关于项链李代数的结构

Le Bruyn和V．Ginzbrug最近引入了项链李代数。它是定义在箭图上的一种无限堆李代数，在非交换几何研究中起了重要作用。本研究项链李代数结构，证明了当箭图中有长度大于1的循环时，其项链李代数不是幂零李代数，我们还给出了没有圈的箭图上项链李代数的分解。     

项链李代数的结构

研究项链李代数的结构,定义了箭图Q的重箭图Q循环上的映射σ,证明了这是一个李运算.引入左右指标数组概念,利用它们把项链李代数N_Q的基分成了5类,并构造了项链李代数的一些有趣的子代数.     

由特殊箭图诱导的项链李子代数

无限维项链李代数是新的一类无限维李代数,本文重点讨论了由特殊箭图诱导的项链李子代数,并证明了其中一些李子代数是半单李代数.     

一类新的对称自对偶李代数

本文刻划了一类幂零根基为二步幂零李代数的新的非可解对称自对偶李代数.当其Levi因子同构于sl(2,C)时,用半单李代数的表示理论具体构造了它们.最后,给出了2中对称自对偶李代数是CS李代数的一个判别准则.     

具有一维、二维 Jacobson根的可解李代数的基结构条件及其分类

<正> 特征0的代数闭域上有限维可解李代数的分类问题,是至今未获解决的难题之一.在这个领域中最重要的结果是 Malcev 的,他把可解李代数的结构与分类归结为对幂零李代数的研究.但是关于幂零李代数的结构及分类,目前进展不大,较好的结果是 MichaelA.Gauger 的[5]中对亚交换李代数所作的分类.此外,[6]、[7]曾分别对六维以下的幂零李代数与可解李代数进行了分类.总的说来,涉及这类李代数的分类问题的文章,数量     

Hom-李超代数的结构

类比于单李超代数的结构性质,证明了单Hom-李超代数没有任何非平凡的左(右)理想、理想.通过给出保积Hom-李超代数的若干性质,建立了保积Hom-李超代数与李超代数之间的关系.特别地,证明了正则Hom-李超代数是可解(幂零)的充要条件是其容许李超代数是可解(幂零)的,并给出了正则Hom-李超代数是单的必要条件为其容许李超代数是单的.     

一类新的对称自对偶李代数

本文刻划了一类幂零根基为二步幂零李代数的新的非可解对称自对偶李代数．当其Ｌｅｖｉ因子同构于ｓｌ（２，Ｃ）时，用半单李代数的表示理论具体构造了它们．最后，给出了■２中对称自对偶李代数是ＣＳ李代数的一个判别准则。     

最简线状n-李代数

定义了一类特殊的幂零n-李代数,即最简线状n-李代数,它是最简线状李代数的推广.确定了m维最简线状n-李代数A的导子代数Der(A)和自同构群Aut(A),定义了n-李代数的全形h(A)=Der(A)( ) A,并证明了当A的基域F的特征P为零或P＞m-n时,Der(A)是不可解的完备李代数,而h(A)的一个子代数是可解的完备李代数,当F的特征为零时,Aut(A)是无中心的不可解群.     

由六个顶点的箭图诱导的项链李子代数

无限维项链李代数是新的一类无限维李代数,本文重点讨论了由六个顶点的箭图诱导的项链李子代数,研究了这类李子代数的子代数,同构和同态,这类李代数是Virasoro-like李代数的推广,并讨论了它的其他一些性质.     

关于可裂李代数的Nil—根和幂零根及低维分类

对可裂李代数的Nil-根和幂零根进行研究,从结构和表示两方面给出了空们相等的两个条件。给出了维数小于等于7的全部非可解可裂李代数的分类。     

Nearby Lagrangians with vanishing Maslov class are homotopy equivalent

We prove that the inclusion of every closed exact Lagrangian with vanishing Maslov class in a cotangent bundle is a homotopy equivalence. We start by adapting an idea of Fukaya-Seidel-Smith to prove that such a Lagrangian is equivalent to the zero section in the Fukaya category with integral coefficients. We then study an extension of the Fukaya category in which Lagrangians equipped with local systems of arbitrary dimension are admitted as objects, and prove that this extension is generated, in the appropriate sense, by local systems over a cotangent fibre. Whenever the cotangent bundle is simply connected, this generation statement is used to prove that every closed exact Lagrangian of vanishing Maslov index is simply connected. Finally, we borrow ideas from coarse geometry to develop a Fukaya category associated to the universal cover, allowing us to prove the result in the general case.     

