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arXiv · gr-qc/9501039

Anisotropic Scalar-Tensor Cosmologies

Jose P. Mimoso·David Wands
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Abstract

We examine homogeneous but anisotropic cosmologies in scalar-tensor gravity theories, including Brans-Dicke gravity. We present a method for deriving solutions for any isotropic perfect fluid with a barotropic equation of state ($p\proptoρ$) in a spatially flat (Bianchi type~I) cosmology. These models approach an isotropic, general relativistic solution as the expansion becomes dominated by the barotropic fluid. All models that approach general relativity isotropize except for the case of a maximally stiff fluid. For stiff fluid or radiation or in vacuum we are able to give solutions for arbitrary scalar-tensor theories in a number of anisotropic Bianchi and Kantowski-Sachs metrics. We show how this approach can also be used to derive solutions from the low-energy string effective action. We discuss the nature, and possibly avoidance of, the initial singularity where both shear and non-Einstein behavior is important.

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Jose P. Mimoso, David Wands. 1995-01-27. Anisotropic Scalar-Tensor Cosmologies. https://doi.org/10.1103/physrevd.52.5612

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