The $\pi$-property of a Banach space along a filter

Abstract

We examine the analyticity of the class of separable Banach spaces possessing the $\pi$-property, defined in terms of convergence along a filter. Our results establish that this class is ${\Sigma }_3^1$ whenever the underlying filter is analytic (as a subset of the Cantor set $\Delta$). Furthermore, we demonstrate that if the filter is countably generated, the class of such spaces is ${\Sigma }_2^1$ with respect to any admissible Polish topology on the family of closed subspaces of $C(\Delta )$.

15 pages