实分片代数曲线的某些研究

分片代数曲线作为二元样条函数的零点集合是经典代数曲线的推广. 利用代数的基本知识, 本文对实分片代数曲线的基本性质进行了初步讨论, 并且将实分片代数曲线与相应的二元样条分类进行讨论. 最后, 对实分片代数曲线上的孤立点进行了研究.     

交换双重Ockham代数

研究一类双重Ockham代数 $(L;∧,V, f, k), 即赋予一对可交换一元运算f和k的有界分配格, 其中f和k是偶格同态. 刻画了其次直不可约代数, 并研究当(L,f)和(L;k)都是de Morgan代数的特殊情形. 利用Priestley对偶理论, 证明这类代数中 仅有9个非同构的次直不可约代数, 而且这些次直不可约代数都是单纯的.     

实Lie超代数的有限维实不可约表示

<正> 本文主要是将有限维实Lie超代数的有限维实不可约表示的分类归结为有限维复Lie超代数的有限维复不可约表示的分类问题(为了简单,以下将“有限维”字样统统略去).由于复的可解与单纯Lie超代数的不可约表示是已知的,从而复的可解与单纯     

G_(2)-型导出Hall代数的PBW基北大核心CSCD

在Dynkin型Ringel-Hall代数中,不可分解模同构类之间的所有拟交换关系的集合S构成理想Id(S)的一个极小Grobner-Shirshov基,并且对于S的所有不可约元素构成Ringel-Hall代数的一个PBW基.本文把此结果推广到G_(2)-型导出Hall代数上.首先用Auslander-Reiten箭图计算不可分解模同构类之间的所有拟交换关系,然后证明这些拟交换关系之间的所有合成都是平凡的,最后给出G_(2)-型导出Hall代数的一个PBW基.     

Lie超代数及二次Lie超代数的分解惟一性

一个带有非退化超对称不变双线性型的Lie超代数称为二次Lie超代数. 考虑Lie超代数的分解, 得到在同构意义下一个Lie超代数分解为不可分解阶化理想直和的方式惟一及在保距同构意义下一个二次Lie超代数分解为不可约非退化阶化理想直和的方式惟一.     

分片代数曲线Bezout数的估计

分片代数曲线定义为二元样条函数的零点集合.首先证明了关于三角剖分的一个猜想. 随后,指出了分片线性代数曲线与四色猜想之间的内在联系.通过经典的Morgan-Scott剖分,指出分片代数曲线的ezout数的不稳定性.利用组合优化方法,得到任意阶光滑分片代数曲线的Bezout数的上界.这个上界不仅适用于三角剖分,而且对任意网线为直线段的剖分均成立.     

B_(m,n)(Ω)算子的换位代数及其K_0群

该文计算了两个指标的Cowen-Douglas算子的换位代数及换位代数的Jacobson根;证明了某一类强不可约的两个指标的Cowen-Douglas算子的换位代数具有本质可交换性,并证明了其换位代数的K_0群同构于整数群Z.     

Special代数S(3,1)的不可约模

该文通过确定生成既约包络代数的极小左理想的极大权向量来确定不可约模,给出了特征p=2上的Special代数S(3,1)的特征标x的高度≤0的不可约模同构类的代表元以及它们的维数.     

半导出Hall代数的Grobner-Shirshov基

在Dynkin型Ringel-Hall代数中,不可分解表示同构类之间的所有拟交换关系之集构成由这些关系生成的理想的一个极小Grobner-Shirshov基,并且相应的不可约元素构成此Ringel-Hall代数的一组PBW基.本文的目的是将把此结果推广到Dynkin箭图的半导出Hall代数上去.为此,首先通过计算所有合成来证明不可分解表示同构类之间的所有拟交换关系之集是一个极小Grobner-Shirshov基.然后,作为一个应用,通过取所有不可约元素构造一组PBW基.     

幂等扩张的有界分配格

考察了扩张的有界分配格类eD即带有自同态k的有界分配格,研究了具有幂等性的eD-代数的表示、同余关系以及次直不可约性,证明了这样的代数类有5个互不同构的次直不可约的幂等扩张的有界分配格。     

Nöther-type theorem of piecewise algebraic curves on triangulation

The piecewise algebraic curve is a kind generalization of the classical algebraic curve. Nöther-type theorem of piecewise algebraic curves on the cross-cut partition is very important to construct the Lagrange interpolation sets for a bivariate spline space. In this paper, using the properties of bivariate splines, the Nöther-type theorem of piecewise algebraic curves on the arbitrary triangulation is presented.     

