# Start a new discussion

## Not signed in

Want to take part in these discussions? Sign in if you have an account, or apply for one below

## Site Tag Cloud

Vanilla 1.1.10 is a product of Lussumo. More Information: Documentation, Community Support.

• CommentRowNumber1.
• CommentAuthorUrs
• CommentTimeApr 24th 2018

the minimum definition and some plain cross-links (we didn’t have this elsewhere, or do we?)

• CommentRowNumber2.
• CommentAuthorUrs
• CommentTimeOct 21st 2020

added the example that every smooth action of a compact Lie group on a smooth manifold is proper (here)

• CommentRowNumber3.
• CommentAuthorUrs
• CommentTimeApr 13th 2021

I have expanded the definition section a little, added mentioning of alternative definitions to the shear map being proper (“Bourbaki properness”), namely Palais’ definition in one of its many forms (“Palais properness”) highlighted the need of local compactness for these to be equivalent, added pointer to the original article by Palais, mentioned his attribution of the concept to Borel. Also pointer to Bourbaki, but didn’t actually look that up.

• CommentRowNumber4.
• CommentAuthorUrs
• CommentTimeApr 13th 2021
• (edited Apr 13th 2021)

also added “Borel properness”, i.e.: the subset of $G$ not translating a given compactum $K$ away from itself is compact (Palais60 on p. 303 attributes this to unpublished work of Borel)