Let $G$ be a lattice in $SL(2,\mathbb{R})$. Is it always true that there exists a finite index subgroup $F$ of $G$ such that the quotient surface $\mathbb{H}/F$ has positive genus? Is the statement true under some general enough set of assumptions? Please can you add a reference?
Positive genus Fuchsian groups
user163814
- 63
- 2