Presentations of the braid group of the complex reflection group $G(d,d,n)$

Abstract

We show that the braid group associated to the complex reflection group $G(d,d,n)$ is an index $d$ subgroup of the braid group of the orbifold quotient of the complex numbers by a cyclic group of order $d$. We also give a compatible presentation of $G(d,d,n)$ and its braid group for each tagged triangulation of the disk with $n$ marked points on its boundary and an interior marked point (interpreted as a cone point of degree $d$) in such a way that the presentations of Broué-Malle-Rouquier correspond to a special tagged triangulation.

arXiv comment50 pages