Prospects of probing quintessence with HI 21-cm intensity mapping survey

TL;DR

This paper explores how future HI 21-cm intensity mapping surveys can distinguish coupled scalar field dark energy models from the standard $\\Lambda$CDM model by analyzing their effects on the 21-cm angular power spectrum at redshift 1.5.

Contribution

It demonstrates that HI 21-cm surveys can statistically differentiate certain dark energy models from $\\Lambda$CDM, providing a new observational avenue for dark energy constraints.

Findings

Models can be distinguished at >3σ with 10,000 hr SKA1-mid observations.

Tracker models are more likely to be ruled out than thawer models.

Future radio surveys can tighten dark energy parameter constraints.

Abstract

We investigate the prospect of constraining scalar field dark energy models using HI 21-cm intensity mapping surveys. We consider a wide class of coupled scalar field dark energy models whose predictions about the background cosmological evolution are different from the $\Lambda$CDM predictions by a few percent. We find that these models can be statistically distinguished from $\Lambda$CDM through their imprint on the 21-cm angular power spectrum. At the fiducial $z= 1.5$, corresponding to a radio interferometric observation of the post-reionization HI 21 cm observation at frequency $568 \rm MHz$, these models can infact be distinguished from the $\Lambda$CDM model at $ {\rm SNR }> 3 \sigma$ level using a 10,000 hr radio observation distributed over 40 pointings of a SKA1-mid like radio-telescope. We also show that tracker models are more likely to be ruled out in comparison with $\Lambda$CDM than the thawer models. Future radio observations can be instrumental in obtaining tighter constraints on the parameter space of dark energy models and supplement the bounds obtained from background studies.