12 citations · 15 across the 2 of their papers we have counts for
7 papers
High energy collision without fine tuning: Acceleration and multiple collisions of shells in a bound system
Takafumi Kokubu
High energy collision of massive bodies is investigated without fine tuning. We study multiple collisions of two spherical concentric shells in a gravitationally bound system and c…
Thin-shell wormholes in Einstein and Einstein-Gauss-Bonnet theories of gravity
Takafumi Kokubu, Tomohiro Harada
We review recent works on the possibility for eternal existence of thin-shell wormholes on Einstein and Einstein-Gauss-Bonnet gravity. We introduce thin-shell wormholes that are ca…
High energy particle collisions in static, spherically symmetric black-hole-like wormholes
Naoki Tsukamoto, Takafumi Kokubu
A Damour-Solodukhin wormhole with a metric which is similar to a Schwarzschild black hole seems to be a black hole mimicker since it is difficult to distinguish them by practical a…
Burst particle creation in gravitational collapse to a horizonless compact object
Takafumi Kokubu, Tomohiro Harada
In the previous paper [Harada, Cardoso, and Miyata, Phys.\ Rev.\ D {\bf 99} (2019), 044039], it is shown that a hollow transmissive shell collapsing to an ultracompact object of ra…
Particle creation in gravitational collapse to a horizonless compact object
Tomohiro Harada, Vitor Cardoso, Daiki Miyata
Black holes (BHs) play a central role in physics. However, gathering observational evidence for their existence is a notoriously difficult task. Current strategies to quantify the…
Effect of Inhomogeneity on Primordial Black Hole Formation in the Matter Dominated Era
Takafumi Kokubu, Koutarou Kyutoku, Kazunori Kohri +1
We investigate the effect of inhomogeneity on primordial black hole formation in the matter dominated era. In the gravitational collapse of an inhomogeneous density distribution, a…