Displaying similar documents to “The Equations for Modular Function Fields of Principal congruence subgroups of prime level.”

Modular embeddings and rigidity for Fuchsian groups

Robert A. Kucharczyk (2015)

Acta Arithmetica

Similarity:

We prove a rigidity theorem for semiarithmetic Fuchsian groups: If Γ₁, Γ₂ are two semiarithmetic lattices in PSL(2,ℝ ) virtually admitting modular embeddings, and f: Γ₁ → Γ₂ is a group isomorphism that respects the notion of congruence subgroups, then f is induced by an inner automorphism of PGL(2,ℝ ).