10 citations · 22 across the 11 of their papers we have counts for
11 papers
Non-Gaussianity and finite length inflation
Shiro Hirai, Tomoyuki Takami
In the present paper, certain inflation models are shown to have large non-Gaussianity in special cases. Namely, finite length inflation models with an effective higher derivative…
Scale dependence of the power spectrum of the curvature perturbation determined using a numerical method in slow-roll inflation
Shiro Hirai, Tomoyuki Takami
The Taylor expansion method has been used to investigate the scale dependence of the power spectrum of the curvature perturbation. In the present study, an alternative numerical me…
Time dependence of cosmological and inflationary parameters in slow-roll inflation
Shiro Hirai, Tomoyuki Takami
The dependence of cosmological and inflationary parameters on time during the last 60 e-folds in inflation is investigated using a slow-roll inflation model. The time dependence of…
Effect of initial condition of inflation on power and angular power spectra in finite slow-roll inflation
Shiro Hirai, Tomoyuki Takami
The effect of the initial condition of inflation on the power spectra of scalar and tensor perturbations is estimated assuming a slow-roll inflation model. By defining a more gener…
Angular Power Spectrum in Modular Invariant Inflation Model
Mitsuo J. Hayashi, Shiro Hirai, Tomoyuki Takami +3
We propose a scalar potential of inflation, motivated by modular invariant supergravity, and compute the angular power spectra of the adiabatic density perturbations that result fr…
Angular Power Spectrum and Dilatonic Inflation in Modular-Invariant Supergravity
Mitsuo J. Hayashi, Shiro Hirai, Yusuke Okame +1
The angular power spectrum is investigated in the model of supergravity, incorporating the target-space duality and the non-perturbative gaugino condensation in the hidden sector.…