Kenji Tomita

On astrophysical explanations due to cosmological inhomogeneities for the observational acceleration (2009)

Tomita, Kenji

We review various cosmological models with a local underdense region (local void) and the averaged models with the backreaction of inhomogeneities, which have been proposed to explain (without...

Probing violation of the Copernican principle via the integrated Sachs-Wolfe effect (2009)

Tomita, Kenji, Inoue, Kaiki Taro

Recent observational data of supernovae indicate that we may live in an underdense region, which challenges the Copernican principle. We show that the integrated Sachs-Wolfe (ISW) effect is an...

Prognostic value of metastin expression in human pancreatic cancer (2009)

Nagai, Kazuyuki, Doi, Ryuichiro, Katagiri, Fumihiko, Ito, Tatsuo, Kida, Atsushi, Koizumi, Masayuki, ...

Abstract Background KiSS-1 was identified as a metastasis-suppressing gene in melanoma cells. The KiSS-1 gene product (metastin) was isolated from human placenta as the ligand of GPR54, a...

Second-order power spectra of CMB anisotropies due to primordial random perturbations in flat cosmological models (2007)

Tomita, Kenji

Second-order power spectra of Cosmic Microwave Background (CMB) anisotropies due to random primordial perturbations at the matter dominant stage are studied, based on the relativistic second-order...

Second Order Gravitational Effects on CMB Temperature Anisotropy in Lambda dominated flat universes (2007)

Tomita, Kenji, Inoue, Kaiki Taro

We study second order gravitational effects of local inhomogeneities on the cosmic microwave background radiation in flat universes with matter and a cosmological constant $\Lambda$. We find that the...

Second-order gravitational effects of local inhomogeneities on CMB anisotropies and non-Gaussian signatures (2005)

Tomita, Kenji

Based on the second-order nonlinear theory of perturbations in non-zero \Lambda flat cosmological models, we study the gravitational effects of local inhomogeneities on cosmic microwave background...

Second-order gravitational effects of local inhomogeneities on CMB anisotropies in nonzero-Lambda flat cosmological models (2005)

Tomita, Kenji

Nonlinear gravitational effects of large-scale inhomogeneities on Cosmic Microwave Background (CMB) anisotropies are studied. based on the relativistic second-order theory of perturbations in...

Relativistic second-order perturbations of nonzero-\Lambda flat cosmological models and CMB anisotropies (2005)

Tomita, Kenji

First the second-order perturbations of nonzero-\Lambda cosmological models are derived with an arbitrary potential function of spatial coordinates, using the nonlinear version of Lifshitz's method...

Junction conditions of cosmological perturbations (2004)

Tomita, Kenji

The behavior of perturbations is studied in cosmological models which consist of two different homogeneous regions connected in a spherical shell boundary. The junction conditions for the metric...

Cluster abundance evolution and the Sunyaev-Zeldovich effect in various cosmological models (2003)

Tomita, Kenji

The redshift dependence of the observed cluster abundance due to the Sunyaev-Zeldovich Effect (SZE) is studied in various cosmological models including flat and open homogeneous (CDM) models and an...

Dipole anisotropies of IRAS galaxies and the contribution of a large-scale local void (2002)

Tomita, Kenji

Recent observations of dipole anisotropies show that the velocity of the Local Group ($\Vec v_{\rm G}$) induced by the clustering of IRAS galax ies has an amplitude and direction similar to those of...

Luminous Matter Distribution, Bulk Flows and Baryon Contents in Cosmological Models with a Local Void (2002)

Tomita, Kenji

First, we consider galaxy formation from the viewpoint of hierarchical clustering theory and discuss the possibility that inhomogeneous models with a local void may be compatible with the observed...

Analyses of Type Ia Supernova Data in Cosmological Models with a Local Void (2001)

Tomita, Kenji

The data of type Ia supernovae observed by the High-z SN Search Team and Supernova Cosmology Project are analyzed in inhomogeneous cosmological models with a local void on scales of about 200 Mpc, to...

A Local Void and the Accelerating Universe (2000)

Tomita, Kenji

Corresponding to the recent observational claims that we are in a local void (an underdense region) on scales of 200 - 300 Mpc, the magnitude-redshift relation in a cosmological model with a local...

Anisotropy of the Hubble Constant in a Cosmological Model with a Local Void on Scales of ~ 200 Mpc (2000)

Tomita, Kenji

A spherical cosmological model with a local void on scales of $\sim 200$ Mpc and with an inhomogeneous Hubble constant was proposed in recent two papers. This model explains consistently the observed...

Temperature correlations in a compact hyperbolic universe (1999)

Inoue, Kaiki Taro, Tomita, Kenji, Sugiyama, Naoshi

The effect of a non-trivial topology on the temperature correlations on the cosmic microwave background (CMB) in a small compact hyperbolic universe with volume comparable to the cube of the...

Distances and lensing in cosmological void models (1999)

Tomita, Kenji

We study the distances and gravitational lensing in spherically symmetric inhomogeneous cosmological models consisting of inner and outer homogeneous regions which are connected by a single shell or...

Bulk flows and CMB dipole anisotropy in cosmological void models (1999)

Tomita, Kenji

The observational behavior of spherically symmetric inhomogeneous cosmological models is studied, which consist of inner and outer homogeneous regions connected by a shell or an intermediate...

Distances in Inhomogeneous Cosmological Models (1999)

Tomita, Kenji, Asada, Hideki, Hamana, Takashi

Distances play important roles in cosmological observations, especially in gravitational lens systems, but there is a problem in determining distances because they are defined in terms of light...

Various Approaches to Cosmological Gravitational Lensing in Inhomogeneous Models (1999)

Tomita, Kenji, Premadi, Premana, Nakamura, Takahiro T.

Gravitational lensing of distant objects caused by gravitational tidal forces from inhomogeneities in the universe is weak in most cases, but it is noticed that it gives a great deal of information...

Plane-Symmetric Vacuum Solutions with Null Singularities for Inhomogeneous Models and Colliding Gravitational Waves (1998)

Tomita, Kenji

New exact vacuum solutions with various singularities in the plane-symmetric spacetime are shown, and they are applied to the analysis of inhomogeneous cosmological models and colliding gravitational...

Angular Diameter Distances in Clumpy Friedmann Universes (1998)

Tomita, Kenji

Solving null-geodesic equations, behavior of angular diameter distances is studied in inhomogeneous cosmological models, which are given by performing N-body simulations with the CDM spectrum. The...

Cosmological Simulation of Gravitational Weak Lensing in Open Models (1998)

Tomita, Kenji

Cosmological simulation of gravitational weak lensing in open models is treated using the direct integration method, which is independent of the mult-lens-plane method. Statistical averages of...