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.
Original language | English (US) |
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Article number | 021 |
Journal | Journal of Cosmology and Astroparticle Physics |
Volume | 2011 |
Issue number | 11 |
DOIs | |
State | Published - Nov 2011 |
Keywords
- alternatives to ination
- cosmic singularity
- cosmology of theories beyond the SM
ASJC Scopus subject areas
- Astronomy and Astrophysics