Searching for the evidence of dynamical dark energy

Abstract

In the statistical framework of model-independent Gaussian processes (GP), we search for the evidence of dynamical dark energy (DDE) using the “Joint Light-curve Analysis” (JLA) Type Ia supernovae (SNe Ia) sample, the 30 latest cosmic chronometer data points (H(z)), Planck’s shift parameter from cosmic microwave background (CMB) anisotropies, the 156 latest HII galaxy measurements and 79 calibrated gamma-ray bursts (GRBs). We find that the joint constraint from JLA + H(z) + CMB + HII + GRB supports the global measurement of H by Planck collaboration very much in the low redshift range z∈ [0 , 0.76] at the 2 σ confidence level (C.L.), gives a cosmological constant crossing (quintom-like) equation of state (EoS) of DE at the 2 σ C.L. and implies that the evolution of the late-time Universe may be actually dominated by the DDE.