1.2k citations · 13.2k across the 177 of their papers we have counts for
8 papers · 1 filter
Gravitational-Wave Constraints on the Abundance of Primordial Black Holes
Ryo Saito, Jun'ichi Yokoyama
We investigate features of Gravitational Waves (GWs) induced by primordial density fluctuations with a large amplitude peak associated with formation of Primordial Black Holes (PBH…
New cosmological constraints on primordial black holes
B. J. Carr, Kazunori Kohri, Yuuiti Sendouda +1
We update the constraints on the fraction of the Universe going into primordial black holes in the mass range 10^9--10^17 g associated with the effects of their evaporations on big…
Cosmic Discordance: Detection of a modulation in the primordial fluctuation spectrum
Kiyotomo Ichiki, Ryo Nagata, Jun'ichi Yokoyama
As a test of the standard inflationary cosmology, which generically predicts nearly scale-invariant spectrum of primordial curvature fluctuations, we perform Markov-Chain Monte-Car…
Gravitational Wave Background and Non-Gaussianity as a Probe of the Curvaton Scenario
Kazunori Nakayama, Jun'ichi Yokoyama
We study observational implications of the stochastic gravitational wave background and a non-Gaussian feature of scalar perturbations on the curvaton mechanism of the generation o…
Analytic solution for matter density perturbations in a class of viable cosmological f(R) models
Hayato Motohashi, Alexei A. Starobinsky, Jun'ichi Yokoyama
For a class of viable cosmological models in gravity which deviation from the Einstein gravity decreases as a inverse power law of the Ricci scalar for large , an ana…
Gravitino Dark Matter and Non-Gaussianity
Tomo Takahashi, Masahide Yamaguchi, Jun'ichi Yokoyama +1
We investigate density fluctuations in a scenario with gravitino dark matter in the framework of modulated reheating, which is known to generate large non-Gaussianity. We show that…