Test of gravity with polarizations of stochastic gravitational waves around 0.1-1 Hz (2009)
Nishizawa, Atsushi, Taruya, Atsushi, Kawamura, Seiji
In general relativity, a gravitational wave (GW) has two polarization modes, while in modified gravity, the GW is allowed to have additional polarizations. Thus, the observation of the GW...
Hirano, Teruyuki, Suto, Yasushi, Taruya, Atsushi, Narita, Norio, Sato, Bun'ei, Johnson, John Asher, ...
We obtain analytical expressions for the velocity anomaly due to the Rossiter-McLaughlin effect, for the case when the anomalous radial velocity is obtained by cross-correlation with a stellar...
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...
Ando, Masaki, Kawamura, Seiji, Sato, Shuichi, Nakamura, Takashi, Tsubono, Kimio, Araya, Akito, ...
DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory), which is a future space gravitational wave antenna. DECIGO is expected...
Nishizawa, Atsushi, Taruya, Atsushi, Hayama, Kazuhiro, Kawamura, Seiji, Sakagami, Masa-aki
In a general metric theory of gravitation in four dimensions, six polarizations of a gravitational wave are allowed: two scalar and two vector modes, in addition to two tensor modes in general...
Hiramatsu, Takashi, Taruya, Atsushi
We present a new numerical scheme to treat the non-linear evolution of cosmological power spectra. Governing equations for matter power spectra have been previously derived by a non-perturbative...
Non-linear Evolution of Matter Power Spectrum in Modified Theory of Gravity (2009)
Koyama, Kazuya, Taruya, Atsushi, Hiramatsu, Takashi
We present a formalism to calculate the non-linear matter power spectrum in modified gravity models that explain the late-time acceleration of the Universe without dark energy. Any successful...
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...
Signature of primordial non-Gaussianity on the matter power spectrum (2008)
Taruya, Atsushi, Koyama, Kazuya, Matsubara, Takahiko
Employing the perturbative treatment of gravitational clustering, we discuss possible effects of primordial non-Gaussianity on the matter power spectrum. As gravitational clustering develops, the...
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...
Signature of Primordial Non-Gaussianity on Matter Power Spectrum (2008)
Taruya, Atsushi, Koyama, Kazuya, Matsubara, Takahiko
Employing the perturbative treatment of gravitational clustering, we discuss possible effects of primordial non-Gaussianity on the matter power spectrum. As gravitational clustering develops, the...
Ando, Masaki, Kawamura, Seiji, Nakamura, Takashi, Tsubono, Kimio, Tanaka, Takahiro, Funaki, Ikkoh, ...
DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected...
The Japanese space gravitational wave antenna; DECIGO (2008)
Kawamura, Seiji, Ando, Masaki, Nakamura, Takashi, Tsubono, Kimio, Tanaka, Takahiro, Funaki, Ikkoh, ...
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. DECIGO is expected to open a new window of observation for gravitational...
Measurement of the Spin-Orbit Angle of Exoplanet HAT-P-1b (2008)
Johnson, John A., Winn, Joshua N., Narita, Norio, Enya, Keigo, Williams, Peter K. G., Marcy, Geoffrey W., ...
We present new spectroscopic and photometric observations of the HAT-P-1 planetary system. Spectra obtained during three transits exhibit the Rossiter-McLaughlin effect, allowing us to measure 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...
The Stokes V parameter characterizes asymmetry of amplitudes between right- and left-handed waves, and non-vanishing value of the V parameter yields a circularly polarized signal. Cosmologically, V...
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...
A Closure Theory for Non-linear Evolution of Cosmological Power Spectra (2007)
Taruya, Atsushi, Hiramatsu, Takashi
We apply a non-linear statistical method in turbulence to the cosmological perturbation theory and derive a closed set of evolution equations for matter power spectra. The resultant closure equations...
We show that pairs of widely separated interferometers are advantageous for measuring the Stokes parameter V of a stochastic background of gravitational waves. This parameter characterizes asymmetry...
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)...
Measurement of the Rossiter--McLaughlin Effect in the Transiting Exoplanetary System TrES-1 (2007)
Narita, Norio, Enya, Keigo, Sato, Bun'ei, Ohta, Yasuhiro, Winn, Joshua N., Suto, Yasushi, ...
