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Characteristic identities for semi-simple Lie algebras

Published online by Cambridge University Press:  17 February 2009

M. D. Gould
Affiliation:
Department of Mathematical Physics, University of Adelaide, G.P.O. Box 498, Adelaide, S. A. 5001.
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Abstract

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We present a new derivation of the polynomial identities satisfied by certain matrices A with entries Aij (i, j = 1,…, n) from the universal enveloping algebra of a semi-simple Lie algebra. These polynomial identities are exhibited in a representation-independent way as p(A) = 0 where p(x) (herein called the characteristic polynomial of A) is a polynomial with coefficients from the centre Z of the universal enveloping algebra. The minimum polynomial identity m(A) = 0 of the matrix A over Z is also obtained and it is shown that p(x) and m(x) possess properties analogous to the characteristic and minimum polynomials respectively of a matrix with numerical entries. Acting on a representation (finite or infinite dimensional) admitting an infinitesimal character these polynomial identities may be expressed in a useful factored form. Our results include the characteristic identities of Bracken and Green [1] as a special case and show that these latter identities hold also in infinite dimensional representations.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1985

References

[1]Bracken, A. J. and Green, H. S., “Vector operators and a polynomial identity for SO(n)”, J. Math. Phys. 12 (1971), 20992106.CrossRefGoogle Scholar
[2]Dirac, P. A. M., “Relativistic wave equations”, Proc Roy. Soc. London Ser. A 155 (1936), 447459.Google Scholar
[3]Dixmier, J., Enveloping algebras (North-Holland, Amsterdam-New York-Oxford, 1977).Google Scholar
[4]Edwards, S. A., “A new approach to the eigenvalues of Gel'fand invariants for the unitary, orthogonal, and symplectic groups”, J. Math. Phys. 19 (1978), 164167.CrossRefGoogle Scholar
[5]Englefield, M. J. and King, R. C., “Symmetric power sum expansions of the eigenvalues of generalised Casimir operators of semi-simple Lie groups’, J. Phys. A 13 (1980), 22972317.CrossRefGoogle Scholar
[6]Gould, M. D., “ A trace formula for semi-simple Lie algebras”, Ann. Inst. H. Poincaré Sect. A (N.S.) 32 (1980), 203219.Google Scholar
[7]Gould, M. D., “On an infinitesimal approach to semisimple Lie groups and raising and lowering operators pf O(n) and U(n)’, J. Math. Phys. 21 (1980), 444453.CrossRefGoogle Scholar
[8]Green, H. S., “Characteristic identities for generators of GL(n), O(n) and Sp(n)”, J. Math. Phys. 12 (1971), 21062113.CrossRefGoogle Scholar
[9]Hannabuss, K. C., “Characteristic equations for semi-simple Lie groups”, preprint Math. Inst. Oxford (1972) (unpublished).Google Scholar
[10]Humphreys, J. E., Introduction to Lie algebras and representation theory (Springer-Verlag, New York-Heidelberg-Berlin, 1972).CrossRefGoogle Scholar
[11]Jarvis, P. D. and Green, H. S., “Casimir invariants and characteristic identities for generators of the general linear, special linear and orthosymplectic graded Lie algebras”, J. Math. Phys. 20 (1979), 21152122.CrossRefGoogle Scholar
[12]Kostant, B., “On the tensor product of a finite and an infinite dimensional representation”, J. Funct. Anal. 20 (1975), 257285.CrossRefGoogle Scholar
[13]Lehrer-Ilamed, Y., Bull. Res. Council Israel 5A (1956), 197.Google Scholar
[14]Louck, J. D.,“Special nature of orbital angular momentum”, Amer. J. Phys. 31 (1963), 378383.CrossRefGoogle Scholar
[15]Louck, J. D. and Galbraith, H. W.,“Application of orthogonal and unitary group methods to the N-body problem”, Rev. Modern Phys. 44 (1972), 504601.CrossRefGoogle Scholar
[16]Mukunda, N.,“Realizations of Lie algebras in classical mechanics”, J. Math. Phys. 8 (1967), 10691072.CrossRefGoogle Scholar
[17]O'Brien, D. M., Cant, A. and Carey, A. L.,“On characteristic identities for Lie algebras”, Ann. Inst. H. Poincaré Sect. A (N.S.) 26 (1977), 405429.Google Scholar
[18]Okubo, S., “Casimir invariants and vector operators in simple and classical Lie algebras”, J. Math. Phys. 18 (1977), 23822394.CrossRefGoogle Scholar
[19]Warner, G., Harmonic analysis on semi-simple Lie groups, Vol. 1 (Springer-Verlag, Berlin, 1972).Google Scholar