Spacetime Equals Entanglement

TL;DR

This paper explores how entanglement in holographic theories can determine the structure of classical spacetimes, suggesting superpositions of such spacetimes can also form valid classical geometries, especially in large degrees of freedom limits.

Contribution

It proposes a novel framework linking entanglement to spacetime geometry, including superpositions of classical spacetimes, within holographic theories.

Findings

Superpositions of classical spacetimes can result in another classical spacetime.

Entanglement structure determines semiclassical geometry in holographic theories.

Model application to cosmological spacetimes supports the framework.

Abstract

We study the Hilbert space structure of classical spacetimes under the assumption that entanglement in holographic theories determines semiclassical geometry. We show that this simple assumption has profound implications; for example, a superposition of classical spacetimes may lead to another classical spacetime. Despite its unconventional nature, this picture admits the standard interpretation of superpositions of well-defined semiclassical spacetimes in the limit that the number of holographic degrees of freedom becomes large. We illustrate these ideas using a model for the holographic theory of cosmological spacetimes.