https://doi.org/10.1140/epjc/s10052-016-4442-9
Regular Article - Theoretical Physics
Double shadow of a regular phantom black hole as photons couple to the Weyl tensor
1
Institute of Physics and Department of Physics, Hunan Normal University, Changsha, 410081, Hunan, People’s Republic of China
2
Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Hunan Normal University, Changsha, 410081, Hunan, People’s Republic of China
3
Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, 410081, Hunan, People’s Republic of China
* e-mail: csb3752@hunnu.edu.cn
** e-mail: csb3752@163.com
Received:
16
June
2016
Accepted:
14
October
2016
Published online:
1
November
2016
We have studied the shadow of a regular phantom black hole as photons couple to the Weyl tensor. We find that due to the coupling photons with different polarization directions propagate along different paths in the spacetime so that there exists a double shadow for a black hole, which is quite different from that in the non-coupling case where only a single shadow emerges. The overlap region of the double shadow, the umbra, of the 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 the Weyl tensor. Our results show that the coupling brings about richer behaviors of the propagation of coupled photon and the shadow of the black hole in the regular phantom black hole spacetime.
© The Author(s), 2016
