Effects of magnetic fields on spinning test particles orbiting Kerr-Bertotti-Robinson black holes

Abstract

In this paper, we study the kinematic effects of spinning test particles orbiting the Kerr-Bertotti-Robinson black hole. Employing with the Mathisson-Papapetrou-Dixon equations, we explore the dynamics of precessing orbits and distinct orbital types, including circular orbits and innermost stable circular orbits. Our results reveal the substantial impact of the magnetic field on the trajectories of spinning particles, particularly in regions characterized by significant radial distances. More importantly, our study shows that an augmented magnetic field necessitates an increased orbital angular momentum to uphold spinning particles within their characteristic orbits at equivalent radial distances. Our result contributes valuable insights to the understanding of the spinning celestial object motion around black holes endowed with magnetic fields.

Figures (4)

• Figure 1: Effective potentials of spinning particles around Kerr-BR black hole. (a) $a=0$, $l=4$, $s=0$. (b) $a=1$, $l=2$, $B=0$. (c) $a=0.1$, $l=4$, $s=0.5$. (d) $a=0.1$, $l=4$, $B=0.05$.
• Figure 2: Precessing orbits of spinning particles around Kerr-BR black hole. The top row shows plots of the intersections between the effective potential and the energy $e$; the middle row presents plots of the precessing orbits of spinning particles; and the bottom row displays plots of the contraction of the particle's four-velocity within the radial range. Each column corresponds to the same parameter set.
• Figure 3: Circular orbits of the spinning particles around Kerr-BR black hole. (a) $a=0.1$, $B=0.025$. (b) $a=0.1$, $s=1$.
• Figure 4: ISCOs (ISCOS/ISCOL) of the spinning particles around a Kerr-BR black hole. (a) ISCOS with $a=0.1$ and $B=0.05$. (b) ISCOL with $a=0.1$ and $B=0.05$. (c) ISCOS with $a=0.1$ and $s=0.5$. (d) ISCOL with $a=0.1$ and $s=0.5$.