Séparation forte -branlante de deux convexes
Separation of two convex sets by operators
Sets of constant width and diametrically complete setes in normed spaces
Simplices rarely contain their circumcenter in high dimensions
Acute triangles are defined by having all angles less than , and are characterized as the triangles containing their circumcenter in the interior. For simplices of dimension , acuteness is defined by demanding that all dihedral angles between -dimensional faces are smaller than . However, there are, in a practical sense, too few acute simplices in general. This is unfortunate, since the acuteness property provides good qualitative features for finite element methods. The property of acuteness...
Solution to a problem of S. Rolewicz
Some characterization of locally nonconical convex sets
A closed convex set in a local convex topological Hausdorff spaces is called locally nonconical (LNC) if for every there exists an open neighbourhood of such that . A set is local cylindric (LC) if for , , there exists an open neighbourhood of such that (equivalently: ) is a union of open segments parallel to . In this paper we prove that these two notions are equivalent. The properties LNC and LC were investigated in [3], where the implication was proved in general, while...
Some geometric properties of typical compact convex sets in Hilbert spaces
An investigation is carried out of the compact convex sets X in an infinite-dimensional separable Hilbert space , for which the metric antiprojection from e to X has fixed cardinality n+1 ( arbitrary) for every e in a dense subset of . A similar study is performed in the case of the metric projection from e to X where X is a compact subset of .
Some intersection and generation properties of convex sets
Some results on groups with unique square roots
Split Faces and Projective Sets in a Metrizable Compact Convex Set.
Stability of Supporting and Exposing Elements of Convex Sets in Banach Spaces
* This work was supported by the CNR while the author was visiting the University of Milan.To a convex set in a Banach space we associate a convex function (the separating function), whose subdifferential provides useful information on the nature of the supporting and exposed points of the convex set. These points are shown to be also connected to the solutions of a minimization problem involving the separating function. We investigate some relevant properties of this function and of its conjugate...
Starshapedness in convexity spaces
Stufenkonvexität in der Geometrie
Sublinear Functions on R.
Suites décroissantes de simplexes
Sur la frontière d'un convexe mobile
Siano , sottoinsiemi convessi, chiusi e limitati di uno spazio normato , con le frontiere , . Dimostriamo che , dove è la metrica di Hausdorff tra sottoinsiemi chiusi di . Studiamo inoltre la continuità e la semicontinuità superiore ed inferiore di una multifunzione di tipo «frontiera».
Sur les automorphismes affines des ouverts convexes saillants
Sur les cônes convexes topologiques
Sur les fonctions affines qui vérifient le calcul barycentrique
Sur un théorème du type Banach-Steinhaus pour les convexes topologiques