Observational constraint on the dark energy scalar field * *H. Li is Supported by the Sino US Cooperation Project of Ministry of Science and Technology (2016YFE0104700), Youth Innovation Promotion Association Project of CAS. The research is also Supported in part by NSFC (11653001) and Pilot B Project of CAS (XDB23020000)

Abstract

In this paper, we study three scalar fields, namely the quintessence, phantom, and tachyon fields, to explore the source of dark energy via the Gaussian processes method from the background and perturbation growth rate data. The corresponding reconstructions suggest that the dark energy should be dynamical. Moreover, the quintom field, which is a combination of the quintessence and phantom fields, is powerfully favored by the reconstruction. The mean values indicate that the potential in the quintessence field is a double exponential function, whereas in the phantom field is a double Gaussian function. This reconstruction can provide an important reference for the scalar field study. The two types of data employed reveal that the tachyon field is disadvantageous for describing the cosmic acceleration.