Itoh, Yousuke, Futamase, Toshifumi, Hattori, Makoto
Gravitational waves propagate along null geodesics like light rays in the geometrical optics approximation, and they may have a chance to suffer from gravitational lensing by intervening objects, as...
Appearance of classical Mixmaster Universe from the No-Boundary Quantum State (2009)
Fujio, Kazuya, Futamase, Toshifumi
We investigate the appearance of the classical anisotropic universe from the no-boundary quantum state according to the prescription proposed by Hartle, Hawking and Hertog. Our model is homogeneous,...
Distance-Redshift Relation in a Realistic Inhomogeneous Universe (2009)
Okamura, Tomohiro, Futamase, Toshifumi
We investigate the distance-redshift relation in a realistic inhomogeneous universe where the mass distribution is described by the mass function of Sheth and Tormen. It is found that the derived...
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...
LoCuSS: Subaru Weak Lensing Study of 30 Galaxy Clusters (2009)
Okabe, Nobuhiro, Takada, Masahiro, Umetsu, Keiichi, Futamase, Toshifumi, Smith, Graham P.
(Abridged) We use Subaru data to conduct a detailed weak-lensing study of the dark matter distribution in a sample of 30 X-ray luminous galaxy clusters at 0.15
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...
A New Method for measuring Weak Gravitational Lensing Shear using Higher Order Spin-2 HOLICs (2008)
Okura, Yuki, Futamase, Toshifumi
We investigate the possibility to use higher order moments of gravitational lensed images in the weak lensing analysis. For this purpose we employ spin-2 component of HOLICs(Higher Order Lensing...
Ando, M., Kawamura, Seiji, Nakamura, T., Tsubono, K., Tanaka, T., Funaki, I., ...
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, M., Nakamura, T., Tsubono, K., Tanaka, T., Funaki, I., ...
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...
The Japanese space gravitational wave antenna - DECIGO (2008)
Kawamura, Seiji, Ando, M., Nakamura, T., Tsubono, K., Tanaka, T., Funaki, I., ...
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. The goal of DECIGO is to detect gravitational waves from various kinds of...
Validity of strong lensing statistics for constraints on the galaxy evolution model (2007)
Matsumoto, Akiko, Futamase, Toshifumi
We examine the usefulness of the strong lensing statistics to constrain the evolution of the number density of lensing galaxies by adopting the values of the cosmological parameters determined by...
Post-Newtonian Hydrodynamic Equations Using the (3+1) Formalism in General Relativity (2007)
Hideki Asada, Masaru Shibata, Toshifumi Futamase
Using the (3+1) formalism in general relativity, we perform the post-Newtonian(PN) approximation to clarify what sort of gauge condition is suitable for numerical analysis of coalescing compact...
A Method for Weak Lensing Flexion Analysis by the HOLICs Moment Approach (2007)
Okura, Yuki, Umetsu, Keiichi, Futamase, Toshifumi
We have developed a method for measuring higher-order weak lensing distortions of faint background galaxies, namely the weak gravitational flexion, by fully extending the Kaiser, Squires & Broadhurst...
The Post-Newtonian Approximation for Relativistic Compact Binaries (2007)
Toshifumi Futamase, Yousuke Itoh
We discuss various aspects of the post-Newtonian approximation in general relativity. After presenting the foundation based on the Newtonian limit, we show a method to derive post-Newtonian equations...
A Phantom does not Result from a Backreaction (2006)
Tanaka, Hisako, Futamase, Toshifumi
The backreaction of nonlinear inhomogeneities to the cosmic expansion is analyzed in the framework of general relativity with a cosmological constant. By defining the spatially averaged matter energy...
A New Measure for Weak Lensing Flexion (2006)
Okura, Yuki, Umetsu, Keiichi, Futamase, Toshifumi
We study a possibility to use the octopole moment of gravitationally lensed images as a direct measure of the third-order weak gravitational lensing effect, or the gravitational flexion. It turns out...
Fukumoto, Takashi, Futamase, Toshifumi, Itoh, Yousuke
We give a straightforward and divergence free derivation of the equation of motion for a small but finite object in an arbitrary background using strong field point particle limit. The resulting...
