Physics Letters B 807, 135535 (2020)                      arXiv link

Bounds on photon spheres and shadows of charged black holes in Einstein-Gauss-Bonnet-Maxwell gravity

Liang Ma, H. Lü

Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, Tianjin 300350, China

Abstract

We consider spherically symmetric and static charged black holes in Einstein-Gauss-Bonnet-Maxwell gravities in general D ≥ 5 dimensions and study their photon spheres and black hole shadows. We show that they all satisfy the sequence of inequalities recently proposed relating a black hole's horizon, photon sphere, shadow and its mass.