Energy extraction from a rotating black hole via magnetic reconnection: Bumblebee gravity

TL;DR

This paper investigates how magnetic reconnection can extract energy from rotating black holes within Bumblebee gravity, analyzing the effects of Lorentz symmetry breaking and Bumblebee charge on energy extraction efficiency.

Contribution

It extends previous models by exploring energy extraction in a Kerr-Sen-like spacetime influenced by Bumblebee gravity, highlighting the impact of additional parameters.

Findings

Energy extraction is more likely with higher Lorentz symmetry breaking and Bumblebee charge.

Energy extraction occurs closer to the black hole's center under certain parameters.

Optimal energy extraction aligns with scenarios near the marginal violation of cosmic censorship.

Abstract

Many efforts were made in order to better understand the energy extraction via magnetic reconnection from a rotating black hole, following the work of Comisso and Asenjo in 2021. We also tried to make some progress in our previous works, in which we discussed differences between bulk plasma with different streamlines and also defined the covering factor as an internal property of an accretion system to quantify its capability on extracting energy via magnetic reconnection from its central black hole. In this study, we aim to explore this topic within the framework of a Kerr-Sen-like spacetime induced from Bumblebee gravity, which, among various alternative theories of gravity beyond pure Einstein gravity, stands out as a promising candidate for explaining certain high energy astrophysical phenomena. More specifically, we would like to analyze the influence of the rate of Lorentz symmetry breaking and the Bumblebee charge, the two additional parameters in Bumblebee gravity except for the black hole mass and spin, on the energy extraction via magnetic reconnection. By analyzing the allowed regions for energy extraction and the variations of covering factor, we find that energy extraction becomes more likely to succeed and tends to occur closer to the central region when the spacetime carries bigger rate of Lorentz symmetry breaking and Bumblebee charge. Furthermore, our results indicate that the most favorable spacetime configuration for energy extraction via magnetic reconnection, when the extractable energy of the central black hole is determined, corresponds to the scenario in which the cosmic censorship hypothesis is marginally not violated.