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A Characterization of Weakly Lindelöf Determined Banach Spaces

Kalenda, Ondřej (2003)

Serdica Mathematical Journal

2000 Mathematics Subject Classification: 46B26, 46B03, 46B04.We prove that a Banach space X is weakly Lindelöf determined if (and only if) each non-separable Banach space isomorphic to a complemented subspace of X has a projectional resolution of the identity. This answers a question posed by S. Mercourakis and S. Negrepontis and yields a converse of Amir-Lindenstrauss’ theorem. We also prove that a Banach space of the form C(K) where K is a continuous image of a Valdivia compactum is weakly Lindelöf...

A characterization of weakly sequentially complete Banach lattices

A. W. Wickstead (1976)

Annales de l'institut Fourier

The equivalence of the two following properties is proved for every Banach lattice E :1) E is weakly sequentially complete.2) Every σ ( E * , E ) -Borel measurable linear functional on E is σ ( E * , E ) -continuous.

A C(K) Banach space which does not have the Schroeder-Bernstein property

Piotr Koszmider (2012)

Studia Mathematica

We construct a totally disconnected compact Hausdorff space K₊ which has clopen subsets K₊” ⊆ K₊’ ⊆ K₊ such that K₊” is homeomorphic to K₊ and hence C(K₊”) is isometric as a Banach space to C(K₊) but C(K₊’) is not isomorphic to C(K₊). This gives two nonisomorphic Banach spaces (necessarily nonseparable) of the form C(K) which are isomorphic to complemented subspaces of each other (even in the above strong isometric sense), providing a solution to the Schroeder-Bernstein problem for Banach spaces...

A class of Banach sequence spaces analogous to the space of Popov

Parviz Azimi, A. A. Ledari (2009)

Czechoslovak Mathematical Journal

Hagler and the first named author introduced a class of hereditarily l 1 Banach spaces which do not possess the Schur property. Then the first author extended these spaces to a class of hereditarily l p Banach spaces for 1 p < . Here we use these spaces to introduce a new class of hereditarily l p ( c 0 ) Banach spaces analogous of the space of Popov. In particular, for p = 1 the spaces are further examples of hereditarily l 1 Banach spaces failing the Schur property.

A coding of separable Banach spaces. Analytic and coanalytic families of Banach spaces

Benoit Bossard (2002)

Fundamenta Mathematicae

When the set of closed subspaces of C(Δ), where Δ is the Cantor set, is equipped with the standard Effros-Borel structure, the graph of the basic relations between Banach spaces (isomorphism, being isomorphic to a subspace, quotient, direct sum,...) is analytic non-Borel. Many natural families of Banach spaces (such as reflexive spaces, spaces not containing ℓ₁(ω),...) are coanalytic non-Borel. Some natural ranks (rank of embedding, Szlenk indices) are shown to be coanalytic ranks. Applications...

A common fixed point theorem for a commuting family of weak* continuous nonexpansive mappings

Sławomir Borzdyński, Andrzej Wiśnicki (2014)

Studia Mathematica

It is shown that if 𝓢 is a commuting family of weak* continuous nonexpansive mappings acting on a weak* compact convex subset C of the dual Banach space E, then the set of common fixed points of 𝓢 is a nonempty nonexpansive retract of C. This partially solves an open problem in metric fixed point theory in the case of commutative semigroups.

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