Intermediate redshift calibration of gamma-ray bursts and cosmic constraints in non-flat cosmology

Abstract

ABSTRACT We propose a new method to calibrate gamma-ray burst (GRB) correlations employing intermediate redshift data sets, instead of limiting to z ≃ 0 catalogues, and applied it to the well-consolidated Amati correlation. This model-independent calibration technique is based on the Bézier polynomial interpolation of the most updated observational Hubble data and baryonic acoustic oscillations (BAO) and alleviates de facto the well-known circularity problem affecting GRB correlations. In doing so, we also investigate the influence of the BAO scales rs, got from Planck results, and $r_{\rm s}^{\rm fid}$, got from the considered fiducial cosmology, by considering the cases $(r_{\rm s}/r_{\rm s}^{\rm fid})=1$ and $(r_{\rm s}/r_{\rm s}^{\rm fid})\ne 1$. We get constraints on the cosmic parameters, using Markov chain–Monte Carlo simulations, first fixing and then leaving free the spatial curvature density parameter Ωk. Compared to previous literature, we obtain tighter constraints on the mass density parameter Ωm. In particular, our findings turn out to be highly more compatible with those got from standard candle indicators within the Lambda cold dark matter paradigm. Finally, we critically re-examine the recent H0 tension in view of our outcomes.