The Dixmier-Douady class and an abelian extension of the homeomorphism group
| Autor: | Maruyama, Shuhei |
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| Rok vydání: | 2020 |
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| Druh dokumentu: | Working Paper |
| Popis: | Let $X$ be a connected topological space and $c \in \mathrm{H}^2(X;\mathbb{Z})$ a non-zero cohomology class. A $\mathrm{Homeo}(X,c)$-bundle is a fiber bundle with fiber $X$ whose structure group reduces to the group $\mathrm{Homeo}(X,c)$ of $c$-preserving homeomorphisms of $X$. If $\mathrm{H}^1(X;\mathbb{Z}) = 0$, then a characteristic class for $\mathrm{Homeo}(X,c)$-bundles called the Dixmier-Douady class is defined via the Serre spectral sequence. We show a relation between the universal Dixmier-Douady class for foliated $\mathrm{Homeo}(X,c)$-bundles and the gauge group extension of $\mathrm{Homeo}(X,c)$. Moreover, under some assumptions, we construct a central $S^1$-extension and a group two-cocycle on $\mathrm{Homeo}(X,c)$ corresponding to the Dixmier-Douady class. Comment: 17 pages |
| Databáze: | arXiv |
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