23 citations · 33 across the 14 of their papers we have counts for
4 papers · 1 filter
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…
New series expansion method for the periapsis shift
Akihito Katsumata, Tomohiro Harada, Kota Ogasawara +1
We propose a new series expansion method for the periapsis shift. The method formulates the periapsis shift in various spacetimes analytically without using special functions and p…
Numerical simulation of type II primordial black hole formation
Koichiro Uehara, Albert Escrivà, Tomohiro Harada +2
This study investigates the formation of type II primordial black holes (PBHs) resulting from extremely large amplitudes of initial fluctuations in a radiation-dominated universe.…