Spacetime from bits

Area of Science:

• Theoretical physics
• Quantum gravity
• Quantum information theory

Background:

• The anti-de Sitter/conformal field theory (AdS/CFT) correspondence links quantum gravity in higher dimensions to quantum field theories in lower dimensions.
• In this framework, spacetime geometry and gravitational physics are encoded within the quantum states of a nongravitational system.

Purpose of the Study:

• To demonstrate that the nongravitational system in the AdS/CFT correspondence can be replaced by a collection of noninteracting systems.
• To provide a new perspective on the emergence of spacetime geometry from quantum entanglement.

Main Methods:

• The study proposes replacing the single nongravitational system with an arbitrarily large collection of noninteracting systems (bits).
• These bits are arranged in a highly entangled state to encode spacetime geometry.
• The proposed structure is analyzed using tensor networks.

Main Results:

• Spacetime geometry is shown to emerge from the entanglement structure of these fundamental degrees of freedom.
• Removing this entanglement leads to the disintegration of spacetime.
• Entangled states encoding spacetimes can be effectively represented by specific tensor networks.

Conclusions:

• This construction offers a manifest demonstration of spacetime emergence from quantum entanglement.
• It provides a novel perspective on the relationship between quantum information and gravitational physics.
• The findings suggest a powerful new way to study quantum gravity using concepts from quantum information and tensor networks.