2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/67077We give an overview of classical summation formulations, such as Poisson's and Voronoi's, and then turn to modern versions involving modular form coefficients. A new formula involving the coefficients of cusp forms on GL(3) is described, and its proof sketched, followed by applications to L-functions. The main method used is the boundary value distribution of automorphic forms.22 pages, to appear in "Non-commutative harmonic analysis: In honor of Jacques Carmona."Number TheoryRepresentation Theorytext