Black hole inner horizon evaporation in semiclassical gravity

In this work we analyse the backreaction of a quantum field on a spherically symmetric black hole geometry with an inner horizon, i.e. an internal boundary of the trapped region. We start with a black hole background with an inner horizon which remains static after its formation. We quantise a massl...

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Detalles Bibliográficos
Autores: Barceló, Carlos, Boyanov Savov, Valentín, Carballo-Rubio, Raúl, Garay Elizondo, Luis Javier
Tipo de recurso: artículo
Fecha de publicación:2021
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/115128
Acceso en línea:https://hdl.handle.net/20.500.14352/115128
Access Level:acceso abierto
Palabra clave:52-33
Semiclassical gravity
Black holes
Inner horizon instability
Hawking evaporation
Astrofísica
21 Astronomía y Astrofísica
Descripción
Sumario:In this work we analyse the backreaction of a quantum field on a spherically symmetric black hole geometry with an inner horizon, i.e. an internal boundary of the trapped region. We start with a black hole background with an inner horizon which remains static after its formation. We quantise a massless scalar field on it and calculate its renormalised stress–energy tensor in the Polyakov approximation. We use this tensor as a source of perturbation on top of the background spacetime. We find that the inner horizon has a tendency to evaporate outward much more quickly than the outer one evaporates inward through the Hawking effect. This suggests a revised picture of a semiclassically self-consistent evaporation in which the dominant dynamical effect comes from the inner horizon, the cause of which can be seen as an interplay between the well-known unstable nature of this horizon and a locally negative energy contribution from the quantum vacuum. We also look at backreaction on backgrounds which resemble gravitational collapse, where the inner horizon moves towards the origin. There we find that, depending on the nature of the background dynamics, horizon-related semiclassical effects can become dominant and invert the collapse.