Timeline for Why sheaves are important and why do we care about them?
Current License: CC BY-SA 4.0
13 events
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| Oct 20, 2018 at 10:15 | history | edited | fosco | CC BY-SA 4.0 |
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| Jun 21, 2018 at 7:53 | comment | added | fosco | There was more effort in the pun about coffee beans and nobody noticed it :-( | |
| Jun 21, 2018 at 3:11 | comment | added | David Roberts♦ | "the mystics claim that in Set every epimorphism has a right inverse." <--- lol | |
| Jun 20, 2018 at 16:38 | history | edited | fosco | CC BY-SA 4.0 |
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| Jun 20, 2018 at 16:10 | vote | accept | Lolman | ||
| Apr 9, 2023 at 17:53 | |||||
| Jun 18, 2018 at 15:34 | comment | added | Ivan Di Liberti | Durov*, sorry, misspelling. | |
| Jun 18, 2018 at 15:28 | comment | added | fosco | <<“ionad” is a Gaelic word meaning “place>> This is a good start. | |
| Jun 18, 2018 at 14:59 | comment | added | Ivan Di Liberti | The interested reader might want to give a look to the notion of Ionad, introduced by Garner and the notion of Vectoid introduced by Dubov. Both are notions of generalized space and rely on the intuition of category of Sheaves. | |
| Jun 17, 2018 at 22:34 | comment | added | fosco | Every presheaf can be replace with its (op)fibration of elements. As for variance, yes, put an "op" everywhere is needed, or say that $C=A^{op}$ :-) | |
| Jun 17, 2018 at 20:11 | comment | added | Qfwfq | Shouldn't all the $C$s be replaced by $C^{\mathrm{op}}$ (assuming you'd write a site as $(C,J)$ of course)? Also, why do you see $\mathrm{Set}$ as a "base" category when it's the target of a sheaf? In the second question I mean: does the Grothendieck "geometric" viepoint have the right "variance" to make heuristic sense here? I think not; rather, in a morphism of type $[C,^{\mathrm{op}},\mathrm{Set}]\to \mathrm{Set}$, or $\mathcal{E}\to\mathrm{Set}$ where $\mathcal{E}$ is any topos, the second "Set" has indeed the role of a "base"; but not in $C^{\mathrm{op}}\to \mathrm{Set}$. | |
| Jun 17, 2018 at 14:15 | history | edited | fosco | CC BY-SA 4.0 |
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| Jun 17, 2018 at 13:59 | history | edited | fosco | CC BY-SA 4.0 |
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| Jun 17, 2018 at 13:53 | history | answered | fosco | CC BY-SA 4.0 |