congruence relation in a sentence

Examples

1. The Eichler Shimura congruence relation and its generalizations to Shimura varieties play a pivotal role in the Langlands program, by identifying a part of the Hasse Weil zeta function of a modular curve or a more general modular variety with the product of Mellin transforms of weight 2 modular forms or a product of analogous automorphic " L "-functions.