×

A new invariant of quadratic Lie algebras. (English) Zbl 1271.17004

In this nice paper, the authors define and study in detail a new invariant of quadratic Lie algebras. This invariant, called the dup-number, essentially measures the decomposability of the 3-form \(I\) defined by \(I(X,Y,Z)=B([X,Y],Z)\), where \(B\) denotes the bilinear form associated to a non-Abelian quadratic Lie algebra. It is shown that the range of the dup-number is \(0,1,3\). With the help of this invariant, the authors classify those quadratic Lie algebras for which the invariant does not vanish. In addition, some relevant questions concerning double extensions and the orbit method are also analyzed.

MSC:

17B05 Structure theory for Lie algebras and superalgebras
17B20 Simple, semisimple, reductive (super)algebras

References:

[1] Bajo, I., Benayadi, S.: Lie algebras admitting a unique quadratic structure. Commun. Algebra 25(9), 2795–2805 (1997) · Zbl 0879.17002 · doi:10.1080/00927879708826023
[2] Bajo, I., Benayadi, S.: Lie algebras with quadratic dimension equal to 2. J. Pure Appl. Algebra 209(3), 725–737 (2007) · Zbl 1112.17004 · doi:10.1016/j.jpaa.2006.07.010
[3] Benayadi, S.: Socle and some invariants of quadratic Lie superalgebras. J. Algebra 261(2), 245–291 (2003) · Zbl 1013.17029 · doi:10.1016/S0021-8693(02)00682-8
[4] Bourbaki, N.: Eléments de Mathématiques. Algèbre, Algèbre Multilinéaire, vol. Fasc. VII, Livre II. Hermann, Paris (1958)
[5] Bourbaki, N.: Eléments de Mathématiques. Algèbre, Formes sesquilinéaires et formes quadratiques, vol. Fasc. XXIV, Livre II. Hermann, Paris (1959) · Zbl 0102.25503
[6] Bourbaki, N.: Eléments de Mathématiques. Groupes et Algèbres de Lie, Chapitre I, Algèbres de Lie. Hermann, Paris (1971) · Zbl 0213.04103
[7] Collingwood, D.H., McGovern, W.M.: Nilpotent Orbits in Semisimple Lie. Algebras, p. 186. Van Nostrand Reihnhold Mathematics Series, New York (1993) · Zbl 0972.17008
[8] Dixmier, J.: Algèbres Enveloppantes, p. 349. Cahiers scientifiques, fasc.37, Gauthier-Villars, Paris (1974)
[9] Favre, G., Santharoubane, L.J.: Symmetric, invariant, non-degenerate bilinear form on a Lie algebra. J. Algebra 105, 451–464 (1987) · Zbl 0608.17007 · doi:10.1016/0021-8693(87)90209-2
[10] Kac, V.: Infinite-Dimensional Lie Algebras, xvii + 280 pp. Cambridge University Press, New York (1985)
[11] Magnin, L.: Determination of 7-dimensional indecomposable Lie algebras by adjoining a derivation to 6-dimensional Lie algebras. Algebr. Represent. Theory 13, 723–753 (2010) · Zbl 1237.17017 · doi:10.1007/s10468-009-9172-3
[12] Medina, A., Revoy, Ph.: Algèbres de Lie et produit scalaire invariant. Ann. Sci. École Norm. Sup. 4, 553–561 (1985) · Zbl 0592.17006
[13] Ooms, A.: Computing invariants and semi-invariants by means of Frobenius Lie algebras. J. Algebra 4, 1293–1312 (2009) · Zbl 1242.17013 · doi:10.1016/j.jalgebra.2008.10.026
[14] Pinczon, G., Ushirobira, R.: New applications of graded Lie algebras to Lie algebras, generalized Lie algebras, and cohomology. J. Lie Theory 17(3), 633–668 (2007) · Zbl 1195.17022
[15] Samelson, H.: Notes on Lie Algebras. Universitext. Springer (1980) · Zbl 0209.06601
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.