Particle collisions near the cosmological horizon of a Reissner-Nordstr\"om de Sitter black hole

TL;DR

This paper demonstrates that particles can collide with arbitrarily high energy near the cosmological horizon of a Reissner-Nordström de Sitter black hole, even without the black hole being extremal, highlighting new conditions for high-energy collisions.

Contribution

It reveals that infinite center-of-mass energy collisions are possible near the cosmological horizon of RN-dS black holes without extremality, expanding understanding of particle acceleration in such spacetimes.

Findings

Infinite CM energy near the cosmological horizon for generic configurations

High charge-to-mass ratio required for particles to achieve critical conditions

No extremality needed for infinite energy collisions in RN-dS spacetime

Abstract

It has recently been shown that black holes can act as particle accelerators and two particles can collide with arbitrarily high center-of-mass (CM) energy under certain critical conditions. In this paper, we investigate particle collisions outside a Reissner-Nordstr\"om de Sitter (RN-dS) black hole. We find that infinite CM energy can be produced near the cosmological horizon for generic spacetime configurations. Remarkably, such infinite CM energy does not require the black hole to be extremal, in contrast to spacetimes in the absence of cosmological constants. However, since the charge of an astrophysical body is negligible, the required charge to mass ratio of the particle is extremely higher than that of any elementary particle.