Interval Garside groups arising from involutions in finite reflection groups

Abstract

We identify and study the interval Garside groups arising from the restriction of the absolute order on a Coxeter group to a lattice $[1,w{]}_T$, where $w$ is an involution. Those involutions $w$ for which $[1,w{]}_T$ is a lattice were previously classified by the second author; every such involution lies in the center of the parabolic subgroup generated by $[1,w{]}_T$. Except in type $B_n$, the obtained groups are isomorphic to (decomposable) right-angled Artin groups. We also investigate the situation for some finite complex reflection groups, mostly in rank two, taking for $w$ a (not necessarily involutive) central element.

18 pages, 3 figures. Comments welcome!