Dark Coupling and Gauge Invariance
Cosmology and Nongalactic Astrophysics
2010-12-17 v2 High Energy Physics - Phenomenology
Abstract
We study a coupled dark energy-dark matter model in which the energy-momentum exchange is proportional to the Hubble expansion rate. The inclusion of its perturbation is required by gauge invariance. We derive the linear perturbation equations for the gauge invariant energy density contrast and velocity of the coupled fluids, and we determine the initial conditions. The latter turn out to be adiabatic for dark energy, when assuming adiabatic initial conditions for all the standard fluids. We perform a full Monte Carlo Markov Chain likelihood analysis of the model, using WMAP 7-year data.
Keywords
Cite
@article{arxiv.1005.0295,
title = {Dark Coupling and Gauge Invariance},
author = {M. B. Gavela and L. Lopez-Honorez and O. Mena and S. Rigolin},
journal= {arXiv preprint arXiv:1005.0295},
year = {2010}
}
Comments
16 pages, 2 figures, version accepted for publication in JCAP