I've been reading a paper on group theory, and have come across this description of a subgroup of the special linear group:
Let $G=SL(d,q)$ and $H< G$ with $H \cong (SL(k,q) \times SL(d-k,q)).(q-1)$
I understand that $(SL(k,q) \times SL(d-k,q))$ is the direct product but what operation does the $.$ represent? Does the $(q-1)$ represent $C_{q-1}$ or some other group?