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Related papers: Types of tightness in spaces with unconditional ba…

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We construct an indecomposable reflexive Banach space $X_{ius}$ such that every infinite dimensional closed subspace contains an unconditional basic sequence. We also show that every operator $T\in \mathcal{B}(X_{ius})$ is of the form…

Functional Analysis · Mathematics 2016-09-22 Spiros A. Argyros , A. Manoussakis

We survey several results concerning norming Markushevich bases (M-bases, for short), focusing in particular on two recent examples of a weakly compactly generated Banach space with no norming M-basis and of an Asplund space with norming…

Functional Analysis · Mathematics 2025-10-01 Petr Hájek , Tommaso Russo

We show examples of compact linear operators between Banach spaces which cannot be approximated by norm attaining operators. This is the negative answer to an open question posed in the 1970's. Actually, any strictly convex Banach space…

Functional Analysis · Mathematics 2014-07-16 Miguel Martin

A new hierarchy of Banach spaces $T_k(d,\theta)$, $k$ any positive integer, is constructed using barriers in high dimensional Ellentuck spaces \cite{DobrinenJSL15} following the classical framework under which a Tsirelson type norm is…

Logic · Mathematics 2018-01-09 Alvaro Arias , Natasha Dobrinen , Gabriel Giron-Garnica , Jose G. Mijares

A local classification of spacelike surfaces in Minkowski 4-space, which are invariant under spacelike rotations, and with mean curvature vector either vanishing or lightlike, is obtained. Furthermore, the existence of such surfaces with…

General Relativity and Quantum Cosmology · Physics 2009-08-05 Stefan Haesen , Miguel Ortega

We investigate the connection between Gaussian processes and Gaussian random elements in reproducing kernel Banach spaces. We show that the covariance operator of a weak second-order Radon probability measure on such a space is uniquely…

Probability · Mathematics 2026-05-28 Toni Karvonen , Rasmus Kleist Hørlyck Sørensen

The main result of this paper is that the space of conformally compact Einstein metrics on a given manifold is a smooth, infinite dimensional Banach manifold, provided it is non-empty, generalizing earlier work of Graham-Lee and Biquard. We…

Differential Geometry · Mathematics 2010-03-16 Michael T. Anderson

A recent result of Freeman, Odell, Sari, and Zheng states that whenever a separable Banach space not containing $\ell_1$ has the property that all asymptotic models generated by weakly null sequences are equivalent to the unit vector basis…

Functional Analysis · Mathematics 2020-03-03 Spiros A. Argyros , Alexandros Georgiou , Pavlos Motakis

Our aim in this paper is to present a new type of the modular space. This space contains the classical modular space. There are some mappings that do not have contractive condition in the usual modular space but become contraction in this…

Functional Analysis · Mathematics 2018-11-14 Muttalip Özavşar , Hatice Çay

Oscillation stability is an important concept in Banach space theory which happens to be closely connected to discrete Ramsey theory. For example, Gowers proved oscillation stability for the Banach space $c_0$ using his now famous Ramsey…

Functional Analysis · Mathematics 2023-03-28 Tristan Bice , Noé de Rancourt , Jan Hubička , Matěj Konečný

We introduce an unconditional concept of almost squareness in order to provide a partial negative answer to the problem of existence of any dual almost square Banach space. We also take advantage of this notion to provide some criterion of…

Functional Analysis · Mathematics 2016-06-09 Luis García-Lirola , Abraham Rueda Zoca

We initiate a study of cohomological aspects of weakly almost periodic group representations on Banach spaces, in particular, isometric representations on reflexive Banach spaces. Using the Ryll-Nardzewski fixed point Theorem, we prove a…

Group Theory · Mathematics 2013-02-12 Uri Bader , Christian Rosendal , Roman Sauer

We extend Pisier's abstract version of Grothendieck's theorem to general non-locally convex quasi-Banach spaces. We also prove a related result on factoring operators through a Banach space and apply our results to the study of…

Functional Analysis · Mathematics 2008-02-03 Nigel J. Kalton , Sik-Chung Tam

Relatively recently it was proved that if $\Gamma$ is an arbitrary set, then any equivalent norm on $c_0(\Gamma)$ can be approximated uniformly on bounded sets by polyhedral norms and $C^\infty$ smooth norms, with arbitrary precision. We…

Functional Analysis · Mathematics 2022-06-14 Richard J. Smith , Stanimir Troyanski

A topological space is said to be sequential if every sequentially closed subspace is closed. We consider Banach spaces with weak*-sequential dual ball. In particular, we show that if $X$ is a Banach space with weak*-sequentially compact…

Functional Analysis · Mathematics 2016-12-20 Gonzalo Martínez-Cervantes

In this note, we study some concentration properties for Lipschitz maps defined on Hamming graphs, as well as their stability under sums of Banach spaces. As an application, we extend a result of Causey on the coarse Lipschitz structure of…

Functional Analysis · Mathematics 2023-01-27 Audrey Fovelle

We study density requirements on a given Banach space that guarantee the existence of subsymmetric basic sequences by extending Tsirelson's well-known space to larger index sets. We prove that for every cardinal $\kappa$ smaller than the…

Functional Analysis · Mathematics 2017-03-27 Christina Brech , Jordi Lopez-Abad , Stevo Todorcevic

In this paper, in particular, we prove the following result: Let $E$ be a reflexive real Banach space and let $C\subset E$ be a closed convex set, with non-empty interior, whose boundary is sequentially weakly closed and non-convex. Then,…

Functional Analysis · Mathematics 2023-08-15 Biagio Ricceri

We investigate possible quantifications of R. C. James' classical work on bases and reflexivity of Banach spaces. By introducing new quantities measuring how far a basic sequence is from being shrinking and/or boundedly complete, we prove…

Functional Analysis · Mathematics 2021-04-15 Dongyang Chen , Tomasz Kania , Yingbin Ruan

Let C(K) be the Banach space of all continuous functions on a given compact space K. We investigate the w*-sequential closure in C(K)* of the set of all finitely supported probabilities on K. We discuss the coincidence of the Baire…

Functional Analysis · Mathematics 2014-06-30 Antonio Avilés , Grzegorz Plebanek , José Rodríguez