To check an alternative gravity theory which is constructed by an improved action if contains dynamical degrees of freedom which possess negative kinetic energy or not

The observed unexpected accelerated expansion of the universe, by Riess and collaborators in 1998, has become one of the most important problems of the contemporary physics.A considerable effort has been spending by theoretical physicists to explain this observation for a while. When one looks at to these attempts more closely, two of approaches attract attention:1)Multi dimensional alternative gravity models,2)Approaches which takes the more general and complex action than it?s original Einstein-Hilbert form, which had been given as Ricci scalar R.The second type of these approaches has to be examined carefully, because they could be generically involves dynamical degrees of freedom which possess negative kinetic energy (shortly be called as ?ghost states? or simply ?ghosts?).In this work, an alternative theory has been studied for to see if it contains ghosts or not.And this model has examined by this way to see if this specific alternative model could be used to explain the present late time acceleration of the universe or not.