Toward a No-Go Theorem for an Accelerating Universe through a Nonlinear Backreaction (2006)
Kasai, Masumi, Asada, Hideki, Futamase, Toshifumi
The backreaction of nonlinear inhomogeneities to the cosmic expansion is re-analyzed in the framework of general relativity. Apparent discrepancies regarding the effect of the nonlinear backreaction,...
Joint LIGO and TAMA300 search for gravitational waves from inspiralling neutron star binaries (2006)
Abbott, B., Abbott, R., Adhikari, R., Ageev, A., Agresti, Juri, Ajith, P., ...
We search for coincident gravitational wave signals from inspiralling neutron star binaries using LIGO and TAMA300 data taken during early 2003. Using a simple trigger exchange method, we perform an...
Akutsu, Tomomi, Akutsu, Tomotadu, Ando, Masaki, Arai, Koji, Araya, Akito, Asada, H., ...
We analyze the data of the TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1M[sun]–3M[sun]. In this...
The Japanese space gravitational wave antenna - DECIGO (2006)
Kawamura, Seiji, Nakamura, T., Ando, M., Seto, N., Tsubono, K., Numata, K., ...
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. It aims at detecting various kinds of gravitational waves between 1 mHz and...
Cosmology with High-redshift Galaxy Survey: Neutrino Mass and Inflation (2005)
Takada, Masahiro, Komatsu, Eiichiro, Futamase, Toshifumi
(abridged) High-z galaxy redshift surveys open up exciting possibilities for precision determinations of neutrino masses and inflationary models. The high-z surveys are more useful for cosmology than...
Discovery of a Strongly Lensed Galaxy at z=3.9 behind a z=0.83 Galaxy Cluster (2005)
Umetsu, Keiichi, Tanaka, Masayuki, Kodama, Tadayuki, Tanaka, Ichi, Futamase, Toshifumi, Kashikawa, Nobunari, ...
We report the discovery and spectroscopic confirmation of three gravitationally-lensed images of a galaxy at z=3.9 in the background of a distant, rich cluster of galaxies at z=0.83, on the basis of...
Upper limits from the LIGO and TAMA detectors on the rate of gravitational-wave bursts (2005)
Abbott, B., Abbott, R., Adhikari, R., Ageev, A., Agresti, Juri, Ajith, P., ...
Ando, M., Arai, K., Aso, Y., Beyersdorf, P. T., Hayama, K., Iida, Y., ...
The Surprisingly Steep Mass Profile of Abell 1689, from a Lensing Analysis of Subaru Images (2004)
Broadhurst, Tom, Takada, Masahiro, Umetsu, Keiichi, Kong, Xu, Arimoto, Nobuo, Chiba, Masashi, ...
Subaru observations of A1689 (z=0.183) are used to derive an accurate, model-independent mass profile for the entire cluster, r
Itoh, Yousuke, Futamase, Toshifumi
A third post-Newtonian (3 PN) equation of motion for an inspiralling binary consisting of two spherical compact stars with strong internal gravity is derived under harmonic coordinate condition using...
Numerical analysis of quasinormal modes in nearly extremal Schwarzschild-de Sitter spacetimes (2003)
Yoshida, Shijun, Futamase, Toshifumi
We calculate high-order quasinormal modes with large imaginary frequencies for electromagnetic and gravitational perturbations in nearly extremal Schwarzschild-de Sitter spacetimes. Our results show...
Itoh,Yousuke, Futamase,Toshifumi
A third post-Newtonian (3 PN) equation of motion for an inspiralling binary consisting of two spherical compact stars with strong internal gravity is derived under harmonic coordinate condition using...
Itoh, Yousuke, Futamase, Toshifumi
A third post-Newtonian (3 PN) equation of motion for an inspiralling binary consisting of two spherical compact stars with strong internal gravity is derived under harmonic coordinate condition using...
The topology of weak lensing field in the neighborhood of MS1054-03 (2002)
Sato, Jun'ichi, Umetsu, Keiichi, Futamase, Toshifumi, Yamada, Toru
We report the first measurement of genus curves for the two-dimensional mass map in the neighborhood of rich, X-ray luminous galaxy cluster MS1054-03 at z=0.83, reconstructed from weak lensing data...
Ohyama, Youichi, Hamana, Takashi, Kashikawa, Nobunari, Chiba, Masashi, Futamase, Toshifumi, Iye, Masanori, ...
