Non-parametric reconstruction of the cosmological jerk parameter

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 Lambda CDM model within the 2 sigma 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 Lambda 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. Lambda CDM model is excluded for some part of the evolution in 1 sigma, but is definitely included in 2 sigma in the domain (0 <= z <= 2.36) of all the reconstructions.

Automated summary

The study reconstructed the cosmological jerk parameter j and deceleration parameter q from observational data, finding the values to be consistent with the standard ΛCDM model within the 2 sigma confidence level. Model dependent data sets did not significantly improve or disprove the confidence level of the ΛCDM model, with the model being excluded for some part of the evolution at 1 sigma but definitely included at 2 sigma within the domain of reconstructions (0 <= z <= 2.36).