CONSTRAINTS IN THE CONTEXT OF INDUCED-GRAVITY INFLATION

Constraints on the required flatness of the scalar potential V(phi) for a cousin model to extended inflation are studied. It is shown that, unlike earlier results, induced-gravity inflation can lead to successful inflation with a very simple Lagrangian and lambda approximately 10(-6), rather than 10(-15) as previously reported. A second order phase transition further enables this model to escape the ''big bubble'' problem of extended inflation, while retaining the latter's motivations based on the low-energy effective Lagrangians of supergravity, superstring, and Kaluza-Klein theories.