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Results tagged with ac.commutative-algebra
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user 91840
Commutative rings, modules, ideals, homological algebra, computational aspects, invariant theory, connections to algebraic geometry and combinatorics.
4
votes
Extension class and cup product
The Yoneda product is the following:
$$Ext^n(M,N)\otimes Ext^m(L,M)\rightarrow Ext^{n+m}(L,N).$$
For $L=\mathbb{Z}$ and $n=0,1$ and M,N sheaves of $\mathbb{Z}$-modules this specializes to
$$Hom(M,N …
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