Constraining the interaction between dark sectors with future HI
  intensity mapping observations
  We study a model of interacting dark matter and dark energy, in which the two
components are coupled. We calculate the predictions for the 21-cm intensity
mapping power spectra, and forecast the detectability with future single-dish
intensity mapping surveys (BINGO, FAST and SKA-I). Since dark energy is turned
on at $z\sim 1$, which falls into the sensitivity range of these radio surveys,
the HI intensity mapping technique is an efficient tool to constrain the
interaction. By comparing with current constraints on dark sector interactions,
we find that future radio surveys will produce tight and reliable constraints
on the coupling parameters.
