Publication

Equivariant vector bundles over classifying spaces for proper actions

Degrijse, Dieter
Leary, Ian
Identifiers
http://hdl.handle.net/10379/11124
https://doi.org/10.13025/27570
Publication Date
2017-01-26
Type
Article
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Citation
Degrijse, Dieter; Leary, Ian (2017). Equivariant vector bundles over classifying spaces for proper actions. Algebraic & Geometric Topology 17 (1), 131-156
Abstract
Let G be an infinite discrete group and let (E) under barG be a classifying space for proper actions of G. Every G-equivariant vector bundle over (E) under barG gives rise to a compatible collection of representations of the finite subgroups of G. We give the first examples of groups G with a cocompact classifying space for proper actions (E) under barG admitting a compatible collection of representations of the finite subgroups of G that does not come from a G-equivariant (virtual) vector bundle over (E) under barG. This implies that the Atiyah-Hirzebruch spectral sequence computing the G-equivariant topological K-theory of (E) under barG has nonzero differentials. On the other hand, we show that for right-angled Coxeter groups this spectral sequence always collapses at the second page and compute the K-theory of the classifying space of a right-angled Coxeter group.
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Publisher
Mathematical Sciences Publishers
Publisher DOI
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Attribution-NonCommercial-NoDerivs 3.0 Ireland