In this paper, we consider the tachyonic instability of Kerr-Newman (KN) black holes in the Einstein-Maxwell-scalar (EMS) theory with nonminimal negative scalar coupling to Maxwell term, and then obtain a bound (r+a≥0.4142) for spin parameter a of KN black hole in the limit of coupling constant α→−∞ by using analytical method. In addition, we perform a (2+1)-dimensional time evolution of linearized scalar field perturbation on the KN black hole background by implementing the hyperboloidal foliation method numerically in the EMS theory. It recovers the \textit{spontaneous scalarization} phenomenon for KN black hole in some certain regions of the parameter spaces. We further plot corresponding threshold curves α(a) which describe a boundary between bald KN black holes and scalarized spinning black holes in the EMS theory.
@article{arxiv.2206.11587,
title = {Spin-induced scalarization of Kerr-Newman black holes in Einstein-Maxwell-scalar theory},
author = {Meng-Yun Lai and Yun Soo Myung and Rui-Hong Yue and De-Cheng Zou},
journal= {arXiv preprint arXiv:2206.11587},
year = {2022}
}