Determination of the kinematic parameters from SNe Ia and cosmic chronometers

Abstract

AbstractIn 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 ($$H_0$$ H 0 ), deceleration parameter ($$q_0$$ q 0 ), jerk ($$j_0$$ j 0 ) and snap ($$s_0$$ 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 $$H_0=68.8^{+3.7}_{-3.6}$$ H 0 = 68 . 8 - 3.6 + 3.7 km/s/Mpc, $$q_0=-0.58\pm 0.13$$ q 0 = - 0.58 ± 0.13 , $$j_0=1.15^{+0.56}_{-0.53}$$ j 0 = 1 . 15 - 0.53 + 0.56 and $$s_0=-0.25^{+0.40}_{-0.30}$$ 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 $$s_0=4.0^{+3.4}_{-3.0}$$ s 0 = 4 . 0 - 3.0 + 3.4 for the model with q linearly dependent on the scale factor.