Prospects of probing quintessence with H i 21-cm intensity mapping survey

Abstract

We investigate the prospect of constraining scalar field dark energy models using H i 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 Λ cold dark matter (ΛCDM) predictions by a few per cent. We find that these models can be statistically distinguished from ΛCDM 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 H i 21-cm observation at frequency 568 MHz, these models can in fact be distinguished from the ΛCDM model at signal-to-noise ratio >3σ level using a 10 000 h 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 ΛCDM 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