N(o)ther-type theorem of piecewise algebraic curves on triangulation

The piecewise algebraic curve is a kind generalization of the classical algebraic curve.N(o)ther-type theorem of piecewise algebraic curves on the cross-cut partition is very important to construct the Lagrange interpolation sets for a bivariate spline space. In this paper, using the properties of bivariate splines, the N(o)ther-type theorem of piecewise algebraic curves on the arbitrary triangulation is presented.     

Nöther-type theorem of piecewise algebraic curves on quasi-cross-cut partition

Nöther’s theorem of algebraic curves plays an important role in classical algebraic geometry. As the zero set of a bivariate spline, the piecewise algebraic curve is a generalization of the classical algebraic curve. Nöther-type theorem of piecewise algebraic curves is very important to construct the Lagrange interpolation sets for bivariate spline spaces. In this paper, using the characteristics of quasi-cross-cut partition, properties of bivariate splines and results in algebraic geometry, the Nöther-type theorem of piecewise algebraic curves on the quasi-cross-cut is presented.     

The Nother and Riemann-Roch type theorems for piecewise algebraic curve

A piecewise algebraic curve is a curve determined by the zero set of a bivariate spline function. In this paper, the Nother type theorems for Cμpiecewise algebraic curves are obtained. The theory of the linear series of sets of places on the piecewise algebraic curve is also established. In this theory, singular cycles are put into the linear series, and a complete series of the piecewise algebraic curves consists of all effective ordinary cycles in an equivalence class and all effective singular cycles which are equivalent specifically to any effective ordinary cycle in the equivalence class. This theory is a generalization of that of linear series of the algebraic curve. With this theory and the fundamental theory of multivariate splines on smoothing cofactors and global conformality conditions, and the results on the general expression of multivariate splines, we get a formula on the index, the order and the dimension of a complete series of the irreducible Cμpiecewise algebraic curves and the degree, the genus and the smoothness of the curves, hence the Riemann-Roch type theorem of the Cμpiecewise algebraic curve is established.     

Geometric control of hybrid systems

In this paper, we present a geometric approach for computing controlled invariant sets for hybrid control systems. While the problem is well studied in the ellipsoidal case, this family is quite conservative for constrained or switched linear systems. We reformulate the invariance of a set as an inequality for its support function that is valid for any convex set. This produces novel algebraic conditions for the invariance of sets with polynomial or piecewise quadratic support functions.     

Isomorphism is equality

The setting of this work is dependent type theory extended with the univalence axiom. We prove that, for a large class of algebraic structures, isomorphic instances of a structure are equal—in fact, isomorphism is in bijective correspondence with equality. The class of structures includes monoids whose underlying types are “sets”, and also posets where the underlying types are sets and the ordering relations are pointwise “propositional”. For monoids on sets equality coincides with the usual notion of isomorphism from universal algebra, and for posets of the kind mentioned above equality coincides with order isomorphism.     

格的模糊软理想

将模糊软集与格的模糊理想概念相结合,引入了格的模糊软理想的概念,给出了它们的若干代数性质.定义了格的模糊软同态(同构)概念,证明了格的一个模糊软理想在模糊软同构(同态)下的像(原像)仍为模糊软理想的结论.     

The Nöther and Riemann-Roch type theorems for piecewise algebraic curve

A piecewise algebraic curve is a curve determined by the zero set of a bivariate spline function. In this paper, the Nöther type theorems for C ^µ piecewise algebraic curves are obtained. The theory of the linear series of sets of places on the piecewise algebraic curve is also established. In this theory, singular cycles are put into the linear series, and a complete series of the piecewise algebraic curves consists of all effective ordinary cycles in an equivalence class and all effective singular cycles which are equivalent specifically to any effective ordinary cycle in the equivalence class. This theory is a generalization of that of linear series of the algebraic curve. With this theory and the fundamental theory of multivariate splines on smoothing cofactors and global conformality conditions, and the results on the general expression of multivariate splines, we get a formula on the index, the order and the dimension of a complete series of the irreducible C ^µ piecewise algebraic curves and the degree, the genus and the smoothness of the curves, hence the Riemann-Roch type theorem of the C ^µ piecewise algebraic curve is established.     

De rham homology for networks of manifolds

This paper describes in terms of differential forms the real homology of a certain class of spaces, which we call networks. Networks include, besides smooth manifolds, singular sets of toral actions, classifying spaces of Lie groups, etc. A generalized Thom isomorphism theorem is also proved in this context.     

AF代数中子代数间等距代数同构的扩张

本文证明了具有二次交换子性质的ＡＦ代数中的子代数间的等距代数同构可以扩张成其包络Ｃ＊代数的＊同构．由此肯定地回答了［４］中２．１２提出的问题．