Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2010-11-29
Phys.Rev.D83:043515,2011
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
17 pages, 5 figures
Scientific paper
10.1103/PhysRevD.83.043515
We study the evolution of matter density perturbations in Galileon cosmology where the late-time cosmic acceleration can be realized by a field kinetic energy. We obtain full perturbation equations at linear order in the presence of five covariant Lagrangians ${cal L}_i$ ($i=1,...,5$) satisfying a Galilean symmetry in the flat space-time. The equations for a matter perturbation as well as an effective gravitational potential are derived under a quasi-static approximation on sub-horizon scales. This approximation can reproduce full numerical solutions with high accuracy for the wavelengths relevant to large-scale structures. For the model parameters constrained by the background expansion history of the Universe the growth rate of matter perturbations is larger than that in the LCDM model, with the growth index $gamma$ today typically smaller than 0.4. We also find that, even on very large scales associated with the Integrated-Sachs-Wolfe (ISW) effect in Cosmic Microwave Background (CMB) temperature anisotropies, the effective gravitational potential exhibits a temporal growth during the transition from the matter era to the epoch of cosmic acceleration. These properties are useful to distinguish the Galileon model from the LCDM in future high-precision observations.
de Felice Antonio
Kase Ryotaro
Tsujikawa Shinji
No associations
LandOfFree
Matter perturbations in Galileon cosmology 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 Matter perturbations in Galileon cosmology, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Matter perturbations in Galileon cosmology will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-220330