$F_{\sigma }$ ideals of perfectly bounded sets

J. Martínez, David Meza-Alcántara, Carlos Uzcátegui

Let $\mathbf{x}=(x_n{)}_n$ be a sequence in a Banach space. A set $A\subseteq \mathbb{N}$ is perfectly bounded, if there is $M$ such that $\Vert {\sum }_{n\in F}{x}_n\Vert \le M$ for every finite $…