We present new optical spectroscopy of the lens elliptical galax in the ``Einstein Cross'' lens system HST 14176+5226, using the Faint Object Camera and Spectrograph (FOCAS) of the Subaru t Our...
Yamamoto, Kazuhiro, Kadoya, Yasufum, Murata, Tsukasa, Futamase, Toshifumi
We assess the feasibility of probing dark energy with strong gravitational lensing systems. The capability of the method, which depends on the accuracy with which the lensing systems are modeled, is...
R-mode Instability of Slowly Rotating Non-isentropic Relativistic Stars (2001)
Yoshida, Shijun, Futamase, Toshifumi
We investigate properties of $r$-mode instability in slowly rotating relativistic polytropes. Inside the star slow rotation and low frequency formalism that was mainly developed by Kojima is employed...
Yamamoto, Kazuhiro, Futamase, Toshifumi
A possible method to reconstruct the cosmic equation of state using strong gravitational lensing systems is proposed. The feasibility of the method is investigated by carrying out the reconstruction...
Implication of Omega_m through the Morphological Analysis of Weak Lensing Fields (2001)
Sato, Jun'ichi, Takada, Masahiro, Jing, Y. P., Futamase, Toshifumi
We apply the morphological descriptions of two-dimensional contour map, the so-called Minkowski functionals (the area fraction, circumference, and Euler characteristics), to the convergence field...
Itoh, Yousuke, Futamase, Toshifumi, Asada, Hideki
We study the equation of motion appropriate to an inspiralling binary star system whose constituent stars have strong internal gravity. We use the post-Newtonian approximation with the strong field...
Futamase, Toshifumi, Yoshida, Shijun
We propose a possible measurement of the time variability of the vacuum energy using strong gravitational lensing events. As an example we take an Einstein cross lens HST 14176+5226 and demonstrate...
Number Count of Peaks in the CMB Map (2000)
Futamase, Toshifumi, Takada, Masahiro
We investigate the dependence of cosmological parameters on the number count of peaks (local maxima and minima) in the cosmic microwave background (CMB) sky. The peak statistics contains the whole...
Effects of weak lensing on the topology of CMB maps (2000)
Schmalzing, Jens, Takada, Masahiro, Futamase, Toshifumi
We investigate the non-Gaussian signatures in Cosmic Microwave Background (CMB) maps induced by the intervening large-scale structure through weak lensing. In order to measure the deviation from the...
Takada, Masahiro, Futamase, Toshifumi
We present quantitative investigations of the weak lensing effect on the two-point correlation functions of local maxima (hotspots), $\xipk(\theta)$, in the cosmic microwave background (CMB) maps....
On the abundance of collapsed objects (2000)
Kerscher, Martin, Buchert, Thomas, Futamase, Toshifumi
The redshift dependence of the abundance of collapsed objects places strong constraints on cosmological models of structure formation. We apply a recently proposed model describing the anisotropic...
Cluster Mass Reconstruction by a Weak Shear Field (2000)
Umetsu, Keiichi, Tada, Masashi, Futamase, Toshifumi
The tidal gravitational field of galaxy clusters causes a coherent distortion of the images of background sources. Since the distribution of image distortions, namely the shear field, traces the...
Umetsu, Keiichi, Futamase, Toshifumi
We present a weak-lensing analysis of a region around the galaxy cluster Cl 1604+4304 (z=0.897) on the basis of the deep observations with the HST/WFPC2. We apply a variant of Schneider's aperture...
Masahiro Takada, Eiichiro Komatsu, Toshifumi Futamase
We investigate the weak gravitational lensing effect that is due to the large-scale structure of the universe on two-point correlations of local maxima (hot spots) in the two-dimensional sky map of...
A new measure of $\sigma_8$ using the lensing dispersion in high-$z$ type Ia SNe (1999)
Hamana, Takashi, Futamase, Toshifumi
The gravitational lensing magnification or demagnification due to large-scale structures induces a scatter in peak magnitudes of high redshift type Ia supernovae (SNe Ia). The amplitude of the...
Itoh, Yousuke, Futamase, Toshifumi, Asada, Hideki
We derive the equation of motion for the relativistic compact binaries in the post-Newtonian approximation taking explicitly their strong internal gravity into account. For this purpose we adopt the...
