Probing a black-bounce-Reissner–Nordström spacetime with precessing and periodic motion

• Published in: The European physical journal. C, Particles and fields Vol. 82; no. 10; pp. 1 - 14
• Main Authors: Zhang, Jing, Xie, Yi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2022; Springer; Springer Nature B.V; SpringerOpen
• Subjects: Astronomy; Astrophysics and Cosmology; Black holes; Circular orbits; Diameters; Elementary Particles; Event horizon; Hadrons; Heavy Ions; Investigations; Measurement Science and Instrumentation; Nuclear Energy; Nuclear Physics; Orbital stability; Orbits; Parameters; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Regular Article - Theoretical Physics; Relativity; Spacetime; String Theory
• ISSN: 1434-6052; 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-022-10846-4

We investigate the precessing and periodic orbits of a test timelike particle around the black-bounce-Reissner–Nordström spacetime which is characterized by its charge and bounce parameter. Its marginally bound orbit and innermost stable circular orbit are obtained in the exact forms. We pay closely attention to its precessing orbits and find the resulting relativistic periastron advance. We also study its periodic orbits and demonstrate that small variations of the charge and bounce parameter can make the motion jump among the periodic and precessing orbits. In these two kinds of orbits, we find a distinct degeneracy that some specific combinations of the charge and bounce parameters can generate exactly the same orbital motion in the black-bounce-Reissner–Nordström spacetime, which can also mimic those of the Schwarzschild black hole. In order to break such a degeneracy, we make use of the precession of S2 star around Sgr A* detected by GRAVITY together with the shadow diameter of Sgr A* measured by Event Horizon Telescope and find preliminary bounds on the charge and bounce parameter.