2pq阶群的自同构群

继续「１～２」等的工作,给出了２ｐｑ阶群Ｇ的自同构群ＡｕｔＧ的准确构造。     

一类交换群的自同构群

本文利用一种新方法,考虑交换群Cp2×Cp 的自同构群,得到了该自同构群的结构.我们的结论是:Aut(Cp2×Cp)[Cp- 1∝(Cp×Cp)]holCp.     

一类亚循环群的自同构群

本文决定了每 Sylow子群循环的有限群 G的自同构群 ,所得结论包含了徐尚进和 Walls的主要结果 .     

p6阶群的自同构群的阶

In this paper, we determine the order of automorphism group of p-groups in the third family (Φ3 ) and the fourth family (Φ4 ) in [ 1 ], whose order is p^6 ( p ≥ 3). Here p denotes an odd prime.     

具有4pq阶自同构群的有限群

本文讨论了自同构群阶为4pq(p,q为不同奇素数)的有限群,得出了它们的构造.     

换位子群为p阶群的有限p-群的自同构群

设G是换位子群为p阶群的有限p-群,确定了AutG的结构,证明了(i)AutG/AutGG≌Zp-1,其中AutGG={α∈AutG|α平凡地作用在G上}.(ii)AutGG/Op(AutG)≌iGL(ni,p)×jSp(2mj,p),其中Op(AutG)是AutG的最大正规p-子群,ni和mj由G惟一确定.     

自同构群阶为prq~2的有限群

本文给出满足|Aut(G)|=prq~2,q>2的有限群 G的完全分类。     

关于一类自同构群

本文给出了所有Ｐ＾３阶（ｐ为素数）群的自同构群的结构。     

含p^n—2阶元的P^n阶p—群的自同构群

一个有限p-群G称为一个LA-群,如果当G是非循环的且|G|>p~2时有|G|/|Aut(G)|,本文证明了一个含有p~(n-2)阶元的p~n阶p-群是一LA-群。     

某些以p群为自同构群的p^6阶群

该文给出了三个以p群为自同构群的p6阶群,并得到了它们的自同构群的阶.在这里p表示奇素数.     

Divisibility in certain automorphism groups

We study solvability of equations of the form x ⁿ = g in the groups of order automorphisms of archimedean-complete totally ordered groups of rank 2. We determine exactly which automorphisms of the unique abelian such group have square roots, and we describe all automorphisms of the general ones.     

The semigroups of order 9 and their automorphism groups

We report the number of semigroups with 9 elements up to isomorphism or anti-isomorphism to be 52?989?400?714?478 and up to isomorphism to be 105?978?177?936?292. We obtained these results by combining computer search with recently published formulae for the number of nilpotent semigroups of degree 3. We further provide a complete account of the automorphism groups of the semigroups with at most 9 elements. We use this information to deduce that there are 148?195?347?518?186 distinct associative binary operations on an 8-element set and 38?447?365?355?811?944?462 on a 9-element set.     

Residual finiteness of outer automorphism groups of certain 1-relator groups

We prove that certain 1-relator groups have Property E. Using this fact, we characterize all conjugacy separable 1-relator groups of the form a,b;(a-αbβaαbγ)t , t 1, having residually finite outer automorphism groups.     

The translation planes of order 49 and their automorphism groups

Using isomorphism invariants, we enumerate the translation planes of order 49 and determine their automorphism groups.

     

Kazhdan groups with infinite outer automorphism group

For each countable group we produce a short exact sequence where has a graphical presentation and is f.g. and satisfies property .

As a consequence we produce a group with property  such that is infinite.

Using the tools developed we are also able to produce examples of non-Hopfian and non-coHopfian groups with property .

One of our main tools is the use of random groups to achieve certain properties.