Properties of particles in the ergosphere of black holes

TL;DR

This paper investigates particle trajectories with negative and zero energies in the ergosphere of rotating black holes, comparing them with positive energy trajectories and analyzing energy growth during collisions.

Contribution

It provides a detailed analysis of particle trajectories with negative and zero energies in the ergosphere, highlighting their properties and implications for energy growth during collisions.

Findings

Trajectories with negative and zero energies exist in the ergosphere.

Comparison with Minkowski space-time reveals unique ergosphere features.

Unbounded energy growth can occur during particle collisions in the ergosphere.

Abstract

A new feature of the rotating black holes is the existence in their ergosphere of trajectories of particles with negative and zero energies. Here we analyze general properties of such trajectories comparing them with usual trajectories of particles with positive energy. A comparison with the situation in rotating coordinate frame in Minkowski space-time is made. The possibility of the unbounded growth of the energy of two colliding particles in the centre of mass frame in the ergosphere is analysed.