Takahiro Nishimichi

Publication List Details

Period

2006 - 2009

Number

12

Co-Authors

Scale Dependence of Halo Bispectrum from Non-Gaussian Initial Conditions in Cosmological N-body Simulations (2009)

Nishimichi, Takahiro, Taruya, Atsushi, Koyama, Kazuya, Sabiu, Cristiano

We study the scale-dependent properties of halo bispectrum from non-Gaussian initial conditions. Based on a set of large $N$-body simulations starting from initial density fields with local type...

Systematic Survey of the Correlation between Northern HECR Events and SDSS Galaxies (2009)

Takami, Hajime, Nishimichi, Takahiro, Sato, Katsuhiko

We find statistically significant spatial correlations between the arrival directions of the highest energy cosmic rays (HECRs) observed by the Akeno Giant Air Shower Array (AGASA) and large-scale...

Non-linear Evolution of Baryon Acoustic Oscillations from Improved Perturbation Theory in Real and Redshift Spaces (2009)

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...

Confronting the damping of the baryon acoustic oscillations with observation (2009)

Nomura, Hidenori, Yamamoto, Kazuhiro, Huetsi, Gert, Nishimichi, Takahiro

We investigate the damping of the baryon acoustic oscillations in the matter power spectrum due to the quasinonlinear clustering and redshift-space distortions by confronting the models with the...

Simulations of Baryon Acoustic Oscillations II: Covariance matrix of the matter power spectrum (2009)

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...

Cross-Correlation between UHECR Arrival Distribution and Large-Scale Structure (2008)

Takami, Hajime, Nishimichi, Takahiro, Yahata, Kazuhiro, Sato, Katsuhiko

We investigate correlation between the arrival directions of ultra-high-energy cosmic rays (UHECRs) and the large-scale structure (LSS) of the universe by using statistical quantities which can find...

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...

Damping of the baryon acoustic oscillations in the matter power spectrum as a probe of the growth factor (2008)

Nomura, Hidenori, Yamamoto, Kazuhiro, Nishimichi, Takahiro

We investigate the damping of the baryon acoustic oscillations (BAO) signature in the matter power spectrum due to the quasi-nonlinear clustering of density perturbations. On the basis of the third...

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)...

Bispectrum and Nonlinear Biasing of Galaxies: Perturbation Analysis, Numerical Simulation and SDSS Galaxy Clustering (2006)

Nishimichi, Takahiro, Kayo, Issha, Hikage, Chiaki, Yahata, Kazuhiro, Taruya, Atsushi, Jing, Y. P., ...

We consider nonlinear biasing models of galaxies with particular attention to a correlation between linear and quadratic biasing coefficients, b_1 and b_2. We first derive perturbative expressions...