Ultraspinning limits and super-entropic black holes

Understand

By employing the new ultraspinning limit we construct novel classes of black holes with non-compact event horizons and finite horizon area and study their thermodynamics.

• Our ultraspinning limit can be understood as a simple generating technique that consists of three steps: i) transforming the known rotating AdS black hole solution to a special coordinate system that rotates (in a given 2-plane) at infinity ii) boosting this rotation to the speed of light iii) compactifying the corresponding azimuthal direction.
• In so doing we qualitatively change the structure of the spacetime since it is no longer possible to return to a frame that does not rotate at infinity.
• The obtained black holes have non-compact horizons with topology of a sphere with two punctures.