2010/09/11 by Taichi Kobayashi, Akira Tomimatsu
Physics and Astronomy · #Angular momentum #Astrophysical Phenomena and Observations #Black hole (networking) #Classical mechanics #Electromagnetic field #Electromagnetic radiation #Electromagnetic spectrum #Energy flux #Field (mathematics) #Laser #Optics #Physics #Plane wave #Quantum electrodynamics #Quantum mechanics #Rotating black hole #Scattering #Superradiance #astro-ph.HE #gr-qc
paper · pdf · doi:10.1103/physrevd.82.084026
published as Phys.Rev.D82:084026,2010 · 15 pages, 2 figures, accepted for publication in Physical Review D
arxiv created 2010/09/11 · openalex publication_date 2010/10/12 · arxiv updated 2014/11/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study electromagnetic perturbations around a Kerr black hole surrounded by a thin disk on the equatorial plane. Our main purpose is to reveal the black hole superradiance of electromagnetic waves emitted from the disk surface. The outgoing Kerr-Schild field is used to describe the disk emission, and the superradiant scattering is represented by a vacuum wave field which is added to satisfy the ingoing condition on the horizon. The formula to calculate the energy flux on the disk surface is presented, and the energy transport in the disk-black hole system is investigated. Within the low-frequency approximation we find that the energy extracted from the rotating black hole is mainly transported back to the disk, and the energy spectrum of electromagnetic waves observed at infinity is also discussed.