Kac-Moody-Virasoro Symmetry Algebra of (2+1)-Dimensional Dispersive Long-Wave Equation with Arbitrary Order Invariant

By Lie symmetry method, the Lie point symmetries and its Kac-Moody-Virasoro (KMV) symmetry algebra of (2+1)-dimensional dispersive long-wave equation (DLWE) are obtained, and the finite transformation of DLWE is given by symmetry group direct method, which can recover Lie point symmetries. Then KMV symmetry algebra of DLWE with arbitrary order invariant is also obtained. On basis of this algebra the group invariant solutions and similarity reductions are also derived.

LIE SUPER-BIALGEBRA STRUCTURES ON GENERALIZED SUPER-VIRASORO ALGEBRAS

In this article, Lie super-bialgebra structures on generalized super-Virasoro algebras/： are considered. It is proved that all such Lie super-bialgebras are coboundary triangular Lie super-bialgebras if and only if Hi（ ） = 0.

A Classical Toda Family with a Common Virasoro Symmetry Algebra

By means of a simple ideal, which is firstly proposed for the continuous system, we present an arbitrary order classical Toda family invariant under common Virasoro-type symmetry algebra.

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

A NEW EXTENSION OF THE HIGH-ORDER VIRASORO ALGEBRA

This paper investigates the high order differential neighbourhoods of holomorphic mappings from S-1 x S-1 to a vector space and gives a new extension of the high-order Virasoro algebra.

N = 2 SCVA's FROM A GENERALIZED CALABI-YAU MANIFOLD AND MIRROR SYMMETRY

We construct an N = 2 superconformal vertex algebra（SCVA） from a generalized Calabi-Yau manifold and compute the BRST cohomology of its associated topological vertex algebras. We show that the BRST cohomology coincides with the generalized Dobeault cohomology. We show that the two topological vertex algebras constructed from the N = 2 SCVA by A and B twist respectively are mirror pairs.

Painlevé property, local and nonlocal symmetries, and symmetry reductions for a (2+1)-dimensional integrable KdV equation

The Painlevé property for a(2+1)-dimensional Korteweg–de Vries(KdV) extension, the combined KP3(Kadomtsev–Petviashvili) and KP4(cKP3-4), is proved by using Kruskal’s simplification. The truncated Painlevé expansion is used to find the Schwartz form, the Bäcklund/Levi transformations, and the residual nonlocal symmetry. The residual symmetry is localized to find its finite Bäcklund transformation. The local point symmetries of the model constitute a centerless Kac–Moody–Virasoro algebra. The local point symmetries are used to find the related group-invariant reductions including a new Lax integrable model with a fourth-order spectral problem. The finite transformation theorem or the Lie point symmetry group is obtained by using a direct method.

Structures of Not-finitely Graded Lie Algebras Related to Generalized Heisenberg–Virasoro Algebras

In this paper, we study the structure theory of a class of not-finitely graded Lie alge- bras related to generalized Heisenberg-Virasoro algebras. In particular, the derivation algebras, the automorphism groups and the second cohomology groups of these Lie algebras are determined.

Lie Bialgebras of Generalized Loop Virasoro Algebras

The first cohomology group of generalized loop Virasoro algebras with coefficients in the tensor product of its adjoint module is shown to be trivial. The result is used to prove that Lie bialgebra structures on generalized loop Virasoro algebras are coboundary triangular. The authors generalize the results to generalized map Virasoro algebras.

Symmetries and Algebras of a (2+1)-Dimensional MKdV-Type System

In this paper, a （2＋1）-dimensional MKdV-type system is considered. By applying the formal series symmetry approach, a set of infinitely many generalized symmetries is obtained. These symmetries constitute a closed infinite-dimensional Lie algebra which is a generalization of w∞ type algebra. Thus the complete integrability of this system is confirmed.

