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

Florian Funke, Dawid Kielak

We investigate Friedl-Lück's universal $L^2$-torsion for descending HNN extensions of finitely generated free groups, and so in particular for $F_n$-by-$\mathbb{Z}$ groups. This in…