\mathcalI_sn -连通空间与度量空间的像

\mathcalI_sn\text- connected spaces and the images of metric spaces

  • 摘要: 在理想收敛的意义下讨论了Tkachuk’s提出的问题,即Tychonoff连通的序列空间是否是连通度量空间的商映射像. 证明了如下结论:设 \mathcalI 是 \bfN 上的一个理想,则拓扑空间 X 是具有 \mathcalI_sn\text-csf\text- 网络的 \mathcalI_sn\text- 连通空间当且仅当 X 是 \mathcalI_sn\text- 连通度量空间的连续 \mathcalI\text- 序列覆盖映射的像. 因此,拓扑空间 X 是具有 \mathcalI_sn\text-csf\text- 网络的连通 \mathcalI_sn\text- 序列空间当且仅当 X 是 \mathcalI_sn\text- 连通度量空间的商 \mathcalI\text- 序列覆盖映射的像. 从而部分解决了Tkachuk’s提出的这个问题.

     

    Abstract: We consider Tkachuk's question under ideal convergence. Namely, is every Tychonoff connected sequential space a quotient image of a connected metric space? We prove that, for an ideal \mathcalI on \mathbfN , a topological space X is an \mathcalI_sn\text- connected space with an \mathcalI_sn\text-csf\text- network if and only if X is the image of a continuous \mathcalI\text- sequence-covering mapping defined on an \mathcalI_sn\text- connected metric space. Consequently, a topological space X is a connected \mathcalI_sn\text- sequential space with an \mathcalI_sn\text-csf\text- network if and only if X is the image of a quotient \mathcalI\text- sequence-covering mapping defined on an \mathcalI_sn\text- connected metric space. This partially answers Tkachuk's question.

     

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