Entanglement and local holography in quantum gravity
Gabriel Wong
TL;DR
The essay tackles the challenge of defining bulk entanglement and Hilbert space factorization in a fluctuating spacetime by embedding the problem in string theory. It proposes entanglement branes and a local holography mechanism, realized concretely in the A-model topological string via local geometric transitions and open–closed string duality, to reproduce gravitational entropy and enable factorization through edge-like degrees of freedom. The work outlines how shrinkable entangling boundaries yield a trace on subregion Hilbert spaces and connects this to $S_{geo} = A/(4G)$ and cobordism defects, with ER=EPR-style interpretations in the bulk. It additionally sketches worldsheet pathways and a B-model extension, aiming to provide a tractable, string-theoretic framework for deriving bulk gravity phenomena from entanglement structure and holography. Overall, the paper lays out a concrete, topologically controlled setting—the A-model—that could illuminate how spacetime and gravity emerge from quantum entanglement in a diffeomorphism-invariant theory.
Abstract
The It from Qubit paradigm proposes that gravitational spacetimes emerge from quantum entanglement. So far, the main evidence for this involves holographic dualities, where the entangled qubits live in a dual nongravitational theory. In this essay, we argue that string theory provides the mechanism to define these entangled qubits in the bulk gravitating theory. This involves a local form of geometric transition, which is the stringy mechanism that underlies \emph{local} holography. We illustrate how this works in the A model topological string,
