Black hole scalarization in Gauss-Bonnet extended Starobinsky gravity

We propose a class of higher-derivative gravities that can be viewed as the Gauss-Bonnet extension Starobinsky model. The theory admits Minkowski spacetime vacuum whose linear spectrum consists graviton and massive scalar mode. In addition to usual Schwarzschild black hole, we use numerical analysis establish in some suitable mass range, new holes carrying hair emerge. hole serves "wall" separating naked singularity wormholes parameter space hair. Our results also indicate although hairy have different geometry, their entropy temperature are same for mass.