Esmaeil Ebrahimi, Ahmad Sheykhi
We investigate the generalized QCD ghost model of dark energy in the framework of Einstein gravity. First, we study the non-interacting generalized ghost dark energy in a flat FRW background. We obtain the equation of state parameter, $w_D=p/\rho$, the deceleration parameter, and the evolution equation of the generalized ghost dark energy. We find that, in this case, $w_D$ cannot cross the phantom line ($w_D>-1$) and eventually the universe approaches a de-Sitter phase of expansion $(w_D\rightarrow-1)$. Then, we extend the study to the interacting ghost dark energy in both flat and non-flat FRW universe. We find out that the equation of state parameter of the interacting generalized ghost dark energy can cross the phantom line ($w_D<-1$) provided the parameters of the model are chosen suitably. We also discuss the values of the deceleration parameter in all cases and present a numerical evaluation of this parameter in different phases of the universe expansion.
View original:
http://arxiv.org/abs/1209.3147
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