Energy extraction from the accelerating Kerr black hole via magnetic reconnection in the plunging region and circular orbit region

TL;DR

This paper explores how magnetic reconnection can be used to extract energy from accelerating Kerr black holes, revealing that acceleration enhances energy extraction efficiency especially near extremality and varies between the plunging and circular orbit regions.

Contribution

It introduces the effects of acceleration on magnetic reconnection energy extraction in Kerr black holes, highlighting differences from non-accelerating cases and analyzing efficiency variations.

Findings

Higher energy extraction efficiency at larger radii in the plunging region for accelerating black holes.

Acceleration parameter enhances energy extraction near extremality but impedes it away from extremality.

Efficiency in the plunging region exceeds that in the circular orbit region, especially with larger acceleration.

Abstract

Based on the magnetic reconnection mechanism, this study investigates how to extract energy effectively from an accelerating Kerr black hole in the plunging region and circular orbit region. After introducing the properties of accelerating black holes, including the event horizon, ergosphere, circular orbits, and innermost stable circular orbit, we investigate the magnetic reconnection process in the plunging region. Specifically, we analyze variations of the azimuthal angle with respect to the acceleration, examine changes in energy per enthalpy of decelerated plasma, and plot energy extraction efficiency along with permissible energy extraction regions. Results show that in the plunging region, at larger radii of reconnection locations, the accelerating black hole exhibits higher energy extraction efficiency than a Kerr black hole. Away from extremality, the acceleration parameter impedes energy extraction, while near extremality, it enhances extraction. We also study energy extraction in circular orbit region by plotting energy extraction efficiency within permissible regions. We find that the permissible energy extraction area is reduced and the efficiency exceeds that of Kerr black holes due to the existence of acceleration parameter. Larger acceleration parameters yield more effective energy extraction regardless of extremality, which is different from that in the plunging region. Additionally, energy extraction efficiency in the plunging region surpasses that in the circular orbit region, aligning with prior conclusions.