Astronomy and Astrophysics – Astrophysics – General Relativity and Quantum Cosmology
Scientific paper
2008-11-27
JCAP 0904:016,2009
Astronomy and Astrophysics
Astrophysics
General Relativity and Quantum Cosmology
18 pages, 11 figures, ReVTeX. Updated to version accepted by JCAP
Scientific paper
10.1088/1475-7516/2009/04/016
The cosmological backreaction arises when one directly averages the Einstein equations to recover an effective Robertson-Walker cosmology, rather than assuming a background a priori. While usually discussed in the context of dark energy, strictly speaking any cosmological model should be recovered from such a procedure. We apply the Buchert averaging formalism to linear Robertson-Walker universes containing matter, radiation and dark energy and evaluate numerically the discrepancies between the assumed and the averaged behaviour, finding the largest deviations for an Einstein-de Sitter universe, increasing rapidly with Hubble rate to a 0.01% effect for h=0.701. For the LCDM concordance model, the backreaction is of the order of Omega_eff~4x10^-6, with those for dark energy models being within a factor of two or three. The impacts at recombination are of the order of 10^-8 and those in deep radiation domination asymptote to a constant value. While the effective equations of state of the backreactions in Einstein-de Sitter, concordance and quintessence models are generally dust-like, a backreaction with an equation of state w_eff<-1/3 can be found for strongly phantom models.
Behrend Juliane
Brown Iain A.
Robbers Georg
No associations
LandOfFree
Averaging Robertson-Walker Cosmologies 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 Averaging Robertson-Walker Cosmologies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Averaging Robertson-Walker Cosmologies will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-709862