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Magnetic Extraction of Spin Energy from a Black Hole

Julian H. Krolik
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Abstract

Numerous variations have been proposed on the original suggestion by Blandford and Znajek that magnetic fields could be used to extract rotational energy from black holes. A new categorization of these variations is proposed so that they may be considered in a systematic way. "Black hole spindown" is defined more precisely, distinguishing decrease in the spin parameter a/M from decreases in angular momentum a and rotational kinetic energy, M - M_i. Several key physical questions are raised: Can the "stretched horizon" of a black hole communicate with the outside world? Do accretion disks bring any net magnetic flux to the black holes at their centers? Is the magnetic field adjacent to a black hole force-free everywhere?

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Julian H. Krolik. 2000-08-23. Magnetic Extraction of Spin Energy from a Black Hole. https://doi.org/10.1063/1.1368257

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