405 citations · 2.7k across the 85 of their papers we have counts for
86 papers
Vaidya-Type Solutions of Quasitopological Gravity Interacting with Nonlinear Electrodynamics
Valeri P. Frolov, Chul-Moon Yoo, Andrei Zelnikov
We construct Vaidya-type solutions of quasitopological gravity coupled to nonlinear electrodynamics in arbitrary spacetime dimensions. Starting from the corresponding static spheri…
Ringdown in Vaidya spacetimes: time-dependent frequencies, Penrose limit and time-domain analyses
Chul-Moon Yoo, Masashi Kimura, Akihiro Ishibashi +1
We examine the possible characterization of ringdown waves in a dynamical Vaidya spacetime using the Penrose limit geometry around the dynamical photon sphere. In the case of a sta…
Spins of primordial black holes formed with a soft equation of state
Daiki Saito, Tomohiro Harada, Yasutaka Koga +1
We investigate the probability distribution of the spins of primordial black holes (PBHs) formed in the universe dominated by a perfect fluid with the linear equation of state $p=w…
Revisiting compaction functions for primordial black hole formation
Tomohiro Harada, Chul-Moon Yoo, Yasutaka Koga
Shibata and Sasaki [arXiv:gr-qc/9905064] introduced the so-called compaction function. Since then, it has been empirically established that the maximum value of this function (or i…
Threshold of Primordial Black Hole Formation against Velocity Dispersion in Matter-Dominated Era
Tomohiro Harada, Kazunori Kohri, Misao Sasaki +2
We study the effects of velocity dispersion on the formation of primordial black holes~(PBHs) in a matter-dominated era. The velocity dispersion is generated through the nonlinear…
The basics of primordial black hole formation and abundance estimation
Chul-Moon Yoo
This paper is a biased review of primordial black hole (PBH) formation and abundance estimation. We first review the three-zone model for PBH formation to help an intuitive underst…