On the Girth of Groups acting on CAT(0) cube complexes

Arka Banerjee, Daniel Gulbrandsen, Pratyush Mishra, Prayagdeep Parija

Published 2024-08-17Version 1

We obtain a sufficient condition for lattices in the automorphism group of a finite dimensional CAT(0) cube complex to have infinite girth. As a corollary, we get a version of Girth Alternative for groups acting geometrically: any such group is either {locally finite}-by-{virtually abelian} or it has infinite girth. We produce counterexamples to show that the alternative fails in the general class of groups acting cocompactly on finite dimensional CAT(0) cube complexes by obtaining examples of non virtually solvable groups which satisfy a law.