We prove endpoint bounds for the square function associated with radial
Fourier multipliers acting on Lp radial functions. This is a consequence
of endpoint bounds for a corresponding square function for Hankel multipliers.
We obtain a sharp Marcinkiewicz-type multiplier theorem for multivariate Hankel
multipliers and Lp bounds of maximal operators generated by Hankel
multipliers as corollaries. The proof is built on techniques developed by
Garrig\'{o}s and Seeger for characterizations of Hankel multipliers.Comment: 26 page