Quasinormal modes of extremal black holes

Author(s)

Richartz, Mauricio

• Document type: Journal article
• Source: PHYSICAL REVIEW D; v. 93, n. 6, p. 17-pg., 2016-03-25.

Abstract

The continued fraction method (also known as Leaver's method) is one of the most effective techniques used to determine the quasinormal modes of a black hole. For extremal black holes, however, the method does not work (since, in such a case, the event horizon is an irregular singular point of the associated wave equation). Fortunately, there exists a modified version of the method, devised by Onozawa et al. [Phys. Rev. D 53, 7033 (1996)], which works for neutral massless fields around an extremal Reissner-Nordstrom black hole. In this paper, we generalize the ideas of Onozawa et al. to charged massless perturbations around an extremal Reissner-Nordstrom black hole and to neutral massless perturbations around an extremal Kerr black hole. In particular, the existence of damped modes is analyzed in detail. Similarities and differences between the results of the original continued fraction method for near extremal black holes and the results of the new continued fraction method for extremal black holes are discussed. Mode stability of extremal black holes is also investigated. (AU)

• FAPESP's process: 13/09357-9 - Physics and geometry of spacetime
• Grantee: Alberto Vazquez Saa
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/14077-0 - Superradiance in dissipative systems
• Grantee: Maurício Richartz
• Support Opportunities: Scholarships abroad - Research