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Related papers: On two problems concerning Eberlein compacta

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We list a number of problems in several topics related to compactness in nonseparable Banach spaces. Namely, about the Hilbertian ball in its weak topology, spaces of continuous functions on Eberlein compacta, WCG Banach spaces, Valdivia…

Functional Analysis · Mathematics 2010-11-08 Antonio Avilés , Ondřej F. K. Kalenda

One shows for Banach bundles in a certain class that having a second countable locally compact Hausdorff base space and separable fibers implies the separability of the Banach space of the all sections that vanish at infinity. In the…

Functional Analysis · Mathematics 2018-02-07 Aldo J. Lazar

Assuming that there is a stationary set in $\omega_{2}$ of ordinals of countable cofinality that does not reflect, we prove that there exists a compact space which is not Corson compact and whose all continuous images of weight at most…

General Topology · Mathematics 2016-08-09 Menachem Magidor , Grzegorz Plebanek

We construct a ZFC example of a nonmetrizable compact space $K$ such that every totally disconnected closed subspace $L\subseteq K$ is metrizable. In fact, the construction can be arranged so that every nonmetrizable compact subspace may be…

General Topology · Mathematics 2015-09-18 Piotr Koszmider

It follows from a theorem of Rosenthal that a compact space is $ccc$ if and only if every Eberlein continuous image is metrizable. Motivated by this result, for a class of compact spaces $\mathcal{C}$ we define its orthogonal…

Functional Analysis · Mathematics 2021-04-14 Antonio Avilés , Gonzalo Martínez-Cervantes , Grzegorz Plebanek

We prove that each metrizable space (of cardinality less or equal to continuum) has a (first countable) uniform Eberlein compactification and each scattered metrizable space has a scattered hereditarily paracompact compactification. Each…

General Topology · Mathematics 2012-12-19 Taras Banakh , Arkady Leiderman

For k being the first uncountable cardinal w_1 or k being the cardinality of the continuum c, we prove that it is consistent that there is no Banach space of density k in which it is possible to isomorphically embed every Banach space of…

Functional Analysis · Mathematics 2011-03-23 Christina Brech , Piotr Koszmider

Given a Banach space we consider the $\sigma$-ideal of all of its subsets which are covered by countably many hyperplanes and investigate its standard cardinal characteristics as the additivity, the covering number, the uniformity, the…

Functional Analysis · Mathematics 2021-05-26 Damian Głodkowski , Piotr Koszmider

The Erberlein-Smulian Theorem asserts that for complete normed spaces, that is Banach spaces, a subset is weak compact if and only if it is weak sequentially compact. In this paper it is shown that the completeness of the normed space is…

Functional Analysis · Mathematics 2007-05-23 Wha Suck Lee

It is a well known open problem if, in ZFC, each compact space with a small diagonal is metrizable. We explore properties of compact spaces with a small diagonal using elementary chains of submodels. We prove that ccc subspaces of such…

General Topology · Mathematics 2012-07-25 Alan Dow , Klaas Pieter Hart

We present a characterization of spaces of strictly decreasing functions on trees in terms of bisequentiality. This characterization answers Questions 6.1 and 6.2 of "A filter on a collection of finite sets and Eberlein compacta" by T.…

General Topology · Mathematics 2018-09-06 Claudio Agostini , Jacopo Somaglia

Assuming $\mathfrak p=\mathfrak c$, we show that for every Eberlein compact space $L$ of weight $\mathfrak c$ there exists a short exact sequence $0\to c_0\to X\to C(L)\to 0$, where the Banach space $X$ is not isomorphic to a $C(K)$-space.

Functional Analysis · Mathematics 2026-02-20 Grzegorz Plebanek , Alberto Salguero-Alarcón

We deeply study retractions associated to suitable models in compact spaces admitting a retractional skeleton and find several interesting consequences. Most importantly, we provide a new characterization of Valdivia compacta using the…

General Topology · Mathematics 2022-02-03 Claudia Correa , Marek Cúth , Jacopo Somaglia

A compact space is said to be weakly Radon-Nikod\'ym if it is homeomorphic to a weak*-compact subset of the dual of a Banach space not containing an isomorphic copy of $\ell_1$. In this work we provide an example of a continuous image of a…

Functional Analysis · Mathematics 2015-09-18 Gonzalo Martínez-Cervantes

We introduce the notions of tauberian, cotauberian and weakly compact pair of closed subspaces of a Banach space. The theory produced by these notions is richer than that of the corresponding operators since an operator can be regarded as a…

Functional Analysis · Mathematics 2026-03-31 Manuel González , Antonio Martínez-Abejón

A Banach space contains either a minimal subspace or a continuum of incomparable subspaces. General structure results for analytic equivalence relations are applied in the context of Banach spaces to show that if $E_0$ does not reduce to…

Functional Analysis · Mathematics 2007-05-23 Christian Rosendal

A Banach space has the weak fixed point property if its dual space has a weak$^*$ sequentially compact unit ball and the dual space satisfies the weak$^*$ uniform Kadec-Klee property; and it has the \fpp if there exists $\epsilon>0$ such…

Functional Analysis · Mathematics 2008-04-04 P. N. Dowling , B. Randrianantoanina , B. Turett

We prove that there is a compact space $L$ and a 1-complemented subspace of the Banach space $C(L)$ which is not isomorphic to a space of continuous functions.

Functional Analysis · Mathematics 2023-05-09 Grzegorz Plebanek , Alberto Salguero Alarcón

In this note we study the structure of Lipschitz-free Banach spaces. We show that every Lipschitz-free Banach space over an infinite metric space contains a complemented copy of $\ell_1$. This result has many consequences for the structure…

Functional Analysis · Mathematics 2018-02-09 Marek Cuth , Michal Doucha , Przemyslaw Wojtaszczyk

Given a compact space in a fixed universe of set theory, one can naturally define its interpretation in any ZFC extension of the universe. We investigate the stability of some classes of compact spaces with respect to extensions of this…

General Topology · Mathematics 2014-02-10 Wiesław Kubiś
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