Testing dark energy after pre-recombination early dark energy

TL;DR

This paper investigates the evolution of dark energy's equation of state after recombination in early dark energy models, finding that current data is consistent with a cosmological constant and evolution is only marginally favored.

Contribution

It introduces parametrizations of dark energy's equation of state in EDE models and analyzes their impact using recent cosmological data.

Findings

Best-fit $w(z)$ aligns with $w_0=-1,w_a=0$ (cosmological constant)

Evolution of $w$ is only marginally favored by data

Little impact on the $H_0$ tension

Abstract

In the studies on pre-recombination early dark energy (EDE), the evolution of Universe after recombination is usually regarded as ${\Lambda}CDM$-like, which corresponds that the equation of state of dark energy responsible for current accelerated expansion is $w=-1$. However, in realistic models, $w$ might be evolving. We consider the parametrizations of $w$ with respect to the redshift $z$ in Axion-like EDE and AdS-EDE models, respectively. We performed the Monte Carlo Markov chain analysis with recent cosmological data, and found that the bestfit $w(z)$ is compatible with $w_0=-1,w_a=0$ (the cosmological constant) and the evolution of $w$ is only marginally favored, which so has little effect on lifting the bestfit value of ${H_0}$.