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arXiv · 2508.21242

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

Tomasz Kania·Jarosław Swaczyna
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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 $\Sigma^1_3$ 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 $\Sigma^1_2$ with respect to any admissible Polish topology on the family of closed subspaces of $C(\Delta)$.

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Tomasz Kania, Jarosław Swaczyna. 2025-08-28. The $\pi$-property of a Banach space along a filter. https://arxiv.org/abs/2508.21242

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