Repetitive Penrose process in Konoplya-Zhidenko rotating non-Kerr black holes

TL;DR

This study explores how the deformation parameter affects the efficiency and energy extraction in the repetitive Penrose process around Konoplya-Zhidenko rotating non-Kerr black holes, revealing optimal conditions for energy utilization.

Contribution

It introduces the analysis of the repetitive Penrose process in non-Kerr black holes with deformation parameters, highlighting their impact on energy extraction efficiency and optimal initial conditions.

Findings

Larger deformation parameter increases energy return and efficiency at higher decay radii.

Smaller deformation parameter yields a higher maximum energy return on investment.

Optimal initial deformation parameter maximizes energy utilization efficiency.

Abstract

This paper investigates the repetitive Penrose process in Konoplya-Zhidenko rotating non-Kerr black hole, exploring the influence of the deformation parameter on the repetitive Penrose process. After a brief review of the Konoplya-Zhidenko rotating non-Kerr black hole, we study the fundamental equations of the Penrose process in this spacetime, examine the iterative stopping conditions required for the repetitive Penrose process, and obtain the corresponding numerical results. It is concluded that, in addition to previously observed phenomena, under the same decay radius, a larger initial dimensionless deformation parameter $\hat{\eta}$ leads to greater values of the energy return on investment and energy utilization efficiency, particularly at higher decay radii. Furthermore, a smaller initial $\hat{\eta}$ results in a larger maximum value of the energy return on investment. For energy utilization efficiency, the initial $\hat{\eta}$ should take an intermediate value to maximize its peak. Additionally, we find that a larger initial $\hat{\eta}$ corresponds to a smaller maximum value of the extracted energy.