Cosmological models with dynamical Λ in scalartensor theories
Abstract
In the context of a family of scalartensor theories with a dynamical Λ that is a binomial on the scalar field, the cosmological equations are considered. A general baryotropic state equation p=(γ1)ρ, for a perfect fluid is used for the matter content of the Universe. Some FriedmannRobertsonWalker exact solutions are found; they have a scale factor which shows exponential or power law dependence on time. For some models the singularity can be avoided. Cosmological parameters such as Ω_{m}, Ω_{Λ}, q_{0}, and t_{0} are obtained and compared with observational data.
 Publication:

Physical Review D
 Pub Date:
 December 1999
 DOI:
 10.1103/PhysRevD.60.123501
 arXiv:
 arXiv:grqc/9907016
 Bibcode:
 1999PhRvD..60l3501D
 Keywords:

 98.80.Cq;
 Particletheory and fieldtheory models of the early Universe;
 General Relativity and Quantum Cosmology
 EPrint:
 20 pages, Latex file, a sign in Eq. (2.17) was corrected, reference [37] was corrected