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arXiv · 2104.01340

Retrolensing by a spherically symmetric naked singularity

Gulmina Zaman Babar·Farruh Atamurotov·Abdullah Zaman Babar·Yen-Kheng Lim
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Abstract

Considering a strong field limit, we investigate the retrolensing phenomenon in the vicinity of a Janis-Newman-Winicour (JNW) naked singularity embedded in a scalar field. We assume that the light rays from a nearby source are reflected by the photon sphere of the naked singularity, acting as a lens, to create a pair of images. The analytic expressions of the lensing coefficients $\bar{a}$ and $\bar{b}$ are obtained, which are scalar dependent and discordant with \cite{Bozza:2002b}. Moreover, considering the powerful supermassive black hole candidates Sgr A* and M87*, we examined the influence of the scalar field on the apparent brightness and angular positions of the parity images. Our results are highlighted in correspondence with a non-scalar field gravity, specifically the Schwarzschild gravity. We have found that the brightness increases in the presence of the scalar field, while, the lensing coefficients $\bar{a}$, $\bar{b}$, the angular positions and the angular separation of the relativistic images experience a reverse effect.

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Gulmina Zaman Babar, Farruh Atamurotov, Abdullah Zaman Babar, Yen-Kheng Lim. 2021-04-03. Retrolensing by a spherically symmetric naked singularity. https://arxiv.org/abs/2104.01340

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