A New Equation of State for Dark Energy Model

TL;DR

This paper introduces a modified dark energy equation of state parameterization, investigates its cosmological implications, and constrains its parameters using current observational data, providing a new approach to modeling dark energy.

Contribution

It proposes a new dark energy EoS parameterization based on Efstathiou's model and analyzes its cosmological constraints with observational data.

Findings

Best-fit matter density: Ω_m=0.2735

Best-fit EoS parameters: w_0=-1.0537, w_a=0.2738

Model consistent with current observational constraints

Abstract

A new parameterization for the dark energy equation of state(EoS) is proposed and some of its cosmological consequences are also investigated. This new parameterization is the modification of Efstathiou' dark energy EoS parameterization. $w (z)$ is a well behaved function for $z\gg1$ and has same behavior in $z$ at low redshifts with Efstathiou' parameterization. In this parameterization there are two free parameter $w_0$ and $w_a$. We discuss the constraints on this model's parameters from current observational data. The best fit values of the cosmological parameters with $1\sigma$ confidence-level regions are: $\Omega_m=0.2735^{+0.0171}_{-0.0163}$, $w_0=-1.0537^{+0.1432}_{-0.1511}$ and $w_a=0.2738^{+0.8018}_{-0.8288}$.