Energy extraction from a Konoplya–Zhidenko rotating non-Kerr black hole

Abstract

We have investigated the properties of the ergosphere and the energy extraction by Penrose process in a Konoplya-Zhidenko rotating non-Kerr black hole spacetime. We find that the ergosphere becomes thin and the maximum efficiency of energy extraction decreases as the deformation parameter increases. For the case with a < M , the positive deformation parameter yields that the maximum efficiency is lower than that in the Kerr black hole with the same rotation parameter.However, for the superspinning case with a > M , we find that the maximum efficiency can reach so high that it is almost unlimited as the positive deformation parameter is close to zero, which is a new feature of energy extraction in such kind of rotating non-Kerr black hole spacetime.

Superradiance in Kerr-like black holes

“…Our results for superspinning configurations shown in Fig. 5 are compatible with the fact that the energy extraction by the Penrose process for the superspinning Johannsen-Psaltis [24] and Konoplya-Zhidenko metric can be significantly larger than for a Kerr black hole [74,75]. Analogously, for negative values of the deformation parameter, which correspond to more compact configurations, the volume of the ergoregion can be larger than that of a Kerr black hole with the same mass and spin, and as a consequence, the superradiant phenomenon can be enhanced.…”

Parametrized black holes: scattering investigation

“…( 2). This particular parametrization describes a black hole with two parameters, namely M and η, and the relation between the event horizon position and the ADM mass M is different from the Schwarzschild case [18,19]. We show the event horizon position as a function of the deformation parameter in Fig.…”

“…These deviations from General Relativity are noticed both in the rotating and non-rotating versions of the Konoplya-Zhidenko spacetime. The shadow [16], the strong gravitational lensing [17], and the energy extraction process [18] were studied for the rotating version of the solution. Additionally, the massless scalar field absorption was analyzed in the static case [19].…”

Particle dynamics in non-rotating Konoplya and Zhidenko black hole immersed in an external uniform magnetic field

“…[11] by Konoplya and Zhidenko (referred in this work as KZ black hole). The main aim behind this metric was to see if the detection of gravitational waves lead to the possibility of modified theories of gravity [12]. Some studies also suggest that a KZ spacetime might describe a real astrophysical black hole [13].…”