A Paradox and its Resolution Illustrate Principles of de Sitter Holography

TL;DR

This paper resolves a paradox in de Sitter holography by showing that the apparent contradiction in correlation functions arises from gauge symmetry and the observer's role, clarifying fundamental principles of holographic duality in de Sitter space.

Contribution

It demonstrates that the paradox in de Sitter holography is resolved by understanding gauge symmetry and the observer's role, clarifying core principles of holographic duality.

Findings

Correlation functions are real due to gauge symmetry.

Time-reversal as a gauge symmetry explains the paradox.

Observer's role is essential in de Sitter holography.

Abstract

Semiclassical gravity and the holographic description of the static patch of de Sitter space appear to disagree about properties of correlation functions. Certain holographic correlation functions are necessarily real whereas their semiclassical counterparts have both real and imaginary parts. The resolution of this apparent contradiction involves the fact that time-reversal is a gauge symmetry in de Sitter space -- a point made by Harlow and Ooguri -- and the need for an observer (or quantum reference frame) as advocated by Chandrasekaran, Longo, Penington, and Witten.