Cargando…

G-Bounce

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...

Descripción completa

Detalles Bibliográficos
Autores principales: Easson, Damien A, Sawicki, Ignacy, Vikman, Alexander
Lenguaje:eng
Publicado: 2011
Materias:
Acceso en línea:https://dx.doi.org/10.1088/1475-7516/2011/11/021
http://cds.cern.ch/record/1380421
Descripción
Sumario: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.