ORDONHO, R. F.; http://lattes.cnpq.br/3448527835893630; ORDONHO, Renato Ferreira.
Résumé:
General Relativity has been very well tested since its formulation. However, with
the evolution of observations in Cosmology, discrepancies between observations and
theoretical calculations arised. These discrepancies are explained by incorporating
the so-called dark matter and dark energy. However, these new components have
never been effectively measured, apart from their gravitational effects. Seeking
alternative routes to avoid or complement the introduction of exotic components, a
huge number of modifications and extensions of the laws of gravity have emerged in
recent decades. However, new proposals also pose new problems. The metric-affine
(or Palatini) formalism is a way of extending GR without introducing new dynamic
degrees of freedom, and maintaining second order field equations. In this work we
analyze the Eddington-Inspired-Born-Infeld gravity model, described in the Palatini
formalism, making use of a powerful tool that allows to build explicit solutions
for the RBG class of theories, to which EiBI belongs. The obtained solutions are
analyzed and discussed thoroughly.