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The Dixmier-Douady class and an abelian extension of the homeomorphism group

Authors :
Maruyama, Shuhei
Publication Year :
2020

Abstract

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.<br />Comment: 17 pages

Subjects

Subjects :
Mathematics - Geometric Topology

Details

Database :
arXiv
Publication Type :
Report
Accession number :
edsarx.2009.03724
Document Type :
Working Paper