2020/07/17 by Kris Schroven, Saskia Grunau · 11 citations
Physics and Astronomy · #Angular momentum #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Black hole (networking) #Charge (physics) #Charged black hole #Charged particle #Coulomb #Coupling (piping) #Electron #Ion #Physics #Pulsars and Gravitational Waves Research #Quantum electrodynamics #Quantum mechanics #RADIUS #Rotating black hole #Schwarzschild radius #Spacetime #gr-qc
paper · pdf · doi:10.1103/physrevd.103.024016
published in Physical review. D/Physical review. D. 103(2) (American Physical Society) · 16 pages, 8 figures
arxiv created 2020/07/17 · openalex created_date 2020/07/23 · openalex publication_date 2021/01/11 · arxiv updated 2021/01/20 · openalex updated_date 2026/08/05
In this article we study the innermost stable circular orbit (ISCO) of electrically charged particles in the electrically charged Reissner-Nordstr"om spacetime, the Kerr-Newman spacetime and the Kerr-Sen spacetime. We find that the radius of the ISCO increases with an increasing particle-black hole charge product |qQ| in the case of attractive Coulomb interaction qQ<0. For repulsive Coulomb interaction, the ISCO radius first decreases to a minimum and then increases again, until it diverges as the charge product approaches one. If the charge Q of the black hole is very small, the minimum of the ISCO radius lies at qQ=0. Repulsive and attractive Coulomb interactions will always increase the ISCO radius in this limit. Stable bound orbits of charged particles cease to exist in the Reissner-Nordstr"om and Kerr-Newman spacetime for qQ\ensuremath≥1. In the Kerr-Sen spacetime the limiting case depends on the charge of the black hole and if dilaton coupling is applied to the test particle. We find qQ\ensuremath≥1+Q2 without dilaton-coupling and qQ\ensuremath≥1+3/2 Q2 with dilaton coupling \ensuremathα=1.