Dark energy constraints using gamma-ray burst correlations with DESI 2024 data

Abstract

Even though the Dark Energy Spectroscopic Instrument (DESI) mission does not exclude a dynamical dark energy evolution, the concordance paradigm, i.e., the $\Lambda$CDM model, remains statistically favored, as it depends on the fewest number of free parameters. In this respect, high redshift astrophysical sources, such as gamma-ray bursts, represent a formidable tool to model the form of dark energy, since they may provide a link between early and local redshift regimes. Hence, the use of these objects as possible distance indicators turns out to be essential to investigate the cosmological puzzle. To this end, we adopt two gamma-ray burst linear correlations, namely the $L_p-E_p$ and $L_0-E_p-T$ relations, to test the flat and non-flat $\Lambda$CDM, $\omega_0$CDM, and $\omega_0\omega_1$CDM cosmological models, i.e., those directly examined by the DESI collaboration. The inferred correlation coefficients and cosmological parameters are thus obtained by considering two independent Monte Carlo Markov chain analyses, the first considering the whole DESI data set and the second excluding a seemingly problematic data point placed at $z_{eff} = 0.51$. Using model selection criteria, the two above correlations do not show a preference on a precise cosmological model although, when the data point at $z_{eff}$ is included, the concordance paradigm appears to be the least favored among the tested cosmological models.