Naturally graded quasi-filiform Leibniz algebras

Abstract

The classification of naturally graded quasi-filiform Lie algebras is known; they have the characteristic sequence .n - 2; 1; 1/ where n is the dimension of the algebra. In the present paper we deal with naturally graded quasi-filiform non-Lie-Leibniz algebras which are described by the characteristic sequence C.L = n -2; 1; 1/ or C.L = n - 2; 2/. The first case has been studied in [Camacho, L.M., Gómez, J.R., González, A.J., Omirov, B.A., 2006. Naturally graded 2-filiform Leibniz Algebra and its applications, preprint, MA1-04-XI06] and now, we complete the classification of naturally graded quasi-filiform Leibniz algebras. For this purpose we use the software Mathematica (the program used is explained in the last section).