Modular symbols, Eisenstein series, and congruences
Let and be an Eisenstein series and a cusp form, respectively, of the same weight and of the same level , both eigenfunctions of the Hecke operators, and both normalized so that . The main result we prove is that when and are congruent mod a prime (which we take in this paper to be a prime of lying over a rational prime ), the algebraic parts of the special values and satisfy congruences mod the same prime. More explicitly, we prove that, under certain conditions, ...