Über Algebren stetiger Operatorfunktionen
Über Boolesche Algebren von Projektionen.
Über die Cunningham-oo-Algebra und den Zentralisator reeller Banachräume.
Über eine Algebra ,,nicht normaler" Wiener-Hopf-Operatoren. I.
Über eine Algebra ,,nicht normaler'4 Wiener-Hopf-Operatoren. II.
Über Klassen schwach kompakter Operatoren in Banachverbänden.
U-ideals of factorable operators
We suggest a method of renorming of spaces of operators which are suitably approximable by sequences of operators from a given class. Further we generalize J. Johnsons’s construction of ideals of compact operators in the space of bounded operators and observe e.g. that under our renormings compact operators are -ideals in the: space of 2-absolutely summing operators or in the space of operators factorable through a Hilbert space.
Un théorème sur les opérateurs linéaires entre espaces de Banach qui se factorisent par un espace de Hilbert
Una caracterización del dual del ideal de los operadores absolutamente sumantes en espacios de Banach.
Unbounded -seminorms, biweights, and -representations of partial -algebras: A review.
Unbounded conditional expectations for partial -algebras.
Unbounded *-representations of tensor product locally convex *-algebras induced by unbounded C*-seminorms
The existence of unbounded *-representations of (locally convex) tensor product *-algebras is investigated, in terms of the existence of unbounded *-representations of the (locally convex) factors of the tensor product and vice versa.
Unconditional ideals of finite rank operators
Let be a Banach space. We give characterizations of when is a -ideal in for every Banach space in terms of nets of finite rank operators approximating weakly compact operators. Similar characterizations are given for the cases when is a -ideal in for every Banach space , when is a -ideal in for every Banach space , and when is a -ideal in for every Banach space .
Unconditionally converging operators in locally convex Hausdorff spaces
Unconditionally p-null sequences and unconditionally p-compact operators
We investigate sequences and operators via the unconditionally p-summable sequences. We characterize the unconditionally p-null sequences in terms of a certain tensor product and then prove that, for every 1 ≤ p < ∞, a subset of a Banach space is relatively unconditionally p-compact if and only if it is contained in the closed convex hull of an unconditionally p-null sequence.
Uniquely Generated Grothendieck Space Ideals.
Unitaires multiplicatifs en dimension finie et leurs sous-objets
On appelle pré-sous-groupe d’un unitaire multiplicatif agissant sur un espace hilbertien de dimension finie une droite vectorielle de telle que . Nous montrons que les pré-sous-groupes sont en nombre fini, donnons un équivalent du théorème de Lagrange et généralisons à ce cadre la construction du “bi-produit croisé”. De plus, nous établissons des bijections entre pré-sous-groupes et sous-algèbres coïdéales de l’algèbre de Hopf associée à , et donc, d’après Izumi, Longo, Popa, avec les...
Unitaires multiplicatifs et dualité pour les produits croisés de -algèbres
Unitary representations of solvable Lie groups