For equivariant stable homotopy theory, equivariant KK–theory and equivariant derived categories, we show how restriction to a subgroup of finite index yields a finite commutative separable extension, analogous to finite étale extensions in algebraic geometry.
Keywords: Restriction, equivariant triangulated categories, separable, étale
Balmer, Paul  1 ; Dell’Ambrogio, Ivo  2 ; Sanders, Beren  3
@article{10_2140_agt_2015_15_3025,
author = {Balmer, Paul and Dell{\textquoteright}Ambrogio, Ivo and Sanders, Beren},
title = {Restriction to finite-index subgroups as \'etale extensions in topology, {KK{\textendash}theory} and geometry},
journal = {Algebraic and Geometric Topology},
pages = {3023--3045},
year = {2015},
volume = {15},
number = {5},
doi = {10.2140/agt.2015.15.3025},
url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2015.15.3025/}
}
TY - JOUR AU - Balmer, Paul AU - Dell’Ambrogio, Ivo AU - Sanders, Beren TI - Restriction to finite-index subgroups as étale extensions in topology, KK–theory and geometry JO - Algebraic and Geometric Topology PY - 2015 SP - 3023 EP - 3045 VL - 15 IS - 5 UR - http://geodesic.mathdoc.fr/articles/10.2140/agt.2015.15.3025/ DO - 10.2140/agt.2015.15.3025 ID - 10_2140_agt_2015_15_3025 ER -
%0 Journal Article %A Balmer, Paul %A Dell’Ambrogio, Ivo %A Sanders, Beren %T Restriction to finite-index subgroups as étale extensions in topology, KK–theory and geometry %J Algebraic and Geometric Topology %D 2015 %P 3023-3045 %V 15 %N 5 %U http://geodesic.mathdoc.fr/articles/10.2140/agt.2015.15.3025/ %R 10.2140/agt.2015.15.3025 %F 10_2140_agt_2015_15_3025
Balmer, Paul; Dell’Ambrogio, Ivo; Sanders, Beren. Restriction to finite-index subgroups as étale extensions in topology, KK–theory and geometry. Algebraic and Geometric Topology, Tome 15 (2015) no. 5, pp. 3023-3045. doi: 10.2140/agt.2015.15.3025
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