The superradiant scattering of a scalar field with frequency and angular momentum (ω, m) by a near-extreme Kerr black hole with mass and spin (M, J) was derived in the seventies by Starobinsky, Churilov, Press and Teukolsky. In this paper we show that for frequencies scaled to the ...
We here investigate parity-even and parity-odd boson stars and their associated hairy black holes. We explore the domain of existence of the solutions and address some of their physical properties. The solutions exhibit close similarity to the corresponding boson stars and Kerr black holes with ...
For Schwarzschild (and many Kerr–Newman) black holes, n(P) is maximal at the horizon. Because the impact parameter of light on the optical black hole must be less than or equal to the radius of the “edge” of the system, i.e., \(\hat{B}\le {P}_{0}\), it is found that ...
In fact, three-dimensional CS theory also has applications in the study of black holes in four-dimensional gravity: the boundary degrees of freedom of a black hole in 4D are also described by an SU(2) CS theory. This allows a calculation of the degrees of freedom of, for example, ...
Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black hol...
We obtain analogs of the Blandford-Znajek split monopole solution for force-free magnetospheres around a slowly rotating Kerr-AdS black hole. For small black holes, we find an analytic solution to first order in the ratio of horizon radius to AdS scale, r H / l , which exhibits a radial...
To introduce various concepts related to black holes we will discuss two examples of black holes. First, let us consider the Schwarzschild black hole in 3+1 dimensions. It is a time independent, spherically symmetric solution of Einstein gravity without matter. The metric is given by (1.2)ds2...
black holes can be destroyed by a scalar field [58]. Using our obtained first law of black hole thermodynamics, we investigate the weak cosmic censorship conjecture for Kerr–Newman Taub–NUT black holes. We find that an extremal Kerr–Newman Taub–NUT cannot be destroyed by a charged test ...
Analog physics allows simulating inaccessible objects, such as black holes, in the lab. We propose to implement an acoustic Kerr black hole with quantized angular momentum in a polariton Bose-Einstein condensate. We show that the metric of the condensate is equivalent to the Kerr's one, exhibiti...
not reproduce the Bekenstein–Hawking entropy of a Kerr black hole. The results are compared with previous estimates obtained by the authors using the Rudjord–Gr∅n–Hervik approach. We conclude that the latter represents better the expected behaviour of the gravitational entropy of black holes....