Modulated inflation from kinetic term
  We study modulated inflation from kinetic term. Using the Mukhanov-Sasaki variable, it is possible to determine how mixing induced by the kinetic term feeds the curvature perturbation with the isocurvature perturbation. We show explicitly that the analytic result obtained from the evolution of the Mukhanov-Sasaki variable is consistent with the $\delta N$-formula. From our results, we find analytic conditions for the modulated fluctuation and the non-Gaussianity parameter. 
Tomohiro Matsuda