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A bounded subset $M$ of a Banach space $X$ is said to be $\varepsilon$-weakly precompact, for a given $\varepsilon\geq 0$, if every sequence $(x_n)_{n\in \mathbb{N}}$ in $M$ admits a subsequence $(x_{n_k})_{k\in \mathbb{N}}$ such that $$…

Functional Analysis · Mathematics 2021-02-03 José Rodríguez

In this paper we define the module extension dual Banach algebras and we use this Banach algebras to finding the relationship between $weak^*-$continuous homomorphisms of dual Banach algebras and Connes-amenability. So we study the…

Functional Analysis · Mathematics 2007-05-23 M. Eshaghi Gordji , F. Habibian , A. Rejali

A remarkable theorem of R. C. James is the following: suppose that $X$ is a Banach space and $C \subseteq X$ is a norm bounded, closed and convex set such that every linear functional $x^* \in X^*$ attains its supremum on $C$; then $C$ is a…

Functional Analysis · Mathematics 2016-09-06 Charles P. Stegall

We prove the following results: (i) Every absolutely weakly compact set in a Banach lattice is absolutely weakly sequentially compact. (ii) The converse of (i) holds if $E$ is separable or $B_{E^{**}}$ is absolutely weak$^*$ compact. (iii)…

Functional Analysis · Mathematics 2023-04-18 Geraldo Botelho , José Lucas P. Luiz , Vinicius C. C. Miranda

It is shown that if the dual of a separable Banach space has Property($K^*$) then the original space has the weak fixed point property. This is an improvement of previously results.

Functional Analysis · Mathematics 2022-09-07 Tim Dalby

We study classes of Banach spaces where the points of weak$^*$-weak continuity for the identity mapping on the dual unit ball form a weak$^*$-dense and weak$^*$-$G_{\delta}$ set. We also discuss how this property behaves in higher duals of…

Functional Analysis · Mathematics 2025-06-11 S. Daptari , V. Montesinos , T. S. S. R. K. Rao

In this paper we show that if $(y_n)$ is a seminormalized sequence in a Banach space which does not have any weakly convergent subsequence, then it contains a wide-$(s)$ subsequence $(x_n)$ which admits an equivalent convex basic sequence.…

Functional Analysis · Mathematics 2018-03-26 C. S. Barroso , V. Ferreira

This paper deals with the problem of when, given a collection $\mathcal C$ of weakly compact operators between separable Banach spaces, there exists a separable reflexive Banach space $Z$ with a Schauder basis so that every element in…

Functional Analysis · Mathematics 2019-09-18 Leandro Antunes , Kevin Beanland , Bruno de Mendonça Braga

We provide sufficient conditions for a Banach space Y to be weakly sequentially complete. These conditions are expressed in terms of the existence of directional derivatives for cone convex mappings with values in Y .

Optimization and Control · Mathematics 2016-02-20 E. M. Bednarczuk , K. Leśniewski

We define and study asymptotically symmetric Banach spaces (a.s.) and its variations: weakly a.s. (w.a.s.) and weakly normalized a.s. (w.n.a.s.). If X is a.s. then all spreading models of X are uniformly symmetric. We show that the converse…

Functional Analysis · Mathematics 2007-05-23 M. Junge , D. Kutzarova , E. Odell

Suppose that $Q$ is a weak$^{\ast }$ compact convex subset of a dual Banach space with the Radon-Nikod\'{y}m property. We show that if $(S,Q)$ is a nonexpansive and norm-distal dynamical system, then there is a fixed point of $S$ in $Q$ and…

Dynamical Systems · Mathematics 2022-01-03 Andrzej Wiśnicki

We show that a representation of a Banach algebra $A$ on a Banach space $X$ can be extended to a canonical representation of $A^{**}$ on $X$ if and only if certain orbit maps $A\to X$ are weakly compact. When this is the case, we show that…

Functional Analysis · Mathematics 2018-03-26 Eusebio Gardella , Hannes Thiel

We extend the duality principle for the $\Gamma$-convergence of convex lower semicontinuous functions, which was previously established only in separable reflexive Banach spaces, to the broader class of weakly compactly generated (WCG)…

Functional Analysis · Mathematics 2026-05-14 Rafael Correa , Pedro Pérez-Aros , José Pablo Santander

In this paper, we study multiplicative weak convergence in Banach f-algebra and multiplicative weak* convergence in its dual.

Functional Analysis · Mathematics 2019-03-19 Zhangjun Wang , Zili Chen , Jinxi Chen

We prove that if X is an infinite-dimensional Banach space with C^p smooth partitions of unity, then X and X\K are C^p diffeomorphic, for every weakly compact subset K of X.

Functional Analysis · Mathematics 2007-05-23 Daniel Azagra , Alejandro Montesinos

In this article we extend the notion of orthogonal metric space to weak orthogonal metric space. Then we establish fixed point results for a mapping satisfying a more general contraction condition. Several nontrivial examples are given in…

Functional Analysis · Mathematics 2018-06-27 Tanusri Senapati

A well known result of Haagerup from 1983 states that every C*-algebra A is weakly amenable, that is, every (associative) derivation from A into its dual is inner. A Banach algebra B is said to be ternary weakly amenable if every continuous…

Operator Algebras · Mathematics 2015-12-11 Tony Ho , Antonio M. Peralta , Bernard Russo

For A a separable unital C*-algebra and M a separable McDuff II_1-factor, we show that the space Hom_w(A,M) of weak approximate unitary equivalence classes of unital *-homomorphisms A \rightarrow M may be considered as a closed, bounded,…

Operator Algebras · Mathematics 2015-12-02 Scott Atkinson

Using a strengthening of the concept of $\K$ set, introduced in this paper, we study a certain subclass of the class of $\K$ Banach spaces; the so called strongly $\K$ Banach spaces. This class of spaces includes subspaces of strongly…

Functional Analysis · Mathematics 2013-04-25 K. K. Kampoukos , S. K. Mercourakis

In this paper the weak topology on a normed space is studied from the viewpoint of infinite-dimensional topology. Besides the weak topology on a normed space $X$ (coinciding with the topology of uniform convergence on finite subsets of the…

General Topology · Mathematics 2019-08-27 Taras Banakh