Formação de estrutura em larga escala em regime não linear

Abstract

The use of long range optical instruments shows the existence of an amazing structure constituted of empty regions interspersed with galaxies, clusters and superclusters of galaxies. The formation process of this large scale structure is an important tool for testing many existing cosmological models. In general one applies the perturbative method to study this formation, considering an expansion of the matter density in terms of small fluctuations. The part of the evolution period in which we can consider only linear terms of the expansion is known as the linear evolution regime. Due to gravitational instability, the small fluctuations become stronger, until the linear approximation turns impracticable. Then we can say that the evolution is in a non linear regime. In the present work we make a detailed revision of the principal analytical method developed to the study of the non linear evolution of matter density fluctuations, obtaining the principal outcomes and exposing them in an intuitive and gradual manner such that even an unfamiliar reader in the subject will be able to understand