Geodesic Structure of Naked Singularities in AdS${}_3$ Spacetime

Abstract

We present a complete study of the geodesics around naked singularities in AdS${}_3$, the three-dimensional anti-de Sitter spacetime. These stationary spacetimes, characterized by two conserved charges --mass and angular momentum--, are obtained through identifications along spacelike Killing vectors with a fixed point. They are interpreted as massive spinning point particles, and can be viewed as three-dimensional analogues of cosmic strings in four spacetime dimensions. The geodesic equations are completely integrated and the solutions are expressed in terms of elementary functions. We classify different geodesics in terms of their radial bounds, which depend on the constants of motion. Null and spacelike geodesics approach the naked singularity from infinity and either fall into the singularity or wind around and go back to infinity, depending on the values of these constants, except for the extremal and massless cases for which a null geodesic could have a circular orbit. Timelike geodesics never escape to infinity and do not always fall into the singularity, namely, they can be permanently bounded between two radii. The spatial projections of the geodesics (orbits) exhibit self-intersections, whose number is particularly simple for null geodesics. As a particular application, we also compute the lengths of fixed-time spacelike geodesics of the static naked singularity using two different regularizations.

22 pages, 6 tables and 4 figures containing 10 geodesics orbits. Some clarifications have been included and some paragraphs were reorganized along the text. Table 6 has been enlarged and a new figure was added

References in corpus (3)

• Entwinement and the emergence of spacetime
• Gravitational perturbation of the BTZ black hole induced by test particles and weak cosmic censorship in AdS spacetime
• Quantum-corrected black holes and naked singularities in (2+1)-dimensions

Cited by in corpus (8)

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• Perihelion Precession and Shadows near Blackholes and Naked Singularities
• Precession and Lense-Thirring effect of hairy Kerr spacetimes
• Energy extraction from Janis-Newman-Winicour naked singularity
• Overspinning naked singularities in AdS${}_3$ spacetime
• Spinning Particle Geometries in AdS${}_3$/CFT${}_2$