Perturba？？es cosmológicas e a taxa de crescimento das flutua？？es da matéria

the observed structures in the universe (galaxies, clusters and superclusters) are the results of gravitational instability. this instability amplifies perturbations, originally very small, to the nonlinear regime. in this paper we compare the growth rates of matter perturbations for several cosmological models. generally, the presence of dark energy reduces the growth. the details depend on the specific features of the model, for example on the coupling with the dark-energy perturbations or on interactions in the dark sector of the universe.