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arXiv · 1303.2372

Towards Anisotropy-Free and Non-Singular Bounce Cosmology with Scale-invariant Perturbations

Taotao Qiu·Xian Gao·Emmanuel N. Saridakis
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Abstract

We investigate non-singular bounce realizations in the framework of ghost-free generalized Galileon cosmology, which furthermore can be free of the anisotropy problem. Considering an Ekpyrotic-like potential we can obtain a total Equation-of-State (EoS) larger than one in the contracting phase, which is necessary for the evolution to be stable against small anisotropic fluctuations. Since such a large EoS forbids the Galileon field to generate the desired form of perturbations, we additionally introduce the curvaton field which can in general produce the observed nearly scale-invariant spectrum. In particular, we provide approximate analytical and exact semi-analytical expressions under which the bouncing scenario is consistent with observations. Finally, the combined Galileon-curvaton system is free of the Big-Rip after the bounce.

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Taotao Qiu, Xian Gao, Emmanuel N. Saridakis. 2013-03-10. Towards Anisotropy-Free and Non-Singular Bounce Cosmology with Scale-invariant Perturbations. https://doi.org/10.1103/physrevd.88.043525

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