Black holes and particles with zero or negative energy

TL;DR

This paper explores particles with zero or negative energy in the ergosphere of rotating black holes, analyzing their properties, implications for black hole extremality, and potential for unlimited energy extraction through collisions.

Contribution

It provides a new proof that extreme black holes cannot exist and examines the energy dynamics of particles with zero or negative energy in black hole ergospheres.

Findings

Sign of particle energy is determined by angular velocity in the ergosphere

Extreme black holes cannot exist, as proven in the paper

Unlimited energy increase possible in particle collisions involving negative or zero energy particles

Abstract

We study properties of particles with zero or negative energy and a nonzero orbital angular momentum in the ergosphere of a rotating black hole. We show that the sign of the particle energy is uniquely determined by the angular velocity of its rotation in the ergosphere. We give a simple proof of the fact that extreme black holes cannot exist. We investigate the question of the possibility of an unlimited energy increase in the center-of-mass system of two colliding particles, one or both of which have negative or zero energy.