Scalar-Gauss–Bonnet gravity and cosmic acceleration: Comparison with quintessence dark energy

Abstract

The late-time cosmic acceleration of the universe is explained in the framework of the Einstein-scalar-Gauss–Bonnet (GB) theory by considering different appropriate forms for the GB coupling parameter and the scalar field. The physical quantities such as the potential energy, the GB coupling parameter, the energy density, the pressure and the deceleration parameter are obtained in an exact parametric form of the volume scale factor of the universe. The behavior of the deceleration parameter shows a transition from the deceleration phase to the acceleration phase at the late times in agreement with the observational data. Finally, the GB energy density ratio is compared to the matter energy density and the scalar (the quintessence) field energy density in the early and late times.