Nonlinearly interacting ghost dark energy in Brans–Dicke cosmology

Abstract

In this paper we extend the form of interaction term into the nonlinear regime in the ghost dark energy model. A general form of the nonlinear interaction term is presented and cosmic dynamic equations are obtained. Next, the model is detailed for two special choices of the nonlinear interaction term. According to this the universe transits at suitable time (z ∼ 0.8) from deceleration to acceleration phase, which alleviate the coincidence problem. Squared sound speed analysis revealed that for one class of nonlinear interaction term [Formula: see text] can become positive. This point is an impact of the nonlinear interaction term and we never find such behavior in non-interacting and linearly interacting ghost dark energy models. Also, statefinder parameters are introduced for this model and we found that for one class the model meets the ΛCDM while in the second choice although the model approaches the ΛCDM, but never matches it.