Induced gravity inflation in the standard model of particle physics

Abstract

We are considering the cosmological consequences of an induced gravity theory coupled to the minimal standard model of particle physics. The non-minimal coupling parameter between gravity and the Higgs field must then be very large, yielding some new cosmological consequences for the early Universe and new constraints on the Higgs mass. As an outcome, new inflation is only possible for very special initial conditions producing first a short contraction era after which an inflationary expansion automatically follows; a chaotic inflationary scenario is successfully achieved. The contrast of density perturbations required to explain the seed of astronomic structures are obtained for very large values of the Higgs mass ($M_{H} >> G_{F}^{-1/2}$), otherwise the perturbations have a small amplitude; in any case, the spectral index of scalar perturbations agrees with the observed one.