Obstacles to bounded recovery.
On a class of Hausdorff compact and GSG Banach spaces
On a conjecture of L. Veselý
On a dual locally uniformly rotund norm on a dual Vašák space
We transfer a renorming method of transfer, due to G. Godefroy, from weakly compactly generated Banach spaces to Vašák, i.e., weakly K-countably determined Banach spaces. Thus we obtain a new construction of a locally uniformly rotund norm on a Vašák space. A further cultivation of this method yields the new result that every dual Vašák space admits a dual locally uniformly rotund norm.
On a Property of the Norm which is Close to Local Uniform Rotundity.
On a recent result of G. Pisier
On a result of J. Johnson
On almost everywhere differentiability of the metric projection on closed sets in ,
Let be a closed subset of and let denote the metric projection (closest point mapping) of onto in -norm. A classical result of Asplund states that is (Fréchet) differentiable almost everywhere (a.e.) in in the Euclidean case . We consider the case and prove that the th component of is differentiable a.e. if and satisfies Hölder condition of order if .
On an extension of norms from a subspace to the whole Banach space keeping their rotundity
Let ℛ denote some kind of rotundity, e.g., the uniform rotundity. Let X admit an ℛ-norm and let Y be a reflexive subspace of X with some ℛ-norm ∥·∥. Then we are able to extend ∥·∥ from Y to an ℛ-norm on X.
On an -Birkhoff orthogonality.
On areas and integral geometry in Minkowski spaces.
On Asplund functions
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.
On Averaging Null Sequences of Real-Valued Functions
If ξ is a countable ordinal and (fk) a sequence of real-valued functions we define the repeated averages of order ξ of (fk). By using a partition theorem of Nash-Williams for families of finite subsets of positive integers it is proved that if ξ is a countable ordinal then every sequence (fk) of real-valued functions has a subsequence (f'k) such that either every sequence of repeated averages of order ξ of (f'k) converges uniformly to zero or no sequence of repeated averages of order ξ of (f'k)...
On Banach spaces which are M-ideals in their biduals.
A Banach space X is an M-ideal in its bidual if the relation ||f + w|| = ||f|| + ||w||holds for every f in X* and every w in X ⊥.The class of the Banach spaces which are M-ideals in their biduals, in short, the class of M-embedded spaces, has been carefully investigated, in particular by A. Lima, G. Godefroy and the West Berlin School. The spaces c0(I) -I any set- equipped with their canonical norm belong to this class, which also contains e.g. certain spaces K(E,F) of compact operators between...
On Banach Spaces with the Gelfand-Philips Property.
On Banach spaces X such that L(Lp,X) = K(Lp,X).
On Bárány's theorems of Carathéodory and Helly type
The paper begins with a self-contained and short development of Bárány’s theorems of Carathéodory and Helly type in finite-dimensional spaces together with some new variants. In the second half the possible generalizations of these results to arbitrary Banach spaces are investigated. The Carathéodory-Bárány theorem has a counterpart in arbitrary dimensions under suitable uniform compactness or uniform boundedness conditions. The proper generalization of the Helly-Bárány theorem reads as follows:...
On basic Hahn-Banach extensions
On bijective isometries
On Busemann surface area of the unit ball in Minkowski spaces.