English

Bulk reconstruction using timelike entanglement in (A)dS

High Energy Physics - Theory 2024-03-12 v3 General Relativity and Quantum Cosmology

Abstract

It is well-known that the entanglement entropies for spacelike subregions, and the associated modular Hamiltonians play a crucial role in the bulk reconstruction program within Anti de-Sitter (AdS) holography. Explicit examples of HKLL map exist mostly for the cases where the emergent bulk region is the so-called entanglement wedge of the given boundary subregion. However, motivated from the complex pseudo-entropy in Euclidean conformal field theories (CFT), one can talk about a `timelike entanglement' in Lorentzian CFTs dual to AdS spacetimes. One can then utilize this boundary timelike entanglement to define a boundary `timelike modular Hamiltonian'. We use constraints involving these Hamiltonians in a manner similar to how it was used for spacelike cases, and write down bulk operators in regions which are not probed by an RT surface corresponding to a single CFT. In the context of two dimensional CFT, we re-derive the HKLL formulas for free bulk scalar fields in three examples: in AdS Poincar\'{e} patch, inside and outside of the AdS black hole, and for de Sitter flat slicings. In this method, one no longer requires the knowledge of bulk dynamics for sub-horizon holography.

Keywords

Cite

@article{arxiv.2312.16056,
  title  = {Bulk reconstruction using timelike entanglement in (A)dS},
  author = {Avijit Das and Shivrat Sachdeva and Debajyoti Sarkar},
  journal= {arXiv preprint arXiv:2312.16056},
  year   = {2024}
}

Comments

Version 2. 51 pages, 13 figures. Minor modifications and corrections. References added. Version 3. Minor changes in abstract and elsewhere. Published version

R2 v1 2026-06-28T14:02:09.710Z