Beyond endoscopy for the relative trace formula I: local theory

Abstract

For the group G = PGL(2) we prove nonstandard matching and the fundamental lemma between two relative trace formulas: on one hand, the relative trace formula of Jacquet for the quotient T\G/T, where T is a nontrivial torus; on the other, the Kuznetsov trace formula with nonstandard test functions. The matching is nonstandard in the sense that orbital integrals are related to each other not one-by-one, but via an explicit integral transform. These results will be used in the sequel to compare the corresponding global trace formulas and reprove the celebrated result of Waldspurger on toric periods.