Primordial Density Perturbation in Effective Loop Quantum Cosmology

TL;DR

This paper demonstrates that loop quantum cosmology can naturally produce a scale-invariant, small-amplitude primordial density perturbation with distinctive features, offering an alternative to standard inflationary models.

Contribution

It shows that loop quantum cosmology induces an inflationary scenario capable of generating observable, scale-invariant primordial perturbations without fine tuning, with unique testable predictions.

Findings

Produces scale-invariant power spectrum

Generates small amplitude primordial perturbations

Features distinguishable from standard inflation

Abstract

It is widely believed that quantum field fluctuation in an inflating background creates the primeval seed perturbation which through subsequent evolution leads to the observed large scale structure of the universe. The standard inflationary scenario produces scale invariant power spectrum quite generically but it produces, unless fine tuned, too large amplitude for the primordial density perturbation than observed. Using similar techniques it is shown that loop quantum cosmology induced inflationary scenario can produce scale invariant power spectrum as well as small amplitude for the primordial density perturbation without fine tuning. Further its power spectrum has a qualitatively distinct feature which is in principle falsifiable by observation and can distinguish it from the standard inflationary scenario.