  We study the potential induced by imaginary self-dual 3-forms in
compactifications of string theory and the cosmological evolution associated
with it. The potential contains exponentials of the volume moduli of the
compactification, and we demonstrate that the exponential form of the potential
leads to a power law for the scale factor of the universe. This power law does
not support accelerated expansion. We explain this result in terms of
supersymmetry and comment on corrections to the potential that could lead to
inflation or quintessence.
