EVOLUTION OF CHARGED EVAPORATING BLACK-HOLES

The evaporative evolution of charged nonrotating black holes is studied by numerically integrating a set of coupled differential equations describing the charge and mass as functions of time. We find that large charged black holes will evolve through a region (in the black-hole configuration space) of positive specific heat, undergoing two phase transitions as they evaporate. The region is approximately bounded by 34<(QM)2<1 and M>2.03×107M. Unlike rotating black holes (which always evolve toward the Schwarzschild limit), sufficiently large charged black holes will initially evolve toward the extreme Reissner-Nordström limit; their lifetime may be many orders of magnitude larger than the lifetime of a Schwarzschild black hole with the same initial mass. © 1990 The American Physical Society.