Linking little rip cosmologies with regular early universes
Abstract
Cosmological fluids with a Generalized Equation of State (GEoS) are here considered, whose corresponding EoS parameter describes a fluid with phantom behavior, namely , but leading to universes free of singularities at any past or future, finite time. Thus avoiding, in particular, the Big Bang and the Big Rip singularities, the last one considered to be typical in phantom fluid models. More specifically, such GEoS fluid cosmologies lead to regular Little Rip universes. A remarkable new property of these solutions is proven here, namely that they avoid the initial singularity at early times; therefore, they are able to describe emergent universes. Solutions of this kind had been studied previously, but only either as late time or as early time solutions; never as solutions covering both epochs simultaneously. Appropriate conditions are proposed here that relate the Little Rip cosmologies with the initial regular universe, for the future and past regimes, respectively. This is done by taking as starting point the conditions under which a given scale factor corresponds to a Little Rip universe.
Keywords
Cite
@article{arxiv.1808.06546,
title = {Linking little rip cosmologies with regular early universes},
author = {Felipe Contreras and Norman Cruz and Emilio Elizalde and Esteban González and Sergei Odintsov},
journal= {arXiv preprint arXiv:1808.06546},
year = {2018}
}
Comments
18 pages, 17 figures, analysis extended