2021/01/19 by Mikael de la Salle, de la Salle, Mikael
Mathematics · #Advanced Banach Space Theory #Advanced Harmonic Analysis Research #Approximation Theory and Sequence Spaces #FOS: Mathematics #Functional Analysis (math.FA)
paper · doi:10.48550/arxiv.2101.07666
openalex publication_date 2021/01/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Given a set B of operators between subspaces of Lp spaces, we characterize the operators between subspaces of Lp spaces that remain bounded on the X-valued Lp space for every Banach space on which elements of the original class B are bounded. This is a form of the bipolar theorem for a duality between the class of Banach spaces and the class of operators between subspaces of Lp spaces, essentially introduced by Pisier. The methods we introduce allow us to recover also the other direction --characterizing the bipolar of a set of Banach spaces--, which had been obtained by Hernandez in 1983.