2211.13326Nov 23, 2022We extended one of the main results proving the Girth Alternative for HNN extensions of word hyperbolic groups (instead of HNN extensions of free groups). Several typing errors corrected, remarks added
Girth Alternative for HNN Extensions
Azer Akhmedov, Pratyush Mishra
Abstract
We prove the Girth Alternative for a sub-class of the HNN extensions of finitely generated groups. We also produce counterexamples to show that beyond our class, the alternative fails in general.