Modelling and testing the equation of state for (Early) dark energy

TL;DR

This paper develops a general equation of state for early dark energy to analyze its impact on cosmic evolution and Hubble tension, exploring singularities and fitting models to observational data.

Contribution

It introduces a new general equation of state for early dark energy and analyzes its effects on cosmological evolution and data fitting.

Findings

Identification of conditions for past and future singularities.

Good data fit for two models compared to standard models.

Insights into dark energy behavior during cosmic expansion.

Abstract

A general equation of state is considered for analysing the possible behaviors for (Early) dark energy that alleviates the Hubble parameter tension problem. By departing from the possible evolution for the (Early) dark energy density and the corresponding dynamical equations, the equation of state is obtained, which allow us to analyze qualitatively the cosmological evolution and the dominance of each term in the equation of state along the cosmic expansion, which show some interesting consequences as the occurrence of (past) future singularities. Then, by considering two general models, their free parameters are fit with different sources of data, showing the goodness of the fits in comparison to more standard models. Results might be considered as a promising starting point to get a better understanding of the cosmological evolution as a whole.