Permanental Polytopes of Doubly Stochastic Matrices

A subpolytope Γ of the polytope Ω_n of all n×n nonnegative doubly stochastic matrices is said to be a permanental polytope if the permanent function is constant on Γ. Geometrical properties of permanental polytopes are investigated. No matrix of the form 1⊕A where A is in Ω₂ is contained in any permanental polytope of Ω₃ with positive dimension. There is no 3-dimensional permanental polytope of Ω₃, and there is essentially a unique maximal 2-dimensional permanental polytope of Ω₃ (a square of side $\text{1}\text{3}$). Permanental polytopes of dimension $\text{(n}{}^2\text{?3n+4)}\text{2}$ are exhibited for each n?4.     

Minimum Permanents of Tridiagonal Doubly Stochastic Matrices

We determine the minimum permanents and minimizing matrices of the tridiagonal doubly stochastic matrices and of certain doubly stochastic matrices with prescribed zero entries.     

Minimum Permanents of Tridiagonal Doubly Stochastic Matrices

We determine the minimum permanents and minimizing matrices of the tridiagonal doubly stochastic matrices and of certain doubly stochastic matrices with prescribed zero entries.     

关于双随机循环矩阵中的素元(英文)

非负矩阵中的素元分类问题在控制和系统论中有重要的应用.本文将研究由G.Picci等所提出的关于双随机循环矩阵中素元的一个问题和一个猜想,得到了一个判别具有位数5的n阶双随机循环矩阵不是素元的充要条件,给出了猜想成立的一些充分条件.     

对称双随机矩阵逆特征值问题

主要研究随机矩阵逆特征值问题．特别是对称双随机矩阵和列随机矩阵逆特征值问题．对参考文献[1]与[2]的结论作了一些推广．并给出了—个数值例子．     

A Birkhoff Theorem for Doubly Stochastic Matrices with Vector Entries

The concept of a doubly stochastic matrix whose entries come from a convex subset of the unit square is defined. It is proved that the only convex subsets of the unit square which contain (0,0) and (1, 1) and allow an extension of Birkhoff's characterization of the extreme points of the set of doubly stochastic matrices are parallelograms. A sufficient condition is given for a matrix to be extreme when the convex subset is not a parallelogram.     

On the Representation of Doubly Stochastic Matrices as Sums of Permutations

Any doubly stochastic finite matrix with integer entries isthe sum of permutation matrices. A lower bound on how many ofthe permutations are equal is obtained.     

广义双随机矩阵反问题及其应用

研究广义双随机矩阵反问题.给出广义双随机矩阵的最小二乘解,得到了解的具体表达形式.并讨论了用广义双随机矩阵构造给定矩阵的最佳逼近问题,给出该问题有解的充分必要条件和解的表达形式.包括算法及数值例子.     

双随机矩阵收敛指数的最好上界

Ｍ．Ｌｅｗｉｎ（１９７４）已得到了ｎ阶本原双随机矩阵收敛（本原）指数的最好上界。本文对不可约非本原和可约双随机矩阵的收敛指数作出估值，从而证明了Ｌｅｗｉｎ的上界是适用于一切双随机矩阵的最好上界。     

具有位数3和4的双随机循环矩阵中的素元

本文研究了双随机循环矩阵中素元的分类问题．由于任一n阶双随机循环矩阵都可以唯一地表示为移位的n-1次一元多项式,从而可把双随机循环矩阵中素元的分类问题简化为解双随机循环矩阵上的一个方程．应用此原理,本文完全解决了判别具有位数3的n阶双随机循环矩阵是否为素元的问题,并给出了n阶双随机循环矩阵中一类具有位数4的素元．     

Minimum Permanents on a Face of the Polytope of Doubly Stochastic Matrices II

We determine the minimum permanents and minimizing matrices on the face of z_3+n, for the fully indecomposable (0,1) matrices of order 3+n, which include an identity submatrix of order n .     

Minimum Permanents on a Face of the Polytope of Doubly Stochastic Matrices II

We determine the minimum permanents and minimizing matrices on the face of ω_3+n , for the fully indecomposable (0,1) matrices of order 3+n, which include an identity submatrix of order n .     

Differentiation of Similar Matrices

Mathematical Notes -     

倒向双重随机微分方程

本文研究了如下倒向随机微分方程Yt=ξ ∫t^Tf(x,Yt,Zt)ds ∫t^TB(ds,g(s,Yt,Zt))-∫t^TZtdW,, 在类似于Yamada条件下，得到了它解的存在唯一性定理，推广了Anis Matoussi和Michael Scheutzow相关结果．拓展倒向随机微分方程在随机控制问题和数理金融等方面的应用。     

正倒向重随机微分方程

该文研究了一类正倒向重随机微分方程, 在某些自然的单调性假设下, 得到了解的存在唯一性结果.     

双对称本原矩阵k-点指数的极矩阵

一个n阶本原矩阵A的k-点指数是A的最小幂指数,使得在这个幂中,存在着k个全1行．最近我们得到了n阶双对称本原矩阵的k-点指数的上确界．本文将在此基础上,以伴随图的形式给出其极矩阵的完全刻划．     

相似变换矩阵的空间结构探讨

给定 n阶方阵及其若当矩阵 ,讨论所有与该若当矩阵可交换的矩阵空间的结构 ,得出方阵的所有相似变换矩阵的空间结构 .     

Counting Singular Matrices with Primitive Row Vectors

We solve an asymptotic problem in the geometry of numbers, where we count the number of singular n×n matrices where row vectors are primitive and of length at most T. Without the constraint of primitivity, the problem was solved by Y. Katznelson. We show that as T, the number is asymptotic to for n3. The 3-dimensional case is the most problematic and we need to invoke an equidistribution theorem due to W. M. Schmidt.     

双对称本原矩阵κ-点指数的极矩阵

一个n阶本原矩阵A的κ-点指数是A的最小幂指数,使得在这个幂中,存在着κ个全1行.最近我们得到了n阶双对称本原矩阵的κ-点指数的上确界.本文将在此基础上,以伴随图的形式给出其极矩阵的完全刻划.