Relations Between O(n)-Invariants of Several Matrices

A linear group G?<?GL(n) acts on d-tuples of n × n matrices by simultaneous conjugation. In Procesi (Adv Math 19:306–381, 1976), Procesi established generators and relations between them for G-invariants, where G is GL(n), O(n), and Sp(n) and the characteristic of base field is zero. We continue generalization of the mentioned results to the case of positive characteristic originated by Donkin (Invent Math 110:389–401, 1992). We investigate relations between generators for O(n)-invariants.     

Defining the Determinant-like Function for m by n Matrices Using the Exterior Algebra

In this paper, we present a function called the Determinant-Like Function that generalises the determinant function to m by n matrices using the Clifford algebra C?(V, 0). By definition, this generalisation satisfies the property that the exterior product of its column vectors has a magnitude that equals its determinant-like function if it has more rows than columns. For matrices which have more columns than rows, we make use of another property that the exterior product of its rows has a magnitude that equals the absolute value of its determinant-like function if it has more columns than rows. Defining the sign of this determinant-like function remains an open question.     

Primitive Ideals in the Algebra of Regular Functions on Quantum m × n Matrices

Mathematical Notes -     

Primitive Ideals and Automorphisms of Quantum Matrices

Let be a field and q be a nonzero element of that is not a root of unity. We give a criterion for 〈0〉 to be a primitive ideal of the algebra of quantum matrices. Next, we describe all height one primes of ; these two problems are actually interlinked since it turns out that 〈0〉 is a primitive ideal of whenever has only finitely many height one primes. Finally, we compute the automorphism group of in the case where m ≠ n. In order to do this, we first study the action of this group on the prime spectrum of . Then, by using the preferred basis of and PBW bases, we prove that the automorphism group of is isomorphic to the torus when m ≠ n and (m,n) ≠ (1, 3),(3, 1). This research was supported by a Marie Curie Intra-European Fellowship within the 6th European Community Framework Programme and by Leverhulme Research Interchange Grant F/00158/X.     

关于满足I(x,n(x))=n(x)的D-蕴涵的刻画

研究I(x,n(x))=n(x),其中I为由连续三角模T、连续三角余模S和强否定n生成的D-蕴涵,即I(x,y)=S(T(n(x),n(y)),y),给出了满足I(x,n(x))=n(x)的充要条件。     

由 n×n 上三角Toeplitz矩阵所构成的 超循环矩阵族

在Feldman和Costakis所做的结果的基础上,进一步考虑了超循环算子族的一些问题,设Τ=(T_1,…,T_m)是一组由m个上三角Toeplitz复矩阵构成的矩阵组,给出了一个Τ是超循环的充分必要条件.     

Lattices with Defining Relations Close to Distributivity

We consider the 3-generated lattices whose generators enjoy the defining relations of the type a∨(b∧c) = (a∨b)∧(a∨c). Moreover, if the lattice is finite then we obtain its diagram; otherwise, we prove that the corresponding lattice is infinite.     

Irreducible Representations of Quantum 3 × 3 Matrices

The irreducible representations of quantum 2×2 and 3×3 matrices at the roots of unity are classified.     

On free semilattice-ordered semigroups satisfying x n =x

Let B(k,0,n) denote the group with k generators which is free in the group variety defined by the identity x ⁿ =1. Let B _slo (k,1,n) denote the semilattice-ordered semigroup with k generators which is free in the semilattice-ordered semigroup variety defined by the identity x ⁿ =x. We prove a generalization of the Green-Rees theorem: B _slo (k,1,n) is finite for all k≥1 if and only if B(k,0,n−1) is finite for all k≥1. We find a formula for card(B _slo (1,1,n)). We construct B _slo (k,1,n) for some concrete values of k and n.     

Randomized Operators on {n\times n} Matrices and Applications

Some combinatorial and probabilistic estimates motivated by earlier works due to S. Kwapien and C. Schütt are proved. We study these estimates in the general setting of rearrangement invariant function and sequence spaces and identify the class of function spaces in which such estimates hold. We demonstrate the sharpness of our results and present some applications, one of which is an alternative proof of a familiar Raynaud–Schütt theorem describing symmetric subspaces in \({L_1}\).     

Coefficient Matrices of a Quantum Discrete Auxiliary Linear Problem

In the present paper, we describe general properties of quantum matrices that are coefficient matrices of an auxiliary problem for quantum discrete three-dimensional integrable models. Our goal is to prove a universal functional equation for the quantum determinant in the case of a finite-dimensional representation of a local Weyl algebra. Bibliography: 4 titles.     

Optimal control of n x n parabolic system involving time lag

In this paper, we study the optimal control problem for an nx n coupled system of second-order parabolic partial differentialequations with infinitely many variables and constant time lag.Making use of the Lions scheme (Lions, 1971, Optimal Controlof Systems Governed by Partial Differential Equations), necessaryand sufficient condition of optimality for the Neumann problemwith quadratic performance functional and constraint controlis derived. Finally, several mathematical examples for derivedoptimality conditions are presented.     

（n1,n2）型二重（r1,r2）—循环矩阵逆矩阵的插值求法

本文用插值法给出n1n2阶（n1，n2）型二重（r1，r2）－循环矩阵逆矩阵计算公式．     

Zur Bestimmung vonE n [x n+2m ]

Remark on the estimation ofE _n [x ^n+2m ]. Let be $$E_n [f]: = \mathop {\inf }\limits_{p \in P_n } \mathop {\sup }\limits_{x \in [ - 1, 1]} |f(x) - p(x)|$$ (P _n : set of all polynomials of degreen). Riess-Johnson [4] proved (3) $$E_n [x^{n + 2m} ] = \frac{{n^{m - 1} }}{{2^{n + 2m - 1} (m - 1)!}}[1 + O(n^{ - 1} )],n even.$$ This degree of approximation is realized by expansion in Chebyshev polynomials and by interpolation at Chebyshev nodes. The purpose of this paper is to give a more precise estimation by constructing the polynomial of best approximation on a finite set. This construction is easily done and one obtains the result, that the termO(n ^?1) in (3) may be replaced by 1/2(m ? 1) (3m + 2)n ^?1 + O(n ^?2).