# Timelike entanglement Timelike entanglement entropy is a quantum information measure that received a good deal of attention recently. It is a complex number, in contrast to spacelike entanglement entropy which is real. It is obtained via analytic continuation. In holography, its real and imaginary parts correspond to different geometric objects in AdS. There are generally multiple (complex) saddles that contribute. ## Refs - originals - [[2022#Doi, Harper, Mollabashi, Takayanagi, Taki]] - [[2023#Doi, Harper, Mollabashi, Takayanagi, Taki]] - [[0026 Bulk reconstruction|bulk reconstruction]] - [[2023#Das, Sachdeva, Sarkar]] - multiple complex saddles - [[2024#Anegawa, Tamaoka]] - no imaginary part if photon sphere present - [[2024#He, Yang]] - alternative proposal for the bulk dual - [[2024#Heller, Ori, Serantes]]: analytic continuation of holographic spacetimes into complex coordinates - imaginary part and twist operators - [[2024#Guo, Xu]] - a general proposal - [[2025#Milekhin, Adamska, Preskill]] - relation between timelike and spacelike - [[2024#Guo, He, Zhang]]: the imaginary component of the timelike entanglement entropy primarily originates from the non-commutativity between the twist operator and its first-order temporal derivative