李代数

All real simple Malcev algebra,are classified according to whether or not they have a compatible complex structure and simultaneously we give all the invariant bilinear forms by the killing form of the real simple Malcev algebra or the killing form of it s complexification .

研究实单Malcev代数上的不变双线性型，仿照李代数的情形给出实Malcev代数上的容许复结构、实Malcev代数的复化以及Malcev代数上的不变双线性型等概念，并通过对实单Malcev代数上容许复结构的讨论，将实单Malcev代数上的不变双线性型分为两种情形。

Let g be a finite dimensional complex semisimple Lie algebra with the Cartan subalgebra h.

令g为一个有限维的复半单李代数，而h是g的Cartan子李代数。

Associated it we define a root system. In a suitable condition we define a Lie algebra to realize this root system, namely, using an Euler cocycle given by intersection matrix, we define an infinitely dimensional vector space with the Lie operation becomes a Lie algebra.

在适当的条件之下，我们给出了该根系的一个李代数实现，即利用该相交矩阵确定的一个欧拉cocycle和根系，我们定义了一个无限维向量空间和李运算，并且证明了这个无限维向量空间在该李运算之下构成一个李代数。

Furthermore, we define a convolution multiplication between characteristic functions of constructible subsets by using push-forward functor from the category of algebraic varieties over C to the category of spaces of constructible functions. We construct geometric model for "intrinsic symmetry" of the octahedral axiom in a triangulated category. Using it, we deduce the multiplication satisfies the Jacobi identity of Lie algebra and then realize infinite dimensional Lie algebras.

进一步，我们使用复代数簇范畴到可构函数空间范畴的pushforward函子，给出了可构集上特征函数的卷积乘法，并构造了三角范畴八面体公理的内蕴对称性的几何模型，最终证明了对于不可分解支撑有界可构集的特征函数，乘法满足李代数定义的Jacobi恒等式，从而给出了无限维李代数的实现。

The latter is essentially derived from the geometric realization of Happels triangulated equivalence between stable module category of repetitive algebra and bounded derived category of finite dimensional algebra. In terms of this realization, we deduce that the Lie algebra realized by derived category of a finite dimensional algebra is isomorphic to the Lie algebra realized by stable module category of the corresponding repetitive algebra.

后者本质上是Happel关于重复代数的稳定模范畴和导出范畴的三角等价的一个几何实现及其应用，使用这种几何实现，我们可以证明在重复代数的稳定模范畴上定义的李代数同构于相应的导出范畴上实现的李代数。

In this paper, we mainly use complex semisimple algebras knowledge. First, we give the structure formula of C. Second, we show that any n x n symmetric matrix A is congruent under the symplectic group to the direct sum of a identity matrix and a tridiagonal matrix.

记正交代数和辛代数的交集构成的李代数为L，本文主要是运用复半单李代数的知识，首先给出了L的结构公式，然后给出了任一n×n对称矩阵A辛合同于一个单位矩阵和一个三对角矩阵的直和。

Based on the Lie algebra that describes the symmetries, it is proved in this dissertation that a sufficiently large class of control Hamiltonians can be provided by the universal enveloping algebra of the Lie algebra, on which the quantum mechanical control systems can be modelled.

基于描述量子力学系统对称性的李代数结构，本文证明该李代数的泛包络代数提供了足够大的一类控制哈密顿量，因而可以在其上建立量子力学控制系统的模型。

For the simplest interactive system of two particles with spin 1/2,the operator of Lie algebra can only realize the transition among the triplets, however, in order to realize the transition between the triplets and the singlet, the operators of Yangian must be involved, that is ,Yangian goes beyond Lie algebra in Quantum Mechanics.

对于最简单的两个-1/2的耦合系统，李代数生成元只能实现其自旋三重态之间的跃迁，而要实现三重态和单态之间的跃迁，必须由Yangian代数中的J 算子所引起，即 J 成为量子力学中超越李代数生成元的算子。

This result is a generalization of the Chevalley basis in case a simply-laced complex simple Lie algebra. Meanwhile, it generalizes also the corresponding Chevalley forms in case affine Lie algebras and 2- extended affine Lie algebras.

该结果是simply-laced复半单李代数情形下Chevalley基的推广，同时也是仿射李代数和2-扩大仿射李代数的相应Chevalley结构形式的推广。

U(4) algebra is very suitable to describe triatomic molecules, for their Fermi interaction can be described by using nondiagonal matrix elements of Majorana operator.

在研究多原子分子的李代数方法中，尤以U(4)代数适合描述三原子分子，这不仅仅是因为U(4)代数完全描述的是三维情形，物理图象更加清晰直观，而且，U(4)代数的Fermi相互作用可以由Majorana算子的非对角元素给出，不需要再引进另外一个代数。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。