We report a measurement of the Rossiter--McLaughlin effect in the transiting extrasolar planetary system TrES-1, via simultaneous spectroscopic and photometric observations with the Subaru and MAGNUM...
Nishimichi, Takahiro, Kayo, Issha, Hikage, Chiaki, Yahata, Kazuhiro, Taruya, Atsushi, Jing, Yi Peng, ...
Ohta, Yasuhiro, Taruya, Atsushi, Suto, Yasushi
We present theoretical predictions for photometric and spectroscopic signatures of rings around transiting extrasolar planets. On the basis of a general formulation for the transiting signature in...
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...
We develop a numerical scheme to make a high-frequency skymap of gravitational-wave backgrounds (GWBs) observed via space-based interferometer. Based on the cross-correlation technique, the intensity...
Himemoto, Yoshiaki, Taruya, Atsushi, Kudoh, Hideaki, Hiramatsu, Takashi
We discuss a robust data analysis method to detect a stochastic background of gravitational waves in the presence of non-Gaussian noise. In contrast to the standard cross-correlation (SCC) statistic...
Detecting a gravitational-wave background with next-generation space interferometers (2005)
Kudoh, Hideaki, Taruya, Atsushi, Hiramatsu, Takashi, Himemoto, Yoshiaki
Future missions of gravitational-wave astronomy will be operated by space-based interferometers, covering very wide range of frequency. Search for stochastic gravitational-wave backgrounds (GWBs) is...
Antonov problem and quasi-equilibrium states in N-body system (2005)
Taruya, Atsushi, Sakagami, Masa-aki
In this paper, a quantitative characterization for the evolutionary sequence of stellar self-gravitating system is investigated, focusing on the pre-collapse stage of the long-term dynamical...
Gravitational Wave Background from Neutrino-Driven Gamma-Ray Bursts (2005)
Hiramatsu, Takashi, Kotake, Kei, Kudoh, Hideaki, Taruya, Atsushi
We discuss the gravitational wave background (GWB) from a cosmological population of gamma-ray bursts (GRBs). Among various emission mechanisms for the gravitational waves (GWs), we pay a particular...
Taruya, Atsushi, Kudoh, Hideaki
We present a perturbative reconstruction method to make a skymap of gravitational-wave backgrounds (GWBs) observed via space-based interferometer. In the presence of anisotropies in GWBs, the...
Measurement of Spin-Orbit Alignment in an Extrasolar Planetary System (2005)
Winn, Joshua N., Noyes, Robert W., Holman, Matthew J., Charbonneau, David, Ohta, Yasuhiro, Taruya, Atsushi, ...
We determine the stellar, planetary, and orbital properties of the transiting planetary system HD 209458, through a joint analysis of high-precision radial velocities, photometry, and timing of the...
Kudoh, Hideaki, Taruya, Atsushi
We discuss the sensitivity to anisotropies of stochastic gravitational-wave backgrounds (GWBs) observed via space-based interferometer. In addition to the unresolved galactic binaries as the most...
Evolution of gravitational waves in the high-energy regime of brane-world cosmology (2004)
Hiramatsu, Takashi, Koyama, Kazuya, Taruya, Atsushi
We discuss the cosmological evolution of gravitational waves (GWs) after inflation in a brane-world cosmology embedded in five-dimensional anti-de Sitter (AdS_5) bulk spacetime. In a brane-world...
Ohta, Yasuhiro, Taruya, Atsushi, Suto, Yasushi
A transiting extrasolar planet sequentially blocks off the light coming from the different parts of the disk of the host star in a time dependent manner. Due to the spin of the star, this produces an...
Cosmological Density Distribution Function from the Ellipsoidal Collapse Model in Real Space (2004)
Ohta, Yasuhiro, Kayo, Issha, Taruya, Atsushi
We calculate the one-point probability distribution function (PDF) for cosmic density in non-linear regime of the gravitational evolution. Under the local approximation that the evolution of cosmic...
Self-gravitating Stellar Systems and Non-extensive Thermostatistics (2003)
Sakagami, Masa-aki, Taruya, Atsushi
After introducing the fundamental properties of self-gravitating systems, we present an application of Tsallis' generalized entropy to the analysis of their thermodynamic nature. By extremizing the...
