Reissner-Nordstrom Near Extremality from a Jackiw-Teitelboim Perspective

In this paper, we investigate the near-extremal thermodynamics of the Reissner-Nordstrom (RN) black hole. Our methodology is based on a duality that exists between the near-horizon geometry of the near-extremal RN sector and Jackiw-Teitelboim (JT) theory. First, the described correspondence is reviewed at the classical level. Next, we consider first-order perturbations in the dual JT geometry by incorporating a quantum scalar field into the formalism. The novelty of our approach is that the matter field is endowed with a 4-dimensional pedigree. We ultimately find that back-reaction effects prohibit the JT black hole from losing all of its mass. This outcome directly implies that an RN black hole can not reach extremality and, moreover, can not even come arbitrarily close to an extremal state.