Cosmological models with dynamicalΛin scalar-tensor theories

1999/07/31 by L. M. Diaz-Rivera, L. M. Díaz-Rivera, Luis O. Pimentel +1
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #gr-qc

paper · pdf · doi:10.1103/physrevd.60.123501

published as Phys.Rev. D60 (1999) 123501 · 20 pages, Latex file, a sign in Eq. (2.17) was corrected, reference [37] was corrected

openalex publication_date 1999/11/03 · arxiv created 1999/11/11 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

In the context of a family of scalar-tensor theories with a dynamical \ensuremathΛ that is a binomial on the scalar field, the cosmological equations are considered. A general baryotropic state equation p=(\ensuremathγ\ensuremath-1)\ensuremathρ, for a perfect fluid is used for the matter content of the Universe. Some Friedmann-Robertson-Walker 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 \ensuremathΩ_m, \ensuremathΩ_\ensuremathΛ, q₀, and t₀ are obtained and compared with observational data.

Citations

• Inflationary cosmology and thermodynamics
• Time-dependent cosmological term
• Evolution of the scale factor with a variable cosmological term
• Cosmological consequences of a rolling homogeneous scalar field