Gamma-ray burst distances and the timescape cosmology

Gamma-ray bursts can potentially be used as distance indicators, providing the possibility of extending the Hubble diagram to redshifts similar to 7. Here we follow the GRB analysis of Schaefer, with the aim of distinguishing the timescape cosmological model from the ? cold dark matter (?CDM) 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 ?CDM model, but that the systematic uncertainties are still too little understood to distinguish the models.