Waldspurger formula

The Waldspurger formula is a significant result in the theory of automorphic forms, specifically in the context of number theory and representation theory. It primarily relates to the relationship between automorphic forms on groups over p-adic fields and their Fourier coefficients. More specifically, the formula connects the values of certain automorphic L-functions with periods of automorphic forms. It can be understood as a way to describe the distribution of Fourier coefficients of cusp forms or the Fourier expansions of automorphic forms.