Accueil > Agenda scientifique

14 mars 2023: 1 événement

  • Séminaire d’Analyse Fonctionnelle

    Mardi 14 mars 13:45-14:45 - Triinu Veeorg - Université de Tartu

    Daugavet and Delta points in Banach spaces

    Résumé : A norm one element $x$ of a Banach space is a Daugavet point (respectively, a $\Delta$-point) if every slice of the unit ball (respectively, every slice of the unit ball containing $x$) contains an element that is almost at distance 2 from $x$.
    We start the talk by characterizing Daugavet points in Lipschitz-free spaces. We apply the characterization to provide an example of a Lipschitz-free space with the Radon-Nikodym property and a Daugavet point, which is the first example of such a Banach space. We also consider renormings of some Banach spaces, including $\ell_2$, that provide $\Delta$-points or Daugavet points.

    En savoir plus : Séminaire d’Analyse Fonctionnelle