Extending the Hubble diagram by gamma ray bursts

TL;DR

This paper proposes a method combining gamma-ray bursts and supernovae to better constrain dark energy models and distinguish them from the standard Lambda Cold Dark Matter model at high redshifts.

Contribution

It introduces a novel approach using GRBs calibrated by SNeIa to extend the Hubble diagram and improve cosmological model discrimination.

Findings

GRBs can serve as effective high-redshift distance indicators.

The combined data helps distinguish dark energy models from LambdaCDM.

The method supports the transition from deceleration to acceleration in cosmic expansion.

Abstract

A new method to constrain the cosmological equation of state is proposed by using combined samples of gamma-ray bursts (GRBs) and supernovae (SNeIa). The Chevallier-Polarski-Linder parameterization is adopted for the equation of state in order to find out a realistic approach to achieve the deceleration/acceleration transition phase of dark energy models. We find that GRBs, calibrated by SNeIa, could be good distance indicators capable of discriminating between cosmological models and $\Lambda$CDM model at high redshift.