Abstract
An analogue of the so—called Sunouchi operator with respect to the Walsh—Kaczmarz system will be investigated. We show the boundedness of this operator if we take it as a map from the dyadic Hardy space H p to L p for all 0<p≤1.. For the proof we consider a multiplier operator and prove its (H p H p)—boundedness for 0<p≤1. Since the multiplier is obviously bounded from L 2 to L 2, a theorem on interpolation of operators can be applied to show that our multiplier is of weak type (1,1) and of type (q q) for all 1<q<∞. The same statements follow also for the Sunouchi operator.