Cosmological models with dynamical lambda in scalar-tensor theories

Abstract

In the context of a family os scalar-tensor theories with a dynamical $\Lambda$, that is a binomial on the scalar field, the cosmological equations are considered. A general barotropic state equation $p=(\gamma -1)\rho$, for a perfect fluid is used for the matter content of the Universe. Some Friedmann- Robertson-Walker exact solutions are found, they have scale factor wich shows exponential or power law dependence on time. For some models the singularity can be avoided. Cosmological parameters as ${\Omega }_m$, ${\Omega }_{\Lambda }$, $q_0$ and $t_0$ are obtained and compared with observational data.

20 pages, Latex file, a sign in Eq. (2.17) was corrected, reference [37] was corrected

References in corpus (1)

• A Low Matter Density Decaying Vacuum Cosmology from Complex Metric

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