A class of convex functions where the sets of subdifferentials behave like the unit ball of the dual space of an Asplund space is found. These functions, which we called Asplund functions also possess some stability properties. We also give a sufficient condition for a function to be an Asplund function in terms of the upper-semicontinuity of the subdifferential map.
In the first part of this paper, we prove that in a sense the class of bi-Lipschitz -convex mappings, whose inverses are locally -convex, is stable under finite-dimensional -convex perturbations. In the second part, we construct two -convex mappings from onto , which are both bi-Lipschitz and their inverses are nowhere locally -convex. The second mapping, whose construction is more complicated, has an invertible strict derivative at . These mappings show that for (locally) -convex mappings...
Nous donnons des conditions permettant de vérifier que l’image d’une mesure cylindrique sur un espace vectoriel topologique , par une application linéaire continue dans un autre espace vectoriel topologique , est une mesure de Randon. Dans une première partie, nous donnons des résultats généraux qui portent, soit sur des propriétés géométriques de l’espace , soit sur la mesure cylindrique . Dans une seconde partie, nous donnons des conditions plus précises quand est une mesure cylindrique...
Relative property (T) has recently been used to show the existence of a variety of new rigidity phenomena, for example in von Neumann algebras and the study of orbit-equivalence relations. However, until recently there were few examples of group pairs with relative property (T) available through the literature. This motivated the following result: A finitely generated group admits a special linear representation with non-amenable -Zariski closure if and only if it acts on an Abelian group (of...