Gaussian-process reconstructions and model building of quintom dark energy from latest cosmological observations

TL;DR

This paper employs Gaussian process reconstruction using recent cosmological data to analyze dark energy dynamics, finding consistency with quintom models and minor modifications to gravity, and unifying various models within effective field theory.

Contribution

It introduces a Gaussian process-based reconstruction of dark energy evolution from latest data and unifies different dark energy models within an effective field theory framework.

Findings

Consistency with quintom dark energy models across data sets

Minor corrections needed to general relativity for structure growth

Unified description of dark energy models in effective field theory

Abstract

In this article we use the latest cosmological observations, including SNe, BAO, CC and RSD, to reconstruct the cosmological evolution via the Gaussian process. At the background level, we find consistency with the quintom dynamics for different data combinations and divide the characteristics of dark energy into three different categories, which are negative-energy dark energy, late-dominated dark energy and oscillating dark energy, respectively. Considering the effect of modified gravity on the growth of matter perturbations, the reconstruction results at the perturbative level show that we only need minor corrections to general relativity. Furthermore, we provide theoretical interpretation for the three different types of dynamical dark-energy behavior, in the framework of modified gravity, scalar fields, and dark-energy equation-of-state parametrizations. Finally, we show that all of these models can be unified in the framework of effective field theory.