Cosmic Acceleration from Quantum Gravity: Emergent Inflation and Dynamical Dark Energy

TL;DR

This paper proposes a quantum gravity-based mechanism that naturally leads to cosmic acceleration, explaining both early inflation and late-time dark energy within a unified framework.

Contribution

It introduces a mean-field approach in Group Field Theory models that accounts for emergent inflation and dynamical dark energy, bridging quantum gravity with cosmological phenomena.

Findings

Supports an emergent inflationary epoch driven by quantum effects

Predicts a late-time dark energy phase with phantom behavior

Transitions smoothly from inflation to a non-accelerating universe

Abstract

We present a mechanism for the emergence of cosmic acceleration within the mean-field approximation of Group Field Theory models of quantum gravity. Depending on the interaction type, the resulting cosmological dynamics can either feature a late-time attractor corresponding to a dynamical dark energy phase, often with characteristic phantom behavior, including in models inspired by simplicial gravity, or instead support an early slow-roll inflationary epoch driven by the same underlying quantum-gravitational effects. This emergent inflation, effectively captured by a single-field description, can sustain the required expansion, naturally avoids the graceful exit problem, and appears to transition into a persistent, non-accelerating phase consistent with classical expectations.