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1. • CommentRowNumber1.
   • CommentAuthorUrs
   • CommentTimeDec 11th 2015
   • (edited Dec 11th 2015)
   • PermaLink
   Author: Urs
   Format: MarkdownItexWay back, in the entry, _[[equivariant cohomology]]_, Mike (I believe) wrote: > [in naive equivariant cohomology] one sees torsion popping up in odd places where one wouldn’t expect it. and then > $RO(G)$-graded Bredon cohomology has lots of formal advantages over the integer-graded theory. For instance, the torsion that popped up in odd places before can now be seen as arising by “shifting” of something in the cohomology of a point in an “off-integer dimension,” which was invisible to the integer-graded theory. Which results is this alluding to? This sounds just like the kind of effect that I was after [here](http://mathoverflow.net/q/224088/381). So is this just a special case of something more general and well known? What would be a reference?

   Way back, in the entry, equivariant cohomology, Mike (I believe) wrote:

   [in naive equivariant cohomology] one sees torsion popping up in odd places where one wouldn’t expect it.

   and then

   $RO(G)$-graded Bredon cohomology has lots of formal advantages over the integer-graded theory. For instance, the torsion that popped up in odd places before can now be seen as arising by “shifting” of something in the cohomology of a point in an “off-integer dimension,” which was invisible to the integer-graded theory.

   Which results is this alluding to?

   This sounds just like the kind of effect that I was after here. So is this just a special case of something more general and well known? What would be a reference?

2. • CommentRowNumber2.
   • CommentAuthorDavid_Corfield
   • CommentTimeDec 11th 2015
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   Author: David_Corfield
   Format: MarkdownItexThat came from Mike's blog [post](https://golem.ph.utexas.edu/category/2010/01/the_sacred_and_the_profane.html#c031280) from discussions with Megan. Page 3 of her [thesis](http://arxiv.org/abs/1405.1770) speaks of "cohomology groups in “off-integer” dimensions".

   That came from Mike’s blog post from discussions with Megan. Page 3 of her thesis speaks of “cohomology groups in “off-integer” dimensions”.