A $p$-arton Model for Modular Cusp Forms

We propose to associate to a modular form (an infinite number of) complex valued functions on the $p$-adic numbers ${\mathbb{Q}}_p$ for each prime $p$. We elaborate on the correspondence and study its consequence in terms of the Mellin transforms and the $L$-functions related to the forms. Further we discuss the case of products of Dirichlet $L$-functions and their Mellin duals, which are convolution products of $\vartheta$-series. The latter are intriguingly similar to non-holomorphic Maass forms of weight zero as suggested by their Fourier coefficients.