Quantum state of the multiverse

TL;DR

This paper applies third quantization to a simplified multiverse model, deriving a well-defined quantum state that aligns with boundary conditions and exhibits properties similar to accelerating universes, while addressing criticisms of the approach.

Contribution

It introduces a specific quantum state of the multiverse using third quantization, connecting it to boundary conditions and universe acceleration.

Findings

Quantum states are squeezed and related to accelerating universes.

States agree with standard boundary condition proposals.

Addresses criticisms of third quantization approach.

Abstract

A third quantization formalism is applied to a simplified multiverse scenario. A well defined quantum state of the multiverse is obtained which agrees with standard boundary condition proposals. These states are found to be squeezed, and related to accelerating universes: they share similar properties to those obtained previously by Grishchuk and Siderov. We also comment on related works that have criticized the third quantization approach.