Photon spheres in Einstein and Einstein-Gauss-Bonnet theories and circular null geodesics in axially-symmetric spacetimes

In this article we extend a recent theorem proven by Hod [Upper bound on the radii of black-hole photon spheres, Phys. Lett. B 727, 345 (2013)] to n-dimensional Einstein and Einstein-Gauss-Bonnet theories, which gives an upper bound for the photon sphere radii of spherically symmetric black holes. A...

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Detalles Bibliográficos
Autores: Gallo, Emanuel, Villanueva, Jose R.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/51365
Acceso en línea:http://hdl.handle.net/11336/51365
Access Level:acceso abierto
Palabra clave:BLACK HOLES
QUASI-NORMAL MODES
PHOTON SPHERES
https://purl.org/becyt/ford/1.3
https://purl.org/becyt/ford/1
Descripción
Sumario:In this article we extend a recent theorem proven by Hod [Upper bound on the radii of black-hole photon spheres, Phys. Lett. B 727, 345 (2013)] to n-dimensional Einstein and Einstein-Gauss-Bonnet theories, which gives an upper bound for the photon sphere radii of spherically symmetric black holes. As applications of these results we give a universal upper bound for the real part of quasinormal modes in the WKB limit and a universal lower bound for the position of the first relativistic image in the strong lensing regime produced by these type of black holes. For the axially-symmetric case, we also make some general comments (independent of the underlying gravitational theory) on the relation between circular null geodesics and the fastest way to circle a black hole.