New answers tagged homological-algebra
3
votes
Accepted
When is the Tor-dimension of $R/(r)$ strictly smaller than that of $R$?
There is no difference between flat (Tor) dimension and global dimension for Noetherian rings. Now, it is well known that for an arbitrary local $R$ and a nonzerodivisor $f\in\mathfrak{m}$ either $\...
- 1,678
8
votes
Accepted
Morita equivalences and centers of some algebras
The answer is that in your matrix $\left(\begin{smallmatrix} 0&x_0\\0&0\end{smallmatrix}\right)$, the $x_0$ denotes the isomorphism of modules given by left multiplication by $x_0$, so it ...
- 8,149
22
votes
Accepted
Who wrote `if only I could understand the equation $d^2=0$'?
Here’s a synthesis of answers and comments by მამუკა ჯიბლაძე and Georges Elencwajg fleshed out by your obedient servant.
On June 25, 1980, Henri Cartan was admitted to the honorary degree of Doctor of ...
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