Cosmological footprints of loop quantum gravity

TL;DR

This paper explores how loop quantum gravity could leave detectable imprints on the primordial tensor perturbation spectrum, offering a new way to test quantum gravity theories through cosmological observations.

Contribution

It demonstrates that holonomy corrections in loop quantum gravity modify the gravitational wave potential, leading to a distinctive tilt in the power spectrum.

Findings

Holonomy corrections alter the gravitational wave potential during inflation.

The power spectrum exhibits a characteristic tilt due to quantum gravity effects.

Provides a potential observational signature for loop quantum gravity in cosmology.

Abstract

The primordial spectrum of cosmological tensor perturbations is considered as a possible probe of quantum gravity effects. Together with string theory, loop quantum gravity is one of the most promising frameworks to study quantum effects in the early universe. We show that the associated holonomy correction should modify the potential seen by gravitational waves during the inflationary amplification. The resulting power spectrum should exhibit a characteristic tilt. This opens a new window for cosmological tests of quantum gravity.