Holography, degenerate horizons and entropy Original Research Article

We show that a realization of the correspondence AdS2/CFT1 for near extremal Reissner–Nordström black holes in arbitrary dimensional Einstein–Maxwell gravity exactly reproduces, via Cardyʹs formula, the deviation of the Bekenstein–Hawking entropy from extremality. We also show that this mechanism is valid for Schwarzschild–de Sitter black holes around the degenerate solution dS2×Sn. These results reinforce the idea that the Bekenstein–Hawking entropy can be derived from symmetry principles.