A World without Pythons would be so Simple

TL;DR

This paper demonstrates a boundary reconstruction method for bulk operators in holography, establishing a duality with a coarse-grained CFT state and providing insights into black hole uniqueness.

Contribution

It introduces a simple wedge reconstruction technique using causal bulk propagation, contrasting the Python's lunch conjecture, and links it to a coarse-grained CFT state and black hole uniqueness.

Findings

Reconstruction of simple wedge operators via causal propagation.

Establishment of the Simple Entropy dual for marginally trapped surfaces.

Identification of a coarse-grained CFT state dual to the simple wedge.

Abstract

We show that bulk operators lying between the outermost extremal surface and the asymptotic boundary admit a simple boundary reconstruction in the classical limit. This is the converse of the Python's lunch conjecture, which proposes that operators with support between the minimal and outermost (quantum) extremal surfaces - e.g. the interior Hawking partners - are highly complex. Our procedure for reconstructing this "simple wedge" is based on the HKLL construction, but uses causal bulk propagation of perturbed boundary conditions on Lorentzian timefolds to expand the causal wedge as far as the outermost extremal surface. As a corollary, we establish the Simple Entropy proposal for the holographic dual of the area of a marginally trapped surface as well as a similar holographic dual for the outermost extremal surface. We find that the simple wedge is dual to a particular coarse-grained CFT state, obtained via averaging over all possible Python's lunches. An efficient quantum circuit converts this coarse-grained state into a "simple state" that is indistinguishable in finite time from a state with a local modular Hamiltonian. Under certain circumstances, the simple state modular Hamiltonian generates an exactly local flow; we interpret this result as a holographic dual of black hole uniqueness.