scholarly journals Effects of inner Alfvén surface location on black hole energy extraction in the limit of a force-free magnetosphere

2017 ◽  
Vol 95 (6) ◽  
Author(s):  
Kevin Thoelecke ◽  
Sachiko Tsuruta ◽  
Masaaki Takahashi
Keyword(s):  
Black Hole ◽  
Energy Extraction ◽  
Hole Energy ◽  
Surface Location

Black Hole Energy Extraction Problems

Nature ◽  
1972 ◽  
Vol 240 (5378) ◽  
pp. 184-184
Keyword(s):  
Black Hole ◽  
Energy Extraction ◽  
Hole Energy

scholarly journals ENERGY EXTRACTION FROM GRAVITATIONAL COLLAPSE TO STATIC BLACK HOLES

2003 ◽  
Vol 12 (01) ◽  
pp. 121-127 ◽  
Author(s):  
REMO RUFFINI ◽  
LUCA VITAGLIANO
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Extraction Process ◽  
Maximum Efficiency ◽  
Energy Extraction ◽  
Mass Energy ◽  
Classical Level ◽  
Static Black Hole ◽  
Exact Analytic Expression ◽  
Analytic Expression

The mass-energy formula of black holes implies that up to 50% of the energy can be extracted from a static black hole. Such a result is reexamined using the recently established analytic formulas for the collapse of a shell and the expression for the irreducible mass of a static black hole. It is shown that the efficiency of energy extraction process during the formation of the black hole is linked in an essential way to the gravitational binding energy, the formation of the horizon and the reduction of the kinetic energy of implosion. Here a maximum efficiency of 50% in the extraction of the mass energy is shown to be generally attainable in the collapse of a spherically symmetric shell: surprisingly this result holds as well in the two limiting cases of the Schwarzschild and extreme Reissner–Nordström space–times. Moreover, the analytic expression recently found for the implosion of a spherical shell to an already formed black hole leads to a new exact analytic expression for the energy extraction which results in an efficiency strictly less than 100% for any physical implementable process. There appears to be no incompatibility between General Relativity and Thermodynamics at this classical level.

Evidence of Spin and Energy Extraction in a Galactic Black Hole Candidate: The [ITAL]XMM-Newton[/ITAL]/EPIC-[CLC]pn[/CLC] Spectrum of XTE J1650−500

2002 ◽  
Vol 570 (2) ◽  
pp. L69-L73 ◽  
Author(s):  
J. M. Miller ◽  
A. C. Fabian ◽  
R. Wijnands ◽  
C. S. Reynolds ◽  
M. Ehle ◽  
...  
Keyword(s):  
Black Hole ◽  
Energy Extraction ◽  
Black Hole Candidate ◽  
Galactic Black Hole

scholarly journals Physics of black hole binaries: Geodesics, relaxation modes, and energy extraction

2019 ◽  
Vol 100 (4) ◽  
Author(s):  
Laura Bernard ◽  
Vitor Cardoso ◽  
Taishi Ikeda ◽  
Miguel Zilhão
Keyword(s):  
Black Hole ◽  
Energy Extraction ◽  
Black Hole Binaries ◽  
Relaxation Modes

Effect of charge and deformation parameter on energy extraction in charged non-Kerr black holes

2019 ◽  
Vol 28 (16) ◽  
pp. 2040012
Author(s):  
Rehana Rahim ◽  
Khalid Saifullah
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Deformation Parameter ◽  
High Efficiency ◽  
Process Efficiency ◽  
Energy Extraction ◽  
Penrose Process ◽  
Kerr Black Holes ◽  
Very High

We analyze the charged Johannsen–Psaltis black hole for energy extraction via the Penrose process. Efficiency of the Penrose process is found to be dependent on the deformation parameter of the metric and charge. Doing the calculations numerically, we find that, in the nonextremal limit, presence of charge leads to lesser efficiency than the Kerr. In the extremal cases with negative deformation parameter, charge leads to a very high efficiency, higher than that of the Kerr and Johannsen–Psaltis black holes.

scholarly journals Energy spectrum of black holes: A new view

2016 ◽  
Vol 32 (02) ◽  
pp. 1750002 ◽  
Author(s):  
Abhishek Majhi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Energy Spectrum ◽  
Loop Quantum Gravity ◽  
Quantization Scheme ◽  
Geometric Description ◽  
Hole Energy ◽  
Energy Quantization ◽  
Asymptotic Energy ◽  
New View

Energy of a black hole is usually quantized by invoking some area quantization scheme after expressing the energy in terms of the horizon area. However, in this approach one has to quantize the local and asymptotic energy of the black hole separately and the two results do not manifest any physical correspondence with each other. Here, as opposed to this practice, we find the unique energy spectrum of black holes by adopting a top-down approach. The physical links among the underlying quantum theory, statistical mechanics and thermodynamics of the black hole horizon play the central role in determining the energy spectrum. The energy spectrum that we obtain explicitly reveals the correspondence between asymptotic and local observations through the presence of the surface gravity of the horizon as a parameter in the spectrum, rather than being expressed as a function of area and consequently getting quantized in the usual approach. Thus, our result presents a new view as far as black hole energy quantization is concerned. The calculations are performed using the quantum geometric description of black hole horizons as laid down by loop quantum gravity.

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