Statut | Confirmé |
Série | SEM-GRECO |
Domaines | gr-qc |
Date | Lundi 2 Novembre 2020 |
Heure | 11:00 |
Institut | IAP |
Salle | zoom details: contact pitrou@iap.fr |
Nom de l'orateur | Anson |
Prenom de l'orateur | Timothy |
Addresse email de l'orateur | timothy [dot] anson [at] th [dot] u-psud [dot] fr |
Institution de l'orateur | LPT Orsay |
Titre | Disforming the Kerr metric |
Résumé | Starting from a recently constructed stealth Kerr solution of higher order scalar tensor theory involving scalar hair, we analytically construct disformal versions of the Kerr spacetime with a constant degree of disformality and a regular scalar field. While the disformed metric has only a ring singularity and asymptotically is quite similar to Kerr, it is found to be neither Ricci flat nor circular. Non-circularity has far reaching consequences on the structure of the solution. As we approach the rotating compact object from asymptotic infinity we find a static limit ergosurface similar to the Kerr spacetime with an enclosed ergoregion. However, the stationary limit of infalling observers is found to be a timelike hypersurface. A candidate event horizon is found in the interior of this stationary limit surface. It is a null hypersurface generated by a null congruence of light rays which are no longer Killing vectors. Under a mild regularity assumption, we find that the candidate surface is indeed an event horizon and the disformed Kerr metric is therefore a black hole quite distinct from the Kerr solution. |
Numéro de preprint arXiv | |
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