Stability of scalarized black hole solutions in scalar-Gauss-Bonnet gravity

Silva, Hector O.; Macedo, Caio F. B.; Sotiriou, Thomas P.; Gualtieri, Leonardo; Sakstein, Jeremy; Berti, Emanuele

Abstract

Scalar-tensor theories of gravity where a new scalar degree of freedom couples to the Gauss-Bonnet invariant can exhibit the phenomenon of spontaneous black hole scalarization. These theories admit both the classic black hole solutions predicted by general relativity as well as novel hairy black hole solutions. The stability of hairy black holes is strongly dependent on the precise form of the scalar-gravity coupling. A radial stability investigation revealed that all scalarized black hole solutions are unstable when the coupling between the scalar field and the Gauss-Bonnet invariant is quadratic in the scalar, whereas stable solutions exist for exponential couplings. Here, we elucidate this behavior. We demonstrate that, while the
quadratic term controls the onset of the tachyonic instability that gives rise to the black hole hair, the higherorder coupling terms control the nonlinearities that quench that instability and, hence, also control the stability of the hairy black hole solutions.

Citation

Silva, H. O., Macedo, C. F., Sotiriou, T. P., Gualtieri, L., Sakstein, J., & Berti, E. (2019). Stability of scalarized black hole solutions in scalar-Gauss-Bonnet gravity. Physical Review D, 99(6), 1-9. https://doi.org/10.1103/physrevd.99.064011

• Journal Article Type: Article
• Acceptance Date: Feb 20, 2019
• Online Publication Date: Mar 12, 2019
• Publication Date: Mar 12, 2019
• Deposit Date: Mar 26, 2019
• Publicly Available Date: Mar 29, 2019
• Journal: Physical Review D
• Print ISSN: 2470-0010
• Electronic ISSN: 2470-0029
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 99
• Issue: 6
• Article Number: 064011
• Pages: 1-9
• DOI: https://doi.org/10.1103/physrevd.99.064011
• Keywords: General Relativity and Quantum Cosmology; High Energy Astrophysical Phenomena; High Energy Physics - Theory
• Public URL: https://nottingham-repository.worktribe.com/output/1688310
• Publisher URL: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.99.064011