Two problems of Calderón-Zygmund theory on product-spaces
R. Fefferman has shown that, on a product-space with two factors, an operator T bounded on maps into BMO of the product if the mean oscillation on a rectangle R of the image of a bounded function supported out of a multiple R’ of R, is dominated by , for some . We show that this result does not extend in general to the case where E has three or more factors but remains true in this case if in addition T is a convolution operator, provided . We also show that the Calderon-Coifman bicommutators,...