Bosch Pablo, Green Stephen R, Lehner Luis
Department of Physics & Astronomy and Guelph-Waterloo Physics Institute, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada.
Phys Rev Lett. 2016 Apr 8;116(14):141102. doi: 10.1103/PhysRevLett.116.141102. Epub 2016 Apr 7.
We describe the full nonlinear development of the superradiant instability for a charged massless scalar field coupled to general relativity and electromagnetism, in the vicinity of a Reissner-Nordström-anti-de Sitter black hole. The presence of the negative cosmological constant provides a natural context for considering perfectly reflecting boundary conditions and studying the dynamics as the scalar field interacts repeatedly with the black hole. At early times, small superradiant perturbations grow as expected from linearized studies. Backreaction then causes the black hole to lose charge and mass until the perturbation becomes nonsuperradiant, with the final state described by a stable hairy black hole. For large gauge coupling, the instability extracts a large amount of charge per unit mass, resulting in greater entropy increase. We discuss the implications of the observed behavior for the general problem of superradiance in black hole spacetimes.
我们描述了在雷斯纳 - 诺德斯特龙 - 反德西特黑洞附近，与广义相对论和电磁学耦合的无质量带电标量场超辐射不稳定性的完全非线性发展。负宇宙学常数的存在为考虑完全反射边界条件以及研究标量场与黑洞反复相互作用时的动力学提供了自然背景。在早期，如线性化研究预期的那样，小的超辐射微扰会增长。然后反作用导致黑洞失去电荷和质量，直到微扰变为非超辐射，最终状态由一个稳定的毛状黑洞描述。对于大规范耦合，不稳定性每单位质量提取大量电荷，导致更大的熵增加。我们讨论了所观察到的行为对黑洞时空超辐射一般问题的影响。
