A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms

A Lie algebra gQ over Q is said to be R-universal if every homomorphism from gQ to gl(n,R) is conjugate to a homomorphism into gl(n,Q) (for every n). By using Galois cohomology, we provide a short proof of the known fact that every real semisimple Lie algebra has an R-universal Q-form. We also provi...

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Veröffentlicht in:Symmetry, Integrability and Geometry: Methods and Applications
Datum:2015
1. Verfasser: Morris, D.W.
Format: Artikel
Sprache:English
Veröffentlicht: Інститут математики НАН України 2015
Online Zugang:https://nasplib.isofts.kiev.ua/handle/123456789/147011
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Назва журналу:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Zitieren:A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms / D.W. Morris // Symmetry, Integrability and Geometry: Methods and Applications. — 2015. — Т. 11. — Бібліогр.: 12 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
id nasplib_isofts_kiev_ua-123456789-147011
record_format dspace
spelling Morris, D.W.
2019-02-12T20:33:33Z
2019-02-12T20:33:33Z
2015
A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms / D.W. Morris // Symmetry, Integrability and Geometry: Methods and Applications. — 2015. — Т. 11. — Бібліогр.: 12 назв. — англ.
1815-0659
2010 Mathematics Subject Classification: 17B10; 17B20; 11E72; 20G30
DOI:10.3842/SIGMA.2015.034
https://nasplib.isofts.kiev.ua/handle/123456789/147011
A Lie algebra gQ over Q is said to be R-universal if every homomorphism from gQ to gl(n,R) is conjugate to a homomorphism into gl(n,Q) (for every n). By using Galois cohomology, we provide a short proof of the known fact that every real semisimple Lie algebra has an R-universal Q-form. We also provide a classification of the R-universal Lie algebras that are semisimple.
It is a pleasure to thank V. Chernousov for a very helpful discussion about Tits algebras of special orthogonal groups, A. Rapinchuk for explaining how to prove Lemma 2.5, and the anonymous referees for numerous very insightful comments on a previous version of this manuscript, including some important corrections.
en
Інститут математики НАН України
Symmetry, Integrability and Geometry: Methods and Applications
A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms
Article
published earlier
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
collection DSpace DC
title A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms
spellingShingle A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms
Morris, D.W.
title_short A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms
title_full A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms
title_fullStr A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms
title_full_unstemmed A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms
title_sort cohomological proof that real representations of semisimple lie algebras have q-forms
author Morris, D.W.
author_facet Morris, D.W.
publishDate 2015
language English
container_title Symmetry, Integrability and Geometry: Methods and Applications
publisher Інститут математики НАН України
format Article
description A Lie algebra gQ over Q is said to be R-universal if every homomorphism from gQ to gl(n,R) is conjugate to a homomorphism into gl(n,Q) (for every n). By using Galois cohomology, we provide a short proof of the known fact that every real semisimple Lie algebra has an R-universal Q-form. We also provide a classification of the R-universal Lie algebras that are semisimple.
issn 1815-0659
url https://nasplib.isofts.kiev.ua/handle/123456789/147011
citation_txt A Cohomological Proof that Real Representations of Semisimple Lie Algebras Have Q-Forms / D.W. Morris // Symmetry, Integrability and Geometry: Methods and Applications. — 2015. — Т. 11. — Бібліогр.: 12 назв. — англ.
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