Entanglement and factorization in axion-de Sitter universes

We study the Renyi entropies and late-time bulk correlators between a pair of asymptotically de Sitter space universes connected through an Euclidean axion wormhole, in arbitrary dimensions. Assuming the validity of the de Sitter (dS)/conformal field theory (CFT) correspondence, we calculate the holographic Renyi entropy between the pair of universes, anchoring the corresponding extremal surfaces to $\mathcal{I}^+$ in each universe. The results can be recast in terms of a reduced density matrix where one of the asymptotically dS universes is traced out, and where the throat of the Euclidean wormhole is associated with the entanglement between the universes. Later, we evaluate two-point correlation functions for heavy particles detected near $\mathcal{I}^+$. The Euclidean wormhole saddle point is responsible for the late-time saturation of the correlators. The result is compatible with each of the asymptotically de Sitter universes being described by a finite-dimensional quantum dual theory. At last, we dimensionally reduce these geometries in terms of dilaton-gravity theory with conformally coupled matter. Further, we discuss recent puzzles associated to the Euclidean path integral for extended wormhole geometries with multiple throats.