Homomorphisms between large-type Artin groups

Martín Blufstein, Alexandre Martin, Nicolas Vaskou

Published 2024-10-24Version 1

In this article, we study homomorphisms between Artin groups that belong to two generic classes. For XL-type Artin groups over complete graphs, we describe all possible homomorphisms with sufficiently large image, and prove in particular that such groups are both hopfian and co-hopfian. For Artin groups with all labels at least $6$, we completely characterise in terms of the presentation graph when these groups have a finite outer automorphism group, as well as when they are co-hopfian. Moreover, when the presentation graph has no cut-vertex, we provide a generating set for their automorphism group.