Commutator subgroups of singular braid groups
Abstract
The singular braids with nn strands, n≥3n≥3, were introduced independently by Baez and Birman. It is known that the monoid formed by the singular braids is embedded in a group that is known as singular braid group, denoted by SGnSGn. There has been another generalization of braid groups, denoted by GVBnGVBn, n≥3n≥3, which was introduced by Fang as a group of symmetries behind quantum quasi-shuffle structures. The group GVBnGVBn simultaneously generalizes the classical braid group, as well as the virtual braid group on nn strands.
We investigate the commutator subgroups SG′n and GVB′n of these generalized braid groups. We prove that SG′n is finitely generated if and only if n≥5, and GVB′n is finitely generated if and only if n≥4. Further, we show that both SG′n and GVB′n are perfect if and only if n≥5.