Virtual braid groups, virtual twin groups and crystallographic groups

Oscar Ocampo; Paulo Cesar Cerqueira dos Santos Júnior

paper

Virtual braid groups, virtual twin groups and crystallographic groups

arXiv:2110.02392

Abstract

Let $n \geq 2$ . Let $V B_{n}$ (resp. $V P_{n}$ ) be the virtual braid group (resp. the pure virtual braid group), and let $V T_{n}$ (resp. $P V T_{n}$ ) be the virtual twin group (resp. the pure virtual twin group). Let $Π$ be one of the following quotients: $V B_{n} / Γ_{2} (V P_{n})$ or $V T_{n} / Γ_{2} (P V T_{n})$ where $Γ_{2} (H)$ is the commutator subgroup of $H$ . In this paper, we show that $Π$ is a crystallographic group and we characterize the elements of finite order and the conjugacy classes of elements in $Π$ . Furthermore, we realize explicitly some Bieberbach groups and infinite virtually cyclic groups in $Π$ . Finally, we also study other braid-like groups (welded, unrestricted, flat virtual, flat welded and Gauss virtual braid group) module the respective commutator subgroup in each case.

arXiv commentIn this new version some general results were added in Section 2