Light trajectory and shadow shape in the rotating naked singularity

• Published in: The European physical journal. C, Particles and fields Vol. 82; no. 9; pp. 1 - 10
• Main Authors: Patel, Vishva, Tahelyani, Divya, Joshi, Ashok B., Dey, Dipanjan, Joshi, Pankaj S.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2022; Springer; Springer Nature B.V; SpringerOpen
• Subjects: Algorithms; Astronomy; Astrophysics and Cosmology; Black holes; Comparative analysis; Coordinate transformations; Cosmology; Elementary Particles; Gravitational lenses; Hadrons; Heavy Ions; Light; Measurement Science and Instrumentation; Nuclear Energy; Nuclear Physics; Photons; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Regular Article - Theoretical Physics; Relativity; Retrograde orbits; Rotation; Shadows; Singularities; Spacetime; String Theory; Theory of relativity
• ISSN: 1434-6052; 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-022-10638-w

In this paper, we investigate the light trajectories and shadow properties in the rotating version of null naked singularity (NNS) spacetime which is derived using the Newman–Janis algorithm without complexification method. We discuss some of the geometrical properties and causal structure of Rotating Naked Singularity (RNS) spacetime. The gravitational lensing in a rotating naked singularity is analyzed, and the results are compared to those of a Kerr black hole. In the case of a Kerr black hole, the photon sphere exists for both prograde and retrograde photon orbits, whereas for RNS, the photon sphere exists only for retrograde photon orbits. As a result, the naked singularity projects an arc-shaped shadow that differs from the contour-shaped shadow cast by a Kerr black hole.