Condensations of Cartesian products

Pavlov, Oleg

Commentationes Mathematicae Universitatis Carolinae, Tome 40 (1999) no. 2, pp. 355-365.

Résumé

We consider when one-to-one continuous mappings can improve normality-type and compactness-type properties of topological spaces. In particular, for any Tychonoff non-pseudocompact space $X$ there is a $\mu$ such that $X^\mu$ can be condensed onto a normal ($\sigma$-compact) space if and only if there is no measurable cardinal. For any Tychonoff space $X$ and any cardinal $\nu$ there is a Tychonoff space $M$ which preserves many properties of $X$ and such that any one-to-one continuous image of $M^\mu$, $\mu\leq\nu$, contains a closed copy of $X^\mu$. For any infinite compact space $K$ there is a normal space $X$ such that $X\times K$ cannot be mapped one-to-one onto a normal space.

Détail

Classification : 54A10, 54B10, 54C10
Keywords: condensation; one-to-one; compact; measurable