50 citations · 541 across the 47 of their papers we have counts for
7 papers · 1 filter
Escape probability of a photon emitted near the black hole horizon
Kota Ogasawara, Takahisa Igata, Tomohiro Harada +1
We investigate the escape of photons from the vicinity of the horizon to infinity in the Kerr-Newmann black hole spacetime. We assume that a light source is at rest in a locally no…
Observability of the innermost stable circular orbit in a near-extremal Kerr black hole
Takahisa Igata, Keisuke Nakashi, Kota Ogasawara
We consider the escape probability of a photon emitted from the innermost stable circular orbit (ISCO) of a rapidly rotating black hole. As an isotropically emitting light source o…
Stable bound orbits around a supersymmetric black lens
Shinya Tomizawa, Takahisa Igata
In higher-dimensional Schwarzschild black hole spacetimes, there are no stable bound orbits of particles. In contrast to this, it is shown that there are stable bound orbits in a f…
Effect of a second compact object on stable circular orbits
Keisuke Nakashi, Takahisa Igata
We investigate how stable circular orbits around a main compact object appear depending on the presence of a second one by using the Majumudar--Papapetrou dihole spacetime, which c…
Massive tensor field perturbations on extremal and near-extremal static black holes
Vitor Cardoso, Takahisa Igata, Akihiro Ishibashi +1
We develop a new perturbation method to study the dynamics of massive tensor fields on extremal and near-extremal static black hole spacetimes in arbitrary dimensions. On such back…
Observability of spherical photon orbits in near-extremal Kerr black holes
Takahisa Igata, Hideki Ishihara, Yu Yasunishi
We investigate the spherical photon orbits in near-extremal Kerr spacetimes. We show that the spherical photon orbits with impact parameters in a finite range converge on the event…