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 st
ring cosmology models from gravitational production of gravitinos, contrary
to expectations, are similar to constraints on other models. (C) 2000 Publ
ished by Elsevier Science B.V. All rights reserved.