Black-hole entropy and minimal diffusion

Understand

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.