Non-unitary representations of nilpotent groups, I: Cohomologies, extensions and neutral cocycles

Let λbe a finite-dimensional representation of a connected nilpotent group Gand Ube a unitary representation of G. We investigate the structure of the extensions of λby Uand, correspondingly, the group H1(λ, U)of 1-cohomologies. A spectral criterion of triviality of H1(λ, U)is proved and systematica...

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Main Authors: Kissin, Edward, Shulman, Victor S.
Format: Article
Language:English
Published: Elsevier 2015
Subjects:
Online Access:https://repository.londonmet.ac.uk/1013/7/SECOND%20SUBMISSION%20TO%20JFA-15-137R1.pdf
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author Kissin, Edward
Shulman, Victor S.
author_facet Kissin, Edward
Shulman, Victor S.
author_sort Kissin, Edward
collection LMU
description Let λbe a finite-dimensional representation of a connected nilpotent group Gand Ube a unitary representation of G. We investigate the structure of the extensions of λby Uand, correspondingly, the group H1(λ, U)of 1-cohomologies. A spectral criterion of triviality of H1(λ, U)is proved and systematically used in the study of various types of decomposition of the extensions. We consider a special type of (λ, U)-cocycles – neutral cocycles, which play a crucial role in the theory of J-unitary representations of groups on Pontryagin Πk-spaces.
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spelling oai:repository.londonmet.ac.uk:10132020-05-29T16:27:50Z http://repository.londonmet.ac.uk/1013/ Non-unitary representations of nilpotent groups, I: Cohomologies, extensions and neutral cocycles Kissin, Edward Shulman, Victor S. 510 Mathematics Let λbe a finite-dimensional representation of a connected nilpotent group Gand Ube a unitary representation of G. We investigate the structure of the extensions of λby Uand, correspondingly, the group H1(λ, U)of 1-cohomologies. A spectral criterion of triviality of H1(λ, U)is proved and systematically used in the study of various types of decomposition of the extensions. We consider a special type of (λ, U)-cocycles – neutral cocycles, which play a crucial role in the theory of J-unitary representations of groups on Pontryagin Πk-spaces. Elsevier 2015-07-22 Article PeerReviewed text en https://repository.londonmet.ac.uk/1013/7/SECOND%20SUBMISSION%20TO%20JFA-15-137R1.pdf Kissin, Edward and Shulman, Victor S. (2015) Non-unitary representations of nilpotent groups, I: Cohomologies, extensions and neutral cocycles. Journal of Functional Analysis, 269 (8). pp. 2564-2610. ISSN 0022-1236 http://dx.doi.org/10.1016/j.jfa.2015.07.003 10.1016/j.jfa.2015.07.003
spellingShingle 510 Mathematics
Kissin, Edward
Shulman, Victor S.
Non-unitary representations of nilpotent groups, I: Cohomologies, extensions and neutral cocycles
title Non-unitary representations of nilpotent groups, I: Cohomologies, extensions and neutral cocycles
title_full Non-unitary representations of nilpotent groups, I: Cohomologies, extensions and neutral cocycles
title_fullStr Non-unitary representations of nilpotent groups, I: Cohomologies, extensions and neutral cocycles
title_full_unstemmed Non-unitary representations of nilpotent groups, I: Cohomologies, extensions and neutral cocycles
title_short Non-unitary representations of nilpotent groups, I: Cohomologies, extensions and neutral cocycles
title_sort non unitary representations of nilpotent groups i cohomologies extensions and neutral cocycles
topic 510 Mathematics
url https://repository.londonmet.ac.uk/1013/7/SECOND%20SUBMISSION%20TO%20JFA-15-137R1.pdf
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