Darstellungen von Liegruppen und Approximationsprozesse auf Banachräumen.
De nouveaux espaces de Banach sans la propriété d'approximation
Density in the space of topological measures
Topological measures (formerly "quasi-measures") are set functions that generalize measures and correspond to certain non-linear functionals on the space of continuous functions. The goal of this paper is to consider relationships between various families of topological measures on a given space. In particular, we prove density theorems involving classes of simple, representable, extreme topological measures and measures, hence giving a way of approximating various topological measures by members...
Density of Polynomials in the L^2 Space on the Real and the Imaginary Axes and in a Sobolev Space
2000 Mathematics Subject Classification: 41A10, 30E10, 41A65.In this paper we consider an L^2 type space of scalar functions L^2 M, A (R u iR) which can be, in particular, the usual L^2 space of scalar functions on R u iR. We find conditions for density of polynomials in this space using a connection with the L^2 space of square-integrable matrix-valued functions on R with respect to a non-negative Hermitian matrix measure. The completness of L^2 M, A (R u iR ) is also established.
Der beschränkte Fall des gewichteten Approximationsproblems für vektorwertige Funktionen.
Die Metrische Struktur der Sonnen in l...(n).
Differentiability of the distance function and points of multi-valuedness of the metric projection in Banach space
Directions d'uniforme convexité dans un espace normé
Dispersed Chebyshev Sets and Coverings by Balls.
Duality, reflexivity and atomic decompositions in Banach spaces
We study atomic decompositions and their relationship with duality and reflexivity of Banach spaces. To this end, we extend the concepts of "shrinking" and "boundedly complete" Schauder basis to the atomic decomposition framework. This allows us to answer a basic duality question: when an atomic decomposition for a Banach space generates, by duality, an atomic decomposition for its dual space. We also characterize the reflexivity of a Banach space in terms of properties of its atomic decompositions....