Matching current observational constraints with nonminimally coupled dark energy

TL;DR

This paper demonstrates that a universe with a nonminimally coupled scalar field can better fit current observational data on cosmic expansion than standard models, especially allowing stable phantom crossing, though evidence remains inconclusive.

Contribution

It introduces a nonminimally coupled dark energy model that improves fit to data and allows stable phantom crossing, a feature not present in minimally coupled models.

Findings

Better fit to observational data than $mbda$CDM

Enables stable phantom crossing behavior

Evidence for the model remains inconclusive

Abstract

We show that a Universe with a nonminimally coupled scalar field can fit current measurements of the expansion rate of the Universe better than the standard $\Lambda$-Cold Dark Matter ($\Lambda$CDM) model or other minimally coupled dark energy models. In particular, the nonminimal coupling in this model allows for the dark energy model to exhibit stable phantom crossing behavior, which seems to be suggested by the constraints on the dark energy equation of state coming from the most recent data. While we find a clear improvement in the goodness of fit for this dark energy model with respect to others that have been considered in the recent literature, using information theoretic criteria, we show that the evidence for it is still inconclusive.