Investigating the Evolution of Amati Parameters with Redshift by Meghendra Singh et al. on Wednesday 23 November

Gamma Ray Bursts (GRB) are among the brightest objects in the Universe and

hence can be observed up to a very high redshift. Properly calibrated empirical

correlations between intensity and spectral correlations of GRBs can be used to

estimate the cosmological parameters. However, the possibility of the evolution

of GRBs with the redshift is a long-standing puzzle. In this work, we used 162

long-duration GRBs to determine whether GRBs below and above a certain redshift

have different properties. The GRBs are split into two groups, and we fit the

Amati relation for each group separately. Our findings demonstrate that

estimations of the Amati parameters for the two groups are substantially

dissimilar. We perform simulations to investigate whether the selection effects

could cause the difference. Our analysis shows that the differences may be

intrinsic, and the selection effects are not their true origin.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.11667v1