Non-parametric reconstruction of the cosmological jerk parameter

Abstract

The cosmological jerk parameter j is reconstructed in a non-parametric way from observational data independent of a fiducial cosmological model. The Cosmic Chronometer data as well as the Supernovae data (the Pantheon compilation) are used for the purpose. The reconstructed values are found to be consistent with the standard Λ CDM model within the 2 σ confidence level. The model dependent sets like Baryon Acoustic Oscillation and the CMB Shift data are also included thereafter, which does not significantly help in improving or de-proving the confidence level in favour of Λ CDM. The deceleration parameter q is also reconstructed from the same data sets. This is used to find the effective equation of state parameter for the model independent datasets only. Λ CDM model is excluded for some part of the evolution in 1 σ, but is definitely included in 2 σ in the domain (0 ≤ z≤ 2.36) of all the reconstructions.