University of Sydney Algebra Seminar

Lewis Combes

Friday 16 May, 12-1pm, in Carslaw 175

Automorphism groups of rooted trees

In this talk we will discuss groups whose elements arise as automorphisms of finite and infinite trees. Of particular interest are automorphism groups of regular trees, which display self-similarity properties, leading to strange and often counterintuitive phenomena. We will discuss the Grigorchuk group, a group famous for having many interesting properties, as well as some other groups, and some links to topology and number theory. The talk is expository and aimed at a wide audience.