Epicyclic oscillations of charged particles in stationary solutions immersed in a magnetic field with application to the Kerr--Newman black hole

TL;DR

This paper derives formulas for the oscillation frequencies of charged particles in stationary spacetimes with magnetic fields, applying them to Kerr--Newman black holes to uncover new stable orbit phenomena.

Contribution

It provides general expressions for epicyclic frequencies of charged particles in stationary magnetic fields, with novel insights into stable orbits around Kerr--Newman black holes.

Findings

Existence of radially and vertically stable orbits inside the event horizon.

New effects related to stable circular orbits in Kerr--Newman spacetime.

Application of formulas to black hole physics with physical implications.

Abstract

We consider a stationary metric immersed in a uniform magnetic field and determine general expressions for the epicyclic frequencies of charged particles. Applications to the Kerr--Newman black hole is reach of physical consequences and reveals some new effects among which the existence of radially and vertically stable circular orbits in the region enclosed by the event horizon and the so-called {\textquotedblleft innermost\textquotedblright} stable circular orbit in the plane of symmetry.