Gravitino production after inflation

We investigate the production of gravitinos in a cosmological background. Gravitinos can be produced during preheating after inflation due to a combined effect of interactions with an oscillating inflation field and the absence of conformal invariance. In order to get insight into the conformal properties of a gravitino we reformulate phenomenological supergravity in an SU(2,2\1)-symmetric way. The Planck mass and F and D terms appear via the gauge-fixed value of a superfield that we call the conformon. We find that in general the probability of gravitino production is not suppressed by the small gravitational coupling. This may lead to the copious production of gravitinos after inflation. The efficiency of the new nonthermal mechanism of gravitino production is sensitive to the choice of the underlying theory. This may put strong constraints on certain classes of inflationary models.