2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/165202The cosmic acceleration is one of the most significant cosmological discoveries over the last century. The two categories of explanation are exotic component (dark energy) and modified gravity. We constrain the two types of model by a joint analysis with perturbation growth and direct $H(z)$ data. Though the minimal $χ^2$ of the $Λ$CDM is almost the same as that of DGP, in the sense of consistency we find that the dark energy ($Λ$CDM) model is more favored through a detailed comparison with the corresponding parameters fitted by expansion data.10 pages, 6 figures, typo correctedAstrophysicsGeneral Relativity and Quantum CosmologyHigh Energy Physics - PhenomenologyHigh Energy Physics - TheoryProbing the nature of cosmic accelerationtext