TITLE: Why S^3-K and SL(2,R)/SL(2,Z) are diffeomorphic? Here K is a trefoil in S^3.
QUESTION [11 upvotes]: I've heard this result from my differential manifold class, and I don't know how to prove it.
Does anyone know how to construct such diffeomorphism? Please tell me, thanks a lot.
Any comments are welcome.

REPLY [5 votes]: There is a proof without words in Etienne Ghys' ICM address. and a short proof with words by Rubinstein and Gardiner. (Compositio, 1979)