Dark Energy Models With Variable Equation Of State Parameter

Two variable $\mathrm{\Lambda }$ models, viz. $\mathrm{\Lambda }\sim (\dot{a}\mathrm{/}a{)}^2$ and $\Lambda \sim \rho$ have been studied under the assumption that the equation of state parameter $\omega$ is a function of time. The selected $\mathrm{\Lambda }$ models are found to be equivalent both in four and five dimensions. The possibility of signature flip of the deceleration parameter is also shown.