Scattering of photons in a two fixed extreme Reissner‐Nordstrom black hole system

We study the scattering of light by two fixed extreme Reissner‐Nordstrom black holes. We identify the set of unstable periodic orbits of the fractal repeller that describes the chaotic escape dynamics of photons. The main quantities of chaos associated with the repeller are obtained from the analysis of the linear stability of these orbits. The escape rate obtained from the periodic orbit theory is compared with the one obtained from the evolution of statistical ensembles of photons. An analytic estimate of the escape rate in the proximity of a perturbed black hole is also provided.