From Big Bang to Asymptotic de Sitter: Complete Cosmologies in a Quantum Gravity Framework

TL;DR

This paper develops a quantum gravity framework using the Einstein-Hilbert approximation to describe the entire cosmological evolution, revealing an oscillatory inflation phase and a late-time de Sitter universe.

Contribution

It introduces a renormalization group approach to quantum gravity in cosmology, connecting quantum effects to all stages of universe evolution with a dynamical cutoff.

Findings

Discovery of oscillatory inflation in early universe

Identification of a mechanism for late-time de Sitter expansion

Framework applicable across all cosmological epochs

Abstract

Using the Einstein-Hilbert approximation of asymptotically safe quantum gravity we present a consistent renormalization group based framework for the inclusion of quantum gravitational effects into the cosmological field equations. Relating the renormalization group scale to cosmological time via a dynamical cutoff identification this framework applies to all stages of the cosmological evolution. The very early universe is found to contain a period of ``oscillatory inflation'' with an infinite sequence of time intervals during which the expansion alternates between acceleration and deceleration. For asymptotically late times we identify a mechanism which prevents the universe from leaving the domain of validity of the Einstein-Hilbert approximation and obtain a classical de Sitter era.