Negative mass black holes in de Sitter space

We show that asymptotically de Sitter black holes of negative mass can exist in Lovelock gravity. Such black holes have horizon geometries with nonconstant curvature and are known as exotic black holes. We explicitly examine the case of Gauss-Bonnet gravity. We briefly discuss the positive mass case where we show how the transverse space geometry affects whether a black hole will exist or not. For negative mass solutions we show how three different black hole spacetimes are possible depending on the transverse space geometry. We also provide closed form bounds for the geometric parameters to ensure that a black hole spacetime is observed. We close with a discussion of the massless case, where there are many different spacetimes that are permitted.

Automated summary

We demonstrate the existence of asymptotically de Sitter black holes of negative mass in Lovelock gravity. These black holes have horizon geometries with nonconstant curvature and are known as exotic black holes. We specifically study the case of Gauss-Bonnet gravity. We discuss the impact of transverse space geometry on the existence of black holes for both positive and negative mass solutions and provide closed form bounds for geometric parameters.