Interpolative construction and factorization of operators

Banach operator ideals generated by interpolative construction applied to p -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 ) -summing operators from C ( K ) -spaces is proved. Applications to Schatten classes are given. It is also shown that certain known results on ( q , p ) -concave operators from Banach lattices can be lifted to a class of generalized concave operators.