Unconditional Bases in Banach Spaces

Abstract

A Schauder basis provides unique series representations of each vector in a Banach space. However, conditionally convergent series are delicate in many respects. For example, if converges conditionally and is a bounded sequence of scalars, P then the series may not converge. Unconditionality is an important property,and in many applications we greatly prefer a basis that is unconditional over one that is conditional. Therefore we study unconditional bases in more detail in this chapter.