Charged and magnetized particle motion around a static black hole in the Starobinsky–Bel–Robinson gravity

Abstract

Abstract In this work we focus on the effects of Starobinsky–Bel–Robinson (SBR) gravity parameter and external magnetic field on the motion of charged test particles and magnetic dipoles moving around a black hole in the selected gravity theory. We take the external magnetic field to be uniform and aligned along the axis of symmetry. Our results reveal that the effect of the SBR gravity parameter is very strong in the close environment of the central black hole while in the farther distances this effects diminishes very quickly. We see that the effect of the external magnetic field on the particle motion is always dominating over the SBR gravity parameter in farther distances. We show that for the motion of charged test particles the magnetic interaction can mimic the spin up to very rapid rotations for prograde motion of particles, while for the motion of magnetic dipoles magnetic interaction can mimic the spin completely for retrograde motion of such particles. We observe that in both scenarios, the SBR gravity parameter behaves as a weak mimicker of the spin of Kerr black hole. We apply the outcomes of our study to the scenario where a neutron star is assumed to behave as a magnetic dipole moving around the supermassive black hole Sgr $$A^\star $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>A</mml:mi> <mml:mo>⋆</mml:mo> </mml:msup> </mml:math> to investigate how the magnetic field and the SBR gravity coupling parameter $$\beta $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>β</mml:mi> </mml:math> affect the orbits of neutron stars orbiting the supermassive black hole.