Factor analysis of the spectral and time behavior of long GRBs

A sample of 197 long BATSE GRBs is studied statistically. In the sample 11 variables, describing for any burst the time behavior of the spectra and other quantities, are collected. The application of the factor analysis on this sample shows that five factors describe the sample satisfactorily. Both the pseudo‐redshifts coming from the variability and the Amati‐relation in its original form are disfavored.