Dark energy reconstructions combining BAO data with galaxy clusters and intermediate redshift catalogs

TL;DR

This paper presents a model-independent reconstruction of dark energy evolution using BAO, galaxy clusters, and supernova data, finding consistency with the cosmological constant at high redshift and hints of slow evolution at low redshift.

Contribution

It introduces a Bézier interpolation method for model-independent reconstruction of dark energy and cosmological parameters from diverse observational data sets.

Findings

Constraints agree with flat ΛCDM at 1-σ CL

Hubble tension is resolved in favor of Planck value

DE shows deviations at low redshift but aligns with cosmological constant at high redshift

Abstract

Cosmological parameters and dark energy (DE) behavior are generally constrained assuming \textit{a priori} models. We work out a model-independent reconstruction to bound the key cosmological quantities and the DE evolution. Through the model-independent \textit{B\'ezier interpolation} method, we reconstruct the Hubble rate from the observational Hubble data and derive analytic expressions for the distances of galaxy clusters, type Ia supernovae, and uncorrelated baryonic acoustic oscillation (BAO) data. In view of the discrepancy between Sloan Digital Sky Survey (SDSS) and Dark Energy Spectroscopic Instrument (DESI) BAO data, they are kept separate in two distinct analyses. Correlated BAO data are employed to break the baryonic--dark matter degeneracy. All these interpolations enable us to single out and reconstruct the DE behavior with the redshift $z$ in a totally model-independent way. In both analyses, with SDSS-BAO or DESI-BAO data sets, the constraints agree at $1$--$\sigma$ confidence level (CL) with the flat $\Lambda$CDM model. The Hubble constant tension appears solved in favor of the Planck satellite value. The reconstructed DE behavior exhibits deviations at small $z$ ($>1$--$\sigma$ CL), but agrees ($<1$--$\sigma$ CL) with the cosmological constant paradigm at larger $z$. Our method hints for a slowly evolving DE, consistent with a cosmological constant at early times.