  The Peccei-Quinn mechanism suffers from the problem of the isocurvature
perturbations. The isocurvature perturbations are suppressed if the
Peccei-Quinn breaking scale is large during inflation. The oscillation of the
Peccei-Quinn breaking field after inflation, however, leads to the formation of
domain walls due to the parametric resonance effect. In this paper, we discuss
the evolution of the Peccei-Quinn breaking field after inflation in detail, and
propose a model where the parametric resonance is ineffective and hence domain
walls are not formed. We also discuss consistency of our model with
supersymmetric theory.

High Energy Physics - Phenomenology;Cosmology and Nongalactic Astrophysics