One-loop contribution to the matter-driven expansion of the Universe

TL;DR

This paper calculates quantum gravity corrections to the early Universe's expansion, revealing that one-loop graviton effects may have significant repulsive influences during the Universe's infancy.

Contribution

It introduces a method to compute one-loop quantum gravity corrections to cosmological solutions, highlighting potential early Universe effects.

Findings

Quantum corrections are UV cutoff dependent.

Corrections exhibit repulsive properties.

Potential significance in the early Universe.

Abstract

Standard perturbative quantum gravity formalism is applied to compute the lowest order corrections to the spatially flat cosmological FLRW solution governed by ordinary matter. The presented approach is analogous to the one used to compute quantum corrections to the Coulomb potential in electrodynamics, or to the approach applied in computation of quantum corrections to the Schwarzschild solution in gravity. In this framework, it is shown that the corrections to the classical metric coming from the one-loop graviton vacuum polarization (self-energy) have (UV cutoff dependent) repulsive properties, which could be not negligible in the very early Universe.