2 citations · 3 across the 8 of their papers we have counts for
9 papers
Simulation of PBH formation in a matter-dominated universe
Chul-Moon Yoo, Albert Escrivà, Tomohiro Harada +1
We investigate primordial black hole (PBH) formation during an early matter-dominated era using fully nonlinear numerical relativity. The initial condition is set by a functional f…
Odd-parity ringdown gravitational waves of a spherically symmetric black hole with perfect fluid accretion
Rikuto Ohashi, Yasutaka Koga, Hiroyuki Nakano +2
The ringdown waves from a black hole offer a clean probe of strong-field gravity, but a matter distribution that may be present around a realistic black hole renders the background…
COSMOS: A numerical relativity code specialized for PBH formation
Chul-Moon Yoo, Hirotada Okawa, Albert Escrivà +7
Primordial black holes (PBHs) are black holes generated in the early universe without having gone through stellar evolution. In the standard formation process, PBHs are formed from…
Gravitational wave emission from nonspherical collapse in an early matter-dominated era using N-body simulations
Albert Escrivà, Tomohiro Harada, Kazunori Kohri +2
We study the dynamics of the collapse of a nonspherical overdense patch during an early matter-dominated era and the associated production of gravitational waves (GWs) using a semi…
Rotating wormholes in five dimensions with equal angular momenta: large asymmetry regime
Keiya Uemichi, Yasutaka Koga, Daiki Saito +2
We clarify the relationship between rotation and the energy condition for stationary rotating wormhole solutions of the Einstein equations coupled to a phantom field in five-dimens…
Primordial Black Hole Formation and Spin in Matter Domination Revisited
Weitao Ye, Yungui Gong, Tomohiro Harada +4
In this article, we calculate the mass distribution of primordial black holes (PBHs) formed in the matter-dominated (MD) era by the peak theory. We apply the Zel'dovich approximati…
Test particle motion around a black hole dressed with a spherically symmetric stationary fluid
Ariadna Uxue Palomino Ylla, Yasutaka Koga, Chul-Moon Yoo
We investigate the motion of a massive particle around a spherically symmetric black hole surrounded by a stationary and radial inflow of perfect fluid. The background spacetime is…
Geometrical origin for the compaction function for primordial black hole formation
Tomohiro Harada, Hayami Iizuka, Yasutaka Koga +1
We propose a geometrical origin for the Shibata-Sasaki compaction function, which is known to be a reliable indicator of primordial black hole formation at least during radiation d…
Revisiting spins of primordial black holes in a matter-dominated era based on peak theory
Daiki Saito, Tomohiro Harada, Yasutaka Koga +1
We estimate the probability distribution for the spins of the primordial black holes (PBHs) that formed during an early matter-dominated era in the Universe. We employ the Zel'dovi…