Gamma-ray bursts can potentially be used as distance indicators, providing the possibility of extending the Hubble diagram to redshifts ∼7. Here we follow the GRB analysis of Schaefer, with the aim of distinguishing the timescape cosmological model from the Λ cold dark matter (ΛCDM) model by means of the additional leverage provided by Gamma-ray bursts (GRBs) in the range 2 ≲z≲ 7. We find that the timescape model fits the GRB sample slightly better than the ΛCDM model, but that the systematic uncertainties are still too little understood to distinguish the models.

Gamma-ray bursts can potentially be used as distance indicators, providing the possibility of extending the Hubble diagram to redshifts ∼7. Here we follow the GRB analysis of Schaefer, with the aim of distinguishing the timescape cosmological model from the Λ cold dark matter (ΛCDM) model by means of the additional leverage provided by Gamma-ray bursts (GRBs) in the range 2 ≲z≲ 7. We find that the timescape model fits the GRB sample slightly better than the ΛCDM model, but that the systematic uncertainties are still too little understood to distinguish the models.