ON STRICTLY SINGULAR OPERATORS BETWEEN SEPARABLE BANACH SPACES

Strictly Singular Non-compact Operators on Hereditarily Indecomposable Banach Spaces

An example is given of a strictly singular non-compact operator on a Hereditarily Indecomposable, reflexive, asymptotic `1 Banach space. The construction of this operator relies on the existence of transfinite c0-spreading models in the dual of the space.

Characterizations of strictly singular operators on Banach lattices

New characterizations of strictly singular operators between Banach lattices are given. It is proved that, for Banach lattices X and Y such that X has finite cotype and Y satisfies a lower 2-estimate, an operator T : X → Y is strictly singular if and only if it is disjointly strictly singular and 2-singular. Moreover, if T is regular then the same equivalence holds provided that Y is just order...

Compact and strictly singular operators on certain function spaces

A Class of Banach Spaces with Few Non Strictly Singular Operators

The original motivation for this paper is based on the natural question left open by the Gowers-Maurey solution of the unconditional basic sequence problem for Banach spaces ([12]). Recall that Gowers and Maurey have constructed a Banach space X with a Schauder basis (en)n but with no unconditional basic sequence. Thus, while every infinite dimensional Banach space contains a sequence (xn)n whi...

Strictly Singular Uniform λ−Adjustment in Banach Spaces

Based on the recently introduced uniform λ−adjustment for closed subspaces of Banach spaces we extend the concept of the strictly singular and nitely strictly singular operators to the sequences of closed subspaces and operators in Banach spaces and prove theorems about lower semi Fredholm stability. We also state some new open questions related to strict singularity and the geometry of Banach ...