Probing the nature of cosmic acceleration

TL;DR

This paper investigates the nature of cosmic acceleration by comparing dark energy and modified gravity models using observational data, finding that the dark energy model is more consistent with the data.

Contribution

It provides a joint analysis of perturbation growth and $H(z)$ data to constrain and compare dark energy and modified gravity models.

Findings

Dark energy ($$CDM) model is more favored than DGP based on data consistency.

Both models have similar minimal  values, but dark energy aligns better with expansion data.

The analysis supports dark energy as the more plausible explanation for cosmic acceleration.

Abstract

The cosmic acceleration is one of the most significant cosmological discoveries over the last century. The two categories of explanation are exotic component (dark energy) and modified gravity. We constrain the two types of model by a joint analysis with perturbation growth and direct $H(z)$ data. Though the minimal $\chi^2$ of the $\Lambda$CDM is almost the same as that of DGP, in the sense of consistency we find that the dark energy ($\Lambda$CDM) model is more favored through a detailed comparison with the corresponding parameters fitted by expansion data.