Thurston and Alexander norms, and the Bieri-Neumann-Strebel invariants for free-by-cyclic groups

24 May 2016
Dawid Kielak

We will introduce the Thurston norm in the setting of 3-manifold groups, and show how the techniques coming from L2-homology allow us to extend its definition to the setting of free-by-cyclic groups.
We will also look at the relationship between this Thurston norm and the Alexander norm, and the BNS invariants, in particular focusing on the case of ascending HNN extensions of the 2-generated free group.