English

Bounce and cyclic cosmology in weakly broken galileon theories

General Relativity and Quantum Cosmology 2017-04-07 v2 Cosmology and Nongalactic Astrophysics High Energy Physics - Theory

Abstract

We investigate the bounce and cyclicity realization in the framework of weakly broken galileon theories. We study bouncing and cyclic solutions at the background level, reconstructing the potential and the galileon functions that can give rise to a given scale factor, and presenting analytical expressions for the bounce requirements. We proceed to a detailed investigation of the perturbations, which after crossing the bouncing point give rise to various observables, such as the scalar and tensor spectral indices and the tensor-to-scalar ratio. Although the scenario at hand shares the disadvantage of all bouncing models, namely that it provides a large tensor-to-scalar ratio, introducing an additional light scalar significantly reduces it through the kinetic amplification of the isocurvature fluctuations.

Keywords

Cite

@article{arxiv.1604.06932,
  title  = {Bounce and cyclic cosmology in weakly broken galileon theories},
  author = {Shreya Banerjee and Emmanuel N. Saridakis},
  journal= {arXiv preprint arXiv:1604.06932},
  year   = {2017}
}

Comments

28 pages, 6 figures,version published in Phys. Rev. D