Collision of two general particles around a rotating regular Hayward's black holes

TL;DR

This paper investigates particle collisions near rotating Hayward black holes, showing that the deviation parameter g influences the ergoregion and collision energy, with extremal cases allowing arbitrarily high energies.

Contribution

It extends the BSW particle acceleration analysis to rotating Hayward black holes, revealing how the deviation parameter g affects collision energies and black hole properties.

Findings

Ergoregion area increases with g.

Extremal Hayward black holes can produce arbitrarily high collision energies.

Nonextremal cases have finite upper bounds for collision energy, increasing with g.

Abstract

The rotating regular Hayward's spacetime, apart from mass ($M$) and angular momentum ($a$), has an additional deviation parameter ($g$) due to the magnetic charge, which generalizes the Kerr black hole when $g\neq0$, and for $g=0$, it goes over to the Kerr black hole. We analyze how the ergoregion is affected by the parameter $g$ to show that the area of ergoregion increases with increasing values of $g$. Further, for each $g$, there exist critical $a_E$, which corresponds to a regular extremal black hole with degenerate horizons $r=r^E_H$, and $a_E$ decrease whereas $r^E_H$ increases with an increase in the parameter $g$. Ban{\~a}dos, Silk and West (BSW) demonstrated that the extremal Kerr black hole can act as a particle accelerator with arbitrarily high center-of-mass energy ($E_{CM}$) when the collision of two particles takes place near the horizon. We study the BSW process for two particles with different rest masses, $m_1$ and $m_2$, moving in the equatorial plane of extremal Hayward's black hole for different values of $g$, to show that $E_{CM}$ of two colliding particles is arbitrarily high when one of the particles takes a critical value of angular momentum. For a nonextremal case, there always exist a finite upper bound for the $E_{CM}$, which increases with the deviation parameter $g$. Our results, in the limit $g \rightarrow 0$, reduces to that of the Kerr black hole.