28 citations · 136 across the 11 of their papers we have counts for
4 papers · 1 filter
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…
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…
Innermost stable circular orbits in Majumdar--Papapetrou dihole spacetime
Keisuke Nakashi, Takahisa Igata
We investigate the positions of stable circular massive particle orbits in the Majumdar--Papapetrou dihole spacetime with equal mass. In terms of qualitative differences of their s…
Null Geodesics and Repulsive Behavior of Gravity in (2+1)-dimensional Massive Gravity
Keisuke Nakashi, Shinpei Kobayashi, Shu Ueda +1
We study the null geodesics in a static circularly symmetric (SCS) black hole spacetime which is a solution in the -dimensional massive gravity proposed by Bergshoeff, Hohm…