Cosmological inflation with orbifold moduli as inflatons

Cosmological inflation is studied in the case where the inflaton is the ove rall modulus T for an orbifold. General forms of the (non-perturbative) sup erpotential are considered to ensure that G = K + ln\W\(2) is modular invar iant. We find generically that these models do not produce a potential flat enough for slow roll to a supersymmetric minimum, although we do find a mo del which produces up to 20 e-folds of inflation to a non-supersymmetric mi nimum. (C) 1998 Elsevier Science B.V. All rights reserved.