2021/03/31 by Linfeng Xiao, Andre A. Costa, Bin Wang · 2 citations
Physics and Astronomy · #astro-ph.CO #gr-qc #hep-ph
paper · pdf · doi:10.1093/mnras/stab3256
20 pages, 13 figures, 9 tables, accepted for publication in MNRAS
arxiv created 2022/01/11 · arxiv updated 2022/01/12
Neutral hydrogen (HI) intensity mapping is a promising technique to probe the large-scale structure of the Universe, improving our understanding on the late-time accelerated expansion. In this work, we first scrutinize how an alternative cosmology, interacting dark energy (IDE), can affect the 21-cm angular power spectrum relative to the concordance ΛCDM model. We re-derive the 21-cm brightness temperature fluctuation in the context of such interaction and uncover an extra new contribution. Then we estimate the noise level of three upcoming HI intensity mapping surveys, BINGO, SKA1-MID Band 1 and Band 2, respectively, and employ a Fisher matrix approach to forecast their constraints on the IDE model. We find that while Planck 2018 maintains its dominion over early-Universe parameter constraints, BINGO and SKA1-MID Band 2 put complementary bounding to the latest CMB measurements on dark energy equation of state w, the interacting strength λi and the reduced Hubble constant h, and SKA1-MID Band 1 even outperforms Planck 2018 in these late-Universe parameter constraints. The expected minimum uncertainties are given by SKA1-MID Band 1+Planck : ∼ 0.34% on w, ∼ 0.22% on h, ∼ 0.64% on HI bias b\rm HI, and an absolute uncertainty of about 3×10-4 (7×10-4) on λ1 (λ2). Moreover, we quantify the effects from systematics of the redshift bin number, redshift-space distortions, foreground residuals and uncertainties on the measured HI fraction, ΩHI(z). Our results indicate a bright prospect for HI intensity mapping surveys in constraining IDE, whether on their own or further by synergies with other measurements.