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On some geometric properties of certain Köthe sequence spaces

Yunan Cui, Henryk Hudzik, Tao Zhang (1999)

Mathematica Bohemica

It is proved that if a Kothe sequence space X is monotone complete and has the weakly convergent sequence coefficient WCS ( X ) > 1 , then X is order continuous. It is shown that a weakly sequentially complete Kothe sequence space X is compactly locally uniformly rotund if and only if the norm in X is equi-absolutely continuous. The dual of the product space ( i = 1 X i ) Φ of a sequence of Banach spaces ( X i ) i = 1 , which is built by using an Orlicz function Φ satisfying the Δ 2 -condition, is computed isometrically (i.e. the exact...

On spreading c 0 -sequences in Banach spaces

Vassiliki Farmaki (1999)

Studia Mathematica

We introduce and study the spreading-(s) and the spreading-(u) property of a Banach space and their relations. A space has the spreading-(s) property if every normalized weakly null sequence has a subsequence with a spreading model equivalent to the usual basis of c 0 ; while it has the spreading-(u) property if every weak Cauchy and non-weakly convergent sequence has a convex block subsequence with a spreading model equivalent to the summing basis of c 0 . The main results proved are the following: (a)...

On suprabarrelledness of c0 (Ω, X).

Manuel López Pellicer, Salvador Moll (2003)

RACSAM

Si Ω­ es un conjunto no vacío y X es un espacio normado real o complejo, se tiene que, con la norma supremo, el espacio c0 (Ω, X) formado por las funciones f : Ω­ → X tales que para cada ε > 0 el conjunto {ω ∈ Ω­ : || f(ω) || > ε} es finito es supratonelado si y sólo si X es supratonelado.

On the classes of hereditarily p Banach spaces

Parviz Azimi, A. A. Ledari (2006)

Czechoslovak Mathematical Journal

Let X denote a specific space of the class of X α , p Banach sequence spaces which were constructed by Hagler and the first named author as classes of hereditarily p Banach spaces. We show that for p > 1 the Banach space X contains asymptotically isometric copies of p . It is known that any member of the class is a dual space. We show that the predual of X contains isometric copies of q where 1 p + 1 q = 1 . For p = 1 it is known that the predual of the Banach space X contains asymptotically isometric copies of c 0 . Here we...

On the Dunford-Pettis property of tensor product spaces

Ioana Ghenciu (2011)

Colloquium Mathematicae

We give sufficient conditions on Banach spaces E and F so that their projective tensor product E π F and the duals of their projective and injective tensor products do not have the Dunford-Pettis property. We prove that if E* does not have the Schur property, F is infinite-dimensional, and every operator T:E* → F** is completely continuous, then ( E ϵ F ) * does not have the DPP. We also prove that if E* does not have the Schur property, F is infinite-dimensional, and every operator T: F** → E* is completely...

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