On the structure of perfect sets in various topologies associated with tree forcings

We prove that the Ellentuck, Hechler and dual Ellentuck topologies are perfect isomorphic to one another. This shows that the structure of perfect sets in all these spaces is the same. We prove this by finding homeomorphic embeddings of one space into a perfect subset of another. We prove also that the space corresponding to eventually different forcing cannot contain a perfect subset homeomorphic to any of the spaces above.     

Generating the surface mapping class group by two elements

Wajnryb proved in 1996 that the mapping class group of an orientable surface is generated by two elements. We prove that one of these generators can be taken as a Dehn twist. We also prove that the extended mapping class group is generated by two elements, again one of which is a Dehn twist. Another result we prove is that the mapping class groups are also generated by two elements of finite order.

     

On a generalized proximal point method for solving equilibrium problems in Banach spaces

We introduce a regularized equilibrium problem in Banach spaces, involving generalized Bregman functions. For this regularized problem, we establish the existence and uniqueness of solutions. These regularizations yield a proximal-like method for solving equilibrium problems in Banach spaces. We prove that the proximal sequence is an asymptotically solving sequence when the dual space is uniformly convex. Moreover, we prove that all weak accumulation points are solutions if the equilibrium function is lower semicontinuous in its first variable. We prove, under additional assumptions, that the proximal sequence converges weakly to a solution.     

Dense computability structures

We examine computability structures on a metric space and the relationships between maximal, separable and dense computability structures. We prove that in a computable metric space which has the effective covering property and compact closed balls for a given computable sequence which is a metric basis there exists a unique maximal computability structure which contains that sequence. Furthermore, we prove that each maximal computability structure on a convex subspace of Euclidean space is dense. We also examine subspaces of Euclidean space on which each dense maximal computability structure is separable and prove that spheres, boundaries of simplices and conics are such spaces.     

On model-theoretical properties in the sense of Peretyat’kin,o-minimality,and mutually interpretable theories

We prove that o-minimality is not a model-theoretical property in the sense of Peretyat’kin. We also prove that existence of a prime models need not be preserved under a passage between mutually interpretable theories.     

Quasi-co-Frobenius Coalgebras. II

Abstract

We prove new characterizations of Quasi-co-Frobenius (QcF) coalgebras and co-Frobenius coalgebras. Among them, we prove that a coalgebra is QcF if and only if C generates every left and every right C-comodule. We also prove that every QcF coalgebra is Morita-Takeuchi equivalent to a co-Frobenius coalgebra.     

INVARIANCE AND STABILITY OF THE PROFILE EQUATIONS OF GEOMETRIC OPTICS

The profile equations of geometric optics are described in a form invariant under the natural transformations of first order systems of partial differential equations. This allows us to prove that various strategies for computing profile equations are equivalent. We prove that if L generates an evolution on L 2 the same is true of the profile equations. We prove that the characteristic polynomial of the profile equations is the localization of the characteristic polynomial of the background operator at (y, dφ(y)) where φ is the background phase. We prove that the propagation cones of the profile equations are subsets of the propagation cones of the background operator.     

On the theoretical properties of swap multimoves

We prove that any permutation can be transformed into any other permutation by the execution of at most two swap multimoves (i.e. the diameter of the neighborhood graph is 2). We also prove that it is NP-hard to search over such a neighborhood.     

Priestley Spaces, Quasi-hyperalgebraic Lattices and Smyth Powerdomains

We introduce the concept of quasi-hyperalgebraic lattice and prove that a complete lattice is a Priestley space with respect to the interval topology if and only if it is quasi-hyperalgebraic. Some characterizations of quasi-hyperalgebraic lattices are presented. We also prove that the Smyth powerdomain of a quasi-hyperalgebraic lattice is hyperalgebraic.