282 citations · 2.7k across the 89 of their papers we have counts for
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What wormhole is traversable?: A case of a wormhole supported by a spherical thin shell
Ken-ichi Nakao, Tatsuya Uno, Shunichiro Kinoshita
We analytically explore the effect of falling matter on a spherically symmetric wormhole supported by a spherical shell composed of exotic matter located at its throat. The falling…
Two-point correlation function of density perturbations in a large void universe
Ryusuke Nishikawa, Chul-Moon Yoo, Ken-ichi Nakao
We study the two-point correlation function of density perturbations in a spherically symmetric void universe model which does not employ the Copernican principle. First we solve p…
Black Hole Universe: Time Evolution
Chul-Moon Yoo, Hirotada Okawa, Ken-ichi Nakao
Time evolution of a black hole lattice universe is simulated. The vacuum Einstein equations in a cubic box with a black hole at the origin are numerically solved with periodic boun…
Ultra-high energy collision with neither black hole nor naked singularity
Ken-ichi Nakao, Masashi Kimura, Mandar Patil +1
We explore the collision between two concentric spherical thin shells. The inner shell is charged, whereas the outer one is either neutral or charged. In the situation we consider,…