Energy Extraction From Non-Coalescing Black Hole Binaries

TL;DR

This paper explores the theoretical possibility of extracting energy from non-coalescing black hole binaries using the Penrose process, analyzing the ergosphere and efficiency in specific spacetime models.

Contribution

It introduces the concept of a generalized ergosphere in binary black hole spacetimes and demonstrates energy extraction mechanisms extending to Kerr black hole pairs.

Findings

Existence of negative energy orbits outside the event horizon.

Energy extraction via particle scattering in binary black hole spacetimes.

Explicit examples of optimized energy extraction processes.

Abstract

We define and sketch the generalized ergosphere of the Majumdar-Papapetrou (MP) spacetime. In particular, we demonstrate the existence of closed orbits of negative energy that live outside the event horizon of such a spacetime. Relying on the Penrose process mechanism, we use these orbits to illustrate the possibility of energy extraction from a MP binary black hole by particle scattering. We also analyze the efficiency of the process, and construct explicit examples that optimize the extraction of energy. Lastly, we show how such concepts can be extended to a pair of non-coalescing Kerr black holes described by the Cabrera-Munguia, Manko and Ruiz (CMMR) metric.