Energetics and optical properties of $6$-dimensional rotating black hole in pure Gauss-Bonnet gravity

Abstract

We study physical processes around a rotating black hole in pure Gauss-Bonnet (GB) gravity. In pure GB gravity, gravitational potential has slower fall off as compared to the corresponding Einstein potential in the same dimension. It is therefore expected that the energetics of pure GB black hole would be weaker, and our analysis bears out that the efficiency of energy extraction by Penrose process is increased to $25.8\%$ and particle acceleration is increased to $55.28\%$, and optical shadow of the black hole is decreased. These are the distinguishing in principle observable features of pure GB black hole.