Parametric and nonparametric methods hint dark energy evolution

TL;DR

This paper investigates dark energy evolution using both parametric and nonparametric methods on cosmological data, finding consistent hints of evolution that are driven by the data itself rather than the analysis approach.

Contribution

It introduces a combined analysis of dark energy using multiple priors and phenomenological functions, providing new constraints and evidence for dark energy evolution.

Findings

Hints at dark energy evolution across methods and priors

Consistent dark energy density shapes suggest data-driven features

Results are robust against different reconstruction approaches

Abstract

We study dark energy through the viewpoints of parametric and nonparametric analyses of late-time cosmological data. We consider four Hubble parameter priors reflecting the Hubble tension and make use of two phenomenological functions, namely, a normalized dark energy density and a compactified dark energy equation of state. We predict the shape of both functions and present new constraints on the dark energy equation of state. The results hint at dark energy evolution regardless of the choice of the method and of the priors. The fact that similar evolutions for the dark energy densities are found through drastically different approaches suggests that the features found in this paper are driven by the data, and are not artifact of the reconstruction methods applied.