Chaos and the Emergence of the Cosmological Horizon

Understand

We construct algebras of diff-invariant observables in a global de Sitter universe with two observers and a free scalar QFT in two dimensions.

• We work in the strict $G_N \rightarrow 0$ limit, but allow the observers to have an order one mass in cosmic units.
• The observers are fully quantized.
• In the limit when the observers have infinite mass and are localized along geodesics at the North and South poles, it was shown in previous work \cite{CLPW} that their algebras are mutually commuting type II$_1$ factors.