Damien Easson, Ignacy Sawicki, Alexander Vikman

Research output: Contribution to journalArticlepeer-review

190 Scopus citations


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 languageEnglish (US)
Article number021
JournalJournal of Cosmology and Astroparticle Physics
Issue number11
StatePublished - Nov 2011


  • alternatives to ination
  • cosmic singularity
  • cosmology of theories beyond the SM

ASJC Scopus subject areas

  • Astronomy and Astrophysics


Dive into the research topics of 'G-bounce'. Together they form a unique fingerprint.

Cite this