Production of fermions in models of string cosmology

Production of spin 1/2 fermions and gravitinos by the standard mechanism of amplification of quantum fluctuations during the dilaton-driven inflation phase in models of string cosmology is highly suppressed. Constraints on string cosmology models from gravitational production of gravitinos, contrary to expectations, are similar to constraints on other models. (C) 2000 Published by Elsevier Science B.V.