Primordial non-gaussianity from the bispectrum of 21-cm fluctuations in the dark ages

The authors study cosmological intensity fluctuations in the Hydrogen 21-cm line as a promising future probe for primordial non-gaussianity, which is beyond the CMB anisotropy sensitivity and would distinguish between different models of inflation. They extract the intrinsic non-gaussian nature of 21-cm fluctuations, forecasting a significantly increased sensitivity.