Double shadow of a regular phantom black hole as photons couple to the Weyl tensor

Yang Huang,Jiliang Jing,Songbai Chen

doi:10.1140/epjc/s10052-016-4442-9

Yang Huang, Jiliang Jing + Show 1 more

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https://doi.org/10.1140/epjc/s10052-016-4442-9

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Abstract

We have studied the shadow of a regular phantom black hole as photons couple to Weyl tensor. We find that the coupling yields that photons with different polarization directions propagate along different paths in the spacetime so that there exits double shadow for a black hole, which is quite different from that in the non-coupling case where only a single shadow emerges. The umbra of black hole increases with the phantom charge and decreases with the coupling strength. The dependence of the penumbra on the phantom charge and the coupling strength is converse to that of the umbra. Combining with the supermassive central object in our Galaxy, we estimated the shadow of the black hole as the photons couple to Weyl tensor. Our results show that the coupling brings richer behaviors of the propagation of coupled photon and the shadow of the black hole in the regular phantom black hole spacetime.

Highlights

It is well known that the shadow of the black hole is determined by the propagation of light ray in the spacetime, which depends on the parameters of background black hole, the properties of light itself and the interactions between light and other fields
Considering that the light radiated from the source could be white light which can be separated into two kinds of linearly polarized light beams, it is naturally expected that there exists a double shadow of a regular phantom black hole as photons couple to the Weyl tensor
One can find that the umbra of the black hole increases with the phantom charge and decreases with the coupling strength

Summary

Introduction

It is well known that the shadow of the black hole is determined by the propagation of light ray in the spacetime, which depends on the parameters of background black hole, the properties of light itself and the interactions between light and other fields. 2, we present equation of motion for the photons coupled to the Weyl tensor in the regular phantom black hole spacetime and study the effects of the coupling on the inner circular orbit radius of the photon around the black hole. 3, we will investigate the dependence of the double shadow on the phantom charge of the black hole, the photon polarization directions and the coupling between photon and Weyl tensor.

Results

Conclusion