论文标题
关于第二位空间的对称性和完美性
On symmetrizability and perfectness of second-countable spaces
论文作者
论文摘要
Arhangelskii的对称性标准意味着，当且仅当它是完美的时，第二个可容纳的Hausdorff空间就可以对称。我们介绍了一个不可用的第二个可分子的基数中性空间$ \ mathfrak Q_0 $，并研究了不可用的$ t_i $ t_i $ t_i $ -space的最小的基数$ \ mathfrak q_i $，用于$ i \ in \ in \ in \ in \ {1,2 \ \ \ \ f {1,2 \ \} $。
A symmetrizability criterion of Arhangelskii implies that a second-countable Hausdorff space is symmetrizable if and only if it is perfect. We present an example of a non-symmetrizable second-countable submetrizable space of cardinality $\mathfrak q_0$ and study the smallest possible cardinality $\mathfrak q_i$ of a non-symmetrizable second-countable $T_i$-space for $i\in\{1,2\}$.
