Automorphism groups of cocompact CAT(0) cube complexes and simplicity
Group Theory
2023-12-07 v1
Abstract
We provide a systematic description of the automorphism groups of specially cocompact CAT(0) cube complexes. We show that these groups are topologically finitely generated, present a method to explicitly obtain generating sets, and prove a dichotomy on their size. Furthermore, we show that, under some extra assumptions, the normal subgroup known as Aut^+ is simple, non-discrete, and tdlc. In particular, we obtain a new class of simple, non-discrete, tdlc groups that are accessible to further study. Finally, we study the relative size of Aut^+ in the automorphism group, providing a sufficient condition for its closure to be finite index and presenting a common example where it is not even cocompact.
Cite
@article{arxiv.2312.03336,
title = {Automorphism groups of cocompact CAT(0) cube complexes and simplicity},
author = {Tobias Hartnick and Merlin Incerti-Medici},
journal= {arXiv preprint arXiv:2312.03336},
year = {2023}
}
Comments
77 pages, 7 figures, comments welcome