The centraliser of the injective tensor product

Abstract

The aim of this note is to obtain an intrinsic product formula for the centraliser of the injective tensor product of a couple of Banach spaces, Z(). More precisely, we are going to prove thatHere, the spaces and depend only on X and Y, respectively, and Xk denotes the topological k-product.A Counterexaple used to demonstrate that the k-product cannot beavoided serves as an answer to a question posed by W. Rueß and D. Werner concerning the behaviour of M-ideals on Y.