Abstract
Phys.Rev. D68 (2003) 075011 Various authors have noted that in particular models, the upper bound on the
axion decay constant may not hold. We point out that within supersymmetry, this
is a generic issue. For large decay constants, the cosmological problems
associated with the axion's scalar partner are far more severe than those of
the axion. We survey a variety of models, both for the axion multiplet and for
cosmology, and find that in many cases where the cosmological problems of the
saxion are solved, the usual upper bound on the axion is significantly relaxed.
We discuss, more generally, the cosmological issues raised by the pseudoscalar
members of moduli multiplets, and find that they are potentially quite severe.