The transient and the late time attractor tachyon dark energy: Can we distinguish it from quintessence ?

Abstract

The string inspired tachyon field can serve as a candidate of dark energy. Its equation of state parameter $w$ varies from 0 to -1. In case of tachyon field potential $V(\varphi )\to 0$ slower(faster) than $1/{\varphi }^2$ at infinity, dark energy(dark matter) is a late time attractor. We investigate the tachyon dark energy models under the assumption that $w$ is close to -1. We find that all the models exhibit unique behavior around the present epoch which is exactly same as that of the thawing quintessence.

Comments: 6 pages, 7 eps figures, Revtex style, minor changes, references added, Accepted in Physical Review D