May 6 – 10, 2024
US/Eastern timezone

Black hole as a semi-classical configuration with maximum entropy

May 9, 2024, 3:10 PM
15m
FAU FTL Room 312

FAU FTL Room 312

Cosmology, Black Holes, and other applications/phenomenology Cosmology, Black Holes, and other applications/phenomenology

Speaker

Yuki Yokokura (RIKEN, Interdisciplinary Theoretical and Mathematical Sciences Program)

Description

One property that characterizes a black hole is that it maximizes entropy in a finite region with a fixed surface area. It may be a more fundamental one than the existence of a horizon in the context of quantum gravity, where there is no notion of continuum geometry. Using this characterization, we consider the interior of a black hole in the 4D semi-classical Einstein equation. For simplicity, we consider spherical static finite configurations for various sufficiently excited quantum states, apply thermodynamic typicality to a small subsystem, and estimate entropy including self-gravity, to derive its upper bound. By the saturation condition and consistency with local thermodynamics, the entropy-maximized configuration is uniquely determined as a radially uniform dense configuration with near-Planckian curvatures and a surface just outside the Schwarzschild radius. The interior metric is a non-perturbative self-consistent solution in the Planck constant. The maximum entropy, given by the volume integral of the entropy density, becomes the Bekenstein-Hawking formula due to the strong self-gravity, yielding the Bousso bound. Thus, this compact dense configuration may be a candidate for black hole in quantum theory. We finally discuss some similarities to quantum gravitational condensation in group field theory.

Author

Yuki Yokokura (RIKEN, Interdisciplinary Theoretical and Mathematical Sciences Program)

Presentation materials

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