首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Normality and dense subspaces
Authors:A V Arhangel'skii
Institution:Department of Mathematics, 321 Morton Hall, Ohio University, Athens, Ohio 45701
Abstract:

In the first section of this paper, using certain powerful results in $C_{p}$-theory, we show that there exists a nice linear topological space $X$of weight $\omega _{1}$ such that no dense subspace of $X$ is normal. In the second and third sections a natural generalization of normality, called dense normality, is considered. In particular, it is shown in section 2 that the space $R^{c}$ is not normal on some countable dense subspace of it, while it is normal on some other dense subspace. An example of a Tychonoff space $X$, which is not densely normal on a dense separable metrizable subspace, is constructed. In section 3, a link between dense normality and relative countable compactness is established. In section 4 the result of section 1 is extended to densely normal spaces.

Keywords:Normal space  extent  Lindel\"{o}f number  Souslin number  $C_{p}$-theory  densely normal  $\kappa $-normal  $X$ normal on $Y$  $A$ concentrated on $Y$  pseudocompact  relative countable compactness  locally connected
点击此处可从《Proceedings of the American Mathematical Society》浏览原始摘要信息
点击此处可从《Proceedings of the American Mathematical Society》下载免费的PDF全文
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号