English
Related papers

Related papers: On thickness and thinness of Banach spaces

200 papers

Let $E$ be one of the spaces $C(K)$ and $L_1$, $F$ be an arbitrary Banach space, $p>1,$ and $(X,\sigma)$ be a space with a finite measure. We prove that $E$ is isometric to a subspace of the Lebesgue-Bochner space $L_p(X;F)$ only if $E$ is…

Functional Analysis · Mathematics 2016-09-06 Alexander Koldobsky

We introduce a notion of p-orthogonality in a general Banach space $1 \le p \le \infty$. We use this concept to characterize $\ell_p$-spaces among Banach spaces and also among complete order smooth p-normed spaces. We further introduce a…

Functional Analysis · Mathematics 2012-12-04 Anil Kumar Karn

A Banach space $X$ is said to have property (K) if every $w^*$-convergent sequence in $X^*$ admits a convex block subsequence which converges with respect to the Mackey topology. We study the connection of this property with strongly weakly…

Functional Analysis · Mathematics 2016-01-25 Antonio Avilés , José Rodríguez

We show some new results about tilings in Banach spaces. A tiling of a Banach space $X$ is a covering by closed sets with non-empty interior so that they have pairwise disjoint interiors. If moreover the tiles have inner radii uniformly…

Functional Analysis · Mathematics 2020-01-14 Robert Deville , Miguel García-Bravo

In this paper we survey known results of characterizations of reflexive Banach spaces, which are based on convergence of usual and generalized arithmetic mean (or Ces\`aro sum), weakly compact subsets, affine sets in a Banach space or its…

Functional Analysis · Mathematics 2025-03-17 Tianyi Zhou

We present an example of a Banach space whose numerical index is strictly greater than the numerical index of its dual, giving a negative answer to a question which has been latent since the beginning of the seventies. We also show a…

Functional Analysis · Mathematics 2015-06-26 Konstantin Boyko , Vladimir Kadets , Miguel Martin , Dirk Werner

We study those Banach spaces $X$ for which $S_X$ does not admit a finite $\eps$-net consisting of elements of $S_X$ for any $\eps < 2$. We give characterisations of this class of spaces in terms of $\ell_1$-type sequences and in terms of…

Functional Analysis · Mathematics 2015-07-16 Vladimir Kadets , Varvara Shepelska , Dirk Werner

In this paper we survey some recent results concerning the numerical index $n(\cdot)$ for large classes of Banach spaces, including vector valued $\ell_p$-spaces and $\ell_p$-sums of Banach spaces where $1\leq p < \infty$. In particular by…

Functional Analysis · Mathematics 2015-03-23 Asuman Guven Aksoy , Grzegorz Lewicki

We explore the $k$-smoothness of bounded linear operators between Banach spaces, using the newly introduced notion of index of smoothness. The characterization of the $k$-smoothness of operators between Hilbert spaces follows as a direct…

Functional Analysis · Mathematics 2024-08-14 Debmalya Sain , Shamim Sohel , Kallol Paul

We give the method of construction of normal but not strongly normal positive cones in Banach space.

Functional Analysis · Mathematics 2011-12-07 Konstantin Storozhuk

In order to measure qualitative properties we introduce a notion of a type for arbitrary normed spaces which measures the worst possible growth of partial sums of sequences weakly converging to zero. The ideas can be traced back to Banach…

Functional Analysis · Mathematics 2012-02-03 Robin Nittka

We describe the surjective isometries of the unit sphere of real Schreier spaces of all orders and their $p$-convexifications, for $1 < p < \infty$. This description allows us to provide for those spaces a positive answer to a special case…

Functional Analysis · Mathematics 2024-12-03 Micheline Fakhoury

The aim of this paper is to establish a strong convergence theorem for a strongly nonexpansive sequence in a Banach space. We also deal with some applications of the convergence theorem.

Functional Analysis · Mathematics 2025-09-17 Koji Aoyama , Masashi Toyoda

In this paper, we extend the Banach contraction principle to metric-like as well as partial metric spaces (not essentially complete) equipped with an arbitrary binary relation. Thereafter, we derive some fixed point results which are…

General Mathematics · Mathematics 2016-12-19 Md Ahmadullah , Abdur Rauf Khan , Mohammad Imdad

The main purpose of the paper is to prove the following results: Let $A$ be a locally finite metric space whose finite subsets admit uniformly bilipschitz embeddings into a Banach space $X$. Then $A$ admits a bilipschitz embedding into $X$.…

Functional Analysis · Mathematics 2013-02-26 Mikhail I. Ostrovskii

See title. (A Banach space is said to be L-embedded if it is complemented in its bidual such that the norm between the two complementary subspaces is additive.)

Functional Analysis · Mathematics 2010-04-02 Hermann Pfitzner

In this paper, we introduce the notion of topologically Banach contraction mapping defined on an arbitrary topological space X with the help of a continuous function $g:X\times X\rightarrow \mathbb{R}$ and investigate the existence of fixed…

General Topology · Mathematics 2020-07-22 Sumit Som , Supriti Laha , Lakshmi Kanta Dey

It is well known that every convex body in a finite dimensional normed space can be uniformly approximated by strictly convex and smooth convex bodies. However, in the case of infinite dimensions, little progress has been made since Klee…

Functional Analysis · Mathematics 2025-10-09 Lixin Cheng , Chunlan Jiang , Liping Yuan

For a certain class of algebras $\cal A$ we give a method for constructing Banach spaces $X$ such that every operator on $X$ is close to an operator in $\cal A$. This is used to produce spaces with a small amount of structure. We present…

Functional Analysis · Mathematics 2008-09-01 W. T. Gowers , B. Maurey

For a real normed space $X$, we study the $n$-dual space of $\left(X,\left\Vert \cdot \right\Vert \right) $ and show that the space is a Banach space. Meanwhile, for a real normed space $X$ of dimension $d\geq n$ which satisfies property…

Functional Analysis · Mathematics 2015-12-08 Yosafat E. P. Pangalela