Deflection of light rays by a spherically symmetric black hole in a dispersive medium

The influence of the medium on gravitational deflection light rays is widely discussed in literature for simplest non-trivial case: cold non-magnetized plasma. In this article, we generalize these studies to case an arbitrary transparent dispersive with a given refractive index. We calculate angle ray moving general spherically symmetric metric presence equation radius circular orbits also derived. discuss detail properties results and various special cases. particular, show that multiplying index by constant does not affect orbits. At same time, dispersion makes trajectories different from vacuum even spatially homogeneous medium. As one applications our results, correction when massive object surrounded but another application, present calculation shadow black hole Our can serve as basis plasma models beyond case.