Akihito Shirata

Modeling Nonlinear Evolution of Baryon Acoustic Oscillations: Convergence Regime of N-body Simulations and Analytic Models (2008)

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...

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...

Characteristic Scales of Baryon Acoustic Oscillations from Perturbation Theory: Non-linearity and Redshift-Space Distortion Effects (2007)

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)...

Galaxy clustering constraints on deviations from Newtonian gravity at cosmological scales II: Perturbative and numerical analyses of power spectrum and bispectrum (2007)

Shirata, Akihito, Suto, Yasushi, Hikage, Chiaki, Shiromizu, Tetsuya, Yoshida, Naoki

We explore observational constraints on possible deviations from Newtonian gravity by means of large-scale clustering of galaxies. We measure the power spectrum and the bispectrum of Sloan Digital...

Galaxy clustering constraints on deviations from Newtonian gravity at cosmological scales (2005)

Shirata, Akihito, Shiromizu, Tetsuya, Yoshida, Naoki, Suto, Yasushi

In spite of the growing observational evidence for dark matter and dark energy in the universe, their physical nature is largely unknown. In fact, several authors have proposed modifications of...