POWER-LAW INFLATION AND CONFORMAL TRANSFORMATIONS

We present a discussion of power-law inflation in higher-order gravity theories. Using the conformal equivalence theorem, we find power-law solutions in the context of pure higher-order gravity theories in arbi trary dimension. We also find a family of polar inflationary solutions . We give a perturbation analysis which establishes that the power-law solutions are stable against homogeneous and isotropic perturbations but that the polar solutions are not.