p-representable operators in Banach spaces

Abstract

Let E and F be Banach spaces. An operator T∈L(E,F) is called p-representable if there exists a finite measure μ on the unit ball, B(E*), of E* and a function g∈Lq(μ,F), 1p+1q=1, such thatTx=∫B(E*)〈x,x*〉g(x*)dμ(x*)for all x∈E. The object of this paper is to investigate the class of all p-representable operators. In particular, it is shown that p-representable operators form a Banach ideal which is stable under injective tensor product. A characterization via factorization through Lp-spaces is given.