
Title: Rationality of torus bundle group
Speaker: Jun Choi - Purdue University
Abstract: Gromov's polynomial growth theorem states that a finitely generated group has a polynomial volume growth if and only if it is virtually-nilpotent. One may ask under what condition the volume of virtually nilpotent groups is a polynomial, or more generally, a rational function. It turns out the rationality depends very much on the structure of the group as well as the choice of the generators. In the first half of the talk, I will give a brief survey on the rational volume growth and the established strategy. In the second half, we will see that the torus bundle group has rational growth using different approach. This work is joint with Turbo Ho and Mark Pengitore.