Invariant Hopf 2-Cocycles for Affine Algebraic Groups

We generalize the theory of the second invariant cohomology group H[superscript 2][subscript inv](G) for finite groups G, developed in [3, 4, 14], to the case of affine algebraic groups G, using the methods of [9, 10, 12]. In particular, we show that for connected affine algebraic groups G over an a...

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Main Authors: Etingof, Pavel I, Gelaki, Shlomo
Other Authors: Massachusetts Institute of Technology. Department of Mathematics
Format: Article
Language:English
Published: Oxford University Press (OUP) 2019
Online Access:https://hdl.handle.net/1721.1/122973
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author Etingof, Pavel I
Gelaki, Shlomo
author2 Massachusetts Institute of Technology. Department of Mathematics
author_facet Massachusetts Institute of Technology. Department of Mathematics
Etingof, Pavel I
Gelaki, Shlomo
author_sort Etingof, Pavel I
collection MIT
description We generalize the theory of the second invariant cohomology group H[superscript 2][subscript inv](G) for finite groups G, developed in [3, 4, 14], to the case of affine algebraic groups G, using the methods of [9, 10, 12]. In particular, we show that for connected affine algebraic groups G over an algebraically closed field of characteristic 0, the map Θ from [14] is bijective (unlike for some finite groups, as shown in [14]). This allows us to compute H[superscript 2][subscript inv](G) in this case, and in particular show that this group is commutative (while for finite groups it can be noncommutative, as shown in [14]).
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spelling mit-1721.1/1229732024-06-14T12:24:53Z Invariant Hopf 2-Cocycles for Affine Algebraic Groups Etingof, Pavel I Gelaki, Shlomo Massachusetts Institute of Technology. Department of Mathematics We generalize the theory of the second invariant cohomology group H[superscript 2][subscript inv](G) for finite groups G, developed in [3, 4, 14], to the case of affine algebraic groups G, using the methods of [9, 10, 12]. In particular, we show that for connected affine algebraic groups G over an algebraically closed field of characteristic 0, the map Θ from [14] is bijective (unlike for some finite groups, as shown in [14]). This allows us to compute H[superscript 2][subscript inv](G) in this case, and in particular show that this group is commutative (while for finite groups it can be noncommutative, as shown in [14]). 2019-11-20T14:05:24Z 2019-11-20T14:05:24Z 2018-03 2019-11-12T17:19:21Z Article http://purl.org/eprint/type/JournalArticle 1073-7928 1687-0247 https://hdl.handle.net/1721.1/122973 Pavel Etingof, and Shlomo Gelaki. "Invariant Hopf 2-Cocycles for Affine Algebraic Groups." International Mathematics Research Notices (March 2018) © The Authors 2018 en http://dx.doi.org/10.1093/imrn/rny025 International Mathematics Research Notices Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Oxford University Press (OUP) arXiv
spellingShingle Etingof, Pavel I
Gelaki, Shlomo
Invariant Hopf 2-Cocycles for Affine Algebraic Groups
title Invariant Hopf 2-Cocycles for Affine Algebraic Groups
title_full Invariant Hopf 2-Cocycles for Affine Algebraic Groups
title_fullStr Invariant Hopf 2-Cocycles for Affine Algebraic Groups
title_full_unstemmed Invariant Hopf 2-Cocycles for Affine Algebraic Groups
title_short Invariant Hopf 2-Cocycles for Affine Algebraic Groups
title_sort invariant hopf 2 cocycles for affine algebraic groups
url https://hdl.handle.net/1721.1/122973
work_keys_str_mv AT etingofpaveli invarianthopf2cocyclesforaffinealgebraicgroups
AT gelakishlomo invarianthopf2cocyclesforaffinealgebraicgroups