Blue Perturbation Spectra from Hybrid Inflation with Canonical Supergravity

Abstract

We construct a hybrid inflationary model associated with the superheavy scale of supersymmetric grand unified theories in which the inflaton potential is provided entirely by canonical supergravity. We find that the spectrum of adiabatic density perturbations is characterized by a strongly varying spectral index which is considerably larger than unity. Moreover, the total number of e-foldings is very limited. Implications of our analysis for other hybrid inflationary scenarios are briefly discussed.