Timeline for Basis for Universal Calculus
Current License: CC BY-SA 2.5
7 events
| when toggle format | what | by | license | comment | |
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| Nov 17, 2009 at 21:16 | comment | added | Mariano Suárez-Álvarez | \ot should be \otimes. (Being able to edit comments would be very, very useful!) | |
| Nov 17, 2009 at 20:28 | comment | added | Jon Awbrey |
What is that "unknown control sequence" \ot supposed to be? Maybe \otimes or maybe \leftarrow?
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| Nov 17, 2009 at 18:47 | vote | accept | Abtan Massini | ||
| Nov 17, 2009 at 18:37 | comment | added | Mariano Suárez-Álvarez | If $A$ is projective over $k$ (for example, if $k$ is a field), then the short exact sequence $0\to \Omega_A\to A\otimes_kA\to A\to 0$ splits in the category of left $A$-modules by the map $s:a\in A\mapsto a\otimes 1\in A\ot A$. It follows that $\Omega_A$ is a direct summand of the free left $A$-module $A\ot A$, so it is projective. It is not free, though, in general, I think. | |
| Nov 17, 2009 at 18:28 | history | edited | Mariano Suárez-Álvarez | CC BY-SA 2.5 |
added 33 characters in body
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| Nov 17, 2009 at 18:28 | comment | added | Abtan Massini | Does there exist an obvious basis over $A$? | |
| Nov 17, 2009 at 18:20 | history | answered | Mariano Suárez-Álvarez | CC BY-SA 2.5 |