Origin of the inflationary Universe

TL;DR

This paper presents a quantum cosmology framework explaining the emergence of the inflationary Universe, emphasizing probability peaks and decoherence effects that constrain particle content in unified theories.

Contribution

It introduces a method to derive probability peaks from the cosmological wave function beyond semiclassical approximations, clarifying the quantum origins of inflation.

Findings

Probability peaks can be obtained from the wave function beyond tree level.

Decoherence suppresses interference between semiclassical branches.

Results impose constraints on particle content in unified theories.

Abstract

We give a consistent description of how the inflationary Universe emerges in quantum cosmology. This involves two steps: Firstly, it is shown that a sensible probability peak can be obtained from the cosmological wave function. This is achieved by going beyond the tree level of the semiclassical expansion. Secondly, due to decoherence interference terms between different semiclassical branches are negligibly small. The results give constraints on the particle content of a unified theory.