Quotient of a topological group by a discrete subgroup
= Quotient of a topological group by a discrete subgroup
If $\Gamma$ is a discrete subgroup of a <topological group> $G$, then left translation by $\Gamma$ is a covering-space action. Choose an identity neighbourhood $U$ with $UU^{-1}\cap\Gamma=\{1\}$; the translates $\gamma U$ are pairwise disjoint, and the quotient map $G\to\Gamma\backslash G$ restricts to a homeomorphism on each translate.