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 the 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 the same as that of the thawing quintessence.

• Received 16 April 2009

DOI:https://doi.org/10.1103/PhysRevD.79.123501