Interpolative construction and factorization of operators

Banach operator ideals generated by interpolative construction applied to pp-summing operators are studied. These ideals are described in terms of factorization through abstract interpolation Lorentz spaces. Relationships between Banach ideals determined by Orlicz sequence spaces are shown and a variant of the Pisier factorization theorem for (p,1)(p,1)-summing operators from C(K)C(K)-spaces is proved. Applications to Schatten classes are given. It is also shown that certain known results on (q,p)(q,p)-concave operators from Banach lattices can be lifted to a class of generalized concave operators.