Rotating non-Kerr black hole and energy extraction

Abstract

The properties of the ergosphere and energy extraction by Penrose process in a rotating non-Kerr black hole are investigated. It is shown that the ergosphere is sensitive to the deformation parameter $\epsilon$ and the shape of the ergosphere becomes thick with increase of the parameter $\epsilon$. It is of interest to note that, comparing with the Kerr black hole, the deformation parameter $\epsilon$ can enhance the maximum efficiency of the energy extraction process greatly. Especially, for the case of $a>M$, the non-Kerr metric describes a superspinning compact object and the maximum efficiency can exceed 60%, while it is only 20.7% for the extremal Kerr black hole.

16 pages, 5 figures, and 2 tables

References in corpus (6)

• A Metric for Rapidly Spinning Black Holes Suitable for Strong-Field Tests of the No-Hair Theorem
• Apparent shape of super-spinning black holes
• How to observe a non-Kerr spacetime
• Spinning Loop Black Holes
• A generalization of Ryan's theorem: probing tidal coupling with gravitational waves from nearly circular, nearly equatorial, extreme-mass-ratio inspirals
• Spacetime Encodings I- A Spacetime Reconstruction Problem

Cited by in corpus (3)

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• Testing the space-time geometry around black hole candidates with the analysis of the broad K$\alpha$ iron line
• Radiation processes in the vicinity of non-Schwarzschild and non-Kerr black holes