Coarse-grained fixed-point tensor networks and holographic reflected entropy in 3D gravity
Open Access
- 10 February 2026
- journal article
- research article
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2026 (2) , 107
Abstract
A bstract: We use the framework of fixed-point BCFT tensor networks to present a microscopic CFT derivation of the correspondence between reflected entropy (RE) and entanglement wedge cross section (EW) in AdS 3 /CFT 2 , for both bipartite and multipartite settings. These fixed-point tensor networks, obtained by triangulating Euclidean CFT path integrals, allow us to explicitly construct the canonical purification via cutting-and-gluing CFT path integrals. Employing modular flow in the large- c limit, we demonstrate that these intrinsic CFT manipulations reproduce bulk geometric prescriptions, without assuming the AdS/CFT dictionary. The emergence of bulk geometry is traced to coarse-graining over heavy states in the large- c limit. Universal coarse-grained BCFT data for compact 2D CFTs, through the relation to Liouville theory with ZZ boundary conditions, yields hyperbolic geometry on the Cauchy slice. The corresponding averaged replica partition functions reproduce all candidate EWs, arising from different averaging patterns, with the dominant one providing the correct RE and EW. In this way, many heuristic tensor-network intuitions in toy models are made precise and established directly from intrinsic CFT data.Keywords
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Funding Information
- Stichting DOEN (5-29073)
This publication has 128 references indexed in Scilit:
- Replica wormholes and entanglement islands in the Karch-Randall braneworldJournal of High Energy Physics, 2025
- AdS/BCFT from conformal bootstrap: construction of gravity with branes and particlesJournal of High Energy Physics, 2023
- Reflected entropy in random tensor networks. Part II. A topological index from canonical purificationJournal of High Energy Physics, 2023
- Defect extremal surface for reflected entropyJournal of High Energy Physics, 2022
- Entanglement of purification: from spin chains to holographyJournal of High Energy Physics, 2018
- Quantum extremal surfaces: holographic entanglement entropy beyond the classical regimeJournal of High Energy Physics, 2015
- Quantum gravity partition functions in three dimensionsJournal of High Energy Physics, 2010
- Black Holes and Wormholes in 2+1 Dimensions2000
- Conformal symmetry in two-dimensional space: Recursion representation of conformal blockTheoretical and Mathematical Physics, 1987
- Central charges in the canonical realization of asymptotic symmetries: An example from three dimensional gravityCommunications in Mathematical Physics, 1986