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相关论文: On $T_0$ spaces determined by well-filtered spaces

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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…

一般拓扑 · 数学 2019-12-02 Xiaoquan Xu , Chong Shen , Xiaoyong Xi , Dongsheng Zhaod

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…

一般拓扑 · 数学 2019-11-27 Xiaoquan Xu , Dongsheng Zhao

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.…

一般拓扑 · 数学 2023-06-22 Chong Shen , Xiaoyong Xi , Xiaoquan Xu , 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…

一般拓扑 · 数学 2020-08-26 Xiaoquan Xu , Chong Shen , Xiaoyong Xi , 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…

一般拓扑 · 数学 2025-12-12 Xiaoquan Xu , Yi Yang , Lizi Chen

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,…

一般拓扑 · 数学 2024-09-04 Hualin Miao , Xiaodong Jia , Ao Shen , Qingguo Li

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…

一般拓扑 · 数学 2021-01-14 Hualin Miao , Longchun Wang , 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…

一般拓扑 · 数学 2019-07-16 Guohua Wu , Xiaoyong Xi , Xiaoquan Xu , Dongsheng Zhao

In this paper, we provide a uniform approach to $d$-spaces, sober spaces and well-filtered spaces, and develop a general framework for dealing with all these spaces. For a subset system H, the theory of H-sober spaces and super H-sober…

一般拓扑 · 数学 2020-03-18 Xiaoquan Xu

Ern\'e weakened the concept of sobriety in order to extend the theory of sober spaces and locally hypercompact spaces to situations where directed joins were missing, and introduced and discussed three kinds of non-sober spaces: cut spaces,…

综合数学 · 数学 2022-04-22 Xinpeng Wen , Xiaoquan Xu

The open well-filtered spaces were introduced by Shen, Xi, Xu and Zhao to answer the problem whether every core-compact well-filtered space is sober. In the current paper we explore further properties of open well-filtered spaces. One of…

一般拓扑 · 数学 2025-02-25 Chong Shen , Xiaoyong Xi , Dongsheng Zhao

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…

一般拓扑 · 数学 2022-07-19 Xiaoquan Xu , Xinpeng Wen , Xiaoyong Xi

Recently, J. D. Lawson encouraged the domain theory community to consider the scientific program of developing domain theory in the wider context of $T_0$ spaces instead of restricting to posets. In this paper, we respond to this calling by…

计算机科学中的逻辑 · 计算机科学 2016-07-06 Hadrian Andradi , Weng Kin Ho

A non-empty subset of a topological space is irreducible if whenever it is covered by the union of two closed sets, then already it is covered by one of them. Irreducible sets occur in proliferation: (1) every singleton set is irreducible,…

计算机科学中的逻辑 · 计算机科学 2016-10-04 Hadrian Andradi , Weng Kin Ho

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…

一般拓扑 · 数学 2026-01-19 Nana Han , Siheng Chen , Qingguo Li

A topological space $X$ is a $\Delta$-space (or $X \in \Delta$) if for any decreasing sequence $\{A_n : n < \omega\}$ of subsets of $X$ with empty intersection there is a (decreasing) sequence $\{U_n : n < \omega\}$ of open sets with empty…

一般拓扑 · 数学 2025-10-07 I. Juhász , J. van Mill , L. Soukup , Z. Szentmiklóssy

In this paper, the concepts of $K$-subset systems and $k$-well-filtered spaces are introduced, which provide another uniform approach to $d$-spaces, $s$-well-filtered spaces (i.e., $\mathcal{U}_{S}$-admissibility) and well-filtered spaces.…

一般拓扑 · 数学 2023-06-22 Mengjie Jin , Qingguo Li

We define a class of subsets of a topological space that coincides with the class of compact saturated subsets when the space is sober, and with enough good properties when the space is not sober. This class is introduced especially in view…

一般拓扑 · 数学 2011-06-21 Paul Poncet

In non-Hausdorff topology, many spaces exhibit significant separation properties, such as sober spaces, well-filtered spaces and d-spaces. These properties serve to fundamentally classify T0 topological spaces. In this paper, we introduce…

一般拓扑 · 数学 2026-01-19 Xiangrui Li , Qingguo Li

The aim of this paper is to study the topological properties of some classes of subsemimodules endowed with a subbasis closed-set topology. We show that such spaces are $T_0$. When the semimodule is finitely generated, those spaces are…

环与代数 · 数学 2023-03-02 Amartya Goswami
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