Black-hole entropy and minimal diffusion

TL;DR

This paper models black-hole entropy using a nonlocal field theory, revealing a minimal diffusion scale where the spectral dimension diverges, impacting holographic entropy bounds.

Contribution

It introduces a diffusion process based on a nonlocal theory that exhibits a finite minimal scale and unusual spectral dimension flow, linking quantum gravity and holography.

Findings

Spectral dimension asymptotes four in the infrared

Diverges at a finite Planckian scale in the ultraviolet

Implications for entropy bounds and spacetime structure

Abstract

The density of states reproducing the Bekenstein-Hawking entropy-area scaling can be modeled via a nonlocal field theory. We define a diffusion process based on the kinematics of this theory and find a spectral dimension whose flow exhibits surprising properties. While it asymptotes four from above in the infrared, in the ultraviolet the spectral dimension diverges at a finite (Planckian) value of the diffusion length, signaling a breakdown of the notion of diffusion on a continuum spacetime below that scale. We comment on the implications of this minimal diffusion scale for the entropy bound in a holographic and field-theoretic context.