Cosmological perturbations in $k$-essence model
High Energy Physics - Theory
2012-06-12 v3 Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
Abstract
Subhorizon approximation is often used in cosmological perturbation theory. In this paper, however, it is shown that the subhorizon approximation is not always a good approximation at least in case of -essence model. We also show that the sound speed given by -essence model exerts a huge influence on the time evolution of the matter density perturbation, and the future observations could clarify the differences between the CDM model and -essence model.
Cite
@article{arxiv.1109.1308,
title = {Cosmological perturbations in $k$-essence model},
author = {Kazuharu Bamba and Jiro Matsumoto and Shin'ichi Nojiri},
journal= {arXiv preprint arXiv:1109.1308},
year = {2012}
}
Comments
21 pages, sentences and equations are corrected, conclusions are changed a little