Constraining a variable dark energy model from the redshift-luminosity distance relations of gamma-ray bursts and type Ia supernovae

TL;DR

This paper constrains a variable dark energy model using gamma-ray burst and supernova data, revealing a transition from quintessence-like to phantom-like behavior around redshift 0.3.

Contribution

It introduces a time-varying equation of state for dark energy and constrains its parameters using MCMC with observational data.

Findings

Dark energy transitions from quintessence-like to phantom-like.

Rapid change in dark energy behavior occurs near redshift 0.3.

Supports dynamic dark energy models over static ones.

Abstract

There are many kinds of models which describe the dynamics of dark energy (DE). Among all we adopt an equation of state (EoS) which varies as a function of time. We adopt Markov Chain Monte Carlo method to constrain the five parameters of our models. As a consequence, we can show the characteristic behavior of DE during the evolution of the universe. We constrain the EoS of DE with use of the avairable data of gamma-ray bursts and type Ia supernovae (SNe Ia) concerning the redshift-luminosity distance relations. As a result, we find that DE is quintessence-like in the early time and phantom-like in the present epoch or near the future, where the change occurs rather rapidly at $z\sim0.3$.