Timeline for (geometric/intuitive) interpretation of ext
Current License: CC BY-SA 3.0
14 events
| when toggle format | what | by | license | comment | |
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| Feb 21, 2023 at 3:35 | comment | added | Timothy Chow | Apropos Daniel Moskovich's comment, here is a more stable link to Daniel Isaksen's paper. See also James Dolan's sci.math posts on the topic. | |
| Dec 12, 2017 at 0:27 | history | edited | Qfwfq | CC BY-SA 3.0 |
deleted 13 characters in body
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| Oct 18, 2013 at 23:07 | review | Close votes | |||
| Oct 19, 2013 at 7:39 | |||||
| Jan 4, 2013 at 20:20 | vote | accept | Johannes | ||
| Jan 4, 2013 at 18:03 | answer | added | Johannes | timeline score: 1 | |
| Jan 4, 2013 at 11:11 | comment | added | Zev Chonoles | Now posted on math.SE: math.stackexchange.com/q/270228/264 | |
| Jan 3, 2013 at 23:04 | comment | added | Fernando Muro | After the edit, I think it's definitely clear that this question is not research level, is it? | |
| Jan 3, 2013 at 22:57 | history | edited | Johannes | CC BY-SA 3.0 |
one more new tag
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| Jan 1, 2013 at 4:16 | comment | added | Daniel Moskovich | math.wayne.edu/~isaksen/Expository/carrying.pdf is a very soft introduction to ext, in terms of elementary school arithmetic and the "carrying" operation. Maybe you could think of it as being an unpacking of part of Fernando Muro's 1 letter and 1 word comment. | |
| Dec 31, 2012 at 18:06 | comment | added | Reladenine Vakalwe | Not quite in line with your question. But if you were dealing with a reasonable topological space $X$, then $Ext$ groups of the constant sheaf with itself (in the category of constructible sheaves) are the cohomology groups of that space. More generally, extensions from the constant sheaf to any complex of sheaves is hypercohomology with coefficients in the complex. | |
| Dec 31, 2012 at 16:02 | comment | added | M T | mathoverflow.net/questions/15016/about-higher-ext-in-r-mod | |
| Dec 31, 2012 at 13:56 | comment | added | Allen | The first ext group of two modules(sheaves) can be explictly understood as the set of elements which fit with the given two modules into a short exact sequence (ref. Griffith Harris). For higher ext we have similar construction by going to a diagram of short exact sequences. | |
| Dec 31, 2012 at 12:49 | comment | added | Fernando Muro | $n$-extensions. | |
| Dec 31, 2012 at 12:42 | history | asked | Johannes | CC BY-SA 3.0 |