The Price of Curiosity: Information Recovery in de Sitter Space

TL;DR

This paper investigates whether an observer in de Sitter space can recover hidden information behind their horizon, revealing that while possible, it leads to a singularity due to the formation of an island in a non-equilibrium setting.

Contribution

It demonstrates the emergence of quantum extremal islands in de Sitter space and analyzes their implications for information recovery and singularity formation in a weak gravity regime.

Findings

Information can be decoded before the Page time

An island appears earlier than expected, indicating non-trivial information dynamics

A singularity forms as a consequence of the island's emergence

Abstract

Recent works have revealed that quantum extremal islands can contribute to the fine-grained entropy of black hole radiation reproducing the unitary Page curve. In this paper, we use these results to assess if an observer in de Sitter space can decode information hidden behind their cosmological horizon. By computing the fine-grained entropy of the Gibbons-Hawking radiation in a region where gravity is weak we find that this is possible, but the observer's curiosity comes at a price. At the same time the island appears, which happens much earlier than the Page time, a singularity forms which the observer will eventually hit. We arrive at this conclusion by studying Jackiw-Teitelboim gravity in de Sitter space. We emphasize the role of the observer collecting radiation, breaking the thermal equilibrium studied so far in the literature. By analytically solving for the backreacted geometry we show how an island appears in this out-of-equilibrium state.