The Gamma Ray Bursts Hubble diagram
  Thanks to their enormous energy release, Gamma Rays Bursts (GRBs) have
recently attracted a lot of interest to probe the Hubble diagram (HD) deep into
the matter dominated era and hence complement Type Ia Supernovae (SNeIa). We
consider here three different calibration methods based on the use of a
fiducial LCDM model, on cosmographic parameters and on the local regression on
SNeIa to calibrate the scaling relations proposed as an equivalent to the
Phillips law to standardize GRBs finding any significant dependence. We then
investigate the evolution of these parameters with the redshift to obtain any
statistical improvement. Under this assumption, we then consider possible
systematics effects on the HDs introduced by the calibration method, the
averaging procedure and the homogeneity of the sample arguing against any
significant bias.
