Number Theory Seminar: Johnson Jia (UBC)

The Yoshida lift is a theta lift that takes a pair of automorphic forms on a definite quaternion algebra to a holomorphic Siegel modular form. We show that a natural refinement of the classical Yoshida lift in fact preserves p-integrality in a suitable sense. Since the result is rather technical, we will motivate it by casting it as the first step in a program sketched out by Harris-Skinner-Li aimed at relating the p-divisibility of the special values of certain automorphic L-functions to the existence of non-trivial elements of a certain Selmer group. Time permitting, we will also discuss a non-vanishing modulo p result of the integral Yoshida lift.