Inflationary universe in loop quantum cosmology

TL;DR

Loop quantum cosmology naturally leads to an inflationary universe after a big bounce, with a super-inflation phase followed by normal inflation, but the quantum effects are too subtle to detect in the primordial spectrum.

Contribution

This paper demonstrates that inflation occurs generically after the big bounce in loop quantum cosmology and analyzes the potential observational signatures of quantum effects.

Findings

A super-inflation phase appears after the bounce.

The quantum imprint on the primordial spectrum is too weak to observe.

Inflation conditions are detailed within the loop quantum cosmology framework.

Abstract

Loop quantum cosmology provides a nice solution of avoiding the big bang singularity through a big bounce mechanism in the high energy region. In loop quantum cosmology an inflationary universe is emergent after the big bounce, no matter what matter component is filled in the universe. A super-inflation phase without phantom matter will appear in a certain way in the initial stage after the bounce; then the universe will undergo a normal inflation stage. We discuss the condition of inflation in detail in this framework. Also, for slow-roll inflation, we expect the imprint from the effects of the loop quantum cosmology should be left in the primordial perturbation power spectrum. However, we show that this imprint is too weak to be observed.