Nearly Degenerate dS Horizons from a 2-D Perspective

Some recent studies have implied that quantum fluctuations will prevent a near-extremal black hole from ever attaining a state of precise extremality. In this paper, we consider the analogous situation for the scenario of a nearly degenerate Schwarzschild-de Sitter black hole (of arbitrary dimensionality). For this purpose, we utilize a holographic type of duality between the solutions of interest and the near-massless sector of (two-dimensional) Jackiw-Teitelboim theory. After explicitly demonstrating this duality, we go on to argue that, on the basis of one-loop considerations, a similar censorship applies in this de Sitter context. That is, quantum back-reaction effects will conspire to prohibit a non-degenerate Schwarzschild-de Sitter spacetime from continuously evolving into a degenerate (i.e., Nariai) black hole solution.