Gravitational instabilities in Kerr spacetimes

• Autores: Dotti, Gustavo; Gleiser, Reinaldo J.; Ranea Sandoval, Ignacio Francisco; Vucetich, Héctor
• Año de publicación: 2008
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Ciencias Astronómicas; Gravity in more than four dimensions, Kaluza-Klein theory, unified field theories; alternative theories of gravity; Classical general relativity; Physics of black holes; Gravitational waves
• Institución: Universidad Nacional de La Plata

In this paper we consider the possible existence of unstable axisymmetric modes in Kerr space times, resulting from exponentially growing solutions of the Teukolsky equation. We describe a transformation that casts the radial equation that results upon separation of variables in the Teukolsky equation, in the form of a Schr\"odinger equation, and combine the properties of the solutions of this equations with some recent results on the asymptotic behaviour of spin weighted spheroidal harmonics to prove the existence of an infinite family of unstable modes. Thus we prove that the stationary region beyond a Kerr black hole inner horizon is unstable under gravitational linear perturbations. We also prove that Kerr space-time with angular momentum larger than its square mass, which has a naked singularity, is unstable.
Facultad de Ciencias Astronómicas y Geofísicas