Moduli-Induced Axion Problem
  We point out that the cosmological moduli problem is not necessarily resolved
even if the modulus mass is heavier than O(10)TeV, contrary to the common
wisdom. The point is that, in many scenarios where the lightest moduli fields
are stabilized by supersymmetry breaking effects, those moduli fields tend to
mainly decay into almost massless axions, whose abundance is tightly
constrained by the recent Planck results. We study the moduli-induced axion
problem in concrete examples, and discuss possible solutions. The problem and
its solutions are widely applicable to decays of heavy scalar fields which
dominate the energy density of the Universe, for instance, the reheating of the
inflaton.
