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We prove that every Banach space admitting a Gateaux smooth norm and containing a complemented copy of $\ell_1$ has an equivalent renorming which is simultaneously G\^ateaux smooth and octahedral. This is a partial solution to a problem…

Functional Analysis · Mathematics 2024-08-08 Ch. Cobollo , P. Hájek

the main goal of this paper is to prove that any Banach space X, that every dual ball in X** is weak* -separable, or every weak* -closed convex subset in X** is weak* -separable, or every norm-closed convex set in X* is constructible,…

Functional Analysis · Mathematics 2009-01-31 Hadi Haghshenas

We study some generalized metric properties of weak topologies when restricted to the unit sphere of some equivalent norm on a Banach space, and their relationships with other geometrical properties of norms. In case of dual Banach space…

Functional Analysis · Mathematics 2021-06-09 S. Ferrari , J. Orihuela , M. Raja

We modify the very well known theory of normed spaces $(E, \norm)$ within functional analysis by considering a sequence $(\norm_n : n\in\N)$ of norms, where $\norm_n$ is defined on the product space $E^n$ for each $n\in\N$. Our theory is…

Functional Analysis · Mathematics 2012-03-20 H. G. Dales , M. E. Polyakov

In this paper, we continue the investigation of topological properties of unbounded norm (un-)topology in normed lattices. We characterize separability and second countability of un-topology in terms of properties of the underlying normed…

Functional Analysis · Mathematics 2021-05-10 Marko Kandić , Aleš Vavpetič

We introduce a new type of norm for ordered vector spaces majorized by a proper (convex) cone that generalizes the notions of order unit norm and base norm. Then we give sufficient conditions to ensure its completeness. In the case of…

Functional Analysis · Mathematics 2022-01-07 Vasco Schiavo

In this paper, we introduce the cone normed spaces and cone bounded linear mappings. Among other things, we prove the Baire category theorem and the Banach--Steinhaus theorem in cone normed spaces.

Functional Analysis · Mathematics 2009-12-08 M. Eshaghi Gordji , M. Ramezani , H. Baghani , H. Khodaei

We prove in this article that every Borelian measure, for example, the distribution of a random variable, in separable Banach space has a support which is compact embedded Banach subspace; and prove that if the norm of the random variable…

Functional Analysis · Mathematics 2008-08-26 E. Ostrovsky

We study integrability and equivalence of L^p-norms of polynomial chaos elements. Relying on known results for Banach space valued polynomials, a simple technique is presented to obtain integrability results for random elements that are not…

Probability · Mathematics 2009-09-11 Andreas Basse

A Banach space contains either a minimal subspace or a continuum of incomparable subspaces. General structure results for analytic equivalence relations are applied in the context of Banach spaces to show that if $E_0$ does not reduce to…

Functional Analysis · Mathematics 2007-05-23 Christian Rosendal

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

For a Banach space $X$ by $Conv_H(X)$ we denote the space of non-empty closed convex subsets of $X$, endowed with the Hausdorff metric. We prove that for any closed convex set $C\subset X$ and its metric component $H_C=\{A\in…

Functional Analysis · Mathematics 2012-12-19 Taras Banakh , Ivan Hetman

Let $\mathcal{P}$ be a class of Banach spaces and let $T=\{T_\alpha\}_{\alpha\in A}$ be a set of metric spaces. We say that $T$ is a set of {\it test-spaces} for $\mathcal{P}$ if the following two conditions are equivalent: (1)…

Functional Analysis · Mathematics 2014-06-05 Mikhail I. Ostrovskii

We study the way in which the Euclidean subspaces of a Banach space fit together, somewhat in the spirit of the Ka\v{s}in decomposition. The main tool that we introduce is an estimate regarding the convex hull of a convex body in John's…

Functional Analysis · Mathematics 2015-05-06 Daniel J. Fresen

We formalize the observation that the same summability methods converge in a Banach space $X$ and its dual $X^*$. At the same time we determine conditions under which these methods converge in the weak and weak*-topologies on $X$ and $X^*$…

Functional Analysis · Mathematics 2023-02-15 Soumitra Ghara , Javad Mashreghi , Thomas Ransford

We construct infinitely differentiable norms and partitions of unity for a class of Banach spaces which includes all spaces $\C(K)$ with $K$ a countable compact space, and all spaces $\C_0[0,\Omega )$ with $\Omega $ an ordinal.

Functional Analysis · Mathematics 2008-02-03 Richard Haydon

We continue with the study of octahedral norms in the context of spaces of Lipschitz functions and in their duals. First, we prove that the norm of $\mathcal F(M)^{**}$ is octahedral as soon as $M$ is unbounded or is not uniformly discrete.…

Functional Analysis · Mathematics 2020-03-27 Johann Langemets , Abraham Rueda Zoca

We set up a descriptive set-theoretic framework to study Lipschitz-free spaces and use the reduction argument of Bossard to prove several results. We prove two universality results: if a separable Banach space is isomorphically universal…

Functional Analysis · Mathematics 2026-02-24 Richard J. Smith

Let X be a separable real Banach space having a k-times continuously Fr\'{e}chet differentiable (i.e. C^k-smooth) norm where k=1,...,\infty. We show that any equivalent norm on X can be approximated uniformly on bounded sets by C^k-smooth…

Functional Analysis · Mathematics 2012-08-22 Petr Hájek , Jarno Talponen

We collect several open questions in Banach spaces, mostly related to measure theoretic aspects of the theory. The problems are divided into five categories: miscellaneous problems in Banach spaces (non-separable $L^p$ spaces, compactness…

Functional Analysis · Mathematics 2016-07-27 Jose Rodriguez