EVENT DETAILS AND ABSTRACT

Title: Uniform denominators growth for noncongruence modular forms
Speaker: Vesselin Dimitrov
Speaker Info: University of Toronto
Brief Description:
Special Note:
Abstract:

(joint work with Frank Calegari and Yunqing Tang) I will explain how to characterize the congruence sublattices of SL_2(Z) in terms of an integrality property of the Fourier expansions of their modular forms at the infinite cusp. Beneath this result, which answers a question asked by Atkin and Swinnerton-Dyer, we look into the question of the slowest possible growth the denominators can have in the noncongruence case. Time allowing, I will explain the generalization of all of this to a vector-valued setting.