Determination of the kinematic parameters from SNe Ia and cosmic chronometers

Abstract

In this work, by assuming a spatially flat Universe, we have tested 8 kinematic parametrization models with H(z) data from Cosmic Chronometers and SNe Ia from Pantheon compilation. Our aim is obtain the current values for the Hubble constant ($H_0$), deceleration parameter ($q_0$), jerk ($j_0$) and snap ($s_0$) parameters independently from a dynamical model. By using a Bayesian model comparison, three models are favoured: a model with the deceleration parameter (q) linearly dependent on the redshift, q linearly dependent on the scale factor and a model with a constant jerk. The model with constant jerk is slightly favoured by this analysis, furnishing $H_0=68.8_{-3.6}^{+3.7}$ km/s/Mpc, $q_0=-0.58\pm 0.13$, $j_0=1.{15}_{-0.53}^{+0.56}$ and $s_0=-0.{25}_{-0.30}^{+0.40}$. The other models are compatible with the constant jerk model, except for the snap parameter, where we have found $s_0=4.0_{-3.0}^{+3.4}$ for the model with q linearly dependent on the scale factor.