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May
29
comment Is there an analogue of Eilenberg-Maclane spaces for homology?
This is essentially this MO question: mathoverflow.net/questions/1438/… , and Mike's accurate answer & comment are essentially Tyler's.
May
27
awarded  Notable Question
May
19
asked Spectral sequence for computing the homotopy fixed points in unstable equivariant homotopy theory
May
15
comment References for equivariant cohomology
You could start with the "What is... equivariant cohomology?" article from the Notices of the AMS. Then I heard there is a book by Bredon on the subject.
May
13
awarded  Nice Answer
May
1
comment Curious remark of D. Ravenel
This article is incredibly funny.
Apr
30
comment If there are injective homomorphisms between two groups in both directions, are they isomorphic?
See also mathoverflow.net/questions/1058/when-does-cantor-bernstein-hold
Apr
16
comment What are some beautiful examples of adjunctions?
math.stackexchange.com/questions/46708/…
Apr
9
revised Computation of $Ext^*_R(k,k)$ as an algebra using a dga-resolution
edited tags
Apr
8
comment Why are functors exact if they preserve all short exact sequences?
At the end of this answer to a related question, I post a link to something I wrote up (in Spanish) which contains exactly what you want. If you understand it and write it up in English and post it as an answer, I'd upvote it :)
Apr
7
revised Computation of $Ext^*_R(k,k)$ as an algebra using a dga-resolution
edited tags
Apr
6
revised Duality between Tor and Ext?
added 28 characters in body
Apr
6
comment Classification of finitely generated multigraded modules over $K[x_1,\ldots,x_n]$?
Why the hell does this have a -3 vote count? (-2 now). Sometimes I really don't understand math.SE user's vote patterns.
Apr
6
answered Duality between Tor and Ext?
Apr
6
comment Ring structure on $Ext$ and $Tor$
Found another reference: Mac Lane's Homology, section VIII (Products). There's also Cartan & Eilenberg which is really comprehensive and immensely general. And I'm going to leave a link to a question I just asked here, because it is somehow related and I think it would be useful to have them formally linked: math.stackexchange.com/questions/1222604/… .
Apr
6
asked Computation of $Ext^*_R(k,k)$ as an algebra using a dga-resolution
Apr
6
comment Reference request: extending tensor product of modules
Do you want a reference where it is used (it's used all over the place!), as you say, or do you want a reference where it is explained? If it's the latter, try KConrad's two blurbs on tensor products, they are very nice. It's called "extension of scalars" or "base change", usually.
Mar
31
comment Explicit example of Koszul complex
Do you have a reference for the content of your post? Thanks.
Mar
31
comment How to compute Ext over an exterior algebra
Also, this question is definitely related, if not almost a duplicate: math.stackexchange.com/questions/366927/…
Mar
30
comment How to compute Ext over an exterior algebra
You should look at Lang's Algebra, almost at the end of the book: it's p. 861 in my edition.