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We prove that every homogeneous countable dense homogeneous topological space containing a copy of the Cantor set is a Baire space. In particular, every countable dense homogeneous topological vector space is a Baire space. It follows that,…

General Topology · Mathematics 2023-09-28 Tadeusz Dobrowolski , Mikołaj Krupski , Witold Marciszewski

In this paper, we study some characterizations of $q$-spaces, strict $q$-spaces and strong $q$-spaces under $\omega$-balanced topological groups as follows: (1) A topological group $G$ is $\omega$-balanced and a $q$-space if and only if for…

General Topology · Mathematics 2023-11-02 Deng-Bin Chen , Hai-Hua Lin , Li-Hong Xie

A Tychonoff space $X$ is called ({\em sequentially}) {\em Ascoli} if every compact subset (resp. convergent sequence) of $C_k(X)$ is equicontinuous, where $C_k(X)$ denotes the space of all real-valued continuous functions on $X$ endowed…

General Topology · Mathematics 2020-04-29 Saak Gabriyelyan

Answering some of the main questions from [MR13], we show that whenever $\kappa$ is a cardinal satisfying $\kappa^{< \kappa} = \kappa > \omega$, then the embeddability relation between $\kappa$-sized structures is strongly invariantly…

Logic · Mathematics 2021-02-18 Filippo Calderoni , Heike Mildenberger , Luca Motto Ros

As it was introduced by Tkachuk and Wilson, a topological space $X$ is cellular-compact if given any cellular, i.e. disjoint, family $\mathcal U$ of non-empty open subsets of $X$ there is a compact subspace $K\subset X$ such that $K\cap…

General Topology · Mathematics 2019-12-19 István Juhász , Lajos Soukup , Zoltán Szentmiklóssy

Finite topological spaces became much more essential in topology, with the development of computer science. The task of this paper is to study and investigate some properties of such spaces with the existence of an ordered relation between…

General Topology · Mathematics 2007-05-23 A. El-Fattah El-Atik , M. E. Abd El-Monsef , E. I. Lashin

We prove that, for every cardinal number $\alpha\geq {\mathfrak c}$, there exists a metrizable space $X$ with $|X|=\alpha$ such that for every pair of quasiorders $\leq_1$, $\leq_2$ on a set $Q$ with $|Q| \leq \alpha$ satisfying the…

General Topology · Mathematics 2007-05-23 Vera Trnkova

The structure of topological spaces is analysed here through the lenses of fibrous preorders. Each topological space has an associated fibrous preorder and those fibrous preorders which return a topological space are called spacial. A…

General Topology · Mathematics 2021-02-22 Nelson Martins-Ferreira

A linear ordering is called context-free if it is the lexicographic ordering of some context-free language and is called scattered if it has no dense subordering. Each scattered ordering has an associated ordinal, called its rank. It is…

Formal Languages and Automata Theory · Computer Science 2019-07-29 Kitti Gelle , Szabolcs Ivan

For a topological space X, let (RX)s := (RX,Ts) be the cartesian product of |X| copies of the real line R with the topology of the uniform convergence on separable subsets of X. In this article we analyze the subspace C(X) of (RX)s of all…

Let G be a group and let O_G denote the set of left orderings on G. Then O_G can be topologized in a natural way, and we shall study this topology to answer three conjectures. In particular we shall show that O_G can never be countably…

Group Theory · Mathematics 2007-05-23 Peter A. Linnell

A metric space is said to be all-set-homogeneous if any of its partial isometries can be extended to a genuine isometry. We give a classification of a certain subclass of all-set-homogeneous length spaces.

Metric Geometry · Mathematics 2025-06-10 Nina Lebedeva , Anton Petrunin

A space $X$ is called $Ps$-normal($Ps$-Tychonoff) space if there exists a normal(Tychonoff) space $Y$ and a bijection $f: X\mapsto Y$ such that $f\lvert_K:K\mapsto f(K)$ is homeomorphism for any pseudocompact subset $K$ of $X$. We establish…

General Topology · Mathematics 2019-07-23 Sagarmoy Bag , Ram Chandra Manna , Sourav Kanti Patra

We answer several questions of V. Tka\v{c}uk from [Point-countable $\pi$-bases in first countable and similar spaces, Fund. Math. 186 (2005), pp. 55--69.] by showing that (1) there is a ZFC example of a first countable, 0-dimensional…

General Topology · Mathematics 2007-05-23 Istvan Juhasz , Lajos Soukup , Zoltan Szentmiklossy

For any Polish space $X$ it is well-known that the Cantor-Bendixson rank provides a co-analytic rank on $F_{\aleph_0}(X)$ if and only if $X$ is a $\sigma$-compact. In the case of $\omega^\omega$ one may recover a co-analytic rank on…

Logic · Mathematics 2018-06-11 Vibeke Quorning

It is shown that if a $T_2$ topological space contains an uncountable closed discrete set, then $\omega_1 \times (\omega_1 + 1)$ embeds as a closed subspace of $(CL(X),\tau_F)$, the hyperspace of nonempty closed subsets of $X$ equipped with…

General Topology · Mathematics 2014-02-19 Lubica Hola

The purpose of this article is to relate coarse cohomology of metric spaces with a more computable cohomology. We introduce a notion of boundedly supported cohomology and prove that coarse cohomology of many spaces are isomorphic to the…

Metric Geometry · Mathematics 2024-01-05 Arka Banerjee

Given a simplicial complex $X$, we construct a simplicial complex $\Omega X$ that may be regarded as a combinatorial version of the based loop space of a topological space. Our construction explicitly describes the simplices of $\Omega X$…

Algebraic Topology · Mathematics 2025-07-17 Gregory Lupton , Jonathan Scott

Given a Tychonoff space $X$, let $F(X)$ and $A(X)$ be respectively the free topological group and the free Abelian topological group over $X$ in the sense of Markov. In this paper, we provide some topological properties of $X$ whenever one…

Group Theory · Mathematics 2015-09-22 Fucai Lin , Chuan Liu , Shou Lin

Let $X$ be a topological vector space of complex-valued sequences and $Y$ be a subset of $X$. We provide conditions for $X \setminus Y \cup \{0\}$ to contain uncountably infinitely many linearly independent dense vector subspaces of $X$. We…

Functional Analysis · Mathematics 2022-11-10 C. A. Konidas