2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/175706Using a general classification of dark enegy models in four classes, we discuss the complementarity of cosmological observations to tackle down the physics beyond the acceleration of our universe. We discuss the tests distinguishing the four classes and then focus on the dynamics of the perturbations in the Newtonian regime. We also exhibit explicitely models that have identical predictions for a subset of observations.18 pages, 18 figuresAstrophysicsGeneral Relativity and Quantum CosmologyHigh Energy Physics - Phenomenologytext