On collisions with unlimited energies in the vicinity of Kerr and Schwarzschild black hole horizons

TL;DR

This paper investigates how particle collisions near Kerr and Schwarzschild black hole horizons can achieve unlimited energies, analyzing the dynamics, velocities, and times involved in such high-energy events.

Contribution

It demonstrates that high-energy collisions near black hole horizons result from large relative velocities and Lorentz factors, providing detailed analysis of their dependence on proximity to the horizon.

Findings

High energies are due to large relative velocities and Lorentz factors.

The relative velocity depends on the distance to the horizon.

Calculated times for particle movement are within reasonable orders.

Abstract

Two particle collisions close to the horizon of the rotating nonextremal Kerr's and Schwarzschild black holes are analyzed. For the case of multiple collisions it is shown that high energy in the centre of mass frame occurs due to a great relative velocity of two particles and a large Lorentz factor. The dependence of the relative velocity on the distance to horizon is analyzed, the time of movement from the point in the accretion disc to the point of scattering with large energy as well as the time of back movement to the Earth are calculated. It is shown that they have reasonable order.