Abstract

We define the (w* -) boundedness property and the (w* -) surjectivity property for sets in normed spaces. We show that these properties are pairwise equivalent in complete normed spaces by characterizing them in terms of a category-like property called (w* -) thickness. We give examples of interesting sets having or not having these properties. In particular, we prove that the tensor product of two w*-thick sets in X** and Y* is a w*-thick subset in L(X,Y)* and obtain as a consequence that the set w*-expBK(l2)* is w*-thick.