Third quantization: modeling the universe as a 'particle' in a quantum field theory of the minisuperspace

TL;DR

This paper explores the third quantization approach in quantum cosmology, modeling the multiverse as a quantum field theory of the universe, revealing insights into entanglement and correlations among multiple universes.

Contribution

It introduces a formalism that treats the universe as a 'particle' in a quantum field, extending quantum principles to the entire multiverse and analyzing entanglement effects.

Findings

Squeezed and entangled states are possible in the multiverse.

The formalism suggests the need to extend quantum principles to the entire space-time.

Correlations among universes can be modeled as interactions in the third quantization.

Abstract

The third quantization formalism of quantum cosmology adds simplicity and conceptual insight into the quantum description of the multiverse. Within such a formalism, the existence of squeezed and entangled states raises the question of whether the complementary principle of quantum mechanics has to be extended to the quantum description of the whole space-time manifold. If so, the 'particle' description entails the consideration of a multiverse scenario and the 'wave' description induces us to consider as well correlations and interactions among the universes of the multiverse.