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This paper deals with the interplay of the geometry of the norm and the weak topology in Banach spaces. Both dual and intrinsic connections between weak forms of rotundity and smoothness ared discussed. Weakly exposed points, weakly locally…

Functional Analysis · Mathematics 2007-06-25 J. Talponen

It is common that a Sobolev space defined on $\mathbb{R}^m$ has a non-compact embedding into an $L^p$-space, but it has subspaces for which this embedding becomes compact. There are three well known cases of such subspaces, the Rellich…

Functional Analysis · Mathematics 2020-03-17 Leszek Skrzypczak , Cyril Tintarev

Several characterizations of weak cotype 2 and weak Hilbert spaces are given in terms of basis constants and other structural invariants of Banach spaces. For finite-dimensional spaces, characterizations depending on subspaces of fixed…

Functional Analysis · Mathematics 2009-09-25 P. Mankiewicz , Nicole Tomczak-Jaegermann

Reflexive cones in Banach spaces are cones with weakly compact intersection with the unit ball. In this paper we study the structure of this class of cones. We investigate the relations between the notion of reflexive cones and the…

Functional Analysis · Mathematics 2012-05-29 Emanuele Casini , Enrico Miglierina , Ioannis A. Polyrakis , Foivos Xanthos

Several recent papers investigated unbounded convergences in Banach lattices. Combine all unbounded convergences, including unbounded order (norm, absolute weak, absolute weak*) convergence, we characterize L-weakly compact sets, L-weakly…

Functional Analysis · Mathematics 2021-04-06 Zhangjun Wang , Zili Chen , Jinxi Chen

We consider weighted composition operators on spaces of analytic functions on the unit disc, which take values in some complex Banach space. We provide necessary and sufficient conditions for the boundedness and (weak) compactness of…

Functional Analysis · Mathematics 2015-02-02 Mostafa Hassanlou , Jussi Laitila , Hamid Vaezi

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

We characterize boundedness, compactness and weak compactness of Volterra operators acting between different weighted Banach spaces of entire functions with weighted sup-norms in terms of the symbol g. Thus we complement recent work by…

Functional Analysis · Mathematics 2014-12-10 José Bonet , Jari Taskinen

We consider the cardinal invariant CG(X) of the minimal number of weakly compact subsets which generate a Banach space X. We study the behavior of this index when passing to subspaces, its relation with the Lindelof number in the weak…

Functional Analysis · Mathematics 2009-03-03 Antonio Avilés

We give a positive answer to the question of K. Bouras [`Almost Dunford-Pettis sets in Banach lattices', \textit{Rend. Circ. Mat. Palermo (2)} \textbf{ 62} (2013), 227--236] concerning weak compactness of almost Dunford-Pettis sets in…

Functional Analysis · Mathematics 2016-09-23 Jin Xi Chen , Lei Li

We show that for "most" compact non metrizable spaces, the unit ball of the Banach space C(K) contains an uncountable 2-equilateral set. We also give examples of compact non metrizable spaces K such that the minimum cardinality of a maximal…

Functional Analysis · Mathematics 2015-01-27 S. K. Mercourakis , G. Vassiliadis

In the context of classical associations between classes of Banach spaces and classes of compact Hausdorff spaces we survey known results and open questions concerning the existence and nonexistence of universal Banach spaces and of…

Functional Analysis · Mathematics 2012-09-20 Piotr Koszmider

This paper is devoted to the study of the relatively compact sets in Quasi-Banach function spaces, providing an important improvement of the known results. As an application, we take the final step in establishing a relative compactness…

Classical Analysis and ODEs · Mathematics 2020-06-24 Weichao Guo , Guoping Zhao

We consider the compact spaces sigma_n(I) of subsets of an uncountable set I of cardinality at most n and their countable products. We give a complete classification of their Banach spaces of continuous functions and a partial topological…

General Topology · Mathematics 2009-03-03 Antonio Avilés

The main purpose of this paper is to treat semigroups properties, like norm continuity, compactness and differentiability for perturbed semigroups in Banach spaces. In particular, we investigate three large classes of perturbations,…

Functional Analysis · Mathematics 2018-12-03 A. Boulouz , H. Bounit , A. Driouich , S. Hadd

A dual pair formulation for asymmetric locally convex spaces is developed that strictly generalises the ordinary vector space setting. The concept of a polar topology carries over to the asymmetric case and some familiar results are…

General Topology · Mathematics 2026-02-24 Jobst Ziebell

A compact space is said to be weakly Radon-Nikod\'{y}m (WRN) if it can be weak*-embedded into the dual of a Banach space not containing $\ell_1$. We investigate WRN Boolean algebras, i.e. algebras whose Stone space is WRN compact. We show…

Functional Analysis · Mathematics 2016-10-17 Antonio Avilés , Gonzalo Martínez-Cervantes , Grzegorz Plebanek

Given a compact space $K$, we denote by $P(K)$ the space of all Radon probability measures on $K$, equipped with the $weak^\ast$ topology inherited from $C(K)^\ast$. For nonmetrizable compacta $K$ even basic properties of $P(K)$ spaces…

General Topology · Mathematics 2024-07-09 Grzegorz Plebanek

The aim of this note is study the topology generated by Lipschitz slices in the unit sphere of a Banach space. We prove that the above topology agrees with the weak topology in the unit sphere and, as a consequence, we obtain Lipschitz…

Functional Analysis · Mathematics 2016-04-18 Julio Becerra Guerrero , Ginés López-Pérez , Abraham Rueda Zoca

Concentration compactness method is a powerful techniques for establishing existence of minimizers for inequalities and of critical points of functionals in general. The paper gives a functional-analytic formulation for the method in Banach…

Analysis of PDEs · Mathematics 2008-03-25 Kyril Tintarev