Tubular algebras and affine Kac-Moody algebras

The purpose of this paper is to construct quotient algebras L(A) 1 ? /I(A) of complex degenerate composition Lie algebras L(A) 1 ? by some ideals, where L(A 1 ? is defined via Hall algebras of tubular algebras A, and to prove that the quotient algebras L(A) 1 ? /I(A) are isomorphic to the corresponding affine Kac-Moody algebras. Moreover, it is shown that the Lie algebra L re(A) 1 ? generated by A-modules with a real root coincides with the degenerate composition Lie algebra L(A) 1 ? generated by simple A-modules.

POLYNOMIAL REPRESENTATIONS OF THE AFFINE NAPPI-WITTEN LIE ALGEBRA H_4

In this paper, the representation theory for the arlene Lie algebra H4 associated to the Nappi-Witten Lie algebra H4 is studied. Polynomial representations of the affine Nappi-Witten Lie algebra H4 are given.

Pairing Problem of Generators in Non twisted Affine Lie Algebras

In this paper, we discuss the pairing problem of generators in four affine Lie algebra. That is, for any given imaginary root vector x∈g(A) , there exists y such that x and y generate a subalgebra containing g′(A).

Cluster algebra structure on the finite dimensional representations of affine quantum group U_q(_3)

In this paper, we prove one case of conjecture given by Hemandez and Leclerc. We give a cluster algebra structuure on the Grothendieck ring of a full subcategory of the finite dimensional representations of affine quantum group Uq（A3）. As a conclusion, for every exchange relation of cluster algebra, there exists an exact sequence of the full subcategory corresponding to it.

P-Twisted Affine Lie Algebras and Their Associated Vertex Algebras

For any finite-dimensional semisimple Lie algebra g, a Z＋-graded vertex algebra is construsted on the vacuum representation Vk（g[θ]of g[θ]）,which is a one-dimentionM central extension of 8-invariant subspace on the loop algebra Lg=g C（（t^1/p））.

Realization of Vertex Operators of 7-Twisted Affine Lie Algebra ■[θ]

In this paper, we construct a new algebra structure 7-twisted atone Lie algebra sl（3,C）[θ] and study its vertex operator representations.

Integral Basis of Affine Vertex Algebra <i>V_k</i>(sl₂) and Virasoro Vertex Algebra <i>V</i>_<i>vir</i>(2<i>k</i>,0)

In this paper, we consider an integral basis for affine vertex algebra Vk (sl2) when the level k is integral by a direct calculation, then use the similar way to analyze an integral basis for Virasoro vertex algebra Vvir (2k,0). Finally, we take the combination of affine algebras and Virasoro Lie algebras into consideration. By analogy with the construction of Lie algebras over Z using Chevalley bases, we utilize the Z-basis of Lav whose structure constants are integral to find an integral basis for the universal enveloping algebra of it.

Imaginary Whittaker Modules of the Twisted Affine Nappi-Witten Lie Algebra <img src="http://admin.scirp.org/Editer/attached/image/Edit_fc740d60-7009-4d6f-939a-ac2a113f1539.bmp"alt=""/>

The Nappi-Witten Lie algebra was first introduced by C. Nappi and E. Witten in the study of Wess-Zumino-Novikov-Witten (WZNW) models. They showed that the WZNW model (NW model) based on a central extension of the two-dimensional Euclidean group describes the homogeneous four-dimensional space-time corresponding to a gravitational plane wave. The associated Lie algebra is neither abelian nor semisimple. Recently K. Christodoulopoulou studied the irreducible Whittaker modules for finite- and infinite-dimensional Heisenberg algebras and for the Lie algebra obtained by adjoining a degree derivation to an infinite-dimensional Heisenberg algebra, and used these modules to construct a new class of modules for non-twisted affine algebras, which are called imaginary Whittaker modules. In this paper, imaginary Whittaker modules of the twisted affine Nappi-Witten Lie algebra are constructed based on Whittaker modules of Heisenberg algebras. It is proved that the imaginary Whittaker module with the center acting as a non-zero scalar is irreducible.

Kac-Moody-Virasoro symmetry algebra of a (2+1)-dimensional bilinear system

Based on some known facts of integrable models, this paper proposes a new （2＋1）-dimensional bilinear model equation. By virtue of the formal series symmetry approach, the new model is proved to be integrable because of the existence of the higher order symmetries. The Lie point symmetries of the model constitute an infinite dimensional Kac- Moody Virasoro symmetry algebra. Making use of the infinite Lie point symmetries, the possible symmetry reductions of the model are also studied

REPRESENTATIONS OF AFFINE HECKEALGE BRAS OF TYPE G_2

Let k be a field and q a nonzero element in k such that the square roots of q are in k. We use Hq to denote an affne Hecke algebra over k of type G2 with parameter q. The purpose of this paper is to study representations of Hq by using based rings of two-sided cells of an affne Weyl group W of type G2. We shall give the classification of irreducible representations of Hq. We also remark that a calculation in [11] actually shows that Theorem 2 in [1] needs a modification, a fact is known to Grojnowski and Tanisaki long time ago. In this paper we also show an interesting relation between Hq and an Hecke algebra corresponding to a certain Coxeter group. Apparently the idea in this paper works for all affne Weyl groups, but that is the theme of another paper.

