Jordan基的结构

用构造性方法证明了以同一个特征向量为终端向量的Jordan链从始端向量到终端向量可以有不同的最大长度,并给出了Jordan基中Jordan链的某些性质,进一步完善了Jordan标准形过渡矩阵求法的补充条件.     

Jordan基的结构

用构造性方法证明了以同一个特征向量为终端向量的Jordan链从始端向量到终端向量可以有不同的最大长度,并给出了Jordan基中Jordan链的某些性质,进一步完善了Jordan标准形过渡矩阵求法的补充条件.     

复向量空间的分解与复线性变换的Jordan标准形*

本文引入表征复线性变换结构的新对象。这些新对象给出复向量空间关于复线性变换分解的新结果且给出构造Jordan标准形的所有Jordan基。因而,它们能够直接导致着名的Jordan定理及空间的第三分解定理,且能给出对Jordan形精致微妙结构的新的深刻洞察。后者表明,复线性变换的Jordan标准形是一种在双重任意选择下具有不变性的结构。     

Jordan标准形定理的初等变换证明

本对Jordan标准形定理给出了一种使用初等变换的证明，直观意义明显、易于理解，可用于线性代数教学。     

Jordan标准形定理的初等变换证明

本文对 Jordan标准形定理给出了一种使用初等变换的证明 ,直观意义明显、易于理解 ,可用于线性代数教学 .     

线性代数中的Fiting定理及其应用

本文直接根据线性变换给出了Ｆｉｔｉｎｇ定理的一个证明，并用它建立了定理１，从而得到一种在相似变换下化简的准对角矩阵，然后在定理２中讨论该准对角矩阵与Ｊｒｏｄａｎ标准形的关系及其应用．     

Jordan标准形过渡矩阵的一种算法

给出Jordan定理的一个证明,以及Jordan标准形过渡矩阵的一种算法:求出一线性方程组解空间的基,解空间即是矩阵关于某特征值的特征向量、广义特征向量所张成的子空间,在该解空间中依次找出各特征向量及所对应的广义特征向量.一个8阶矩阵的计算实例表明算法简便实用.     

构造正交向量的一个新方法及其应用

利用向量的数量积及行列式的按行(列)展开定理,构造出一个n维向量,它能够与n-1个n维向量都正交.这种构造正交向量的方法简单明了.应用这种方法很容易证明克莱姆法则.对这种构造方法加以改进,给出了线性空间Rn中扩充一组正交基的新方法.     

Hamilton-Cayley定理的证明

Hamilton-Cayley定理是《高等代数》中最基本与深刻的定理之一,也是其中课程中知识与方法的集散点之一.它的证明方式涉及几乎所有《高等代数》的知识,引伸出的涵义也多种多样.文中回顾了Cayley,Hamilton与Frobenius的三种原始证明,并梳理了目前《高等代数》教材中的数种证明,最后讨论不同证明之间的联系.     

循环子空间的若干应用

从线性变换诱导的循环子空间出发,推导出了Cayley-Hamilton定理,并给出了循环子空间在相似标准形理论以及一些相关问题中的若干应用.     

A short proof of the jordan decomposition theorem

We present a short proof of the Jordan Decomposition Theorem     

Independence of vectors in codes over rings

We study codes over Frobenius rings. We describe Frobenius rings via an isomorphism to the product of local Frobenius rings and use this decomposition to describe an analog of linear independence. Special attention is given to codes over principal ideal rings and a basis for codes over principal ideal rings is defined. We prove that a basis exists for any code over a principal ideal ring and that any two basis have the same number of vectors. Hongwei Liu is supported by the National Natural Science Foundation of China (10571067).     

The Dimensions of Certain Symmetry Classes of Tensors

Commutative Rings, by Irving Kaplansky. Revised edition. The University of Chicago Press, Chicago and London, 1974, ix+182pp.($9.75)

Symmetry Groups and their Applications, by Willard Miller, Jr. Academic Press.     

Approximation for Frobenius algebraic equations in Witt vectors

We prove an approximation property for solutions to difference equations in excellent discrete valuation rings satisfying an appropriate Hensel's lemma, analog to a theorem of Greenberg [M. Greenberg, Rational points in henselian discrete valuation rings, Publ. Math. Inst. Hautes Études Sci. 31 (1966) 59–64]. In the case of Witt vectors we obtain a Nullstellensatz for Frobenius algebraic equations.     

Équations aux différences dans les vecteurs de Witt

We prove an approximation property for Frobenius difference equations in the Witt vectors, analog to a theorem of Greenberg [Publ. Math. IHES 31 (1966) 59–64]. To cite this article: L. Bélair, C. R. Acad. Sci. Paris, Ser. I 340 (2005).     

Plethystic algebra

The notion of a Z-algebra has a non-linear analogue, whose purpose it is to control operations on commutative rings rather than linear operations on abelian groups. These plethories can also be considered non-linear generalizations of cocommutative bialgebras. We establish a number of category-theoretic facts about plethories and their actions, including a Tannaka-Krein-style reconstruction theorem. We show that the classical ring of Witt vectors, with all its concomitant structure, can be understood in a formula-free way in terms of a plethystic version of an affine blow-up applied to the plethory generated by the Frobenius map. We also discuss the linear and infinitesimal structure of plethories and explain how this gives Bloch's Frobenius operator on the de Rham-Witt complex.     

On the eigenvalues of specially low-rank perturbed matrices

We study the eigenvalues of a matrix A perturbed by a few special low-rank matrices. The perturbation is constructed from certain basis vectors of an invariant subspace of A, such as eigenvectors, Jordan vectors, or Schur vectors. We show that most of the eigenvalues of the low-rank perturbed matrix stayed unchanged from the eigenvalues of A; the perturbation can only change the eigenvalues of A that are related to the invariant subspace. Existing results mostly studied using eigenvectors with full column rank for perturbations, we generalize the results to more general settings. Applications of our results to a few interesting problems including the Google’s second eigenvalue problem are presented.     

Non-self-adjoint sturm-liouville operators with matrix potentials

We obtain asymptotic formulas for non-self-adjoint operators generated by the Sturm-Liouville system and quasiperiodic boundary conditions. Using these asymptotic formulas, we obtain conditions on the potential for which the system of root vectors of the operator under consideration forms a Riesz basis.