Shadows and photon spheres with spherical accretions in the four-dimensional Gauss–Bonnet black hole

Abstract We investigate the shadows and photon spheres of the four-dimensional Gauss–Bonnet black hole with the static and infalling spherical accretions. We show that, for both cases, there always exist shadows and photon spheres. The radii of the shadows and photon spheres are independent of the p... View More