Coherent State Representation of Semiclassical Quantum Gravity

TL;DR

This paper develops a coherent state framework for semiclassical quantum gravity, showing how classical spacetime can emerge from quantum states by exactly reproducing classical back-reaction effects.

Contribution

It introduces a specific coherent state representation that yields classical spacetime from semiclassical quantum gravity derived from the Wheeler-DeWitt equation.

Findings

Coherent state representation reproduces classical back-reaction exactly

Classical spacetime emerges naturally from quantum states

Provides a new link between quantum states and classical geometry

Abstract

We elaborate the recently introduced asymptotically exact semiclassical quantum gravity derived from the Wheeler-DeWitt equation by finding a particular coherent state representation of a quantum scalar field in which the back-reaction of the scalar field Hamiltonian exactly gives rise to the classical one. In this coherent state representation classical spacetime emerges naturally from semiclassical quantum gravity.