Interpolating between multi-boundary wormholes and single-boundary geometries in holography

TL;DR

This paper explores how couplings between boundary conformal field theories can transform multi-boundary wormholes into traversable geometries, bridging the gap between disconnected and connected holographic spacetimes.

Contribution

It introduces a method to interpolate between multi-boundary wormholes and single-boundary geometries by reintroducing couplings, enabling traversability in holographic models.

Findings

Couplings can make wormholes traversable.

Interpolating geometries connect multi-boundary and single-boundary states.

Holographic approximations can be dynamically modified.

Abstract

The recent paper 1809.01197 described how states of a holographic CFT can be approximated by states of a large collection of non-interacting BCFTs, such that the dual of the new system accurately approximates an arbitrarily large causal patch of the original geometry. In this paper, we first describe in more detail the geometries dual to such discrete BCFT systems, emphasizing that they are multi-boundary wormholes in which it is not possible to move causally between different asymptotic regions. By reintroducing couplings between the BCFTs in various ways, we show that the wormholes can be made traversable, giving an intermediate class of geometries that interpolate between the multi-boundary wormhole and the original geometry that it approximates.