A late-time transition in the cosmic dark energy?
Astrophysics
2009-11-07 v1 General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
Abstract
We study constraints from the latest CMB, large scale structure (2dF, Abell/ACO, PSCz) and SN1a data on dark energy models with a sharp transition in their equation of state, w(z). Such a transition is motivated by models like vacuum metamorphosis where non-perturbative quantum effects are important at late times. We allow the transition to occur at a specific redshift, z_t, to a final negative pressure -1 < w_f < -1/3. We find that the CMB and supernovae data, in particular, prefer a late-time transition due to the associated delay in cosmic acceleration. The best fits (with 1 sigma errors) to all the data are z_t = 2.0^{+2.2}_{-0.76}, \Omega_Q = 0.73^{+0.02}_{-0.04} and w_f = -1^{+0.2}.
Cite
@article{arxiv.astro-ph/0203383,
title = {A late-time transition in the cosmic dark energy?},
author = {Bruce A. Bassett and Martin Kunz and Joseph Silk and Carlo Ungarelli},
journal= {arXiv preprint arXiv:astro-ph/0203383},
year = {2009}
}
Comments
6 Pages, 5 colour figures, MNRAS style