PRIMORDIAL SPECTRAL INDEXES FROM GENERALIZED EINSTEIN THEORIES

Primordial spectral indices are calculated to second order in slow-roll parameters for three closely related models of inflation, all of which contain a scalar field nonminimally coupled to the Ricci curvature scalar. In most cases, n(s) may be written as a function of the nonminimal curvature coupling strength xi alone, with n(s) (xi) less than or equal to 1, although the constraints on xi differ greatly between ''new inflation'' and ''chaotic inflation'' initial conditions. Under ''new inflation'' initial conditions, there are discrepancies between the values of n(s) as calculated in the Einstein frame and the Jordan frame. The sources for these discrepancies are addressed, and shown to have negligible effects on the numerical predictions for n(s). No such discrepancies affect the calculations under ''chaotic inflation'' initial conditions.