Stability of Ghost Dark Energy in CBD Model of Gravity

Abstract

We study the stability of the ghost dark energy model versus perturbation. Since this kind of dark energy is instable in Einsteinian general relativity theory, then we study a new type of Brans-Dicke theory which has non-minimal coupling with matter which is called chameleon Brans-Dicke (CBD) model of gravity. Due to this coupling the equation of conservation energy is modified. For considering the stability of the model we use the adiabatic squared sound speed, $c_s^2$, whose sign of it determines the stability of the model in which for $c_s^2 >0 $ the model is stable and for $c_s^2 <0 $ the model is instable. However, we study the interacting and non-interacting version of chameleon Brans-Dicke ghost dark energy (CBDGDE) with cold dark matter in non flat FLRW metric. We show that in all cases of investigation the model is stable with a suitable choice of parameters.

17 pages, 7 figures, Latex