Take the 2-minute tour ×
Mathematics Stack Exchange is a question and answer site for people studying math at any level and professionals in related fields. It's 100% free, no registration required.

I am using the definition of compactly generated space from The Category of CGWH Spaces, which is

In $\mathcal{Top}$, $k$-closed subset $Y\subset X$, means $u^{-1}(Y)$ is closed in $C$ for any $u: C\to X$ where $C$ is compact Hausdorff.

A compactly generated space means all $k$-closed subset is closed

locally compact means every point has a compact local base

this is different from the definition from Wikipedia

so, is any compact space compactly generated?

and, is any locally compact space compactly generated?

share|improve this question
For your first question, if $X$ is compact Hausdorff, consider taking $C=X$ and $u$ the identity. –  Nate Eldredge May 6 at 5:12
Yes, I know this. But I want to know what about non-Hausdorff space –  Minghao Liu May 6 at 5:59
The term compactly generated is used differently by different authors. Sometimes is denotes a space where a subset is closed if it intersects each compact subset in a closed set, let's call these c-spaces. Other times it denotes a space as you describe it, but these are also called k-spaces. Both compact and locally compact spaces are c-spaces. So you are actually searching for a space that is a c-space but not a k-space. –  Stefan Hamcke May 19 at 14:48
It seems that both your question and this require a space with many compact subsets which are not images of compact Hausdorff spaces. –  Stefan Hamcke May 19 at 14:49

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.