Black-hole evaporation, cosmic censorship, and a quantum lower bound on the Bekenstein-Hawking temperature

The semi-classical Hawking evaporation process of Reissner-Nordstroem black holes is analyzed. It is shown that this quantum mechanism may turn a near-extremal black-hole spacetime with T_BH 2/G²M³ into an horizonless naked singularity, thus violating the Penrose cosmic censorship conjecture. It is therefore conjectured that, within the framework of a self-consistent quantum theory of gravity, the Bekenstein-Hawking temperature should be bounded from below by the simple relation T_BH >or similar ℎ²/G²M³. (orig.)