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Related papers: On exposed points of Lipschitz free spaces

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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

For a complete metric space $M$, we prove that the finitely supported extreme points of the unit ball of the Lipschitz-free space $\mathcal{F}(M)$ are precisely the elementary molecules $(\delta(p)-\delta(q))/d(p,q)$ defined by pairs of…

Functional Analysis · Mathematics 2022-03-16 Ramón J. Aliaga , Eva Pernecká

We study Daugavet points and $\Delta$-points in Lipschitz-free Banach spaces. We prove that, if $M$ is a compact metric space, then $\mu\in S_{\mathcal F(M)}$ is a Daugavet point if, and only if, there is no denting point of $B_{\mathcal…

Functional Analysis · Mathematics 2021-01-13 Mingu Jung , Abraham Rueda Zoca

We analyse the relationship between different extremal notions in Lipschitz free spaces (strongly exposed, exposed, preserved extreme and extreme points). We prove in particular that every preserved extreme point of the unit ball is also a…

Functional Analysis · Mathematics 2017-07-31 Luis García-Lirola , Colin Petitjean , Antonin Procházka , Abraham Rueda Zoca

In this paper, we present some sufficient conditions on a metric space $M$ for which every molecule is a strongly subdifferentiable (SSD, for short) point in the Lipschitz-free space $\mathcal{F}(M)$ over $M$. Our main result reads as…

Functional Analysis · Mathematics 2024-09-26 Christian Cobollo , Sheldon Dantas , Petr Hájek , Mingu Jung

We show that, for a separable and complete metric space $M$, the Lipschitz-free space $\mathcal F(M)$ embeds linearly and almost-isometrically into $\ell_1$ if and only if $M$ is a subset of an $\mathbb R$-tree with length measure 0.…

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

Let $\|\cdot\|$ be a norm on $\mathbb{R}^N$ and let $M$ be a closed $C^1$-submanifold of $\mathbb{R}^N$. Consider the pointed metric space $(M,d)$, where $d$ is the metric given by $d(x,y)=\|x-y\|$, $x,y\in M$. Then the Lipschitz-free space…

Functional Analysis · Mathematics 2022-06-13 Richard J. Smith , Filip Talimdjioski

We prove that every element of a Lipschitz-free space admits an expression as a convex series of elements with compact support. As a consequence, we conclude that all extreme points of the unit ball of Lipschitz-free spaces are elementary…

Functional Analysis · Mathematics 2026-03-17 Ramón J. Aliaga , Eva Pernecká , Richard J. Smith

We investigate when the local Lipschitz property of the real-valued function $g(z) = d_Y (f(z),A)$ implies the global Lipschitz property of the mapping $f:X\to Y$ between the metric spaces $(X,d_X)$ and $(Y,d_Y)$. Here, $d_Y(y,A)$ denotes…

Complex Variables · Mathematics 2025-07-22 Marijan Markovic

Let $X$ be a compact metric space and $\mathcal M_X$ be the set of isometry classes of compact metric spaces $Y$ such that the Lipschitz distance $d_L(X,Y)$ is finite. We show that $(\mathcal M_X, d_L)$ is not separable when $X$ is a closed…

Metric Geometry · Mathematics 2015-09-15 Kohei Suzuki , Yohei Yamazaki

Let $D$ be a nonempty open set in a metric space $(X,d)$ with $\partial D\neq \emptyset$. Define \begin{equation*} h_{D,c}(x,y)=\log\left(1+c\frac{d(x,y)}{\sqrt{d_D(x)d_D(y)}}\right), \end{equation*} where $d_D(x)=d(x,\partial D)$ is the…

Metric Geometry · Mathematics 2023-09-08 Yinping Wu , Gendi Wang , Gaili Jia , Xiaohui Zhang

We show that the standard partition of unity subordinate to an open cover of a metric space has Lipschitz constant $\max(1,M-1)/\mathcal{L}$, where $\mathcal{L}$ is the Lebesgue number and $M$ is the multiplicity of the cover. If the metric…

Metric Geometry · Mathematics 2024-05-22 Martin W. Licht

A norm one element $x$ of a Banach space is a Daugavet-point (respectively, a $\Delta$-point) if every slice of the unit ball (respectively, every slice of the unit ball containing $x$) contains an element, which is almost at distance 2…

Functional Analysis · Mathematics 2021-11-30 Triinu Veeorg

Given a pointed metric space $M$, we study when there exist $n$-dimensional linear subspaces of $\operatorname{Lip}_0(M)$ consisting of strongly norm-attaining Lipschitz functionals, for $n\in\mathbb{N}$. We show that this is always the…

Functional Analysis · Mathematics 2022-03-04 Vladimir Kadets , Óscar Roldán

For $\sigma>0$, the Bernstein space \ $B^1_{\sigma}$ consists of those $L^1(R)$\ functions whose Fourier transforms are supported by $[-\sigma,\sigma]$. Since $B^1_{\sigma}$ is separable and dual to some Banach space, the closed unit ball…

Functional Analysis · Mathematics 2020-09-11 Saulius Norvidas

We call a closed subset M of a Banach space X a free basis of X if it contains the null vector and every Lipschitz map from M to a Banach space Y, which preserves the null vectors can be uniquely extended to a bounded linear map from X to…

Functional Analysis · Mathematics 2024-05-07 E. Pernecká , J. Spěvák

We consider two questions on the geometry of Lipschitz free $p$-spaces $\mathcal F_p$, where $0<p\leq 1$, over subsets of finite-dimensional vector spaces. We solve an open problem and show that if $(\mathcal M, \rho)$ is an infinite…

Functional Analysis · Mathematics 2023-03-07 Jan Bíma

A norm one element $x$ of a Banach space is a Daugavet-point (respectively,~a $\Delta$-point) if every slice of the unit ball (respectively,~every slice of the unit ball containing $x$) contains an element that is almost at distance 2 from…

Functional Analysis · Mathematics 2022-06-08 Triinu Veeorg

In this article, we investigate some fixed point results satisfying a new generalized $\Delta$-implicit contractive condition in ordered complete multiplicative $\mathbf{G}_\mathcal{M}-$metric space. Also, some new definitions and fixed…

Functional Analysis · Mathematics 2022-06-14 Mohamed Gamal , Fu-Gui Shi

We show that, given a Banach space $X$, the Lipschitz-free space over $X$, denoted by $\mathcal{F}(X)$, is isomorphic to $(\sum_{n=1}^\infty \mathcal{F}(X))_{\ell_1}$. Some applications are presented, including a non-linear version of…

Functional Analysis · Mathematics 2014-11-13 Pedro Levit Kaufmann
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