论文标题

弱选择和可亚顺序的可迁移空间

Weak Selections and Suborderable Metrizable Spaces

论文作者

Gutev, Valentin

论文摘要

$ x $的每个连续弱选择都定义了$ x $的粗略拓扑,称为选择拓扑。拓扑由此类选择拓扑的集合确定的空间称为连续弱选择空间。对于此类空间,Garc \'ıa-Ferreira,Miyazaki,Nogura和Tomita考虑了最小数字$ \ text {cws}(x)选择拓扑的$ x $的原始拓扑,并称其为$ x $的CWS-number。在本文中,我们表明每个半订购空间$ x $的$ \ text {cws}(x)\ leq 2 $,而$ \ text {cws}(x)(x)= 2 $准确地是当这样的空间$ x $具有两个组件时,并且不可订购。互补的结果,我们还表明,对于每个可下订单的可分离空间$ x $,$ \ text {cws}(x)= 1 $,至少具有3个组件。

Each continuous weak selection for a space $X$ defines a coarser topology on $X$, called a selection topology. Spaces whose topology is determined by a collection of such selection topologies are called continuous weak selection spaces. For such spaces, Garc\'ıa-Ferreira, Miyazaki, Nogura and Tomita considered the minimal number $\text{cws}(X)$ of selection topologies which generate the original topology of $X$, and called it the cws-number of $X$. In this paper, we show that $\text{cws}(X)\leq 2$ for every semi-orderable space $X$, and that $\text{cws}(X)=2$ precisely when such a space $X$ has two components and is not orderable. Complementary to this result, we also show that $\text{cws}(X)=1$ for each suborderable metrizable space $X$ which has at least 3 components.

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