SOME RESULTS OF MODULAR LIE SUPERALGEBRAS

In the present article, the authors give some properties on subinvariant subalgebras of modular Lie superalgebras and obtain the derivation tower theorem of modular Lie superalgebras, which is analogous to the automorphism tower theorem of finite groups. Moreover, they announce and prove some results of modular complete Lie superalgebras.     

Homogeneity for Surfaces in Four-Dimensional Vector Space Geometry

We classify all surfaces in R ⁴ which are homogeneous in the sense of equi-centroaffine differential geometry. There result 21 group classes, some of them depending on one or two real parameters. The classification is cleared up, i.e. each copy is equivalent to exactly one representative. This applies as well to the corresponding groups as to the orbits (and also to the parameter cases). In particular, we can characterize the Clifford tori in a purely affine manner and determine all homogeneous centroaffine spheres. This answers a former question on the existence of centroaffine spheres which are not contained in a hyperplane. The classification and, in particular, the uniqueness is based on geometric insight and is essentially not computer dependent. The leading ideas are of a general nature and may also be applied to homogeneity for higher-dimensional cases and for related geometries.     

李超代数的c-可补子代数(英文)

李超代数L的一个子代数B称为c-可补的,若存在L的一个理想B使得L=B+C和B∩C(?)B_L,此处B_L是包含在B且为L的理想中最大的一个,本文把c-可补子代数理论发展到李超代数,并利用它们得到了可解李超代数的一些刻画.同时也得到了E-李超代数的一些性质.     

Some Theorems on Leibniz Algebras

If U is a subnormal subalgebra of a finite-dimensional Leibniz algebra L and M is a finite-dimensional irreducible L-bimodule, then all U-bimodule composition factors of M are isomorphic. If U is a subnormal subalgebra of a finite-dimensional Leibniz algebra L, then the nilpotent residual of U is an ideal of L. Engel subalgebras of finite-dimensional Leibniz algebras are shown to have similar properties to those of Lie algebras. A subalgebra is shown to be a Cartan subalgebra if and only if it is minimal Engel, provided that the field has sufficiently many elements.     

On maximal injective subalgebras of tensor products of von Neumann algebras

Let Mi be a von Neumann algebra, and Bi be a maximal injective von Neumann subalgebra of Mi, i=1,2. If M₁ has separable predual and the center of B₁ is atomic, e.g., B₁ is a factor, then is a maximal injective von Neumann subalgebra of . This partly answers a question of Popa.     

有限BCK-代数子代数个数估计定理

设X是一个n阶BCK-代数,我们用N(i)来表示X中i阶子代数的个数,其中1≤i≤n.本文的目的是证明有限BCK-代数子代数个数估计定理. 定理 设X是n(≥1)阶BCK-代数,则,i=1,2,…,n. 关于BCK-代数的定义和基本性质可参阅文献[1]和[2].为了引用的方便,我们列出一个BCK-代数必须满足的五条公理: