English

Kinematic constraints beyond $z\simeq0$ using calibrated GRB correlations

Cosmology and Nongalactic Astrophysics 2020-10-13 v1

Abstract

The dynamics of the Universe are revised using high-redshift data from gamma-ray bursts to constrain cosmographic parameters by means of model-independent techniques. Considering samples from four gamma-ray burst correlations and two hierarchies up to j0j_0 and s0s_0, respectively, we derived limits over the expansion history of the Universe. Since cosmic data span outside z0z\simeq0, we investigated additional cosmographic methods such as auxiliary variables and Pad\'e approximations. Bezi\'er polynomials were employed to calibrate our correlations and heal the circularity problem. Several Markov chain Monte Carlo simulations were performed on the model-independently calibrated Amati, Ghirlanda, Yonetoku, and combo correlations to obtain 11--σ\sigma and 22--σ\sigma confidence levels and to test the standard cosmological model. Reasonable results are found up to j0j_0 and s0s_0 hierarchies, respectively, only partially alleviating the tension on local H0H_0 measurements as j0j_0 hierarchy is considered. Discussions on systematic errors have been extensively reported here. Our findings show that the Λ\LambdaCDM model is not fully confirmed using gamma-ray bursts. Indications against a genuine cosmological constant are summarized and commented on in detail.

Keywords

Cite

@article{arxiv.2010.05218,
  title  = {Kinematic constraints beyond $z\simeq0$ using calibrated GRB correlations},
  author = {Orlando Luongo and Marco Muccino},
  journal= {arXiv preprint arXiv:2010.05218},
  year   = {2020}
}

Comments

15 pages, 7 figures, 7 tables

R2 v1 2026-06-23T19:14:58.410Z