Quantum-Corrected Hawking Radiation from Near-Extremal Kerr-Newman Black Holes

Abstract: Near-extremal black holes have a long AdS$_2$ throat in their near-horizon region. Quantum fluctuations in the throat region are effectively governed by a quantum version of Jackiw-Teitelboim gravity with matter and are strongly coupled at low temperatures. We investigate how these quantum fluctuations affect the spectrum of emission of particles during Hawking radiation. We systematically consider the cases of Kerr and Kerr-Newman black holes for emission of scalar particles and discuss photon and graviton emission from the Kerr background. We find that at very low temperatures the quantum fluctuations radically change the nature of particle emission. Unlike the generic suppression of particle emission in the spherically symmetric Reissner-Nordstr\"om case, we uncover that for particles with non-vanishing angular momentum, the quantum-corrected emission can be substantially enhanced with respect to the standard semiclassical result.