Adiabatic Spectra During Slowly Evolving
  In general, for single field, the scale invariant spectrum of curvature
perturbation can be given by either its constant mode or its increasing mode.
We show that during slowly expanding or contracting, the spectrum of curvature
perturbation given by its increasing mode can be scale invariance. The
perturbation mode can be naturally extended out of horizon, and the amplitude
of perturbation is consistent with the observations. We briefly discuss the
implement of this scenario.
