Distinctive features of hairy black holes in teleparallel GaussBonnet gravity
 verfasst von
 Sebastian Bahamonde, Daniela d. Doneva, Ludovic Ducobu, Christian Pfeifer, Stoytcho s. Yazadjiev
 Abstract
We examine the teleparallel formulation of nonminimally coupled scalar EinsteinGaussBonnet gravity. In the teleparallel formulation, gravity is described by torsion instead of curvature, causing the usual GaussBonnet invariant expressed through curvature to decay into two separate invariants built from torsion. Consequently, the teleparallel formulation permits broader possibilities for nonminimal couplings between spacetime geometry and the scalar field. In our teleparallel theory, there are two different branches of equations in spherical symmetry depending on how one solves the antisymmetric part of the field equations, leading to a real and a complex tetrad. We first show that the real tetrad seems to be incompatible with the regularity of the equations at the event horizon, which is a symptom that scalarized black hole solutions beyond the Riemannian EinsteinGaussBonnet theory might not exist. Therefore, we concentrate our study on the complex tetrad. This leads to the emergence of scalarized black hole solutions, where the torsion acts as the scalar field source. Extending our previous work, we study monomial nonminimal couplings of degrees 1 and 2, which are intensively studied in conventional, curvaturebased, scalar EinsteinGaussBonnet gravity. We discover that the inclusion of torsion can potentially alter the stability of the resulting scalarized black holes. Specifically, our findings indicate that for a quadratic coupling, which is entirely unstable in the pure curvature formulation, the solutions induced by torsion may exhibit stability within certain regions of the parameter space. In a limiting case, we were also able to find black holes with a strong scalar field close to the horizon but with a vanishing scalar charge.
 Externe Organisation(en)

Universität Bremen
 Typ
 Artikel
 Journal
 Physical Review D
 Band
 108
 ISSN
 24700010
 Publikationsdatum
 25.09.2023
 Publikationsstatus
 Veröffentlicht
 Peerreviewed
 Ja
 ASJC Scopus Sachgebiete
 Kern und Hochenergiephysik
 Elektronische Version(en)

https://doi.org/10.1103/PhysRevD.108.064044 (Zugang:
Unbekannt)