduard Schesler.
