×

On Fuchsian groups with the same set of fixed points of parabolic elements. (English) Zbl 1188.30051

It is known that two arithmetic Fuchsian groups with the same set of axes of hyperbolic elements are necessarily commensurable. Similarly, the author proves that two arithmetic Fuchsian groups containing parabolic elements and having the same set of fixed points of parabolic elements are necessarily commensurable. This result does not extend to arbitrary cofinite Fuchsian groups.

MSC:

30F35 Fuchsian groups and automorphic functions (aspects of compact Riemann surfaces and uniformization)
20H10 Fuchsian groups and their generalizations (group-theoretic aspects)
11F06 Structure of modular groups and generalizations; arithmetic groups
30F40 Kleinian groups (aspects of compact Riemann surfaces and uniformization)