Is Planckian discreteness observable in cosmology?

TL;DR

This paper explores how a quantum gravity theory with fundamental discreteness at the Planck scale could explain key cosmological phenomena, including the origin of the universe, dark matter, and the observed perturbation spectrum.

Contribution

It proposes that Planck-scale quantum geometry effects during inflation can account for cosmological observations and major puzzles.

Findings

Predicts a scale-invariant spectrum of inhomogeneities

Results in a very small tensor-to-scalar ratio

Suggests a natural dark matter genesis scenario

Abstract

A Planck scale inflationary era -- in a quantum gravity theory predicting discreteness of quantum geometry at the fundamental scale -- produces the scale invariant spectrum of inhomogeneities with very small tensor-to-scalar ratio of perturbations and a hot big bang leading to a natural dark matter genesis scenario. Here we evoke the possibility that some of the major puzzles in cosmology would have an explanation rooted in quantum gravity.