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We characterise Tychonoff spaces X so that C(X) is universally {\sigma}-complete and universally complete, respectively.

Functional Analysis · Mathematics 2021-05-12 Jan Harm van der Walt

We study the question for which Tychonoff spaces $X$ and locally convex spaces $E$ the space $C_p(X,E)$ of continuous $E$-valued functions on $X$ contains a complemented copy of the space $(c_0)_p=\{x\in\mathbb{R}^\omega\colon x(n)\to0\}$,…

Functional Analysis · Mathematics 2023-06-29 Christian Bargetz , Jerzy Kąkol , Damian Sobota

Being motivated by the study of the space $C_c(X)$ of all continuous real-valued functions on a Tychonoff space $X$ with the compact-open topology, we introduced in [15] the concepts of a $cp$-network and a $cn$-network (at a point $x$) in…

General Topology · Mathematics 2014-12-05 S. S. Gabriyelyan , J. Kakol

We give a characterization of the $\Delta_1$-property of any Tychonoff space $X$ in terms of the function space $B_1(X)$ of all Baire-one real-valued functions on a space $X$ with the topology of pointwise convergence. We establish that for…

General Topology · Mathematics 2025-04-16 Alexander V. Osipov

Let $T$ be a compact, metrisable and strongly countable-dimensional topological space. Let $\mathcal{M}^T$ be the set of all metrics $d$ on $T$ compatible with its topology, and equip $\mathcal{M}^T$ with the topology of uniform…

Functional Analysis · Mathematics 2024-05-31 Filip Talimdjioski

Let $X$ be a zero-dimensional space and $C_c(X)$ be the set of all continuous real valued functions on $X$ with countable image. In this article we denote by $C_c^K(X)$ (resp., $C_{c}^{\psi}(X)$) the set of all functions in $C_c(X)$ with…

General Topology · Mathematics 2015-07-01 Alireza Olfati

Let X be a topological space, and let C(X) be the complex of singular cochains on X with real coefficients. We denote by Cc(X) the subcomplex given by continuous cochains, i.e. by such cochains whose restriction to the space of simplices…

Geometric Topology · Mathematics 2010-04-02 Roberto Frigerio

A topological gyrogroup is a gyrogroup endowed with a topology such that the binary operation is jointly continuous and the inverse mapping is also continuous. In this paper, it is proved that if $G$ is a sequential topological gyrogroup…

General Topology · Mathematics 2021-03-23 Meng Bao , Xiaoyuan Zhang , Xiaoquan Xu

All spaces are assumed to be separable and metrizable. Consider the following properties of a space $X$. (1) $X$ is Polish. (2) For every countable crowded $Q\subseteq X$ there exists a crowded $Q'\subseteq Q$ with compact closure. (3)…

General Topology · Mathematics 2014-06-02 Andrea Medini , Lyubomyr Zdomskyy

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

A topological space $X$ is Baire if the intersection of any sequence of open dense subsets of $X$ is dense in $X$. Let $C_p(X,[0,1])$ denote the space of all continuous $[0,1]$-valued functions on a Tychonoff space $X$ with the topology of…

General Topology · Mathematics 2022-03-14 Alexander V. Osipov , Evgenii G. Pytkeev

In this paper we obtain results indicating that fine shape is tractable and "not too strong" even in the non-locally compact case, and can be used to better understand infinite-dimensional metrizable spaces and their homology theories. We…

Geometric Topology · Mathematics 2022-11-22 Sergey A. Melikhov

C(X) denotes the space of continuous complex-valued functions on the compact Hausdorff space X. X has the CSWP if every subalgebra of C(X) which separates points and contains the constant functions is dense in C(X). W. Rudin showed that all…

General Topology · Mathematics 2007-05-23 Kenneth Kunen

This article is a fundamental study in computable analysis. In the framework of Type-2 effectivity, TTE, we investigate computability aspects on finite and infinite products of effective topological spaces. For obtaining uniform results we…

Logic in Computer Science · Computer Science 2015-07-01 Robert Rettinger , Klaus Weihrauch

We generalize some classical results about quasicontinuous and separately continuous functions with values in metrizable spaces to functions with values in certain generalized metric spaces, called Maslyuchenko spaces. We establish…

General Topology · Mathematics 2021-11-01 Taras Banakh

Using approximation by continuous functions we prove the following statements to types of tightness in a space $Q_p(X, \mathbb{R})$ of all quasicontinuous real-valued functions with the topology $\tau_p$ of pointwise convergence: the…

General Topology · Mathematics 2025-03-06 Anton E. Lipin , Alexander V. Osipov

We show that the space of continuous functions over a compact space X admits an equivalent pointwise-lowersemicontinuous locally uniformly rotund norm whenever X admits a fully closed map onto a compact Y such that C(Y) and the spaces of…

Functional Analysis · Mathematics 2023-12-27 Todor Manev

A space $X$ is called a $k_{R}$-space, if $X$ is Tychonoff and the necessary and sufficient condition for a real-valued function $f$ on $X$ to be continuous is that the restriction of $f$ on each compact subset is continuous. In this paper,…

Group Theory · Mathematics 2017-06-08 Fucai Lin , Shou Lin , Chuan Liu

A convex subset X of a linear topological space is called compactly convex if there is a continuous compact-valued map $\Phi:X\to exp(X)$ such that $[x,y]\subset\Phi(x)\cup \Phi(y)$ for all $x,y\in X$. We prove that each convex subset of…

Functional Analysis · Mathematics 2012-12-19 T. Banakh , M. Mitrofanov , O. Ravsky

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