Kerr metric Killing bundles: Killing horizons confinement, light-surfaces and horizons replicas


Pugliese D. Quevedo H.
March 2021Springer Science and Business Media Deutschland GmbH

European Physical Journal C
2021#81Issue 3

We provide a complete characterization of the metric Killing bundles (or metric bundles) of the Kerr geometry. Metric bundles can be generally defined for axially symmetric spacetimes with Killing horizons and, for the case of Kerr geometries, are sets of black holes (BHs) or black holes and naked singularities (NSs) geometries. Each metric of a bundle has an equal limiting photon (orbital) frequency, which defines the bundle and coincides with the frequency of a Killing horizon in the extended plane. In this plane each bundle is represented as a curve tangent to the curve that represents the horizons, which thus emerge as the envelope surfaces of the metric bundles. We show that the horizons frequency can be used to establish a connection between BHs and NSs, providing an alternative representation of such spacetimes in the extended plane and an alternative definition of the BH horizons. We introduce the concept of inner horizon confinement and horizons replicas and study the possibility of detecting their frequencies. We study the bundle characteristic frequencies constraining the inner horizon confinement in the outer region of the plane i.e. the possibility of detect frequency related to the inner horizon, and the horizons replicas, structures which may be detectable for example from the emission spectra of BHs spacetimes. With the replicas we prove the existence of photon orbits with equal orbital frequency of the horizons. It is shown that such observations can be performed close to the rotation axis of the Kerr geometry, depending on the BH spin. We argue that these results could be used to further investigate black holes and their thermodynamic properties.



Text of the article Перейти на текст статьи

Research Centre of Theoretical Physics and Astrophysics, Institute of Physics, Silesian University in Opava, Bezručovo náměstí 13, Opava, 74601, Czech Republic
Dipartimento di Fisica, Università di Roma “La Sapienza”, Rome, 00185, Italy
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, AP 70543, Mexico, 04510, DF, Mexico
Department of Theoretical and Nuclear Physics, Kazakh National University, Almaty, 050040, Kazakhstan

Research Centre of Theoretical Physics and Astrophysics
Dipartimento di Fisica
Instituto de Ciencias Nucleares
Department of Theoretical and Nuclear Physics

10 лет помогаем публиковать статьи Международный издатель

Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026