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On property (β) of Rolewicz in Musielak-Orlicz sequence spaces equipped with the Orlicz norm

Paweł Kolwicz (2005)

Banach Center Publications

We prove that the Musielak-Orlicz sequence space with the Orlicz norm has property (β) iff it is reflexive. It is a generalization and essential extension of the respective results from [3] and [5]. Moreover, taking an arbitrary Musielak-Orlicz function instead of an N-function we develop new methods and techniques of proof and we consider a wider class of spaces than in [3] and [5].

On r -reflexive Banach spaces

Iryna Banakh, Taras O. Banakh, Elena Riss (2009)

Commentationes Mathematicae Universitatis Carolinae

A Banach space X is called r -reflexive if for any cover 𝒰 of X by weakly open sets there is a finite subfamily 𝒱 𝒰 covering some ball of radius 1 centered at a point x with x r . We prove that an infinite-dimensional separable Banach space X is -reflexive ( r -reflexive for some r ) if and only if each ε -net for X has an accumulation point (resp., contains a non-trivial convergent sequence) in the weak topology of X . We show that the quasireflexive James space J is r -reflexive for no r . We do not know...

On Riesz homomorphisms in unital f -algebras

Elmiloud Chil (2009)

Mathematica Bohemica

The main topic of the first section of this paper is the following theorem: let A be an Archimedean f -algebra with unit element e , and T A A a Riesz homomorphism such that T 2 ( f ) = T ( f T ( e ) ) for all f A . Then every Riesz homomorphism extension T ˜ of T from the Dedekind completion A δ of A into itself satisfies T ˜ 2 ( f ) = T ˜ ( f T ( e ) ) for all f A δ . In the second section this result is applied in several directions. As a first application it is applied to show a result about extensions of positive projections to the Dedekind completion. A second application...

On Schwartz groups

L. Außenhofer, M. J. Chasco, X. Domínguez, V. Tarieladze (2007)

Studia Mathematica

We introduce a notion of a Schwartz group, which turns out to be coherent with the well known concept of a Schwartz topological vector space. We establish several basic properties of Schwartz groups and show that free topological Abelian groups, as well as free locally convex spaces, over hemicompact k-spaces are Schwartz groups. We also prove that every hemicompact k-space topological group, in particular the Pontryagin dual of a metrizable topological group, is a Schwartz group.

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