Induced-gravity inflation

In a Ginzburg-Landau model of induced gravity based on the Lagrangian density L=-{ε}φ²R/2-∂^μ{φ}∂_μ{φ}/2 -{λ}(φ²-v²{)}²$/8, we investigate the semiclassical evolution of {φ} from {φ}{≠}v to the spontaneous-symmetry-breaking minimum {φ}=v [v{≡}ε^-1/2(8{π}G)^-1/2]. We show that for {ε}, {λ}{}1 the transition is inflationary, both in the case that the initial value of {φ}=0 (``ordinary new inflation'') and in the case that the initial value of {φ}{}v (Linde's ``chaotic'' inflation). The value of {λ} required to ensure density inhomogeneities of the proper size is {ε} dependent and typically {≤}10^-12.