Abstract
We show that for a sequence in a Banach space, the property of being stable under large perturbations characterizes the property of being equivalent to the unit vector basis of l 1. We show that a normalized unconditional basic sequence in l 1 that is semi-normalized in l ∞ is equivalent to the standard unit vector basis of l 1.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have