Timelike entanglement entropy in dS<inf>3</inf>/CFT<inf>2</inf>

Abstract

Abstract In the context of dS3/CFT2, we propose a timelike entanglement entropy defined by the renormalization group flow. This timelike entanglement entropy is calculated in CFT by using the Callan-Symanzik equation. We find an exact match between this entanglement entropy and the length of a timelike geodesic connecting two different spacelike surfaces in dS3. The counterpart of this entanglement entropy in AdS3 is a spacelike one, also induced by RG flow and extends all the way into the bulk of AdS3. As a result, in both AdS3/CFT2 and dS3/CFT2, there exist exactly three entanglement entropies, providing precisely sufficient information to reconstruct the three-dimensional bulk geometry.