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1. • CommentRowNumber1.
   • CommentAuthorUrs
   • CommentTimeFeb 3rd 2021
   • (edited Feb 3rd 2021)
   • PermaLink
   Author: Urs
   Format: MarkdownItexI have added a subsection _Applications -- In Cohomotopy and Cobordism theory_ highlighting how the properness of maps from compact to Hausdorff spaces is what makes the unstable Pontryagin-Thom isomorphism tick -- for _closed_ (hence compact) manifolds. (This seems profound enough an example to justify mentioning. Also, it's a point that tends to get lost in accounts of the theorem...) <a href="https://ncatlab.org/nlab/revision/diff/maps+from+compact+spaces+to+Hausdorff+spaces+are+closed+and+proper/14">diff</a>, <a href="https://ncatlab.org/nlab/revision/maps+from+compact+spaces+to+Hausdorff+spaces+are+closed+and+proper/14">v14</a>, <a href="https://ncatlab.org/nlab/show/maps+from+compact+spaces+to+Hausdorff+spaces+are+closed+and+proper">current</a>

   I have added a subsection Applications – In Cohomotopy and Cobordism theory highlighting how the properness of maps from compact to Hausdorff spaces is what makes the unstable Pontryagin-Thom isomorphism tick – for closed (hence compact) manifolds.

   (This seems profound enough an example to justify mentioning. Also, it’s a point that tends to get lost in accounts of the theorem…)

   diff, v14, current