Gravitino production after inflation - art. no. 103503

We investigate the production of gravitinos in a cosmological background. G ravitinos can be produced during preheating after inflation due to a combin ed effect of interactions with an oscillating inflation field and the absen ce of conformal invariance. In order to get insight into the conformal prop erties 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 gau ge-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 sm all gravitational coupling. This may lead to the copious production of grav itinos after inflation. The efficiency of the new nonthermal mechanism of g ravitino production is sensitive to the choice of the underlying theory. Th is may put strong constraints on certain classes of inflationary models.