We study the classifying space of a twisted loop group LσG, where G is a compact Lie group and σ is an automorphism of G of finite order modulo inner automorphisms. Equivalently, we study the σ–twisted adjoint action of G on itself. We derive a formula for the cohomology ring H∗(BLσG) and explicitly carry out the calculation for all automorphisms of simple Lie groups. More generally, we derive a formula for the equivariant cohomology of compact Lie group actions with constant rank stabilizers.
Keywords: loop groups, twisted conjugacy, twisted adjoint action, equivariant cohomology, classifying spaces, gauge groups
Baird, Thomas J  1
@article{10_2140_agt_2016_16_211,
author = {Baird, Thomas J},
title = {Classifying spaces of twisted loop groups},
journal = {Algebraic and Geometric Topology},
pages = {211--229},
year = {2016},
volume = {16},
number = {1},
doi = {10.2140/agt.2016.16.211},
url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2016.16.211/}
}
Baird, Thomas J. Classifying spaces of twisted loop groups. Algebraic and Geometric Topology, Tome 16 (2016) no. 1, pp. 211-229. doi: 10.2140/agt.2016.16.211
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