Dynamics of charged particles and magnetic dipoles around magnetized quasi-Schwarzschild black holes

Abstract

In the present paper, we have investigated the motion of charged particles together with magnetic dipoles to determine how well the spacetime deviation parameter epsilon and external uniform magnetic field can mimic the spin of a rotating Kerr black hole. Investigation of charged particle motion has shown that the deviation parameter epsilon in the absence of an external magnetic fields can mimic the rotation parameter of the Kerr spacetime up to a/M approx 0.5. The combination of an external magnetic field and deviation parameter can do even a better job mimicking the rotation parameter up to a/Msimeq 0.93, which corresponds to the rapidly rotating case. Study of the dynamics of the magnetic dipoles around quasi-Schwarzschild black holes in the external magnetic field has shown that there are degeneracy values of the ISCO radius of test particles at epsilon _{cr}>epsilon ge 0.35 which may lead to two different values of the innermost stable circular orbit (ISCO) radius. When the deviation parameter is in the range of epsilon in (-1, 1), it can mimic the spin of a rotating Kerr black hole in the range a/M in (0.0537, 0.3952) for magnetic dipoles with values of the magnetic coupling parameter beta in [-0.25, 0.25] in corotating orbits.