We prove that an irreducible quasifinite module over the central extension of the Lie algebra of N

We compute the low dimensional cohomologies H q(gcN,C), Hq(gcN,C) of the infinite rank general Lie conformal algebras gcN with trivial coefficients for q<3, N51 or q<2, N>2. We also prove that the cohomology of gcN with coeffi-cients in its natural module is trivial, i.e., H*(gcN,C[э]N)=0, and thus partially solve an open problem of Bakalov-Kac-Voronov

Abstract. For an (є; Ґ)-color-commutative associative algebra A with an identity element over a field F of characteristic not 2, and for a color-commutative color-derivation subalgebra D of A, denote by A[D] the associative subalgebra of End(A) generated by A (regarding as operators on A via multiplication) and D. It is proved that, as an associative algebra, A[D] is Ґ-graded simple if and only if A is Ґ-graded D-simple. Suppose A is Ґ-graded D-simple. Then, (a) A[D] is a free left A-module; (b) as a Lie color algebra, the subquotient [A[D];A[D]]=Z(A[D])\[A[D];A[D]] is simple (except one minor case), where Z(A[D]) is the color center of A[D]. The structure of this subquotient is explicitly described.

确定了特征0的代数闭域上与局部有限导子相关的中心单Poisson代数的结构。这些Poisson代数的Lie代数结构一般来说不是有限阶化的。

In this paper, we determine the isomorphism classes of contact simple Lie algebras constructed from locally-finite commuting derivations, introduced earlier by the second author. These algebras are in general not finitely graded.