English
Related papers

Related papers: Examples of asymptotically \ell_^1 Banach spaces

200 papers

A. Szankowski's example is used to construct a Banach space similar to that of "An example of an asymptotically Hilbertian space which fails the approximation property", P.G. Casazza, C.L. Garc\'{\i}a, W.B. Johnson [math.FA/0006134…

Functional Analysis · Mathematics 2007-05-23 Oleg I. Reinov

We show that a separable real Banach space embeds almost isometrically in a space $Y$ with a shrinking 1-unconditional basis if and only if $\lim_{n \to \infty} \|x^* + x_n^*\| = \lim_{n \to \infty} \|x^* - x_n^*\|$ whenever $x^* \in X^*$,…

Functional Analysis · Mathematics 2008-09-17 S. R. Cowell , N. J. Kalton

Let $X$ be a Banach space with an unconditional finite-dimensional Schauder decomposition $(E_n)$. We consider the general problem of characterizing conditions under which one can construct an unconditional basis for $X$ by forming an…

Functional Analysis · Mathematics 2009-09-25 Peter G. Casazza , Nigel J. Kalton

Following Davie's example of a Banach space failing the approximation property [D], we show how to construct a Banach space E which is asymptotically Hilbertian and fails the approximation property. Moreover, the space E is shown to be a…

Functional Analysis · Mathematics 2007-05-23 P. G. Casazza , C. L. Garcia , W. B. Johnson

We prove that there exist Banach spaces not containing $\ell_1$, failing the point of continuity property and satisfying that every semi-normalized basic sequence has a boundedly complete basic subsequence. This answers in the negative the…

Functional Analysis · Mathematics 2009-02-20 Gines Lopez Perez

For a large class of Banach spaces, a general construction of subspaces without local unconditional structure is presented. As an application it is shown that every Banach space of finite cotype contains either $l_2$ or a subspace without…

Functional Analysis · Mathematics 2016-09-06 R. Komowski , Nicole Tomczak-Jaegermann

We construct a reflexive Banach space $X_\mathcal{D}$ with an unconditional basis such that all spreading models admitted by normalized block sequences in $X_\mathcal{D}$ are uniformly equivalent to the unit vector basis of $\ell_1$, yet…

Functional Analysis · Mathematics 2026-01-28 Harrison Gaebler , Pavlos Motakis , Bunyamin Sari

We analyse several examples of separable Banach spaces, some of them new, and relate them to several dichotomies obtained in the previous paper Banach spaces without minimal subspaces, by classifying them according to which side of the…

Functional Analysis · Mathematics 2011-04-26 Valentin Ferenczi , Christian Rosendal

If $X$ is a closed subspace of a Banach space $L$ which embeds into a Banach lattice not containing $\ell_\infty^n$'s uniformly and $L/X$ contains $\ell_\infty^n$'s uniformly, then $X$ cannot have local unconditional structure in the sense…

Functional Analysis · Mathematics 2016-09-07 William B. Johnson

For every Banach space $Z$ with a shrinking unconditional basis satisfying upper $p$-estimates for some $p > 1$, an isomorphically polyhedral Banach space is constructed having an unconditional basis and admitting a quotient isomorphic to…

Functional Analysis · Mathematics 2008-09-11 Ioannis Gasparis

For every $ 1 < p < \infty $ an isomorphically polyhedral Banach space $E_p$ is constructed having an unconditional basis and admitting a quotient isomorphic to $\ell_p$. It is also shown that $E_p$ is not isomorphic to a subspace of a…

Functional Analysis · Mathematics 2008-09-11 Ioannis Gasparis

Several new characterizations of Banach spaces containing a subspace isomorphic to $\ell^1$, are obtained. These are applied to the question of when $\ell^1$ embeds in the injective tensor product of two Banach spaces.

Functional Analysis · Mathematics 2007-11-01 Haskell P. Rosenthal

Any regular mixed Tsirelson space $T(\theta_n,S_n)_{\N}$ for which $\frac{\theta_n}{\theta^n} \to 0$, where $\theta=\lim_n \theta_n^{1/n}$, is shown to be arbitrarily distortable. Certain asymptotic $\ell_1$ constants for those and other…

Functional Analysis · Mathematics 2008-02-03 George Androulakis , Edward Odell

The relation between different notions measuring proximity to $\ell_1$ and distortability of a Banach space is studied. The main result states that a Banach space, whose all subspaces have Bourgain $\ell_1$ index greater than…

Functional Analysis · Mathematics 2008-03-14 Anna Maria Pelczar

We construct a Banach space that does not contain any infinite unconditional basic sequence.

Functional Analysis · Mathematics 2009-09-25 W. T. Gowers , Bernard Maurey

In this work we construct a ``Tsirelson like Banach space'' which is arbitrarily distortable.

Functional Analysis · Mathematics 2007-06-13 Thomas Schlumprecht

We show that the problem whether every $1$-separably injective Banach space contains an isomorphic copy of $\ell_\infty$ is undecidable. Namely, unlike under the continuum hypothesis, assuming Martin's axiom and the negation of the…

Functional Analysis · Mathematics 2018-01-31 Antonio Avilés , Piotr Koszmider

We explore the diversity of subsymmetric basic sequences in spaces with a subsymmetric basis. We prove that the subsymmetrization $Su(T^*)$ of Tsirelson's original Banach space provides the first known example of a space with a unique…

Functional Analysis · Mathematics 2021-12-20 Peter G. Casazza , Stephen J. Dilworth , Denka Kutzarova , Pavlos Motakis

We construct for each $0<p\le 1$ an infinite collection of subspaces of $\ell_p$ that extend the example from [J. Lindenstrauss, On a certain subspace of $\ell_{1}$, Bull. Acad. Polon. Sci. S\'er. Sci. Math. Astronom. Phys. 12 (1964),…

Functional Analysis · Mathematics 2019-12-19 Fernando Albiac , José L. Ansorena , Przemysław Wojtaszczyk

Within the class of reflexive Banach spaces, we prove a metric characterization of the class of asymptotic-$c_0$ spaces in terms of a bi-Lipschitz invariant which involves metrics that generalize the Hamming metric on $k$-subsets of…

Functional Analysis · Mathematics 2020-04-13 Florent P. Baudier , Gilles Lancien , Pavlos Motakis , Thomas Schlumprecht