Model independent cosmographic constraints from DESI 2024

Abstract

In this study, we explore model independent constraints on the universe kinematics up to the snap and jerk hierarchical terms. To do so, we consider the latest Baryon Acoustic Oscillation (BAO) release provided by the DESI collaboration, tackling the $r_d$ parameter to span within the range $[144,152]$ Mpc, with fixed step, $\delta r_d=2$ Mpc, aligning with Planck and DESI results. Thus, employing Monte Carlo Markov chain analyses, we place stringent constraints on the cosmographic series, incorporating three combinations of data catalogs: the first BAO with observational Hubble data, the second BAO with type Ia supernovae, and the last including all three data sets. Our results conclusively constrain the cosmographic series, say the deceleration $q_0$, the jerk $j_0$, and the snap $s_0$ parameters, at the $2$--$\sigma$ level, showcasing a significant departure on $j_0$ even at $1$--$\sigma$ confidence level, albeit being compatible with the $\Lambda$CDM paradigm on $q_0$ and $s_0$, at $2$--$\sigma$ level. Analogously, the $h_0$ tension appears alleviated in the second hierarchy, say including snap. Finally, a direct comparison with the $\Lambda$CDM, $w$CDM models and the Chevallier-Polarski-Linder parametrization is reported, definitively favoring the wCDM scenario.

arXiv comment11 pages, 5 tables, 3 figures