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Wavelet transform for functions with values in UMD spaces

Cornelia Kaiser, Lutz Weis (2008)

Studia Mathematica

We extend the classical theory of the continuous and discrete wavelet transform to functions with values in UMD spaces. As a by-product we obtain equivalent norms on Bochner spaces in terms of g-functions.

Weak compactness and σ-Asplund generated Banach spaces

M. Fabian, V. Montesinos, V. Zizler (2007)

Studia Mathematica

σ-Asplund generated Banach spaces are used to give new characterizations of subspaces of weakly compactly generated spaces and to prove some results on Radon-Nikodým compacta. We show, typically, that in the framework of weakly Lindelöf determined Banach spaces, subspaces of weakly compactly generated spaces are the same as σ-Asplund generated spaces. For this purpose, we study relationships between quantitative versions of Asplund property, dentability, differentiability, and of weak compactness...

Weak moduli of convexity.

Javier Alonso, Antonio Ullán (1991)

Extracta Mathematicae

Let E be a real normed linear space with unit ball B and unit sphere S. The classical modulus of convexity of J. A. Clarkson [2] δE(ε) = inf {1 - 1/2||x + y||: x,y ∈ B, ||x - y|| ≥ ε} (0 ≤ ε ≤ 2)is well known and it is at the origin of a great number of moduli defined by several authors. Among them, D. F. Cudia [3] defined the directional, weak and directional weak modulus of convexity of E, respectively, asδE(ε,g) = inf {1 - 1/2||x + y||: x,y ∈ B, g(x-y) ≥ ε}δE(ε,f) = inf {1 - 1/2 f(x,y): x,y...

Weak orthogonality and weak property ( β ) in some Banach sequence spaces

Yunan Cui, Henryk Hudzik, Ryszard Płuciennik (1999)

Czechoslovak Mathematical Journal

It is proved that a Köthe sequence space is weakly orthogonal if and only if it is order continuous. Criteria for weak property ( β ) in Orlicz sequence spaces in the case of the Luxemburg norm as well as the Orlicz norm are given.

Weak uniform normal structure and iterative fixed points of nonexpansive mappings

T. Domínguez Benavides, G. López Acedo, Hong Xu (1995)

Colloquium Mathematicae

This paper is concerned with weak uniform normal structure and iterative fixed points of nonexpansive mappings. Precisely, in Section 1, we show that the geometrical coefficient β(X) for a Banach space X recently introduced by Jimenez-Melado [8] is exactly the weakly convergent sequence coefficient WCS(X) introduced by Bynum [1] in 1980. We then show in Section 2 that all kinds of James' quasi-reflexive spaces have weak uniform normal structure. Finally, in Section 3, we show that in a space X with...

Weak uniform normal structure in direct sum spaces

Tomás Domínguez Benavides (1992)

Studia Mathematica

The weak normal structure coefficient WCS(X) is computed or bounded when X is a finite or infinite direct sum of reflexive Banach spaces with a monotone norm.

Weak uniform rotundity of Musielak--Orlicz spaces

Małgorzata Doman (1991)

Commentationes Mathematicae Universitatis Carolinae

We give necessary and sufficient conditions for weak uniform rotundity of Musielak–Orlicz spaces L ϕ with the Luxemburg norm. The result is a generalization of a theorem by Kami’nska and Kurc.

Weakly compact sets in Orlicz sequence spaces

Siyu Shi, Zhong Rui Shi, Shujun Wu (2021)

Czechoslovak Mathematical Journal

We combine the techniques of sequence spaces and general Orlicz functions that are broader than the classical cases of N -functions. We give three criteria for the weakly compact sets in general Orlicz sequence spaces. One criterion is related to elements of dual spaces. Under the restriction of lim u 0 M ( u ) / u = 0 , we propose two other modular types that are convenient to use because they get rid of elements of dual spaces. Subsequently, by one of these two modular criteria, we see that a set A in Riesz spaces l p ...

Weakly uniformly rotund Banach spaces

Aníbal Moltó, Vicente Montesinos, José Orihuela, Stanimir L. Troyanski (1998)

Commentationes Mathematicae Universitatis Carolinae

The dual space of a WUR Banach space is weakly K-analytic.

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