  Spectator field models such as the curvaton scenario and the modulated
reheating are attractive scenarios for the generation of the cosmic curvature
perturbation, as the constraints on inflation models are relaxed. In this
paper, we discuss the effect of Hubble induced masses on the dynamics of
spectator fields after inflation. We pay particular attention to the Hubble
induced mass by the kinetic energy of an oscillating inflaton, which is
generically unsuppressed but often overlooked. In the curvaton scenario, the
Hubble induced mass relaxes the constraint on the property of the inflaton and
the curvaton, such as the reheating temperature and the inflation scale. We
comment on the implication of our discussion for baryogenesis in the curvaton
scenario. In the modulated reheating, the predictions of models e.g. the
non-gaussianity can be considerably altered. Furthermore, we propose a new
model of the modulated reheating utilizing the Hubble induced mass which
realizes a wide range of the local non-gaussianity parameter.