Hiramatsu, Takashi, Koyama, Kazuya, Taruya, Atsushi
We study the evolution of gravitational waves(GWs) after inflation in a brane-world cosmology embedded in five-dimensional anti-de Sitter spacetime. Contrary to the standard four-dimensional results,...
Minkowski Functionals of SDSS galaxies I : Analysis of Excursion Sets (2003)
Hikage, Chiaki, Schmalzing, Jens, Buchert, Thomas, Suto, Yasushi, Kayo, Issha, Taruya, Atsushi, ...
We present a first morphometric investigation of a preliminary sample from the SDSS of 154287 galaxies with apparent magnitude 14.5
Taruya, Atsushi, Sakagami, Masa-aki
With particular attention to the recently postulated introduction of a non-extensive generalization of Boltzmann-Gibbs statistics, we study the long-term stellar dynamical evolution of...
Biasing and Genus Statistics of Dark Matter Halos in the Hubble Volume Simulation (2003)
Hikage, Chiaki, Taruya, Atsushi, Suto, Yasushi
We present a numerical analysis of genus statistics for dark matter halo catalogs from the Hubble volume simulation. The huge box-size of the Hubble volume simulation enables us to carry out a...
Evolution of Cosmological Density Distribution Function from the Local Collapse Model (2003)
Ohta, Yasuhiro, Kayo, Issha, Taruya, Atsushi
We present a general framework to treat the evolution of one-point probability distribution function (PDF) for cosmic density $\delta$ and velocity-divergence fields $\theta$. In particular, we...
Minkowski Functionals of SDSS galaxies I: Analysis of Excursion Sets (2003)
Chiaki Hikage, Jens Schmalzing, Thomas Buchert, Yasushi Suto, Issha Kayo, Atsushi Taruya, ...
We present a rst morphometric investigation of a preliminary sample from the SDSS of 154287 galaxies with apparent magnitude 14:5 < m r < 17:5 and redshift 0:001 < z < 0:4. We measure the...
Taruya, Atsushi, Sakagami, Masa-aki
We revisit the issues on the thermodynamic property of stellar self-gravitating system arising from Tsallis' non-extensive entropy. Previous papers (Taruya & Sakagami, Physica A 307 (2002) 185...
Non-Gaussian Tails of Cosmological Density Distribution Function from Dark Halo Approach (2002)
Taruya, Atsushi, Hamana, Takashi, Kayo, Issha
We present a simple model based on the dark halo approach which provides a useful way to understand key points determining the shape of the non-Gaussian tails of the dark matter one-point probability...
Three-Dimensional Genus Statistics of Galaxies in the SDSS Early Data Release (2002)
Hikage, Chiaki, Suto, Yasushi, Kayo, Issha, Taruya, Atsushi, Matsubara, Takahiko, Vogeley, Michael S., ...
We present the first analysis of three-dimensional genus statistics for the SDSS EDR galaxy sample. Due to the complicated survey volume and the selection function, analytic predictions of the genus...
Kuwabara, Takeshi, Taruya, Atsushi, Suto, Yasushi
We derive the pairwise peculiar velocity distribution function of dark matter particles applying the dark matter halo approach. Unlike the previous work, we do not assume a Gaussian velocity...
Strong Gravitational Lensing Time Delay Statistics and the Density Profile of Dark Halos (2001)
Oguri, Masamune, Taruya, Atsushi, Suto, Yasushi, Turner, Edwin L.
The distribution of differential time delays \Delta t between images produced by strong gravitational lensing contains information on the mass distributions in the lensing objects as well as on...
Suginohara, Tatsushi, Taruya, Atsushi, Suto, Yasushi
The well-known self-similar solution for the two-point correlation function of the density field is valid only in an Einstein-de Sitter universe. We attempt to extend the solution for non-Einstein-de...
Gravothermal Catastrophe and Generalized Entropy of Self-Gravitating Systems (2001)
Taruya, Atsushi, Sakagami, Masa-aki
We present a first physical application of Tsallis' generalized entropy to the thermodynamics of self-gravitating systems. The stellar system confined in a spherical cavity of radius $r_e$ exhibits...
