Maximal slicing of D-dimensional spherically-symmetric vacuum spacetime (2009)
Nakao, Ken-ichi, Abe, Hiroyuki, Yoshino, Hirotaka, Shibata, Masaru
We study the foliation of a $D$-dimensional spherically symmetric black-hole spacetime with $D\ge 5$ by two kinds of one-parameter family of maximal hypersurfaces: a reflection-symmetric foliation...
Higher-dimensional numerical relativity: Formulation and code tests (2009)
Yoshino, Hirotaka, Shibata, Masaru
We derive a formalism of numerical relativity for higher-dimensional spacetimes and develop numerical codes for simulating a wide variety of five-dimensional (5D) spacetimes for the first time....
On the existence of a static black hole on a brane (2008)
We study a static black hole localized on a brane in the Randall-Sundrum (RS) II braneworld scenario. To solve this problem numerically, we develop a code having the almost 4th-order accuracy. This...
Solitonlike solutions of magnetostatic equilibria: Plane-symmetric case (2008)
Yoshino, Hirotaka, Onda, Kohei
We present the plane-symmetric solitonlike solutions of magnetostatic equilibria by solving the nonlinear Grad-Shafranov (GS) equation numerically. The solutions have solitonlike and periodic...
Highly distorted apparent horizons and the hoop conjecture (2007)
By analyzing the apparent horizon (AH) formation in the collision of two pp-waves with rectangular sources in four dimensions, we study to what extent the AH can be distorted without violating the...
Collision of high-energy closed strings: Formation of a ring-like apparent horizon (2007)
Yoshino, Hirotaka, Shiromizu, Tetsuya
We study collisions of two high-energy closed strings in the framework of $D$-dimensional general relativity. The model of a high-energy closed string is introduced as a {/it pp}-wave generated by a...
Apparent horizon formation in the head-on collision of gyratons (2007)
Yoshino, Hirotaka, Zelnikov, Andrei, Frolov, Valeri P.
The gyraton model describes a gravitational field of an object moving with the velocity of light which has finite energy and spin distributed during some finite time interval $L$. A gyraton may be...
Yoshino, Hirotaka, Shiromizu, Tetsuya, Shibata, Masaru
Scenarios of large extra dimensions have enhanced the importance for the study of black holes in higher dimensions. In this paper, we analyze an axisymmetric system of two black holes. Specifically,...
Positive energy theorem implies constraints on static steller models (2006)
Shiromizu, Tetsuya, Yoshino, Hirotaka
Using the positive energy theorem, we derive some constraints on static steller models in asymptotically flat spacetimes in a general setting without imposing spherical symmetry. We show that there...
Holographic entanglement entropy of de Sitter braneworld (2006)
Iwashita, Yukinori, Kobayashi, Tsutomu, Shiromizu, Tetsuya, Yoshino, Hirotaka
We study the holographic representation of the entanglement entropy, recently proposed by Ryu and Takayanagi, in a braneworld context. The holographic entanglement entropy of a de Sitter brane...
Black hole formation in the head-on collision of ultrarelativistic charges (2006)
Yoshino, Hirotaka, Mann, Robert B.
We study black hole formation in the head-on collision of ultrarelativistic charges. The metric of charged particles is obtained by boosting the Reissner-Nordstr\"om spacetime to the speed of light....
On existence of matter outside a static black hole (2006)
Shiromizu, Tetsuya, Yamada, Sumio, Yoshino, Hirotaka
It is expected that matter composed of a perfect fluid cannot be at rest outside of a black hole if the spacetime is asymptotically flat and static (non-rotating). However, there has not been a...
High-energy effective theory for orbifold branes (2006)
Shiromizu, Tetsuya, Fujii, Shunsuke, De Rham, Claudia, Yoshino, Hirotaka
We derive an effective theory on the orbifold branes of the Randall-Sundrum 1 (RS1) braneworld scenario in the presence of a bulk brane. We concentrate on the regime where the three branes are close...
High-energy effective theory for a bulk brane (2005)
De Rham, Claudia, Fujii, Shunsuke, Shiromizu, Tetsuya, Yoshino, Hirotaka
We derive an effective theory describing the physics of a bulk brane in the context of the RS1 model. This theory goes beyond the usual low energy effective theory in that it describes the regime...
Yoshino, Hirotaka, Shiromizu, Tetsuya, Shibata, Masaru
Motivated by the TeV-scale gravity scenarios, we study gravitational radiation in the head-on collision of two black holes in higher dimensional spacetimes using a close-limit approximation. We...
Gravitational collapse disturbs the dS/CFT correspondence? (2005)
Iwashita, Yukinori, Yoshino, Hirotaka, Shiromizu, Tetsuya
We study the gravitational collapse in five-dimensional de Sitter (dS) spacetime and discuss the existence of the conformal boundaries at future timelike infinity from the perspective of the dS/CFT...
Mitsuda, Eiji, Yoshino, Hirotaka, Tomimatsu, Akira
Dynamical evolution of test fields in background geometry with a naked singularity is an important problem relevant to the Cauchy horizon instability and the observational signatures different from...
Improved analysis of black hole formation in high-energy particle collisions (2005)
Yoshino, Hirotaka, Rychkov, Vyacheslav S.
We investigate formation of an apparent horizon (AH) in high-energy particle collisions in four- and higher-dimensional general relativity, motivated by TeV-scale gravity scenarios. The goal is to...
Lightlike limit of the boosted Kerr black holes in higher-dimensional spacetimes (2004)
Deriving the gravitational field of the high-energy objects is an important theme because the black holes might be produced in particle collisions in the brane world scenario. In this paper, we...
Black ring formation in particle systems (2004)
Yoshino, Hirotaka, Nambu, Yasusada
It is known that the formation of apparent horizons with non-spherical topology is possible in higher-dimensional spacetimes. One of these is the black ring horizon with $S^1\times S^{D-3}$ topology...
Yoshino, Hirotaka, Ohba, Tohru, Tomimatsu, Akira
Using perturbative techniques, we investigate the existence and properties of a new static solution for the Einstein equation with a negative cosmological constant, which we call the deformed black...
Black hole formation in the grazing collision of high-energy particles (2002)
Yoshino, Hirotaka, Nambu, Yasusada
We numerically investigate the formation of D-dimensional black holes in high-energy particle collision with the impact parameter and evaluate the total cross section of the black hole production. We...
High-energy head-on collisions of particles and hoop conjecture (2002)
Yoshino, Hirotaka, Nambu, Yasusada
We investigate the apparent horizon formation for high-energy head-on collisions of particles in multi-dimensional spacetime. The apparent horizons formed before the instance of particle collision...
Hoop conjecture for colliding black holes : non-time-symmetric initial data (2001)
Yoshino, Hirotaka, Nambu, Yasusada, Tomimatsu, Akira
The hoop conjecture is well confirmed in momentarily static spaces, but it has not been investigated systematically for the system with relativistic motion. To confirm the hoop conjecture for...