Construction of Simple Modules over the Quantum Affine Space

The coordinate ring O_(q)(K^(n))of quantum affine space is the K-algebra presented by generators x_(1),...,x_(n) and relations x_(i)x_(j)=q_(ij)a_(j)a_(i) for all i,j.We construct simple O_(q)(K^(n))-modules in a more general setting where the parameters qij lie in a torsion subgroup of K^(*)and show that analogous results hold as in the uniparameter case.

法式tubular代数与仿射Kac-Moody代数

彭联刚-肖杰等利用有限维遗传代数A的根范畴的Ringel-Hall李代数实现所有可对称化Kac-Moody代数,其中Ringel-Hall李代数的李乘不完全由Hall积提供.本文通过新方法实现仿射Kac-Moody代数,李代数L(A)1C/I的李乘完全由Hall积给出.对任意D4(1),E6(1),E7(1)或E8(1)型扩张Dynkin图Δ,在型为Δ的法式tubular代数A的退化合成李代数L(A)1C上构造它关于一个具体李理想I的商代数L(A)1C/I,证明商代数L(A)1C/I同构于对应的Δ型仿射Kac-Moody代数.这将有助于利用法式tubular代数的模范畴研究仿射Kac-Moody代数.

NON-COMMUTATIVE POISSON ALGEBRA STRUCTURES ON LIE ALGEBRA sl_n(_q) WITH NULLITY M

Non-commutative Poisson algebras are the algebras having both an associa- tive algebra structure and a Lie algebra structure together with the Leibniz law. In this paper, the non-commutative poisson algebra structures on the Lie algebras sln（Cq^-） are determined.

Extensions of quantum enveloping algebras

In this paper, we define a class of extended quantum enveloping algebras Uq （f（K, J）） and some new Hopf algebras, which are certain extensions of quantum enveloping algebras by a Hopf algebra H. This construction generalizes some well-known extensions of quantum enveloping algebras by a Hopf algebra and provides a large of new noncommutative and nonco- commutative Hopf algebras.

k=3扭仿型Kac-Moody代数的表示及生成关系

本文应用具有阶为 3的图自同构 μ诱导的有限维单李代数g的自同构μ的特征子空间阶化g=g0 g1 g2 ,论证了 :(i) μ诱导的g的自同构 μ的不动点集g0 是G2 -型的单李代数以及g0 的生成元和定义关系 .(ii)g i(i=1 ,2 )构成g0 模的作用乘法和生成关系和g1 、g2 作为g0 -模的结构 .(iii)对g进行齐次仿射、中心、导子扩张得到扭仿型Kac-Moody代数g(A( 3) ) ;给出了g(A( 3) )

P-twisted affine Lie algebra and its realizations by twisted vertex operators

In this paper, we define a P-twisted affine Lie algebra, and construct its realizations by twisted vertex operators.

一种AES S盒改进方案及其硬件设计

为提高高级加密标准(advanced encryption standard, AES)算法的安全性,提出了一种新的S盒生成方案。在分析了现有S盒存在的问题后,基于S盒的构造原理和密码学性质,通过选择新的不可约多项式和仿射变换对,同时调整仿射变换与乘法逆的运算顺序,构造出一种新的S盒;对生成的新S盒与AES的S盒以及其他改进S盒在代数式项数、严格雪崩标准距离等方面进行了比较,结果显示,新S盒具有更好的代数性质,能够有效抵御代数攻击;还对新S盒进行了硬件设计并优化,DC综合结果显示新S盒复域优化实现消耗的资源比传统复域实现少12%,比查找表法实现少41%。新S盒在安全性方面优于现有S盒,将其应用于AES软件设计和硬件设计,并通过仿真测试验证了其正确性。

Affine bracket algebra theory and algorithms and their applications in mechanical theorem proving

This paper discusses two problems:one is some important theories and algorithms of affine bracket algebra;the other is about their applications in mechanical theorem proving.First we give some efficient algorithms including the boundary expanding algorithm which is a key feature in application.We analyze the characteristics of the boundary operator and this is the base for the implementation of the system.We also give some new theories or methods about the exact division,the representations and structure of affine geometry and so on.In practice,we implement the mechanical auto-proving system in Maple 10 based on the above algorithms and theories.Also we test about more than 100 examples and compare the results with the methods before.

Quantizations of the Extended Affine Lie Algebra Sl2（Cq）

In this paper, the extended affine Lie algebra sl2（Cq） is quantized from three different points of view, which produces three non-commutative and non-cocommutative Hopf algebra structures, and yields other three quantizations by an isomorphism of sl2 （Cq） correspondingly. Moreover, two of these quantizations can be restricted to the extended affine Lie algebra sl2（Cq）.

Some conjectures on modular representations of affine sl_2 and Virasoro algebra

We conjecture an explicit bound on the prime characteristic of a field, under which the Weyl modules of affine sl_2 and the minimal series modules of Virasoro algebra remain irreducible, and Goddard-Kent-Olive coset construction for affine sl_2 is valid.