Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-24T08:06:40.910Z Has data issue: false hasContentIssue false

On the Classification of Rational Quantum Tori and the Structure of Their Automorphism Groups

Published online by Cambridge University Press:  20 November 2018

Karl-Hermann Neeb*
Affiliation:
Technische Universität Darmstadt, Schlossgartenstrasse 7, D-64289 Darmstadt, Deutschland e-mail: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

An $n$-dimensional quantum torus is a twisted group algebra of the group ${{\mathbb{Z}}^{n}}.$ It is called rational if all invertible commutators are roots of unity. In the present note we describe a normal form for rational $n$-dimensional quantum tori over any field. Moreover, we show that for $n\,=\,2$ the natural exact sequence describing the automorphism group of the quantum torus splits over any field.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 2008

References

[1] Allison, B. N., Berman, S., Faulkner, J. R., and Pianzola, A., Realization of graded-simple algebras as loop algebras. arXiv:math/RA.0511723.Google Scholar
[2] Allison, B. N., Azam, S., Berman, S., Gao, Y., and Pianzola, A., Extended Affine Lie Algebras and Their Root Systems. Memoirs of the Amer. Math. Soc. 126(1997), no. 603.Google Scholar
[3] Berman, S., Gao, Y., and Krylyuk, Y. S., Quantum tori and the structure of elliptic quasi-simple Lie algebras. J. Funct. Anal. 135(1996), no. 2, 339389.Google Scholar
[4] Bonahon, F., and Xiaobo, L., Representations of the quantum Teichmüller space and invariants of surface diffeomorphisms. arXiv:math.GT/0407086v3,16.11.2004.Google Scholar
[5] Brenken, B. A., Representations and automorphisms of the irrational rotation algebra. Pacific J. Math. 111(1984), no. 2, 257282.Google Scholar
[6] Brown, K. S., Cohomology of Groups. Graduate Texts in Mathematics 87, Springer-Verlag, New York, 1982.Google Scholar
[7] Brown, W. C., Matrices over Commutative Rings. Monographs and Textbooks in Pure and Applied Mathematics 169, Marcel Dekker, New York, 1993.Google Scholar
[8] de Concini, C., and Procesi, C., Quantum groups. In: -Modules, Representation Theory, and Quantum Groups. Lecture Notes in Math. 1565, Springer, Berlin, 1993, pp. 31140.Google Scholar
[9] Elliott, G. A., The diffeomorphism group of the irrational rotation C*-algebra. C. R. Math. Rep. Acad. Sci. Canada 8(1986), no. 5, 329334.Google Scholar
[10] Fuchs, L., Infinite Abelian Groups. I. Pure and Applied Math. 36, Academic Press, New York, 1970.Google Scholar
[11] Gille, P. and Pianzola, A., Galois cohomology and forms of algebras over Laurent polynomial rings. Math. Ann. 338(2007), no. 2, 497543.Google Scholar
[12] Gracia-Bondía, J. M., Vasilly, J. C., and Figueroa, H., Elements of Noncommutative Geometry. Birkhäuser Boston, Boston, MA, 2001.Google Scholar
[13] de la Harpe, P., Topics in Geometric Group Theory. The University of Chicago Press, Chicago, 2000.Google Scholar
[14] Hughes, N. J. S., The use of bilinear mappings in the classification of groups of class 2 . Proc. Amer. Math. Soc. 2(1951), 742747.Google Scholar
[15] Ismagilov, R. S., The integral Heisenberg group as an infinite amalgam of commutative groups. Math. Notes 74(2003), no. 5, 630636 Google Scholar
[16] Jacobson, N., Structure of Rings. American Mathematical Society Colloquium Publications 37, American Mathematical Society, Providence, RI, 1956.Google Scholar
[17] Kirkman, E., Procesi, C., and Small, L., A q-analog of the Virasoro algebra. Comm. Alg. 22(1994), no. 10, 37553774.Google Scholar
[18] Lang, S., Algebra. Third edition. Addison Wesley, London, 1993.Google Scholar
[19] Newman, M., Integral Matrices. Pure and Applied Mathematics 45, Academic Press, New York, 1972.Google Scholar
[20] Osborn, J. M. and Passman, D. S., Derivations of skew polynomial rings. J. Algebra 176(1995), 417448.Google Scholar
[21] Panov, A. N., Skew fields of twisted rational functions and the skew field of rational functions on GL q (n, ). St. Petersburg Math. J. 7(1996), 129143.Google Scholar