759 citations · 4.7k across the 147 of their papers we have counts for
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Sunyaev-Zel'dovich power spectrum with decaying cold dark matter
Keitaro Takahashi, Masamune Oguri, Kiyotomo Ichiki
Recent studies of structures of galaxies and clusters imply that dark matter might be unstable and decay with lifetime about the age of universe. We study the effects of t…
WMAP constraints on scalar-tensor cosmology and the variation of the gravitational constant
Ryo Nagata, Takeshi Chiba, Naoshi Sugiyama
We present observational constraints on a scalar-tensor gravity theory by test for CMB anisotropy spectrum. We compare the WMAP temperature power spectrum with the harmonic a…
Causal Structure and Gravitational Waves in Brane World Cosmology
Kiyotomo Ichiki, Kouji Nakamura
The causal structure of the flat brane universe of RSII type is re-investigated to clarify the boundary conditions for stochastic gravitational waves. In terms of the Gaussian norm…
New Classes of Cosmic Energy and Primordial Black-Hole Formation
K. Ichiki, M. Orito, T. Kajino
It has recently been suggested that the formation of horizon-size primordial black hole (PBH) from pre-existing density fluctuations is effective during the cosmic QCD phase transi…