Pair production in near extremal Kerr-Newman black holes

The spontaneous pair production of charged scalars in a near-extremal Kerr-Newman (KN) black hole is analytically studied. It is shown that the existence condition for pair production is equivalent to the violation of the Breitenlohner-Freedman bound in an AdS2 space. The mean number of produced pairs in the extremal black hole has a thermal interpretation, in which the effective temperature for the Schwinger effect in the AdS2 space persistently holds, while the mean number in the near-extremal black hole has an additional factor of the Schwinger effect in the Rindler space. In addition, the holographic dual conformal field theory (CFT) descriptions of charged scalar pair production are realized in both the J and Q pictures in terms of the KN/CFTs correspondence.