Revisiting subregion holography using OPE blocks

Abstract

In this paper, we revisit the entanglement wedge representation of AdS3 bulk fields in terms of CFT operator product expansion (OPE) blocks for a general class of blocks. Given a boundary interval and its associated causal diamond, the OPEs involve boundary operators with or without spin, and located either at spacelike or timelike edges of the diamond. Only for a subset of these cases, can the OPE block be dual to a geodesic bulk field. We show that when applied to de Sitter, a suitable combination of Euclidean OPE blocks can represent a dS scalar integrated over the timelike extremal surfaces, which play an important role in defining pseudoentropy. We also work out some simple higher dimensional examples. © 2025 authors. Published by the American Physical Society.