Holographic dark energy model in the DGP braneworld with time varying holographic parameter

We study the cosmological dynamics of holographic dark energy in a DGP braneworld in which the holographic parameter c2 is slowly varying with time. In our model, two famous IR cutoffs including the Hubble radius and the Granda-Oliveros cutoffs are considered. Our study shows that, for both cutoffs, there is a transition from a deceleration phase to an accelerated one for the universe which is in agreement with recent observations. It has been obtained that, even in the absence of an interaction between the dark sectors of cosmos, the equation of state parameter of the model with the Hubble radius as IR cutoffs can cross the phantom line, namely ωD<−1.