Encoding beyond cosmological horizons in de Sitter JT gravity

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.

Automated summary

Black holes and cosmology share common properties, leading to the question of whether our understanding of black holes can apply to cosmology. We discuss a paradox that arises if observers can access what lies beyond their cosmological horizon in the same way as they can access what lies beyond a black hole horizon, violating the no-cloning theorem of quantum mechanics. However, we argue that the paradox can be avoided in controlled examples through the use of the gravity path integral.