ASYMPTOTIC PROPERTIES OF ELEMENTS IN GROUP RINGS OF FINITE GROUPS

A relation between algebraic degrees of eigenvalues of an element in the group ring Z G of a finite group G and their multiplicities is obtained. This result can be regarded as a theorem on asymptotic behavior of parameters in group rings of finite groups which is a parallel result of several well known theorems concerning the relationships of parameters in finite groups.     

CLOSED SUBMODULES OF NORMALIZING BIMODULES OVER SEMIPRIME RINGS

In this paper we study closed sub-bimodules of normalizing bimodules over semiprime rings. We extend the main results which are known for centred bimodules and several other results which are new even for centred bimodules are also obtained. In particular, we prove that the theorem on one-to-one correspondence between closed submodules obtained in former papers for centred bimodules is also true for normalizing bimodules. Finally, we give some applications of the main results.

     

CODIMENSION AND REGULARITY OVER COHERENT SEMILOCAL RINGS

In this paper, the results on codimension and regularity over noetherian local rings and coherent local rings are extended to coherent semilocal rings and some useful examples of coherent semilocal rings are constructured.     

正则环上矩阵分解

利用幂等矩阵和单边可逆阵,给出了正则环上具有群逆的矩阵结构,并证明了具有奇数特征的单边单位正则环上的矩阵都可分解为两个单边可逆矩阵和形式。     

ON EXCHANGE RINGS WITH BOUNDED INDEX OF NILPOTENCE

This paper studies exchange rings R such that R/J(R) has bounded index of nilpotence. We give several characterizations of such rings. We prove that if a semiprimitive exchange ring R has index n, then for any maximal two-sided I of R, if R/I has length n, then there exists a central idempotent element e in R such that eRe is an n by n full matrix ring over some exchange ring with central idempotents, and the restriction π from eRe to R/I is surjective.     

一类Artin模的自同态环的K0群

本文确定了一类Ａｒｔｉｎ模的自同态环的Ｋ０群，并给出Ａｒｔｉｎ模的几条有趣的特征性质。     

交换环上矩阵的Drazin逆

本文应用子式讨论交换环上矩阵的Drazin逆和群逆,给出了矩阵A的Drazin逆和群逆的整体和单个元素的表达式.     

EXPLICIT CONSTRUCTION OF HARMONIC MAPS FROM R^2 TO U（N）

ＥＸＰＬＩＣＩＴＣＯＮＳＴＲＵＣＴＩＯＮＯＦＨＡＲＭＯＮＩＣＭＡＰＳＦＲＯＭＲ~２ＴＯＵ（Ｎ）￥ＧｕＣＨＡＯＨＡＯＨｕＨＥＳＨＥＮＧＡｂｓｔｒａｃｔ：Ｄａｒｂｏｕｘｔｒａｎｓｆｏｒｍａｔｉｏｎｍｅｔｈｏｄｉｓｕｓｅｄｆｏｒｃｏｎｓｔｒｕｃｔｉｎｇｈａ?..     

ANTI-SADDLES OF A POLYNOMIAL SYSTEM

ＡＮＴＩ－ＳＡＤＤＬＥＳＯＦＡＰＯＬＹＮＯＭＩＡＬＳＹＳＴＥＭ￥ＹＥＹＡＮＱＩＡＮ（ＤｅｐａｒｔｍｅｌｌｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＮａｍｉｎｇＵｎｉｖｅｒｓｉｔｙ，Ｎａｍｉｎｇ２１０００８，Ｃｈｉｎａ．）（Ｐｒｏｊｅｃｔｓｕｐｐｏｒｔｅｄｂｙｔｈ...     

Explicit irreducible representations of the¶Iwahori–Hecke algebra of Type F4

A general method for computing irreducible representations of Weyl groups and Iwahori–Hecke algebras was introduced by the first author in [10]. In that paper the representations of the algebras of types A _n , B _n , D _n and G _n were computed and it is the purpose of this paper to extend these computations to F ₄. The main goal here is to compute irreducible representations of the Iwahori–Hecke algebra of type F ₄ by only using information in the character table of the Weyl group. Received: Received: 30 July 1998     

THE CONJUGACY PROBLEM IN SMALL GAUSSIAN GROUPS

Small Gaussian groups are a natural generalization of spherical Artin groups, namely groups of fractions of monoids in which the existence of least common multiples is kept as an hypothesis, but the relations between the generators are not supposed to necessarily be of Coxeter type. We show here how to extend the Elrifai–Morton solution for the conjugacy problem in braid groups to every small Gaussian group.     

Artin局部主理想环上多项式理想的Grobner基的标准型

本文给出Artin局部主理想环上单变元多项式理想的极小Gr     

一类新的交错群Cayley网络

本文利用交错群的Ｃａｙｌｅｙ图构作了一类互连网络,进而讨论了它的直径,容错度,容错直径和Ｈａｍｉｌｔｏｎ连通性,这些性质表明它优于利用交错群构作的网络ＡＧｎ,且相似于著名的星形网络。     

ON PARTIALLY SATURATED FORMATIONS AND RESIDUALS OF FINITE GROUPS

Partially saturated formations of finite groups are studied with the help of group functions. The results are applied for studying F-groups of automorphisms and π-complements to F-residuals.     

Four algorithms for the the efficient computation of truncated pivoted QR approximations to a sparse matrix

Summary. In this paper we propose four algorithms to compute truncated pivoted QR approximations to a sparse matrix. Three are based on the Gram–Schmidt algorithm and the other on Householder triangularization. All four algorithms leave the original matrix unchanged, and the only additional storage requirements are arrays to contain the factorization itself. Thus, the algorithms are particularly suited to determining low-rank approximations to a sparse matrix. Received February 23, 1998 / Revised version received April 16, 1998     

Perturbation analysis for block downdating of a Cholesky decomposition

Summary. Let the Cholesky decomposition of be , where is upper triangular. The Cholesky block downdating problem is to determine such that , where is a block of rows from the data matrix . We analyze the sensitivity of this block downdating problem of the Cholesky factorization. A measure of conditioning for the Cholesky block downdating is presented and compared to the single row downdating case. Received September 15, 1993     

Orbit Equivalence and Topological Conjugacy of Affine Actionson Compact Abelian Groups

 We study topological rigidity of affine actions on compact connected metrizable abelian groups. We also classify one parameter flows of translations up to orbit equivalence and discrete group actions by translations up to topological conjugacy. (Received 21 December 1998; in revised form 2 June 1999)     

Prosolvable subgroups of free products of profinite groups

In this paper we establish several equivalent conditions for a commutative ring in which every principal ideal is a finite intersection of prime power ideals to be a general ZPI-ring. Using these results, we establish some equivalent conditions for a commutative ring in which every principal ideal is a finite intersection of primary ideals to be a general ZPI-ring.