Particle motions around regular black holes

Abstract

We investigate the bound orbits of massive/massless, neutral particles and photons moving around regular black holes of Fan and Wang. For massive particles, we show the existence of stable/unstable circular orbits and the charge dependence of the radius of the innermost stable circular orbit. Remarkably, we find an unstable circular orbit of photons inside the event horizon. For massless particles and photons, we show that both stable and unstable circular orbits can exist in a regular and horizonless spacetime with a slight overcharge. Then, we also discuss the periapsis shift of massive neutral particles orbiting around the black hole, and show that the charge gives a negative correction to the shift for black holes with small nonlinearity of electrodynamics.

19 pages, 8 figures; v2: analysis of photon orbits improved, refs added, 21 pages; v3: published version, fixed minor typos, fixed figures, 20 pages

References in corpus (10)

• Construction of Regular Black Holes in General Relativity
• Light ring stability in ultra-compact objects
• Light rings as observational evidence for event horizons: long-lived modes, ergoregions and nonlinear instabilities of ultracompact objects
• Circular motion of neutral test particles in Reissner-Nordström spacetime
• Regular black holes: Electrically charged solutions, Reissner-Nordström outside a de Sitter core
• Gravitational lensing by a regular black hole
• Circular geodesics of Bardeen and Ayon-Beato-Garcia regular black-hole and no-horizon spacetimes
• Relaxations of perturbations of spacetimes in general relativity coupled to nonlinear electrodynamics
• Quest for realistic non-singular black-hole geometries: Regular-center type
• Can a light ray distinguish charge of a black hole in nonlinear electrodynamics?

Cited by in corpus (4)

• Light rings and causality for nonsingular ultracompact objects sourced by nonlinear electrodynamics
• The Existence and Distribution of Photon Spheres Near Spherically Symmetric Black Holes -- A Geometric Analysis
• A General Discussion on Photon Spheres in Different Categories of Spacetimes
• Gravitational Entropy of Hayward Black Hole