Speaker
Description
In this talk I examine four dimensional, near-extremal black holes in the presence of a finite boundary obeying conformal boundary conditions, where the conformal class of the induced metric and the trace of the extrinsic curvature are fixed. Working in Euclidean signature, I will describe the quasi-local gravitational thermodynamics, where the near-extremal regime is dominated by a double-scaling limit which reveals new scaling laws for the entropy at low temperatures. Upon spherical dimensional reduction, the effective two-dimensional dilaton-gravity theory that describes the near-extremal regime is shown not to be Jackiw-Teitelboim gravity (as is the case for finite Dirichlet boundaries). Working in Lorentzian signature, I will review the system’s linearized dynamics, characterizing the modes of metric perturbations. When the finite boundary is near the horizon of a near-extremal black hole, the system is rendered linearly stable. This provides the first example of a black hole in the presence of conformal boundaries that is well-posed, and both thermodynamically and (linearly) dynamically stable.