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arXiv · gr-qc/0405141

Decaying Lambda cosmology, varying G and holography

S. Carneiro·J. A. S. Lima
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Abstract

We discuss a class of uniform and isotropic, spatially flat, decaying Lambda cosmologies, in the realm of a model where the gravitation constant G is a function of the cosmological time. Besides the usual de Sitter solution, the models at late times are characterized by a constant ratio between the matter and total energy densities. One of them presents a coasting expansion where the matter density parameter is equal to 1/3, and the age of the universe satisfies Ht = 1. From considerations in line with the holographic conjecture, it is argued that, among the non-decelerating solutions, the coasting expansion is the only acceptable from a thermodynamic viewpoint, and that the time varying cosmological term must be proportional to the square of the Hubble parameter, a result earlier obtained using different arguments.

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S. Carneiro, J. A. S. Lima. 2005-03-05. Decaying Lambda cosmology, varying G and holography. https://doi.org/10.1142/s0217751x0502478x

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