Gerbal central extensions of reductive groups by K3
We classify central extensions of a reductive group G by K3 and BK3, the sheaf of third Quillen K-theory groups and its classifying stack. These turn out to be parametrized by the group of Weyl-invariant quadratic forms on the cocharacter lattice valued in k× and the group of integral Weyl-invariant...
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Format: | Journal article |
Language: | English |
Published: |
Elsevier
2015
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