Timeline for Interpretation of the monomorphism $H^2(\pi_1(X),\mathbb{Z}) \rightarrow H^2(X,\mathbb{Z})$
Current License: CC BY-SA 3.0
3 events
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| Apr 16, 2015 at 8:58 | history | edited | Konrad Waldorf | CC BY-SA 3.0 |
added 5 characters in body
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| Apr 16, 2015 at 8:57 | comment | added | Konrad Waldorf | If $E$ is a central extension of $\pi_1(X)$ by $\mathbb{Z}$, we have the class in $H^2(X,\mathbb{Z})$ represented by a gerbe with structure group $\mathbb{Z}$, rather than by a principal bundle with structure group $\mathbb{C}^{\times}$. | |
| Apr 16, 2015 at 8:50 | history | answered | Konrad Waldorf | CC BY-SA 3.0 |