IR quantum gravity solves naturally cosmic acceleration and its coincidence problem

TL;DR

This paper proposes that infrared quantum gravity modifications at astrophysical scales can naturally explain cosmic acceleration and address the coincidence problem without introducing new energy scales, aligning with observational data.

Contribution

It introduces a model where matter structures induce a scale-dependent cosmological constant via quantum gravity, naturally explaining acceleration and coincidence.

Findings

Model fits observational data well

Statistically equivalent to ΛCDM

Resolves dark energy and coincidence problem

Abstract

The novel idea is that the undergoing accelerated expansion of the universe happens due to infrared quantum gravity modifications at intermediate astrophysical scales of galaxies or galaxy clusters, within the framework of Asymptotically Safe gravity. The reason is that structures of matter are associated with a scale-dependent positive cosmological constant of quantum origin. In this context, no extra unproven energy scales or fine-tuning are used. Furthermore, this model was confronted with the most recent observational data from a variety of probes, and with the aid of Bayesian analysis, the most probable values of the free parameters were extracted. Finally, the model proved to be statistically equivalent with $\Lambda$CDM, and thus being able to resolve naturally the concept of dark energy and its associated cosmic coincidence problem.