Saito, Shun, Takada, Masahiro, Taruya, Atsushi
Future or ongoing galaxy redshift surveys can put stringent constraints on neutrinos masses via the high-precision measurements of galaxy power spectrum, when combined with cosmic microwave...
Taruya, Atsushi, Nishimichi, Takahiro, Saito, Shun, Hiramatsu, Takashi
We study the non-linear evolution of baryon acoustic oscillations in the matter power spectrum and correlation function from the improved perturbation theory (PT). Based on the framework of...
Takahashi, Ryuichi, Yoshida, Naoki, Takada, Masahiro, Matsubara, Takahiko, Sugiyama, Naoshi, Kayo, Issha, ...
We use 5000 cosmological N-body simulations of 1(Gpc/h)^3 box for the concordance LCDM model in order to study the sampling variances of nonlinear matter power spectrum. We show that the non-Gaussian...
Nishimichi, Takahiro, Shirata, Akihito, Taruya, Atsushi, Yahata, Kazuhiro, Saito, Shun, Suto, Yasushi, ...
We use a series of cosmological N-body simulations and various analytic models to study the evolution of the matter power spectrum in real space in a \Lambda Cold Dark Matter universe. We compare the...
Probing reheating temperature of the universe with gravitational wave background (2008)
Nakayama, Kazunori, Saito, Shun, Suwa, Yudai, Yokoyama, Jun'ichi
Thermal history of the universe after big-bang nucleosynthesis (BBN) is well understood both theoretically and observationally, and recent cosmological observations also begin to reveal the...
Space laser interferometers can determine the thermal history of the early Universe (2008)
Nakayama, Kazunori, Saito, Shun, Suwa, Yudai, Yokoyama, Jun'ichi
It is shown that space-based gravitational wave detectors such as DECIGO and/or Big Bang Observer (BBO) will provide us with invaluable information on the cosmic thermal history after inflation and...
Simulations of Baryon Acoustic Oscillations I: Growth of Large-Scale Density Fluctuations (2008)
Takahashi, Ryuichi, Yoshida, Naoki, Matsubara, Takahiko, Sugiyama, Naoshi, Kayo, Issha, Nishimichi, Takahiro, ...
We critically examine how well the evolution of large-scale density perturbations is followed in cosmological $N$-body simulations. We first run a large volume simulation and perform a mode-by-mode...
Impact of massive neutrinos on nonlinear matter power spectrum (2008)
Saito, Shun, Takada, Masahiro, Taruya, Atsushi
We present the first attempt to analytically study the nonlinear matter power spectrum for a mixed dark matter (cold dark matter plus neutrinos of total mass ~0.1eV) model based on cosmological...
Probing polarization states of primordial gravitational waves with CMB anisotropies (2007)
Saito, Shun, Ichiki, Kiyotomo, Taruya, Atsushi
We discuss the polarization signature of primordial gravitational waves imprinted in cosmic microwave background (CMB) anisotropies. The high-energy physics motivated by superstring theory or...
Nishimichi, Takahiro, Ohmuro, Hiroshi, Nakamichi, Masashi, Taruya, Atsushi, Yahata, Kazuhiro, Shirata, Akihito, ...
An acoustic oscillation of the primeval photon-baryon fluid around the decoupling time imprints a characteristic scale in the galaxy distribution today, known as the baryon acoustic oscillation (BAO)...