Endpoint bounds of square functions associated with Hankel multipliers

We prove endpoint bounds for the square function associated with radial Fourier multipliers acting on L^p 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 L^p bounds of maximal operators generated by Hankel multipliers as corollaries. The proof is built on techniques developed by Garrigós and Seeger for characterizations of Hankel multipliers.