CAT(0) and cubulated Shephard groups

Abstract

Shephard groups are common generalizations of Coxeter groups, Artin groups, and graph products of cyclic groups. Their definition is similar to that of a Coxeter group, but generators may have arbitrary order rather than strictly order 2. We extend a well-known result that Coxeter groups are $\mathrm{CAT}\left(0\right)$ to a class of Shephard groups that have ‘enough’ finite parabolic subgroups. We also show that in this setting, if the associated Coxeter group is type (FC), then the Shephard group acts properly and cocompactly on a $\mathrm{CAT}\left(0\right)$ cube complex. As part of our proof of the former result, we introduce a new criteria for a complex made of $A_3$ simplices to be $\mathrm{CAT}\left(1\right)$.