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

Abstract

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.

Optical properties of a Brane-World black hole as photons couple to the Weyl tensor

“…And they coincide with the conclusions in Ref. [57]. In order to see more clearly the effect of β and the coupling parameter λ on the angular radius of penumbra of the black hole θ sh , we have made Fig.…”

“…Recently, Chen studied the strong gravitational lensing for the photons coupled to Weyl tensor in Schwarzschild and Kerr black hole spacetimes [55,56]. And Huang discussed the double shadow of a regular phantom black hole as photons couple to the Weyl tensor [57]. Abbas studied the strong gravitational lensing for photons coupled to Weyl tensor in Kiselev black hole [58].…”

Chaotic shadow of a non-Kerr rotating compact object with quadrupole mass moment

“…Moreover, the shadows of black holes characterizing by other parameters have been studied recently [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49], which indicate that these parameters give rise to the richer silhouettes for black hole shadows in various theories of gravity.…”

Polarization effects in Kerr black hole shadow due to the coupling between photon and bumblebee field

“…Repeating the similar operations in refs. [43][44][45][46][47][48][49][50][51][52][53][54], one can obtain the position of photon's image in observer's sky 11) where the spatial position of observer is set to (r obs , θ obs ). In figures 2-5, we present black hole shadow for the different coupling constant α and rotation parameter a.…”

“…Generally, the black hole shadow in the observer's sky is determined by black hole, the propagation of light ray and the position of observer. It is shown that black hole shadow depends also on the polarization of light itself if we consider some interactions between electromagnetic and gravitational fields, such as Weyl tensor coupling [11], which can be attributed to the birefringence phenomenon of light originating from such kinds of couplings. This interesting feature could trigger the further study of black hole shadows under interactions between electromagnetic and other fields.…”