Probing the Core Structure of Dark Halos with Tangential and Radial Arc Statistics (2001)
Oguri, Masamune, Taruya, Atsushi, Suto, Yasushi
We study the arc statistics of gravitational lensing generated by dark matter halos in order to probe their density profile. We characterize the halo profile by two parameters, the inner slope of the...
Kayo, Issha, Taruya, Atsushi, Suto, Yasushi
We quantitatively study the probability distribution function (PDF) of cosmological nonlinear density fluctuations from N-body simulations with Gaussian initial condition. In particular, we examine...
Yoshikawa, Kohji, Taruya, Atsushi, Jing, Y. P., Suto, Yasushi
We perform an extensive analysis of nonlinear and stochastic biasing of galaxies and dark halos in spatially flat low-density CDM universe using cosmological hydrodynamic simulations. We compare...
Genus statistics for galaxy clusters and nonlinear biasing of dark matter halos (2001)
Hikage, Chiaki, Taruya, Atsushi, Suto, Yasushi
We derive an analytic formula of genus for dark matter halos assuming that the primordial mass density field obeys the random-Gaussian statistics. In particular, we for the first time take account of...
The effect of bias and redshift distortions on a geometric test for the cosmological constant (2000)
Yamamoto, Kazuhiro, Nishioka, Hiroaki, Taruya, Atsushi
We revisit the feasibility of a cosmological test with the geometric distortion focusing on an ambiguous factor of the evolution of bias. Starting from defining estimators for the spatial two-point...
Isodensity Statistics on Clustering of High-z Objects in Cosmological Redshift-spaces (2000)
Taruya, Atsushi, Yamamoto, Kazuhiro
We discuss the systematic effects arising from the cosmological redshift-space (geometric) distortion on the statistical analysis of isodensity contour using high-redshift catalogs. Especially, we...
Nonlinear stochastic biasing from the formation epoch distribution of dark halos (2000)
Taruya, Atsushi, Suto, Yasushi
We propose a physical model for nonlinear stochastic biasing of one-point statistics resulting from the formation epoch distribution of dark halos. In contrast to previous works on the basis of...
Stochastic Biasing and Weakly Non-linear Evolution of Power Spectrum (1999)
Distribution of galaxies may be a biased tracer of the dark matter distribution and the relation between the galaxies and the total mass may be stochastic, non-linear and time-dependent. Since many...
Constraints on a non-gaussian ($\chi_m^2$) CDM model (1999)
Koyama, Kazuya, Soda, Jiro, Taruya, Atsushi
We consider constraints on the structure formation model based on non-Gaussian fluctuations generated during inflation, which have $\chi_m^2$ distributions. Using three data sets, the abundance of...
Solutions of gauge invariant cosmological perturbations in long-wavelength limit (1998)
Nambu, Yasusada, Taruya, Atsushi
We investigate gauge invariant cosmological perturbations in a spatially flat Friedman-Robertson-Walker universe with scalar fields. It is well known that the evolution equation for the gauge...
Moderately Chaotic Hamiltonian Systems: Structure and Motion in High-dimensional Phase Spaces (1997)
Yamaguchi Y. Yoshiyuki, Yasusada Nambu, Atsushi Taruya, Kenji Imai, Masaharu Ishii
tent discussions always gave me useful comments. It is great happiness for me that he was one of my roommates. I thank the Computer Center of the Institute for Molecular Science, for the use of the...
Evolution of Cosmological Perturbation in Reheating Phase of the Universe (1996)
Nambu, Yasusada, Taruya, Atsushi
The evolution of the cosmological perturbation during the oscillatory stage of the scalar field is investigated. For the power law potential of the inflaton field, the evolution equation of the...
Taruya, Atsushi, Nambu, Yasusada
As an application of Gradient Expansion (long-wavelength) approximation, we studied the inhomogeneous universe including the gravitational wave(GW). For a plane-symmetric cosmological model, we could...
Application of Gradient Expansion to Inflationary Universe (1994)
Nambu, Yasusada, Taruya, Atsushi
Using the long wave perturbation scheme(gradient expansion), the effect of inhomogeneity on the inflationary phase is investigated. We solved the perturbation equation of which source term comes from...