Circular geodesic orbits in the equatorial plane of a charged rotating disc of dust

Abstract

Equatorial circular geodesic orbits of neutral test particles in the exterior spacetime of a charged rotating disc of dust are analyzed in dependence of its specific charge and a relativity parameter. The charged rotating disc of dust is an axisymmetric, stationary solution of the Einstein-Maxwell equations in terms of a post-Newtonian expansion. In particular, photon, marginally bound and marginally stable orbits are discussed. It turns out that general formulae in closed form for angular velocity, specific energy and specific angular momentum of the test particles can be derived, which hold for any (exterior) asymptotically flat, axisymmetric, stationary and reflection symmetric (electro-)vacuum spacetime. Furthermore, circular motion in the exterior spacetime of the charged rotating disc of dust is qualitatively very similar to that around a Kerr-Newman black hole for sufficiently large radii, but differs strongly in the respective closer vicinity.

12 pages, 8 figures; v2: final version, to appear in Phys. Rev. D

References in corpus (4)

• On the black hole limit of rotating discs of charged dust
• Post-Newtonian expansion of a rigidly rotating disc of dust with a constant specific charge
• Geometry of charged rotating discs of dust in Einstein-Maxwell theory
• Multipole moments of a charged rotating disc of dust in general relativity

Cited by in corpus (2)

• Imaging the destruction of a rotating regular black hole
• Equatorial stability analysis of dust particle orbits within a charged rotating disc of dust