Dynamics of a quintom dark energy model non-minimally coupled with a mixed kinetic geometric term

Abstract

Within this work, a new dark energy model is proposed by taking into account a non-minimally mixed kinetic geometric coupling between the two fields, which constructs a quintom model. By considering numerical analysis of the corresponding field equations, the evolution of the Universe in the present model has been analyzed, taking into account different viable potentials. For exponential potentials, the model presents an accelerated expansion, and the dark energy equation of state exhibits phantom divide line crossing. However, for a steeper potential, for example, a mixed potential, it is observed that the Universe can manifest Big Crunch singularities in the distant future, and the moment for which the singularity occurs is sensitive to the value of the mixed coupling strength embedded into the η coefficient. The results show that an increase of the η parameter induces a delay in the Big Crunch time in the distant future. In the present context, the choice of the potential function plays a fundamental role in the evolution of the dynamical system, leading to very distinct cosmological scenarios.