Shadow of Schwarzschild-Tangherlini black holes (1707.07125v1)

Abstract: We study the shadow cast by the H$D$ Schwarzschild-Tangherlini black hole, and analytically calculate the influence of extra dimensions on the shadow of a black hole. A black hole casts a shadow as an optical appearance because of its strong gravitational field which is known to be a dark zone covered by a circle for a Schwarzschild black hole. We demonstrate that the null geodesic equation can be integrated by Hamilton-Jacobi approach, which enables us to investigate the shadow cast by the H$D$ Schwarzschild-Tangherlini black holes. Interestingly, it turns out that, for fixed values of the mass parameter, the shadow in H$D$ spacetimes are smaller when compared with 4$D$ Schwarzschild black hole. Further, the shadows of H$D$ Schwarzschild-Tangherlini black holes are concentric circles with a radius of the circle decreases with increase in $D$. We visualize the photon regions and the shadows in various dimensions for different values of the parameters, and the energy emission rates are is also investigated. Our results, in the limit $D=4$, reduced exactly to \emph{vis-$\grave{a}$-vis} Schwarzschild black hole case.