Speaker
Description
Boundaries play a foundational role in gravity. In this talk, I will review the novelty of finite timelike boundaries, particularly in the context of gravitational thermodynamics. Specifically, I will demonstrate how finite Dirichlet boundaries resolve prior confusions about the thermal description of the de Sitter static patch. Then I will show that finite conformal boundaries, where the conformal class of the boundary induced metric and the trace of the extrinsic curvature are fixed, yield new kinds of horizon thermodynamics. Notably, systems with cosmological horizons are rendered thermally stable, while the entropy for near-extremal black holes features new scaling laws at low-temperature. Moreover, the effective two-dimensional dilaton-gravity characterizing deviations away from extremality is not JT gravity, and the effective description of a dynamical conformal boundary in 3D gravity looks like Schwarzian theory coupled to one-dimensional quantum gravity.
