2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/67277We study non-linear evolution equations with periodic initial conditions. In particular, we use the graph method introduced by Galavotti to prove the existence of global solution of Hamiltonian perturbation of KdV without any restriction on the size of the initial condition, in contrast with previous results on this subject.67 pages, in frenchAnalysis of PDEsMathematical Physics35Q53text