ROTATING NON-KERR BLACK HOLE AND ENERGY EXTRACTION

Abstract

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