G-Bounce
Abstract
We present a wide class of models which realise a bounce in a spatially flat Friedmann universe in standard General Relativity. The key ingredient of the theories we consider is a noncanonical, minimally coupled scalar field belonging to the class of theories with Kinetic Gravity Braiding / Galileon-like self-couplings. In these models, the universe smoothly evolves from contraction to expansion, suffering neither from ghosts nor gradient instabilities around the turning point. The end-point of the evolution can be a standard radiation-domination era or an inflationary phase. We formulate necessary restrictions for Lagrangians needed to obtain a healthy bounce and illustrate our results with phase portraits for simple systems including the recently proposed Galilean Genesis scenario.
Keywords
Cite
@article{arxiv.1109.1047,
title = {G-Bounce},
author = {Damien A. Easson and Ignacy Sawicki and Alexander Vikman},
journal= {arXiv preprint arXiv:1109.1047},
year = {2011}
}
Comments
28 pages. v2 reflects version accepted for publication in JCAP. References and minor comments added