Regular Article - Theoretical Physics
Magnetic-induced spontaneous scalarization in dynamical Chern–Simons gravity
Institute for Theoretical Physics and Cosmology, Zhejiang University of Technology, 310032, Hangzhou, China
2 United Center for Gravitational Wave Physics, Zhejiang University of Technology, 310032, Hangzhou, China
3 Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, 225009, Yangzhou, China
4 Shanghai Frontier Science Center for Gravitational Wave Detection, Shanghai Jiao Tong University, 200240, Shanghai, China
5 Physics Department, National Technical University of Athens, Zografou Campus, 15780, Athens, Greece
6 GCAP-CASPER, Physics Department, Baylor University, 76798-7316, Waco, TX, USA
Accepted: 21 January 2023
Published online: 31 January 2023
In the framework of the dynamical Chern–Simons gravity, we study the scalar field perturbations of the Reissner–Nordström–Melvin spacetime, which describes a charged black hole permeated by a uniform magnetic field. In the presence of the magnetic field, the scalar field acquires an effective mass whose square takes negative value in the half domain of the angular direction. This inevitably introduces the tachyonic instability and associated spontaneous scalarization as long as the coupling constant between the scalar field and the Chern–Simons invariant exceeds a threshold value. We study the object pictures of the time evolutions of the scalar field perturbations at the linear level, and find that the presence of the magnetic field will dramatically change the waveforms and associated ringdown modes. Nonlinear evolutions for the unstable perturbations are also performed in the decoupling limit, which demonstrate the scalar cloud as the final fate. Influences of the coupling constant and the black hole charge on the wave dynamics are also studied.
© The Author(s) 2023
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3. SCOAP3 supports the goals of the International Year of Basic Sciences for Sustainable Development.