High energy physics in the vicinity of rotating black holes

TL;DR

This paper investigates particle collisions near rotating black holes, revealing conditions under which extremely high energies can be achieved, especially involving particles on specific geodesic trajectories within the ergosphere.

Contribution

It classifies all relevant geodesics near extremal rotating black holes and analyzes scenarios leading to unlimited collision energies, including critical particle trajectories.

Findings

High-energy collisions possible near black hole horizons.

Classification of geodesics based on extremal spherical orbits.

Conditions for unlimited energy growth in particle collisions.

Abstract

The aim of the paper is the consideration of particle collisions in the vicinity of the horizon of rotating black holes. Existence of geodesics for massive and massless particles arising from the region inside of the gravitational radius in ergosphere leads to the different possibilities to get very high energy in the centre mass frame of two particles. The classification of all such geodesics on the basis of the proved theorem for extremal spherical orbits is given. Case of the unlimited growth of energy for the situation when one of the particles (the critical one) is moving along the "white hole" geodesic with the close to the upper limit angular momentum while the other particle is on the usual geodesic and the case of the unlimited negative angular momentum of the first particle are considered.