Generalization of Selberg’s 3/16 theorem for finitely generated subgroups of SL(2,Z)

Generalization of Selberg’s 3/16 theorem for finitely generated subgroups of SL(2,Z)

-
Hee Oh, Yale University
Fine Hall 314

A celebrated theorem of Selberg in 1965 states that for congruence subgroups of SL(2,Z) there are no exceptional eigenvalues below 3/16. We will discuss how Selberg’s theorem can be generalized to finitely generated subgroups of SL(2,Z) which are of infinite index.  This talk is based on joint work with Dale Winter