Model-independent cosmographic constraints from DESI 2024

¹ Università di Camerino, Divisione di Fisica, Via Madonna delle carceri 9, 62032 Camerino, Italy
² SUNY Polytechnic Institute, Utica, NY 13502, USA
³ INFN, Sezione di Perugia, Perugia 06123, Italy
⁴ INAF – Osservatorio Astronomico di Brera, Milano, Italy
⁵ Al-Farabi Kazakh National University, Al-Farabi av. 71, 050040 Almaty, Kazakhstan
⁶ ICRANet, P.zza della Repubblica 10, 65122 Pescara, Italy
e-mail: marco.muccino@lnf.infn.it

Received: 25 April 2024
Accepted: 24 June 2024

Abstract

Context. We explore model-independent constraints on the Universe kinematics up to the snap and jerk hierarchical terms, considering the latest baryon acoustic oscillation (BAO) release provided by the DESI collaboration.

Aims. We intend to place novel and more stringent constraints on the cosmographic series, incorporating three combinations of data catalogs: the first made by BAO and observational cosmic chronometers, the second made by BAO and type Ia supernovae, and the last including all the cited data sets.

Methods. Considering the latest BAO data provided by the DESI collaboration and tackling the r_d parameter to span within the range [144,152] Mpc, with a fixed step of δr_d = 2 Mpc, we employed Monte Carlo Markov chain analyses based on the Metropolis algorithm to fix novel bounds on the cosmographic series, fixing the deceleration, q₀ , the jerk, j₀ , and the snap, s₀, parameters, up to the 2σ level. A comparison between the results of the Planck satellite with those obtained by the DESI collaboration is also reported.

Results. Our findings showcase a significant departure in terms of j₀ even at the 1σ confidence level, albeit compatible with the ACDM paradigm in regard to q₀ and s₀ at the 2σ level. Analogously, the h₀ tension appears alleviated in the second hierarchy when including snap.

Conclusions. Our method excludes models that significantly depart from the standard cosmological model. Particularly, direct comparisons with the ACDM and wCDM models and the Chevallier-Polarski-Linder parameterisation are explored, which definitively favour the wCDM scenario over other approaches, contradicting the findings of the original DESI collaboration.