40 citations · 359 across the 20 of their papers we have counts for
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Full nonlinear growing and decaying modes of superhorizon curvature perturbations
Yu-ichi Takamizu, Jun'ichi Yokoyama
We clarify the behavior of curvature perturbations in a nonlinear theory in case the inflaton temporarily stops during inflation. We focus on the evolution of curvature perturbatio…
The effect of varying sound velocity on primordial curvature perturbations
Masahiro Nakashima, Ryo Saito, Yu-ichi Takamizu +1
We study the effects of sudden change in the sound velocity on primordial curvature perturbation spectrum in inflationary cosmology, assuming that the background evolution satisfie…
Non-Gaussianity of superhorizon curvature perturbations beyond N formalism
Yu-ichi Takamizu, Shinji Mukohyama, Misao Sasaki +1
We develop a theory of nonlinear cosmological perturbations on superhorizon scales for a single scalar field with a general kinetic term and a general form of the potential. We emp…