Bounce and cyclic cosmology in new gravitational scalar-tensor theories
Abstract
We study the bounce and cyclicity realization in the framework of new gravitational scalar-tensor theories. In these theories the Lagrangian contains the Ricci scalar and its first and second derivatives, in a specific combination that makes them free of ghosts, and transformed into the Einstein frame they are proved to be a subclass of bi-scalar extensions of general relativity. We present analytical expressions for the bounce requirements, and we examine the necessary qualitative behavior of the involved functions that can give rise to a given scale factor. Having in mind these qualitative forms, we reverse the procedure and we construct suitable simple Lagrangian functions that can give rise to a bounce or cyclic scale factor.
Cite
@article{arxiv.1807.00346,
title = {Bounce and cyclic cosmology in new gravitational scalar-tensor theories},
author = {Emmanuel N. Saridakis and Shreya Banerjee and R. Myrzakulov},
journal= {arXiv preprint arXiv:1807.00346},
year = {2018}
}
Comments
9 pages, 8 figures