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Related papers: Further studies on open well-filtered spaces

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We introduce and study a new class of $T_0$ spaces, called open well-filtered spaces. The main results we proved include (1) every well-filtered space is an open well-filtered space; (2) every core-compact open well-filtered space is sober.…

General Topology · Mathematics 2023-06-22 Chong Shen , Xiaoyong Xi , Xiaoquan Xu , Dongsheng Zhao

In the past few years, the research on sober spaces and well-filtered spaces has got some breakthrough progress. In this paper, we shall present a brief summarising survey on some of such development. Furthermore, we shall pose and…

General Topology · Mathematics 2020-05-05 Xiaoquan Xu , Dongsheng Zhao

We first introduce and investigate a new class of $T_0$ spaces -- strong R-spaces, which are stronger than both R-spaces and strongly well-filtered spaces. It is proved that any sup-complete poset equipped with the upper topology is a…

General Topology · Mathematics 2025-12-12 Xiaoquan Xu , Yi Yang , Lizi Chen

Based on topological Rudin's Lemma, we investigate two new kinds of sets - Rudin sets and well-filtered determined sets in $T_0$ topological spaces. Using such sets, we formulate and prove some new characterizations for well-filtered spaces…

General Topology · Mathematics 2019-11-27 Xiaoquan Xu , Dongsheng Zhao

We prove that a $T_0$ topological space is $\omega$-well-filtered if and only if it does not admit either the natural numbers with the cofinite topology or with the Scott topology as its closed subsets in the strong topology. Based on this,…

General Topology · Mathematics 2024-09-04 Hualin Miao , Xiaodong Jia , Ao Shen , Qingguo Li

We prove that for every $T_0$ space $X$, there is a well-filtered space $W(X)$ and a continuous mapping $\eta_X: X\lra W(X)$ such that for any well-filtered space $Y$ and any continuous mapping $f: X\lra Y$ there is a unique continuous…

General Topology · Mathematics 2019-07-16 Guohua Wu , Xiaoyong Xi , Xiaoquan Xu , Dongsheng Zhao

We first introduce and study two new classes of subsets in $T_0$ spaces - $\omega$-Rudin sets and $\omega$-well-filtered determined sets lying between the class of all closures of countable directed subsets and that of irreducible closed…

General Topology · Mathematics 2019-12-02 Xiaoquan Xu , Chong Shen , Xiaoyong Xi , Dongsheng Zhaod

In this paper, we mainly discuss some basic properties of Scott power spaces. For a $T_0$ space $X$, let $\mathsf{K}(X)$ be the poset of all nonempty compact saturated subsets of $X$ endowed with the Smyth order. It is proved that the Scott…

General Topology · Mathematics 2022-07-19 Xiaoquan Xu , Xinpeng Wen , Xiaoyong Xi

The Hofmann-Mislove theorem states that in a sober space, the nonempty Scott open filters of its open set lattice correspond bijectively to its compacts saturated sets. In this paper, the concept of $c$-well-filtered spaces is introduced.…

General Topology · Mathematics 2023-06-22 Liping Zhang , Xiangnan Zhou , Qingguo Li

We first introduce and study two new classes of subsets in $T_0$ spaces - Rudin sets and $\wdd$ sets lying between the class of all closures of directed subsets and that of irreducible closed subsets. Using such subsets, we define three new…

General Topology · Mathematics 2019-09-23 Xiaoquan Xu , Chong Shen , Xiaoyong Xi , Dongsheng Zhao

We investigate some versions of $d$-space, well-filtered space and Rudin space concerning various countability properties. The main results include: (i) if the sobrification of a $T_0$ space $X$ is first-countable, then $X$ is an…

General Topology · Mathematics 2020-08-26 Xiaoquan Xu , Chong Shen , Xiaoyong Xi , Dongsheng Zhao

Recently, Xu proposed a strongly well-filtered space in [24] and systematically investigated some of its properties and characterizations. In this paper, we introduce a new class of T0-spaces called S*-well-filtered spaces, which is…

General Topology · Mathematics 2026-01-19 Nana Han , Siheng Chen , Qingguo Li

In this thesis, we introduce the subject of D-spaces and some of its most important open problems which are related to well known covering properties. We then introduce a new approach for studying D-spaces and covering properties in…

General Topology · Mathematics 2025-04-17 Talal Alrawajfeh , Hasan Z. Hdeib

M. Escard\'o et al. asked whether the core compactly generated topology of a sober space is again sober and the sobrification of a core compactly generated space again core compactly generated. In this note, we answer the problem by…

General Topology · Mathematics 2023-05-02 Qingguo Li , Hualin Miao

In this paper, we obtain some sufficient conditions for the D-completion of a T0 space to be the well-filterification of this space, the well-filterification of a T0 space to be the sobrification of this space and the D-completion of a T0…

General Topology · Mathematics 2021-01-14 Hualin Miao , Longchun Wang , Qingguo Li

Let $X$ be the prime spectrum of a ring. In [arXiv:0707.1525] the authors define a topology on $X$ by using ultrafilters and they show that this topology is precisely the constructible topology. In this paper we generalize the construction…

Commutative Algebra · Mathematics 2013-09-23 Carmelo A. Finocchiaro

In this paper, we investigate the sobriety of weakly first-countable spaces and give some sufficient conditions that the Scott topologies of the open set lattices are sober. The main results are: (1) Let $P$ and $Q$ be two posets. If…

General Topology · Mathematics 2025-04-09 Zhengmao He

In this paper, we highlight some open problems stated by Xu and Zhao. In particular, we focus on strong $d$-spaces and answer two open problems concerning strong $d$-spaces. One is about the product space of an arbitrary family of strong…

General Topology · Mathematics 2021-09-24 Mengjie Jin , Hualin Miao , Qingguo Li

Employing a formal analogy between ordered sets and topological spaces, over the past years we have investigated a notion of cocompleteness for topological, approach and other kind of spaces. In this new context, the down-set monad becomes…

Category Theory · Mathematics 2013-05-28 Dirk Hofmann

We study the relation between the Hurewicz and Menger properties of filters considered topologically as subspaces of P(\omega) with the Cantor set topology.

General Topology · Mathematics 2018-09-19 Rodrigo Hernández-Gutiérrez , Paul J. Szeptycki
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