Five-dimensional Myers-Perry Black Holes as Particle Accelerators

TL;DR

This paper investigates the particle acceleration capabilities of five-dimensional Myers-Perry black holes, revealing conditions for ultraenergetic collisions and novel properties distinct from four-dimensional black holes.

Contribution

It provides a systematic analysis of five-dimensional Myers-Perry black holes, including proofs and conditions for high-energy collisions, and explores effects of naked singularities.

Findings

Unextremal black holes cannot produce high-energy collisions.

Critical particle parameters enable ultraenergetic collisions in extremal black holes.

Divergent CM energy can occur at naked singularities.

Abstract

It has been shown that black holes could be used as particle accelerators to create arbitrarily high center-of-mass (CM) energy if certain critical conditions are satisfied. Most studies so far are confined in four-dimensional spacetimes. In this paper, we present a systematic analysis on five-dimensional Myers-Perry black holes and find some novel properties compared to four-dimensional Kerr black holes. Firstly, we give a rigorous proof that untrhigh energy collisions cannot occur near a five-dimensional nonextremal black hole. Secondly, For extremal black holes, we find a critical condition on the particles' parameters causing ultraenergetic collisions. Thirdly, when the spacetime contains a naked singularity, we show that the CM energy could diverge at the singularity if one of the particle just bounces back at the singularity. Finally, we explore a special and important case where the naked singularity just begins to form. Surprisingly, the ultraenergetic collisions do not need any fine-turning in that case. However, we find that one of the conserved angular momentums must be nonzero.