Stable averages of central values of Rankin–Selberg L -functions: Some new variants

Abstract

As shown by Michel and Ramakrishnan (2007) and later generalized by Feigon and Whitehouse (2008), there are “stable” formulas for the average central L -value of the Rankin–Selberg convolutions of some holomorphic forms of fixed even weight and large level against a fixed imaginary quadratic theta series. We obtain exact finite formulas for twisted first moments of Rankin–Selberg L -values in much greater generality and prove analogous “stable” formulas when one considers either arbitrary modular twists of large prime power level or real dihedral twists of odd type associated to a Hecke character of mixed signature.