Probing primordial non-Gaussianity with 21 cm fluctuations from minihalos

We investigate future constraints on primordial local-type non-Gaussianity from 21 cm angular power spectrum from minihalos. We particularly focus on the trispectrum of primordial curvature perturbations which are characterized by the non-linearity parametersτ_NL and g_NL. We show that future measurements of minihalo 21 cm angular power spectrum can probe these non-linearity parameters with an unprecedented precision of τ_NL ~ 30 and g_NL ~ 2 × 10³ for Square Kilometre Array (SKA) and τ_NL ~ 0.6 and g_NL ~ 8 × 10² for Fast Fourier Transform Telescope (FFTT). These levels of sensitivity would give significant implications for models of the inflationary Universe and the origin of cosmic density fluctuations.