Revisiting statefinder via Gaussian process

Abstract

The statefinder diagnostic is useful to discriminate dark energy models. In this paper, under the minimum assumption of a spatially flat Friedmann–Lemaître–Robertson–Walker Universe, we reconstruct the statefinder pair $\{r(z),s(z)\}$ in addition to the deceleration parameter q(z) via the Gaussian process from the cosmic observational data points which include the recently released Pantheon+ SN Ia samples and the observational Hubble data H(z). The reconstructed evolution trajectories are shown on the $r-q$, $r-s$ planes. The reconstructed q(z) is consistent with previous studies. Meanwhile, a novel quantity named suitability is introduced on the $r-q$, $r-s$ planes to assess the validation of a dark energy model.