Talk detail

Participant	Salgado, Marcelo
Institution	Instituto de Ciencias Nucleares, UNAM - Ciudad Universitaria - Mexico DF - Mexico - Mexico

Session	CM2	Accepted		Order	Time
Talk	Oral abstract	Title	f(R) cosmology revisited
Co-authors
Abstract	I shall present various results concerning the analysis of several f(R) models in a FRW spacetime. The analysis is based on an approach where the f(R) theory is not mapped to a Scalar-Tensor Theory in order to avoid the use of potentials that may be ill defined (e.g multivalued). Thus, the Ricci scalar itself is one of the fundamental variables instead of the scalar f'(R). The system of equations is then solved numerically as an initial value problem constrained by the modified-gravity Hamiltonian. This in turn is used to monitor the accuracy of the numerical integration at every time step. Among the results I shall present are the behavior of the matter-dominated and accelerated eras, the age of the Universe and the confrontation with SNIa data. I intend to discuss the differences and similarities of our findings relative to previous results. In particular, I will analyze three inequivalent equations of state associated with the geometric dark energy that have been proposed in the past and point out their positive and negative features.