有限域乘法群结构定理及其拓广

有限域乘法群结构定理在理论研究及工程应用上均具有重要意义.主要介绍了有限域乘法群结构定理的三种证明方法,并做了一些拓广.     

一类关于两个子群的相对差集

本文在一般有限群 G=G_1×G_2上,利用它的两个子群 G_1、G_2构作了一类新的相对差集,给出了一些简单性质(第一节),得到了由群差集构造这类相对差集的一般方法(第二节)。证明了由这类相对差集可以得到一类相应的,具有3个结合类的 PBIB 设计(第三节)。最后给出了二个构造性结果(第四节)。     

有限域上型$B_n$的Chevalley群之间的同态

研究了特征为$p$的有限域上型$B_{n}$的Chevalley群的结构,并确定了特征为$p \ (p\neq 2)$的有限域上型$B_{n}$的Chevalley群 之间的非平凡同态.     

有限域上一类方程解数的直接公式

本文给出有限域F=Fq上一类方程a1xd111…xd1n1n1 … an1xdn111…xdn1n1n1 an1 1xdn1 111…xdn1 1n2n2 … an2x1dn21…xdn2n2n2=b 当指数满足一定条件时,在Fn2上解数的一个直接公式,这里dij>0,ai ∈F*,b ∈F,q=pf,f≥1, p足一个奇素数,0相似文献   

有限域上一类方程解数的直接公式

本文给出有限域F=Fq上一类方程(?)当指数满足一定条件时,在Fn2上解数的一个直接公式,这里dij＞0,ai∈F*,b∈F,q=pf,f≥1,p是一个奇素数,0＜n1 ≤ n2.     

特征不为 2 的有限域上酉群的极小生成元集

设K=Fq2为含有q2个元素的有限域,q为奇素数的幂,*：a→a*=aq是Fq2的一个二阶自同构．本文用几何方法证明了除K为F32而n=4的情形外,Fq2上的酉群Un（V）可由2个元素生成．     

特征不为 2的有限域上的酉群的极小生成元集

设K=F     

关于有限域F_q上矩阵阶的研究

详细地研究了有限域 Fq上的矩阵的阶的问题 ,得到了相当理想的结果 .并给出一类矩阵方幂的极小多项式的求法     

域上矩阵群逆的加法保持映射

在本文中,我们刻画了保持域上矩阵群逆的加法映射的形式.     

Looking for Difference Sets in Groups with Dihedral Images

We prove four theorems about groups with a dihedral (or cyclic) image containing a difference set. For the first two, suppose G, a group of order 2p with p an odd prime, contains a nontrivial (v, k, ) difference set D with order n = k – prime to p and self-conjugate modulo p. If G has an image of order p, then 0 2a + 2 for a unique choice of = ±1, and for a = (k – )/2p. If G has an image of order 2p, then and ( – 1)/( – 1). There are further constraints on n, a and . We give examples in which these theorems imply no difference set can exist in a group of a specified order, including filling in some entries in Smith's extension to nonabelian groups of Lander's tables. A similar theorem covers the case when p|n. Finally, we show that if G contains a nontrivial (v, k, ) difference set D and has a dihedral image D _2m with either (n, m) = 1 or m = p ^t for p an odd prime dividing n, then one of the C ₂ intersection numbers of D is divisible by m. Again, this gives some non-existence results.     

On Relative Difference Sets in Dihedral Groups

In this paper, we study extensions of trivial difference sets in dihedral groups. Such relative difference sets have parameters of the form (uλ,u,uλ, λ) or (uλ+2,u, uλ+1, λ) and are called semiregular or affine type, respectively. We show that there exists no nontrivial relative difference set of affine type in any dihedral group. We also show a connection between semiregular relative difference sets in dihedral groups and Menon–Hadamard difference sets. In the last section of the paper, we consider (m, u, k, λ) difference sets of general type in a dihedral group relative to a non-normal subgroup. In particular, we show that if a dihedral group contains such a difference set, then m is neither a prime power nor product of two distinct primes.     

On Sylow Subgroups of Abelian Affine Difference Sets

An n-subsetD of a group G of order is called an affine difference set of G relativeto a normal subgroup N of G of order if the list of differences containseach element of G-N exactly once and no elementof N. It is a well-known conjecture that if Dis an affine difference set in an abelian group G,then for every prime p, the Sylow p-subgroupof G is cyclic. In Arasu and Pott [1], it was shownthat the above conjecture is true when . In thispaper we give some conditions under which the Sylow p-subgroupof G is cyclic.     

New Constructions of Disjoint Distinct Difference Sets

New constructions of regular disjoint distinct difference sets (DDDS) are presented. In particular, multiplicative and additive DDDS are considered.     

Constructions of Nested Partial Difference Sets with Galois Rings

There have been several recent constructions of partial difference sets (PDSs) using the Galois rings for p a prime and t any positive integer. This paper presents constructions of partial difference sets in where p is any prime, and r and t are any positive integers. For the case where 2$$ " align="middle" border="0"> many of the partial difference sets are constructed in groups with parameters distinct from other known constructions, and the PDSs are nested. Another construction of Paley partial difference sets is given for the case when p is odd. The constructions make use of character theory and of the structure of the Galois ring , and in particular, the ring × . The paper concludes with some open related problems.     

相对差集和组合集的构造

利用Galois环、Bent函数、Gaolis环上的部分指数和等技巧,构造了指数不超过4的有限交换群上的分裂型相对差集和一类非分裂型组合集.     

A note on products of Relative Difference Sets

Relative Difference Sets with the parameters k = n have been constructed many ways (see (Davis, forthcoming; Elliot and Butson 1966; and Jungnickel 1982)). This paper proves a result on building new RDS by taking products of others (much like (Dillon 1985)), and this is applied to several new examples (primarily involving (p ⁱ, p ^j, p ⁱ, p ^i–j)).     

加权和法在Vague集中的应用

针对应用广泛的加权和法的特征,研究在Vague集中应用加权和法,提出了在Vague集中应用加权和的方法,并通过实际算例验证了此方法的有效性.     

Multiplicative Difference Sets via Additive Characters

We use Fourier analysis on the additive group of to give an alternative proof of the recent theorem of Maschietti and to prove recent conjectures of No, Chung and Yun and No, Golomb, Gong, Lee and Gaal on difference sets in the multiplicative group of , m odd. Along the ay e prove a stronger form of a celebrated theorem of Welch on the 3-valued cross-correlation of maximal length sequences.     

New Classes of Groups Containing Menon Difference Sets

A theorem due to Davis on the existence of Menon difference sets in 2-groups is generalised to non-2-groups. The existence of Menon difference sets in many new non-abelian groups is established.