Uma análise dos dados das supernovas em modelos cosmológicos de branas.

Abstract

In this work we discuss models of the Universe that take into account the existence of extra dimensions. The Kaluza-Klein theory, the ADD model and the Randall-Sundrum models are examples of theories that describe the universe with extra dimensions. In the ADD and Randall-Sundrum models our universe is considered as a hypersurface embedded in a higher dimension space . This hypersurface is what we call brane. We focus our work on the RSII model, testing this brane model by using the observational data of type Ia supernovae (SNeIa) compiled by di erent research groups as the Legacy Survey Supernova Cosmology Project, and the Gold Essence Sample Team . With these data we study the Randall-Sundrum II model in cosmological context, determining the free parameters of the model such as density of matter ( m), the cosmological constant ( ) and tension ( ). We found that the best t values of the parameters, in the case of at spatial section k = 0, suggest that the universe is in a phase of accelerated expansion.