Renormalization group equations in curved space-time with non-trivial   Topology
  Renormalization group equations for massless GUT's in curved space-time with non-trivial topology are formulated. The asymptotics of the effective action both at high and low energies are obtained. It is shown that the Casimir energy contribution at high curvature (early Universe) becomes non-essential in the effective action. 
E. Elizalde and S.D. Odintsov (Department E.C.M., Faculty of Physics,   University of Barcelona, Spain)