A Study of Cosmological Models Based on the Long Gamma-Ray Burst Duration Histogram

Abstract The duration of more than one thousand gamma-ray bursts (GRBs) was measured by using the Swift satellite. Besides the redshift distribution of GRBs, the burst duration is another significant property of GRBs that can be analyzed. In this paper, we first find the detection rate of Swift/Burst Alert Telescope for a cosmological model with the ω CDM model. Then, by performing a Monte Carlo simulation, we find the "long" GRB duration histogram to compare the cosmological model with the ω CDM model and the ΛCDM model. The χ 2 minimization method is employed to determine the optimal value of α in the dark energy equation of state, P = cω ( z ) ρ , with ω ( z ) = −1 + α z. We show that for the ωCDM model, all values of α within α = [0, 0.16] range are considered acceptable within two standard deviations.