Ringing black holes are superradiant: The case of ultralight scalar fields
Abstract
Superradiance has been studied quite extensively in the context of static (charged) and rotating black hole spacetime. In this paper, we report for the first time that for a minimally coupled scalar field, the absorption cross section of a Schwarzschild black hole in its ringdown phase can be superradiant. Treating the scattered scalar field as axion, we further computed its observable effects on the rotation of the plane of polarization of photon, neutron dipole moment, and fermionic spin precession. All those observables turned out to have interesting time dependence induced by the ringing black hole background. Our present result opens up an intriguing possibility of observing the black hole merging phenomena through other fundamental fields.
- Publication:
-
Physical Review D
- Pub Date:
- May 2022
- DOI:
- 10.1103/PhysRevD.105.104045
- arXiv:
- arXiv:2109.10940
- Bibcode:
- 2022PhRvD.105j4045K
- Keywords:
-
- General Relativity and Quantum Cosmology;
- Astrophysics - High Energy Astrophysical Phenomena;
- High Energy Physics - Theory
- E-Print:
- A new section has been added on obsevables effects. Also, few typos are corrected and some references have been added. Accepted for publication in Phys. Rev. D