All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 5 Next

Displaying 81 – 100 of 118

Showing per page

Remarks on the complementability of spaces of Bochner integrable functions in spaces of vector measures

Giovanni Emmanuele (1996)

Commentationes Mathematicae Universitatis Carolinae

In the paper [5] L. Drewnowski and the author proved that if X is a Banach space containing a copy of c 0 then L 1 ( μ , X ) is not complemented in c a b v ( μ , X ) and conjectured that the same result is true if X is any Banach space without the Radon-Nikodym property. Recently, F. Freniche and L. Rodriguez-Piazza ([7]) disproved this conjecture, by showing that if μ is a finite measure and X is a Banach lattice not containing copies of c 0 , then L 1 ( μ , X ) is complemented in c a b v ( μ , X ) . Here, we show that the complementability of L 1 ( μ , X ) in c a b v ( μ , X ) together...

Remarks on the Istratescu measure of noncompactness.

Janusz Dronka (1993)

Collectanea Mathematica

In this paper we give estimations of Istratescu measure of noncompactness I(X) of a set X C lp(E1,...,En) in terms of measures I(Xj) (j=1,...,n) of projections Xj of X on Ej. Also a converse problem of finding a set X for which the measure I(X) satisfies the estimations under consideration is considered.

Renormings of c 0 and the minimal displacement problem

Łukasz Piasecki (2015)

Annales UMCS, Mathematica

The aim of this paper is to show that for every Banach space (X, || · ||) containing asymptotically isometric copy of the space c0 there is a bounded, closed and convex set C ⊂ X with the Chebyshev radius r(C) = 1 such that for every k ≥ 1 there exists a k-contractive mapping T : C → C with [...] for any x ∊ C.

Report on twisted sums of Banach spaces.

Félix Cabello, Jesús M. Fernández Castillo (1996)

Extracta Mathematicae

This note is to report some of the advances obtained as a follow-up of the book [2] on the topic of twisted sums of Banach spaces. Since this announcement is no longer enough to contain the theory being developed, we submit the interested reader to [2] and to [1], where full details and proofs shall appear.

Representable Banach Spaces and Uniformly Gateaux-Smooth Norms

Frontisi, Julien (1996)

Serdica Mathematical Journal

It is proved that a representable non-separable Banach space does not admit uniformly Gâteaux-smooth norms. This is true in particular for C(K) spaces where K is a separable non-metrizable Rosenthal compact space.

Representation of operators with martingales and the Radon-Nikodým property.

Manuel González, Antonio Martínez-Abejón, Javier Pello-García (2004)

Extracta Mathematicae

The Radon-Nikodým property was introduced to describe those Banach spaces X for which all operators acting between L1 and X have a representation function. These spaces can be characterized in terms of martingales, as those spaces in which every uniformly bounded martingale converges. In the present work we study some classes of operators defined upon their behaviour with respect to the convergence of such martingales. We prove that an operator preserves the non-convergence of uniformly bounded...

Currently displaying 81 – 100 of 118