Model-independent estimation of the cosmography parameters using cosmic chronometers

Abstract

Measurement of the universe expansion rate through the cosmic chronometers proves to be a novel approach to understanding cosmic history. Although it provides a direct determination of the Hubble parameters at different redshifts, it suffers from underlying systematic uncertainties. In this work, we analyze the recent cosmic chronometer data with and without systematic uncertainties and investigate how they affect the results. We perform our analysis in both model-dependent and independent methods to avoid any possible model bias. In the model-dependent approach, we consider the $\Lambda$CDM, wCDM and CPL models. On the Other hand, since the Gaussian process provides a unique tool to study data including a non-diagonal covariance matrix, our model-independent analysis is based on the Gaussian process.