Encoding beyond cosmological horizons in de Sitter JT gravity

TL;DR

This paper explores the parallels between black hole and cosmological horizons in de Sitter JT gravity, addressing a quantum no-cloning paradox arising from horizon observer-dependence and analyzing how gravity path integrals resolve it.

Contribution

It introduces a paradox related to observer-dependent cosmological horizons and demonstrates how gravity path integrals can resolve this issue in de Sitter JT gravity.

Findings

The paradox arises from horizon observer-dependence and potential information cloning.

Gravity path integrals can avoid the paradox in controlled examples.

The study extends black hole horizon understanding to cosmological horizons.

Abstract

Black hole event horizons and cosmological event horizons share many properties, making it natural to ask whether our recent advances in understanding black holes generalize to cosmology. To this end, we discuss a paradox that occurs if observers can access what lies beyond their cosmological horizon in the same way that they can access what lies beyond a black hole horizon. In particular, distinct observers with distinct horizons may encode the same portion of spacetime, violating the no-cloning theorem of quantum mechanics. This paradox is due precisely to the observer-dependence of the cosmological horizon -- the sharpest difference from a black hole horizon -- although we will argue that the gravity path integral avoids the paradox in controlled examples.