scholarly journals Wavefront twisting by rotating black holes: Orbital angular momentum generation and phase coherent detection

2014 ◽  
Vol 90 (2) ◽  
Author(s):  
Huan Yang ◽  
Marc Casals
Author(s):  
F. Tamburini ◽  
F. Feleppa ◽  
B. Thidé

We describe and present the first observational evidence that light propagating near a rotating black hole is twisted in phase and carries orbital angular momentum. The novel use of this physical observable as an additional tool for the previously known techniques of gravitational lensing allows us to directly measure, for the first time, the spin parameter of a black hole. With the additional information encoded in the orbital angular momentum, not only can we reveal the actual rotation of the compact object, but we can also use rotating black holes as probes to test general relativity.


2007 ◽  
Vol 22 (26) ◽  
pp. 4849-4858 ◽  
Author(s):  
A. SHEYKHI ◽  
N. RIAZI

We consider charged black holes with curved horizons, in five-dimensional dilaton gravity in the presence of Liouville-type potential for the dilaton field. We show how, by solving a pair of coupled differential equations, infinitesimally small angular momentum can be added to these static solutions to obtain charged rotating dilaton black hole solutions. In the absence of dilaton field, the nonrotating version of the solution reduces to the five-dimensional Reissner–Nordström black hole, and the rotating version reproduces the five-dimensional Kerr–Newman modification thereof for small rotation parameter. We also compute the angular momentum and the angular velocity of these rotating black holes which appear at the first order.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
S. H. Hendi ◽  
M. Allahverdizadeh

We study charged slowly rotating black hole with a nonlinear electrodynamics (NED) in the presence of cosmological constant. Starting from the static solutions of Einstein-NED gravity as seed solutions, we use the angular momentum as the perturbative parameter to obtain slowly rotating black holes. We perform the perturbations up to the linear order for black holes in 4 dimensions. These solutions are asymptotically AdS and their horizon has spherical topology. We calculate the physical properties of these black holes and study their dependence on the rotation parameteraas well as the nonlinearity parameterβ. In the limitβ→∞, the solution describes slowly rotating AdS type black holes.


2012 ◽  
Vol 21 (08) ◽  
pp. 1250068 ◽  
Author(s):  
ALEXIS LARRAÑAGA

In this paper, we analyze the area spectrum of BTZ three-dimensional black holes by considering an outgoing wave and relating its period of motion with the period of the gravitational system with respect to Euclidean time. The area spectra obtained for the rotating and non-rotating black holes are equally spaced and it is important to note that in this paper, we do not need to use the small angular momentum assumption which is necessary in the quasinormal mode approach for rotating black holes. The results suggest that the periodicity of the black hole gravitational system may be the origin of area quantization.


2006 ◽  
Vol 21 (35) ◽  
pp. 2621-2635 ◽  
Author(s):  
JUTTA KUNZ ◽  
FRANCISCO NAVARRO-LÉRIDA

Stationary black holes in five-dimensional Einstein–Maxwell–Chern–Simons theory possess surprising properties. When considering the Chern–Simons coefficient λ as a parameter, two critical values of λ appear: the supergravity value λ SG = 1, and the value λ = 2. At λ = 1, supersymmetric black holes with vanishing horizon angular velocity, but finite angular momentum exist. As λ increases beyond λ SG a rotational instability arises, and counterrotating black holes appear, whose horizon rotates in the opposite sense to the angular momentum. Thus supersymmetry is associated with the borderline between stability and instability. At λ = 2, rotating black holes with vanishing angular momentum emerge. Beyond λ = 2, black holes may possess a negative horizon mass, while their total mass is positive. Charged rotating black holes with vanishing gyromagnetic ratio appear, and black holes are no longer uniquely characterized by their global charges.


Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 1017
Author(s):  
Bogeun Gwak

We investigate the energy of the gravitational wave from a binary black hole merger by the coalescence of two Kerr black holes with an orbital angular momentum. The coalescence is constructed to be consistent with particle absorption in the limit in which the primary black hole is sufficiently large compared with the secondary black hole. In this limit, we analytically obtain an effective gravitational spin–orbit interaction dependent on the alignments of the angular momenta. Then, binary systems with various parameters including equal masses are numerically analyzed. According to the numerical analysis, the energy of the gravitational wave still depends on the effective interactions, as expected from the analytical form. In particular, we ensure that the final black hole obtains a large portion of its spin angular momentum from the orbital angular momentum of the initial binary black hole. To estimate the angular momentum released by the gravitational wave in the actual binary black hole, we apply our results to observations at the Laser Interferometer Gravitational-Wave Observatory: GW150914, GW151226, GW170104, GW170608 and GW170814.


1996 ◽  
Vol 28 (11) ◽  
pp. 1393-1400 ◽  
Author(s):  
J. M. Aguirregabiria ◽  
A. Chamorro ◽  
K. S. Virbhadra

2019 ◽  
Vol 100 (4) ◽  
Author(s):  
Pratik Tarafdar ◽  
Deepika A. Bollimpalli ◽  
Sankhasubhra Nag ◽  
Tapas K. Das

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