DARK ENERGY MODELS WITH VARIABLE EQUATION OF STATE PARAMETER

摘要

Two phenomenological variable Λ models, viz. Λ - ( a/a)2 and Λ - ρ, have been studied under the assumption that the equation of state parameter ω is a function of time. The selected Λ models are found to be equivalent both in four and five dimensions. The possibility of signature flip of the deceleration parameter is also shown.