Soft coincidence in late acceleration
Astrophysics
2009-11-13 v1 General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
High Energy Physics - Theory
Abstract
We study the coincidence problem of late cosmic acceleration by assuming that the present ratio between dark matter and dark energy is a slowly varying function of the scale factor. As dark energy component we consider two different candidates, first a quintessence scalar field, and then a tachyon field. In either cases analytical solutions for the scale factor, the field and the potential are derived. Both models show a good fit to the recent magnitude-redshift supernovae data. However, the likelihood contours disfavor the tachyon field model as it seems to prefer a excessively high value for the matter component.
Keywords
Cite
@article{arxiv.astro-ph/0506482,
title = {Soft coincidence in late acceleration},
author = {Sergio del campo and Ramon Herrera and Diego Pavon},
journal= {arXiv preprint arXiv:astro-ph/0506482},
year = {2009}
}
Comments
27 pages, 10 eps figures, to be published in Physical Review D