Revisiting a non-parametric reconstruction of the deceleration parameter from combined background and the growth rate data

Understand

The cosmic deceleration parameter $q$ has been reconstructed in a non-parametric way using various combinations of recent observational datasets.

• The Pantheon compilation of the Supernova (SN) distance modulus data, the Cosmic Chronometer (CC) measurements of the Hubble parameter including the full systematics and the Baryon Acoustic Oscillation (BAO) data have been considered in this work.
• The redshift $z_t$, where the transition from a past decelerated to a late-time accelerated phase of evolution occurs, is estimated from the reconstructed $q$.
• The possible effect of a non-zero spatial curvature from the Planck 2020 estimate is checked.