Prospects of high redshift constraints on dark energy models with the Ep- Eiso correlation in long Gamma Ray Bursts

TL;DR

This paper investigates high-redshift constraints on dark energy models using gamma-ray bursts and supernova data, finding that evolving dark energy models with scalar fields are favored by current observations.

Contribution

It introduces a comprehensive analysis of dark energy models using GRB and SNIa data, employing MCMC and AIC to compare models and identify the most supported scenario.

Findings

Evolving dark energy with scalar fields is favored by data.

Models with early dark energy are consistent with observations.

Scalar field models outperform static dark energy models in fit quality.

Abstract

So far large and different data sets revealed the accelerated expansion rate of the Universe, which is usually explained in terms of dark energy. The nature of dark energy is not yet known, and several models have been introduced: a non zero cosmological constant, a potential energy of some scalar field, effects related to the non homogeneous distribution of matter, or effects due to alternative theories of gravity. Recently, a tension with the flat {\Lambda}CDM model has been discovered using a high-redshift Hubble diagram of supernovae, quasars, and gamma-ray bursts. Here we use the Union2 type Ia supernovae (SNIa) and Gamma Ray Bursts (GRB) Hubble diagram, and a set of direct measurements of the Hubble parameter to explore different dark energy models. We use the Chevallier-Polarski- Linder (CPL) parametrization of the dark energy equation of state (EOS), a minimally coupled quintessence scalar field, and, finally, we consider models with dark energy at early times (EDE). We perform a statistical analysis based on the Markov chain Monte Carlo (MCMC) method, and explore the probability distributions of the cosmological parameters for each of the competing models. We apply the Akaike Information Criterion (AIC) to compare these models: our analysis indicates that an evolving dark energy, described by a scalar field with exponential potential seems to be favoured by observational data.