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In this paper, the main aim is to discuss the existence of the extreme points and support points of families of harmonic Bloch mappings and little harmonic Bloch mappings. First, in terms of the Bloch unit-valued set, we prove a necessary…

Complex Variables · Mathematics 2019-09-10 Hua Deng , Saminthan Ponnusamy , Jinjing Qiao

We characterise the class of those Banach spaces in which every convex combination of slices of the unit ball intersects the unit sphere as the class of those spaces in which every convex combination of slices of the unit ball contains two…

Functional Analysis · Mathematics 2019-01-24 Gines Lopez-Perez , Miguel Martin , Abraham Rueda Zoca

We show that the class of Lipschitz-free spaces over closed subsets of any complete metric space $M$ is closed under arbitrary intersections, improving upon the previously known finite-diameter case. This allows us to formulate a general…

Functional Analysis · Mathematics 2022-03-16 Ramón J. Aliaga , Eva Pernecká , Colin Petitjean , Antonín Procházka

In Euclidean spaces, every closed, bounded, convex set can be characterized by two equivalent notions of separation properties. This is not true in general for arbitrary Banach spaces. In this work, we present a ball separation…

Functional Analysis · Mathematics 2025-11-12 Sudeshna Basu , Susmita Seal

Denote by $X$ a Banach space and by $T : X \to X$ a bounded linear operator with non-trivial kernel satisfying suitable conditions. We consider the concepts of entropy - for $T$-invariant probability measures - and pressure for H\"older…

Dynamical Systems · Mathematics 2022-08-02 Artur O. Lopes , Victor Vargas

For a complex Banach space $X$ with open unit ball $B_X,$ consider the Banach algebras $\mathcal H^\infty(B_X)$ of bounded scalar-valued holomorphic functions and the subalgebra $\mathcal A_u(B_X)$ of uniformly continuous functions on…

Functional Analysis · Mathematics 2019-02-06 Richard M. Aron , Verónica Dimant , Silvia Lassalle , Manuel Maestre

Let $ E $ be a space of holomorphic functions on the unit ball $ B_X $ of a Banach space $ X.$ In this work, we introduce a Banach structure associated to $ E $ on the linear space $ WE(Y) $ containing $ Y$-valued holomorphic functions on $…

Functional Analysis · Mathematics 2022-03-08 Thai Thuan Quang

The geometric notion of huskability initiated and developed in [B3], [BR] ,[EW], [GM] was subsequently extensively studied in the context of dentability and Radon Nikodym Property in [GGMS]. In this work, we introduce a new geometric…

Functional Analysis · Mathematics 2021-08-06 Sudeshna Basu , Susmita Seal

We consider a general notion of snowflake of a metric space by composing the distance by a nontrivial concave function. We prove that a snowflake of a metric space $X$ isometrically embeds into some finite-dimensional normed space if and…

Metric Geometry · Mathematics 2016-09-13 Enrico Le Donne , Tapio Rajala , Erik Walsberg

We study properties of inner and outer functions in the Hardy space of the quaternionic unit ball. In particular, we give sufficient conditions as well as necessary ones for functions to be inner or outer.

Complex Variables · Mathematics 2019-03-06 Alessandro Monguzzi , Giulia Sarfatti , Daniel Seco

For a compact Hausdorff space $S$, we prove that the closed unit ball of a closed linear subalgebra of the space of real-valued continuous functions on $S$, denoted by $C(S)$, satisfies property-$(P_1)$ (the set-valued generalization of…

Functional Analysis · Mathematics 2023-03-21 Teena Thomas

We construct an example of a real-valued continuous non-constant function $f$ defined on a connected complete metric space $X$ such that every point of $X$ is a point of local minimum or local maximum for $f$. The space $X$ is connected but…

General Topology · Mathematics 2008-11-12 T. Banakh , M. Vovk , M. R. Wojcik

We make a study of Weinstein functionals, first defined in ~\cite{W}, on the hyperbolic space $\mathbb{H}^n$. We are primarily interested in the existence of Weinstein functional maximisers, or, in other words, existence of extremal…

Analysis of PDEs · Mathematics 2015-07-14 Mayukh Mukherjee

This article aims to examine the Hahn-Banach smoothness of Banach spaces and its connections to various geometrical aspects. We examine the circumstances that allow linear functionals to have unique norm-preserving extensions, with…

Functional Analysis · Mathematics 2026-03-25 Sainik Karak

A banach space X is a normed vector space, which is complete with respect to the metric induced by the norm. Given a bounded linear operator T acting on a banach space X, T is said to attain its norm if there is a unit vector z in X, such…

Functional Analysis · Mathematics 2019-07-30 Samuel Gomez , James Rose , Ryan Maguire

If $X$ is an infinite-dimensional uniform algebra, if $X$ has the Daugavet property or if $X$ is a proper $M$-embedded space, every relatively weakly open subset of the unit ball of the Banach space $X$ is known to have diameter 2, i.e.,…

Functional Analysis · Mathematics 2013-04-29 Trond Abrahamsen , Vegard Lima , Olav Nygaard

Let $X$ be a Banach space, let $(\Omega,\mu)$ be a $\sigma$-finite measure space and let $A,B\colon\Omega\to B(X)$ be strongly measurable $\gamma$-bounded functions. We show that for all $x\in X$ and all $x^*\in X^*$, there exist a Hilbert…

Functional Analysis · Mathematics 2024-02-19 Christian Le Merdy

The notion of adequate function has been recently introduced in order to characterize the essentially strictly functions on a reflexive Banach space among the weakly lower semicontinuous ones. In this paper we reinforce this concept and…

Optimization and Control · Mathematics 2012-03-07 Michel Volle , Constantin Zalinescu

We study the Banach space $D([0,1]^m)$ of functions of several variables that are (in a certain sense) right-continuous with left limits, and extend several results previously known for the standard case $m=1$. We give, for example, a…

Probability · Mathematics 2020-04-02 Svante Janson

We conjecture that whenever $M$ is a metric space of density at most continuum, then the space of Lipschitz functions is $w^*$-separable. We prove the conjecture for several classes of metric spaces including all the Banach spaces with a…

Functional Analysis · Mathematics 2025-03-14 Leandro Candido , Marek Cuth , Benjamin Vejnar