Let G be a group acting on a regular tree. The ‘local’ actions that vertex stabilisers in G induce on balls around the fixed vertex are innately connected to the ‘global’ structure of G. I demonstrate this relationship and define a particularly accessible class of groups acting on (locally finite) regular trees by ‘prescribing’ said local actions, following Burger-Mozes. Being defined solely in terms of finite permutation groups, these groups allow us to introduce computational methods to the world of locally compact groups: I will outline the capabilities of a recently developed GAP package that provides methods to create, analyse and find suitable local actions.

Joint work with Khalil Hannouch.

This video was uploaded to YouTube by Newcastle University, Australia. It is part of the 64th annual meeting of the Australian Mathematical Society, which was held (virtually) at the University of New England.