Probing dark energy with gamma-ray bursts

Abstract

We propose a new method to use gamma-ray bursts (GRBs) as an alternative probe of the dark energy. By calibrating luminosity-variability and luminosity-lag time relations at low redshift where distance-redshift relations have been already determined from type Ia supernova (SNIa), GRBs at high redshift can be used as a distance indicator. We investigate the potential impact of future GRB data on determining the current matter density $Ω_{m}$ and the dark energy equation of state $w$ which is assumed to be constant. We show that a combined analysis of a data set expected from the {\it Swift} and the current SNIa data results in excellent determination of both $Ω_{m}$ and $w$.