*7.1. Evolution Effects*

GRBs are observed from a large redshift range and in principle correlation parameters may evolve with the redshift. In some cases, to estimate the cosmological parameters, a correction of the kind of (1 + *z*) −*d* to the energy or luminosity parameters is needed, introducing a further parameter to fit. However, though tested for subsamples of GRBs and several correlations, this issue is still ongoing [143].
