176 citations · 1.1k across the 44 of their papers we have counts for
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Limits on Isocurvature Perturbations from Non-Gaussianity in WMAP Temperature Anisotropies
Chiaki Hikage, Kazuya Koyama, Takahiko Matsubara +2
We study the effect of primordial isocurvature perturbations on non-Gaussian properties of CMB temperature anisotropies. We consider generic forms of the non-linearity of isocurvat…
Non-Gaussianity and Baryonic Isocurvature Fluctuations in the Curvaton Scenario
Takeo Moroi, Tomo Takahashi
We discuss non-Gaussianity and baryonic isocurvature fluctuations in the curvaton scenario, assuming that the baryon asymmetry of the universe originates only from the decay produc…
Adiabatic fluctuations from cosmic strings in a contracting universe
Robert H. Brandenberger, Tomo Takahashi, Masahide Yamaguchi
We show that adiabatic, super-Hubble, and almost scale invariant density fluctuations are produced by cosmic strings in a contracting universe. An essential point is that isocurvat…
Primordial Curvature Fluctuation and Its Non-Gaussianity in Models with Modulated Reheating
Kazuhide Ichikawa, Teruaki Suyama, Tomo Takahashi +1
We investigate non-Gaussianity in the modulated reheating scenario where fluctuations of the decay rate of the inflaton generate adiabatic perturbations, paying particular attentio…
Probing the Effective Number of Neutrino Species with Cosmic Microwave Background
Kazuhide Ichikawa, Toyokazu Sekiguchi, Tomo Takahashi
We discuss how much we can probe the effective number of neutrino species N_nu with cosmic microwave background alone. Using the data of WMAP, ACBAR, CBI and BOOMERANG experiments,…
Non-Gaussianity, Spectral Index and Tensor Modes in Mixed Inflaton and Curvaton Models
Kazuhide Ichikawa, Teruaki Suyama, Tomo Takahashi +1
We study non-Gaussianity, the spectral index of primordial scalar fluctuations and tensor modes in models where fluctuations from the inflaton and the curvaton can both contribute…