Timeline for Does a topological hypercover always have free degeneracies?
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4 events
| when toggle format | what | by | license | comment | |
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| Aug 4, 2015 at 23:48 | comment | added | Zhen Lin | @JesseC.McKeown That is correct. In topos-theoretic language, my argument amounts to the observation that a sheaf whose espace étalé is Hausdorff is a decidable object, i.e. $A \times A \cong \Delta_A \amalg B$, where $\Delta_A$ is the diagonal; a simplicial sheaf that is degreewise decidable will then have free degeneracies. | |
| Aug 4, 2015 at 20:51 | comment | added | Jesse C. McKeown | Don't know the answer, but: if I'm understanding the definition of hypercover, it seems to induce a simplicial object in the topos generated by open Sets of $X$, with an epimorphism property at every level; D+I have arranged their definition the other way around, starting with sSpaces over X and then paring down what kind of Spaces are in each level. | |
| Aug 4, 2015 at 16:57 | answer | added | Zhen Lin | timeline score: 2 | |
| Aug 3, 2015 at 4:00 | history | asked | Zhaoting Wei | CC BY-SA 3.0 |