Rotating and twisting charged black holes with cloud of strings and quintessence as a particle accelerator

TL;DR

This paper investigates how various parameters like rotation, twist, string cloud, quintessence, and charge influence the horizons and ergosphere of charged black holes, and explores conditions for particle acceleration to arbitrarily high energies near extremal black holes.

Contribution

It derives equations of motion and effective potential for particles around such black holes and analyzes the conditions under which the center-of-mass energy can become arbitrarily large.

Findings

CM energy can be arbitrarily high for extremal black holes with suitable particle angular momentum.

Non-extremal black holes do not allow infinite CM energy regardless of particle angular momentum.

Parameters like rotation, twist, and string cloud significantly affect black hole horizons and particle dynamics.

Abstract

In this paper, we study the effects of the rotation parameter $a$, the twist parameter $n$, the string cloud parameter $b$, the quintessence state parameter $\omega _{q}$ and the charge parameter $q$ on the horizons and ergosphere of rotating and twisting charged black holes with cloud of strings and quintessence, and obtain the equations of motion and effective potential of the particle on the equatorial plane of black hole. We find that a particle with the critical angular momentum $L = L_C$ falling from infinity reaches the event horizon($u^r$=0) and satisfies the circular orbit condition $V_{e f f}={V_{e f f}}'=0$. We derive the expression of the centre-of-mass (CM) energy of two particles with different masses from the equations of particle motion. We show that the CM energy can be arbitrarily large for extremal black holes when the particles reach the event horizon by adjusting the angular momentum of the incident particles. However, for non-extremal black holes, the CM energy of particles that reach the event horizon cannot diverge by adjusting the angular momentum of the incident particles.