Takada, Masahiro, Komatsu, Eiichiro, Futamase, Toshifumi
We investigate the weak gravitational lensing effect due to the large-scale structure of the universe on two-point correlations of local maxima ({\em hotspots}) in the 2D sky map of the cosmic...
Hamana, Takashi, Martel, Hugo, Futamase, Toshifumi
We compute statistical properties of weak gravitational lensing by large-scale structure in three Cold Dark Matter models. We use a P$^3$M $N$-body code to simulate the formation and evolution of...
Komatsu, Eiichiro, Futamase, Toshifumi
We present complete constraints imposed from observations of the cosmic microwave background radiation (CMBR) on the chaotic inflationary scenario with a nonminimally coupled inflaton field proposed...
Takada, Masahiro, Futamase, Toshifumi
We develop the formalism to investigate the relation between the evolution of the large-scale (quasi) linear structure and that of the small-scale nonlinear structure in Newtonian cosmology within...
Takada, Masahiro, Futamase, Toshifumi
We point out the existence of a new type of growing transverse mode in the gravitational instability. This appears as a post-Newtonian effect to Newtonian dynamics. We demonstrate this existence by...
Collapsing open isotropic universe generated by nonminimally coupled scalar field (1998)
Morishima, Takahiro, Futamase, Toshifumi
We investigated the behavior of an open isotropic universe generated by a scalar field which couples with background curvature nonminimally with the coupling constant $\xi$. In particular we focus on...
Post-Newtonian Approximation (1998)
Asada, Hideki, Futamase, Toshifumi
We discuss various aspects of the post-Newtonian approximation in general relativity. After presenting the foundation based on the Newtonian limit, we use the (3+1) formalism to formulate the...
Komatsu, Eiichiro, Futamase, Toshifumi
We investigate a possibility to restrict the chaotic inflationary scenario with "large" nonminimally coupled inflaton("phi") field considered by Fakir and Unruh by means of the observed CMBR...
Post-Newtonian Lagrangian Perturbation Approach to the Large-Scale Structure Formation (1997)
Takada, Masahiro, Futamase, Toshifumi
We formulate the Lagrangian perturbation theory to solve the non-linear dynamics of self-gravitating fluid within the framework of the post-Newtonian approximation in general relativity, using the...
Propagation of gravitational waves from slow motion sources in a Coulomb type potential (1997)
Asada, Hideki, Futamase, Toshifumi
We consider the propagation of gravitational waves generated by slow motion sources in Coulomb type potential due to the mass of the source. Then, the formula for gravitational waveform including...
Chaotic inflation with running nonminimal coupling (1997)
Futamase, Toshifumi, Tanaka, Masahiro
We have found a successful model of chaotic inflation with an inflaton coupled nonminimally with gravity. The nonminimal coupling constant $\xi$ runs with the evolution of the inflaton. The running...
Post-Newtonian Hydrodynamic Equations Using the (3+1) Formalism in General Relativity (1996)
Asada, Hideki, Shibata, Masaru, Futamase, Toshifumi
Using the (3+1) formalism in general relativity, we perform the post-Newtonian(PN) approximation to clarify what sort of gauge condition is suitable for numerical analysis of coalescing compact...
Futamase,Toshifumi, Schutz,Bernard F.
We examine the gravitational radiation emitted by a sequence of spacetimes whose near-zone Newtonian limit we have previously studied. The spacetimes are defined by initial data which scale in a...
Futamase, Toshifumi, Schutz, Bernard F.
We examine the gravitational radiation emitted by a sequence of spacetimes whose near-zone Newtonian limit we have previously studied. The spacetimes are defined by initial data which scale in a...
Newtonian and post-Newtonian approximations are asymptotic to general relativity (1983)
Futamase,Toshifumi, Schutz,Bernard F.
A precise definition of the Newtonian and post-Newtonian hierarchy of approximations to general relativity is given by studying a C [infinity] sequence of solutions to Einstein's equations that is...
Newtonian and post-Newtonian approximations are asymptotic to general relativity (1983)
Futamase, Toshifumi, Schutz, Bernard F.
A precise definition of the Newtonian and post-Newtonian hierarchy of approximations to general relativity is given by studying a C [infinity] sequence of solutions to Einstein's equations that is...