Physics – High Energy Physics – High Energy Physics - Theory
Scientific paper
2008-10-31
Phys.Lett.B675:1-8,2009
Physics
High Energy Physics
High Energy Physics - Theory
12 pages, 5 figures, uses ReVTeX. Added references, minor corrections
Scientific paper
10.1016/j.physletb.2009.03.060
We derive conditions under which f(G) gravity models, whose Lagrangian densities f are written in terms of a Gauss-Bonnet term G, are cosmologically viable. The most crucial condition to be satisfied is that f_GG, the second derivative of f with respect to G, must be positive, which is required to ensure the stability of a late-time de-Sitter solution as well as the existence of standard radiation/matter dominated epochs. We present a number of explicit f(G) models in which a cosmic acceleration is followed by the matter era. We find that the equation of state of dark energy can cross the phantom divide before reaching the present Universe. The viable models have asymptotic behavior f_GG goes to +0 when |G| goes to infinity, in which case a rapid oscillation of perturbations occurs unless such an oscillating degree of freedom is suppressed relative to a homogeneous mode in the early universe. We also introduce an iterative method to avoid numerical instabilities associated with a large mass of the oscillating mode.
de Felice Antonio
Tsujikawa Shinji
No associations
LandOfFree
Construction of cosmologically viable f(G) gravity models does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Construction of cosmologically viable f(G) gravity models, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Construction of cosmologically viable f(G) gravity models will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-457211