Understand
The primordial non-Gaussianity induces scale-dependent bias of the \hi with respect to the underlying dark matter, which exhibits features on the very large scales of the 21-cm power spectrum potentially observable with \hi intensity mapping observations.
- We forecast the prospective constraints on the four fundamental shapes of primordial non-Gaussianity (local, equilateral, orthogonal, and enfolded), with the current and future \hi intensity mapping experiments, BINGO, FAST, and SKA-I.
- With the current configuration of the experiments and assumed one-year observation time, we find that the SKA-I will provide tighter constraints on the local shape of primoridal non-Gaussianity than Planck.
- The results are $(\sigma_{f^{\rm local}_{\rm NL}},\sigma_{f^{\rm equil}_{\rm NL}},\sigma_{f^{\rm orth}_{\rm NL}},\sigma_{f^{\rm enfold}_{\rm NL}})_{\rm SKA-I}=(0.54, 86, 25, 43)$, $(\sigma_{f^{\rm local}_{\rm NL}},\sigma_{f^{\rm equil}_{\rm NL}},\sigma_{f^{\rm orth}_{\rm NL}},\sigma_{f^{\rm enfold}_{\rm NL}})_{\rm BINGO}=(17, 100, 128, 164)$, $(\sigma_{f^{\rm local}_{\rm NL}},\sigma_{f^{\rm equil}_{\rm NL}},\sigma_{f^{\rm orth}_{\rm NL}},\sigma_{f^{\rm enfold}_{\rm NL}})_{\rm FAST}=(9.5, 44, 75, 94)$.