  Three-dimensional neutral hydrogen mapping using the redshifted 21 cm line
has recently emerged as a promising cosmological probe. Within the framework of
slow-roll reconstruction, we analyze how well the inflationary potential can be
reconstructed by combining data from 21 cm experiments and cosmic microwave
background data from the Planck satellite. We consider inflationary models
classified according to the amplitude of their tensor component, and show that
21 cm measurements can significantly improve constraints on the slow-roll
parameters and determine the shape of the inflationary potential.