Generalized symmetries of an N=1 supersymmetric Boiti–Leon–Manna–Pempinelli system

The formal series symmetry approach （FSSA）, a quite powerful and straightforward method to establish infinitely many generalized symmetries of classical integrable systems, has been successfully extended in the supersymmetric framework to explore series of infinitely many generalized symmetries for supersymmetric systems. Taking the N = 1 supersymmetric Boiti-Leon-Manna-Pempinelli system as a concrete example, it is shown that the application of the extended FSSA to this supersymmetric system leads to a set of infinitely f（t）. Some interesting special cases of symmetry algebras are commutativity of higher order generalized symmetries. many generalized symmetries with an arbitrary function presented, including a limit case f（t） = 1 related to the

一类与Virasoro代数密切相关的W-型李代数的最高权表示

W-代数是用来描述理论物理中的共形场论的一类代数,它的结构理论和表示理论我们都知之甚少。本文研究一类与Virasoro代数密切相关的W型-李代数的最高权表示理论。

Lie Bialgebras of Generalized Virasoro-like Type

In this paper, Lie bialgebra structures on generalized Virasoro-like algebras are studied. It is proved that all such Lie bialgebras are triangular coboundary.

李代数W(2,2)上的Poisson结构

Poisson代数是指同时具有代数结构和李代数结构的一类代数,其乘法和李代数乘法满足Leibniz法则.李代数W(2,2)在权为2的向量生成的顶点算子代数的分类中起着重要作用.文章主要确定了李代数W(2,2)上的Poisson结构,并得到了Virasoro代数上一般的非结合的Poisson结构,改进了文[姚裕丰.Witt代数和Virasoro代数上的Poisson代数结构[J].数学年刊,2013,34A(1):111-128]的部分结果.

无中心扩张的广义超Virasoro代数的Leibniz二上循环

研究了无中心扩张的广义超Virasoro代数S的Leibniz二上循环,从而确定了它的Leibniz二上同调群.

Lin-Reissner-Tsien方程的一般对称及W_∞代数

对（２＋１）维的Ｌｉｎ－Ｒｅｉｓｓｎｅｒ－Ｔｓｉｅｎ方程，利用形式级数对称的方法，得到了包含任意时间函数的无穷多截断对称．这些对称构成的无限维李代数为广义Ｗ∞代数．

一类原始形变Schrdinger-Virasoro代数的双导子（英文）

对于给定的李代数L,如果一个双线性映射f:L×L→L对于每个变元都是导子,则称f是L的双导子。原始形变Schrdinger-Virasoro代数W^g(0,1)是Witt代数和它的一类张量密度模的半直积,在没有反对称条件下确定了W^g(0,1)的双导子,发现这类李代数具有对称非内的双导子,丰富了李代数的结构理论。

广义Virasoro代数到中间序列模的导子

设L是以{Lg,c g∈G}为基的广义Virasoro李代数,其中G是复数域C上的具有有限生成元的非零加法子群.本文研究L的中间序列模的导子,用W表示模,首先证明了L到模W的所有导子都由零次导子和内导子构成.通过计算零次导子,得出广义Virasoro李代数L到三类中间序列模Aa,b(G),Aa(G)和Ba(G)的导子及1-上同调群.

Super W_(1+∞) n-Algebra in the Supersymmetric Landau Problem

We analyze the super n-bracket built from associative operator products.Since the super n-bracket with n even satisfies the so-called generalized super Jacobi identity,we deal with the n odd case and give the generalized super Bremner identity.For the infinite conserved operators in the supersymmetric Landau problem,we derive the super W_(1+∞) n-algebra which satisfies the generalized super Jacobi and Bremner identities for the n even and odd cases,respectively.Moreover the super W_(1+∞) sub-2n-algebra is also given.

Kac-Moody-Virasoro可积系统

通过研究Kadomtsev-Petviashvilli(KP)方程对称,得到相应的无穷维李代数——Kac-Moody-Virasoro(KMV)代数,并运用KMV代数的生成元和其中一个子代数——Virasoro代数的延拓结构,推导出熟知的Kadomtsev-Petviashvilli(KP)方程,并以此为基础得到更多高阶(2+1)维和(3+1)维的可积模型,并且这些模型都具有KMV代数性质.