INFLATIONARY COSMOLOGY WITH A R+LAMBDA-R(MU-NU)R(MU-NU)/R LAGRANGIAN

We consider an alternative fourth-order gravity Lagrangian which is nonanalytic in the Ricci scalar, and apply it to a Robertson-Walker metric. We find vacuum solutions which undergo power-law inflation. Once matter is introduced the theory behaves very much like ordinary General Relativity, except that the radiation evolution a similar to root t is not allowed since it corresponds to R = O. We comment on the possibility of wormhole solutions in such a theory.