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Related papers: On uniformly continuous surjections between functi…

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Let $X$ be metrizable, $Y$ be perfectly normal and suppose that there exists a uniformly continuous surjection $T: C_{p}(X) \to C_{p}(Y)$ (resp., $T: C_{p}^*(X) \to C_{p}^*(Y)$), where $C_{p}(X)$ (resp., $C_{p}^*(X)$) denotes the space of…

General Topology · Mathematics 2025-05-06 A. Eysen , A. Leiderman , V. Valov

Let $X$ and $Y$ be compact Hausdorff spaces and suppose that there exists a linear continuous surjection $T:C_{p}(X) \to C_{p}(Y)$, where $C_{p}(X)$ denotes the space of all real-valued continuous functions on $X$ endowed with the pointwise…

General Topology · Mathematics 2016-05-18 Kazuhiro Kawamura , Arkady Leiderman

For any Tychonoff space $X$ let $D(X)$ be either the set $C(X)$ of all continuous functions on $X$ or the set $C^*(X)$ of all bounded continuous functions on $X$. When $D(X)$ is endowed with the point convergence topology, we write…

General Topology · Mathematics 2026-04-29 Vesko Valov

We prove that for every finite dimensional compact metric space $X$ there is an open continuous linear surjection from $C_p[0,1]$ onto $C_p(X)$. The proof makes use of embeddings introduced by Kolmogorov and Sternfeld in connection with…

General Topology · Mathematics 2008-06-18 Michael Levin

As proved in [16], for a Tychonoff space $X$, a locally convex space $C_{p}(X)$ is distinguished if and only if $X$ is a $\Delta$-space. If there exists a linear continuous surjective mapping $T:C_p(X) \to C_p(Y)$ and $C_p(X)$ is…

General Topology · Mathematics 2021-07-13 Jerzy Kakol , Arkady Leiderman

For a completely regular space $X$, denote by $C_p(X)$ the space of continuous real-valued functions on $X$, with the pointwise convergence topology. In this article we strengthen a theorem of O. Okunev concerning preservation of some…

General Topology · Mathematics 2023-09-28 Mikolaj Krupski

For any Tychonoff space $X$ let $C_p(X)$ (resp., $C^*_p(X)$) be the set of all continuous (resp., and bounded) functions on $X$ with the pointwise convergence topology. Given Tychonoff spaces $X$ and $Y$, Uspenskij \cite{us} proved that if…

General Topology · Mathematics 2026-05-05 Vesko Valov

In this paper we develop a technique of constructing uni- formly continuous maps between function spaces Cp(X) endowed with the pointwise topology. We prove that if a space X is compact metrizable and strongly countable-dimensional, then…

General Topology · Mathematics 2017-10-31 Rafal Gorak , Mikolaj Krupski , Witold Marciszewski

In our paper [18] we showed that a Tychonoff space $X$ is a $\Delta$-space (in the sense of [20], [30]) if and only if the locally convex space $C_{p}(X)$ is distinguished. Continuing this research, we investigate whether the class $\Delta$…

General Topology · Mathematics 2021-04-22 Jerzy Kakol , Arkady Leiderman

We study separating function sets. We find some necessary and sufficient conditions for $C_p(X)$ or $C_p^2(X)$ to have a point-separating subspace that is a metric space with certain nice properties. One of the corollaries to our discussion…

General Topology · Mathematics 2017-08-29 Raushan Buzyakova , Oleg Okunev

We employ the theory of elementary submodels to improve a recent result by Aron, Jaramillo and Le Donne (Ann. Acad. Sci. Fenn. Math., to appear) concerning restricting uniformly open, continuous surjections to smaller subspaces where they…

General Topology · Mathematics 2017-07-11 Tomasz Kania , Martin Rmoutil

Cembranos and Freniche proved that for every two infinite compact Hausdorff spaces $X$ and $Y$ the Banach space $C(X\times Y)$ of continuous real-valued functions on $X\times Y$ endowed with the supremum norm contains a complemented copy of…

General Topology · Mathematics 2022-06-09 Jerzy Kąkol , Witold Marciszewski , Damian Sobota , Lyubomyr Zdomskyy

In this erratum, we recover the results from an earlier paper of the author's which contained a gap. Specifically, we prove that if X is a Banach space with an unconditional basis and admits a C^{p}-smooth, Lipschitz bump function, and Y is…

Functional Analysis · Mathematics 2015-05-13 R. Fry

We present a short, direct proof of the uniform convexity of L^p spaces for 1<p<\infty.

Functional Analysis · Mathematics 2007-05-23 Harald Hanche-Olsen

We give an example of an infinite metrizable space $X$ such that the space $C_p(X)$, of continuous real-valued function on $X$ endowed with the pointwise topology, is not homeomorphic to its own square $C_p(X)\times C_p(X)$. The space $X$…

General Topology · Mathematics 2018-12-12 Mikołaj Krupski , Witold Marciszewski

We prove that the locally convex space $C_{p}(X)$ of continuous real-valued functions on a Tychonoff space $X$ equipped with the topology of pointwise convergence is distinguished if and only if $X$ is a $\Delta$-space in the sense of \cite…

General Topology · Mathematics 2020-12-01 Jerzy Kakol , Arkady Leiderman

We present new results regarding calibers in the function spaces $C_p(X)$. Our main theorem is that $C_p(X)$ is strongly \v{S}anin whenever $X$ is a submetrizable space; this improves an earlier result due to Tkachuk: $C_p(X)$ is \v{S}anin…

General Topology · Mathematics 2024-08-09 Alejandro Ríos-Herrejón , Ángel Tamariz-Mascarúa

Given an infinite-dimensional Banach space $X$ and a Banach space $Y$ with no finite cotype, we determine whether or not every continuous linear operator from $X$ to $Y$ is absolutely $(q;p)$-summing for almost all choices of $p$ and $q$,…

Functional Analysis · Mathematics 2015-10-06 Geraldo Botelho , Daniel Pellegrino

We give a characterization of countable discrete subspace $A$ of a topological space $X$ such that there exists a (linear) continuous mapping $\varphi:C_p^*(A)\to C_p(X)$ with $\varphi(y)|_A=y$ for every $y\in C_p^*(A)$. Using this…

General Topology · Mathematics 2016-04-22 V. Mykhaylyuk

Answering a question of Sakai, we show that the minimal cardinality of a set of reals X such that C_p(X) does not have the Pytkeev property is equal to the pseudo-intersection number p. Our approach leads to a natural characterization of…

General Topology · Mathematics 2010-11-05 Petr Simon , Boaz Tsaban
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