Jordan norms for multilinear maps on C*-algebras and Grothendieck's inequalities

Abstract

There exists a generalization of the concept, completely bounded norm for multilinear maps on C*-algebras. We will use the word, Jordan norm, for this norm. The Jordan norm of a multilinear map is obtained via factorizations of the map, such that bounded operators and Jordan homomorphisms form a long product, as in the case of a completely bounded multilinear map. We show that any bounded bilinear form on a pair of C*-algebras is Jordan bounded and its Jordan norm is at most twice the norm.