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Related papers: A generalization of $\varkappa$-metrizable spaces

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This article fits in the context of the approach to topological problems in terms of the underlying convergence space structures, and serves as yet another illustration of the power of the method. More specifically, we spell out…

General Topology · Mathematics 2020-01-01 Fadoua Chigr , Frédéric Mynard

By a recent result of Juh\'{a}sz and van Mill, a locally compact topological group whose dense subspaces are all separable is metrizable. In this note we investigate the following question: is every locally compact group having all dense…

Group Theory · Mathematics 2024-12-16 Dekui Peng

We consider special subclasses of the class of Lindel\"of Sigma-spaces obtained by imposing restrictions on the weight of the elements of compact covers that admit countable networks: A space $X$ is in the class $L\Sigma(\leq\kappa)$ if it…

General Topology · Mathematics 2012-10-23 Wieslaw Kubis , Oleg Okunev , Paul J. Szeptycki

We say that a Tychonoff space $X$ is a $\kappa$-space if it is homeomorphic to a closed subspace of $C_p(Y)$ for some locally compact space $Y$. The class of $\kappa$-spaces is strictly between the class of Dieudonn\'{e} complete spaces and…

General Topology · Mathematics 2025-07-16 Saak Gabriyelyan , Evgenii Reznichenko

In this paper, we present a constructive generalization of metric and uniform spaces by introducing a new class of spaces, called cover spaces. These spaces form a topological concrete category with a full reflective subcategory of complete…

General Topology · Mathematics 2024-12-31 Valery Isaev

To give characterizations of monotonically countably paracompact spaces with set-valued maps, Yamazaki [22] introduced the notion of strictly increasing closed cover of a topological space with which the boundedness of a set-valued map was…

General Topology · Mathematics 2019-10-08 Er-Guang Yang

We prove that each non-metrizable sequential rectifiable space $X$ of countable $cs^*$-character contains a clopen rectifiable submetrizable $k_\omega$-subspace $H$ and admits an open disjoint cover by subspaces homeomorphic to clopen…

General Topology · Mathematics 2017-07-11 Taras Banakh , Dusan Repovs

We introduced the concept of a metric value set (MVS) in an earlier paper \cite{GM} and developed the idea further in \cite{AS}. In this paper we study locally $M$-metrizable spaces and the products of $M$-metrizable spaces. Finally we…

General Topology · Mathematics 2017-07-04 Olli Hella

In \cite[\, An, V.T., Tuyen, Q.L. and Dung, V.N., Stone-type theorem on $b$-metric spaces and applications, Topology Appl. 185-186 (2015), 50-64.]{an}, An et al. had provided a sufficient condition for $b$-metric spaces to be metrizable.…

General Topology · Mathematics 2020-05-28 Sumit Som , Adrian Petrusel , Lakshmi Kanta Dey

We show that any metacompact Moore space is monotonically metacompact and use that result to characterize monotone metacompactness in certain generalized ordered (GO)spaces. We show, for example, that a generalized ordered space with a…

General Topology · Mathematics 2011-08-29 Harold R. Bennett , Klaas Pieter Hart , David J. Lutzer

A metric space $(M, d)$ is said to be universal for a class of metric spaces if all metric spaces in the class can be isometrically embedded into $(M, d)$. In this paper, for a metrizable space $Z$ possessing abundant subspaces, we first…

Metric Geometry · Mathematics 2024-09-27 Yoshito Ishiki , Katsuhisa Koshino

Metric spaces are generalized by many scholars. Recently, Khatami and Mirzavaziri use a mapping called $t$-definer to popularize the triangle inequality and give a generalization of the notion of a metric, which is called a $\star$-metric.…

General Topology · Mathematics 2021-11-30 Shi-yao He , Li-Hong Xie , Peng-Fei Yan

A topological space $X$ is called strongly $\sigma$-metrizable if $X=\bigcup_{n\in\omega}X_n$ for an increasing sequence $(X_n)_{n\in\omega}$ of closed metrizable subspaces such that every convergence sequence in $X$ is contained in some…

General Topology · Mathematics 2016-11-17 Taras Banakh

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

A topological space is almost locally compact if it contains a dense locally compact subspace. We generalize a result from \cite{Ma}, showing that isomorphism on Borel classes of almost locally compact Polish metric structures is always…

Logic · Mathematics 2025-08-12 Maciej Malicki

We prove that every point-finite family of nonempty functionally open sets in a topological space $X$ has the cardinality at most an infinite cardinal $\kappa$ if and only if $w(X)\leq\kappa$ for every Valdivia compact space $Y\subseteq…

General Topology · Mathematics 2015-12-25 V. V. Mykhaylyuk

We study isometric $G$-spaces and the question of when their maximal equivariant compactification is the Gromov compactification (meaning that it coincides with the compactification generated by the distance functions to points). Answering…

Dynamical Systems · Mathematics 2021-01-14 Tomás Ibarlucía , Michael Megrelishvili

In this manuscript, we claim that the newly introduced $\mathcal{F}$-metric space \cite[\, M.~Jleli and B.~Samet, On a new generalization of metric spaces, J. Fixed Point Theory Appl, 20(3) 2018]{JS1} is metrizable. Also, we deduce that the…

Functional Analysis · Mathematics 2018-08-09 Sumit Som , Ashis Bera , Lakshmi Kanta Dey

We prove that if $K$ is a compact space and the space $P(K\times K)$ of regular probability measures on $K\times K$ has countable tightness in its $weak^*$ topology, then $L_1(\mu)$ is separable for every $\mu\in P(K)$. It has been known…

Functional Analysis · Mathematics 2014-05-13 Grzegorz Plebanek , Damian Sobota

The space $S_\kappa$ is the Stone space of the $\kappa$-saturated Boolean algebra of cardinality $\kappa$. It exists provided that $\kappa = \kappa^{<\kappa}$, and is characterised topologically as the unique $\kappa$-Parovichenko space of…

General Topology · Mathematics 2014-06-02 Max F. Pitz , Rolf Suabedissen