Interacting ghost dark energy in Brans-Dicke theory

We investigate the QCD ghost model of dark energy in the framework of Brans-Dicke cosmology. First. we study the non-interacting ghost dark energy in a flat Brans-Dicke theory. In this case we obtain the equation of state and the deceleration parameters and a differential equation governing the evolution of ghost energy density. Interestingly enough, we find that the equation of state parameter of the non-interacting ghost dark energy can cross the phantom line (w(D) = 1) provided the parameters of the model are chosen suitably. Then, we generalize the study to the interacting ghost dark energy in both flat and non-flat Brans-Dicke framework and find out that the transition of w(D) to phantom regime can be more easily achieved for than when resort to the Einstein field equations is made. (C) 2011 Elsevier B.V. All rights reserved.