A generalized equation of state for dark energy

Abstract

A generalized parameterization $w_β(z)$ for the dark energy equation of state (EoS) is proposed and some of its cosmological consequences are investigated. We show that in the limit of the characteristic dimensionless parameter $β\to +1, 0$ and -1 some well-known EoS parameterizations are fully recovered whereas for other values of $β$ the proposed parameterization admits a wider and new range of cosmological solutions. We also discuss possible constraints on the $w_β(z)$ parameters from current observational data.

6 pages, 4 figures, Accepted for publication in Phys. Rev. D