Um índice de somabilidade para operadores entre espaços de Banach.

Abstract

In this work we introduce a summability index that indicates how far some multilinear and polynomial operators are from being absolutely summing. We also de ne a new ideal of operators related to this index; basic properties of this ideal are presented. The precise index of summability is obtained in some special cases and, in other cases, we provide some lower and upper estimates for it.