有限域上F4和G2型Chevalley群的二元生成

本文证明了有限域上F4和G2型Chevalley群均可由两个元素生成.     

例外型Chevalley群G_2(q)的h函数值

设G是有限群,πe(G)表示G中元素的阶的集合,h(πe(G))表示满足πe(H)=πe(G)条件的有限群H的同构类类数,本文证明了例外型Chevalley群G2(q)的h函数值为1或∞.     

ON THE HARISH－CHANDRA HOMOMORPHISM FOR THE CHEVALLEY GROUPS OVER P－ADIC FIELD

ＯＮＴＨＥＨＡＲＩＳＨ－ＣＨＡＮＤＲＡＨＯＭＯＭＯＲＰＨＩＳＭＦＯＲＴＨＥＣＨＥＶＡＬＬＥＹＧＲＯＵＰＳＯＶＥＲＰ－ＡＤＩＣＦＩＥＬＤ￥ＣＨＥＮＺＨＯＮＧＨＵ（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｈｅｍａｔｉｃｓ，ＸｉａｎｇｔａｎＵｎｉｖｅｒｓｉｔｙｔＸｉ...     

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.     

特征标次数的商与有限群结构

本文考察特征标次数的商如何影响有限群的结构.设G是非线性不可约特征标次数的商都是n次方自由的有限群,首先,对可解群G证明了它的导长能被一个仅依赖于n的函数所界定;其次,给出了当n≤3时有限群G的结构.     

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．     

有限群的Deskins极大完备

对于有限群G的一个极大予群M,Deskins称子群C为M的一个完备,如果C(?)M,但C的G-不变真子群包含在M中.令I(M)表示M的所有完备之集. I(M)的一个极大元叫做M的一个极大完备.利用极大完备,本文获得关于群的可解性和超可解性某些新的刻划.     

半次覆盖远离子群和有限群的可解性

本文定义了有限群的半次覆盖远离子群概念,研究了半次覆盖远离子群和有限群的可解性问题.利用某些半次覆盖远离子群刻划了有限群的可解性,得到了若所有的sylow子群(或极大子群)半次覆盖远离则群可解,推广了文献[6]中的结果.     

理想类群指数≤2的虚二次函数域

本文给出虚二次函数域K=k~（1/2）D（k=Fq（x）,2+q）的理想类群指数≤2的一个必要条件.在某些条件下,这个条件也是充分的.特别地,给出了Louboutin[1]一个结果在函数域情形的模拟.     

一类2nm(m为奇数)阶有限群的构造

本文研究了一类2nm(m为奇数)阶有限群的构造,利用解数论同余方程的方法和群的扩张理论等知识,得到了具有奇数m阶循环正规子群、其补子群为循环群的2nm阶有限群的构造及相关的计数定理.     

Connectedness of Kisin varieties for GL2

We show that the Kisin varieties associated to simple φ-modules of rank 2 are connected in the case of an arbitrary cocharacter. This proves that the connected components of the generic fiber of the flat deformation ring of an irreducible 2-dimensional Galois representation of a local field are precisely the components where the multiplicities of the Hodge–Tate weights are fixed.     

M/(G1, G2)/1 retrial queue under Bernoulli vacation schedules with general repeated attempts and starting failures

This paper investigates a batch arrival retrial queue with general retrial times, where the server is subject to starting failures and provides two phases of heterogeneous service to all customers under Bernoulli vacation schedules. Any arriving batch finding the server busy, breakdown or on vacation enters an orbit. Otherwise one customer from the arriving batch enters a service immediately while the rest join the orbit. After the completion of two phases of service, the server either goes for a vacation with probability p or may wait for serving the next customer with probability (1 − p). We construct the mathematical model and derive the steady-state distribution of the server state and the number of customers in the system/orbit. Such a model has potential application in transfer model of e-mail system.     

Cocycle d'Euler etK2

In this paper we construct a canonical 2-cocycle on the groupP SL(2,k) with values in the Witt groupW(k) of the fieldk. This allows us to produce anatural homomorphism :H ₂(SL(2,k); Z)I ²(k), whereI ²(k) is the square of the fundamental ideal. We prove that this homomorphism is in fact a lift of Milnor's symbol.

     

On K1 and K2 of Algebraic Surfaces

In this paper we study higher Chow groups of smooth, projective surfaces over a field k of characteristic zero, using some new Hodge theoretic methods which we develop for this purpose. In particular we investigate the subgroup of CH ^r+1 (X,r) with r = 1,2 consisting of cycles that are supported over a normal crossing divisor Z on X. In this case, the Hodge theory of the complement forms an interesting variation of mixed Hodge structures in any geometric deformation of the situation. Our main result is a structure theorem in the case where X is a very general hypersurface of degree d in projective 3-space for d sufficiently large and Z is a union of very general hypersurface sections of X. In this case we show that the subgroup of CH ^r+1 (X,r) we consider is generated by obvious cycles only arising from rational functions on X with poles along Z. This can be seen as a generalization of the Noether–Lefschetz theorem for r = 0. In the case r = 1 there is a similar generalization by Müller-Stach, but our result is more precise than it, since it is geometric and not only cohomological. The case r = 2 is entirely new and original in this paper. For small d, we construct some explicit examples for r = 1 and 2 where the corresponding higher Chow groups are indecomposable, i.e. not the image of certain products of lower order groups. In an appendix Alberto Collino constructs even more indecomposable examples in CH ³ (X,2) which move in a one-dimensional family on the surface X.Contribution to appendix.     

COMPUTATION OF K2Z[1＋（-35的平根号）／2 ]

The author shows that K2Z[1+（-35的平根号）/2 ]?A ≈Z/2Z. The method of proof is a generalization of the Tate‘s method.     

Hasse's norm theorem forK2

In this paper, we prove Hasse's principle onK ₂ for a certain two-dimensional semi-global field. And, as a bi-product, we have the isomorphism theorem of the class field theory of such a field.     

Computation of K2 for the ring of integers of quadratic imaginary fields

This paper presents a method to get improved bounds for norms of exceptional v ’ s in computing the group K₂ 0_F, where F is a quadratic imaginary field, and as an application we show that      

A conjecture on a class of elements of finite order in K2Fp

For a local field F the finite subgroups of K₂ F are expressed by a class of special elements of finite order, which makes a famous theorem built by Moore, Carroll, Tate and Merkurjev more explicit and also disproves a conjecture posed by Browkin.     

线性子空间上求解矩阵方程组A_1XB_1=C_1,A_2XB_2=C_2的迭代算法

应用共轭梯度方法,结合线性投影算子,给出迭代算法求解了线性矩阵方程组A_1XB_1=C_1,A_2XB_2=C_2在任意线性子空间上的约束解及其最佳逼近.当矩阵方程组A_1XB_1=C_1,A_2XB_2=C_2相容时,可以证明,所给迭代算法经过有限步迭代可得到矩阵方程组的约束解、极小范数解和最佳逼近.文中的数值例子证实了该算法的有效性.     

ON IDEAL CLASS GROUPS AND UNITS IN TERMS OF THE QUADRATIC FORM x^2＋32y^2

§1. IntroductionIt is a classical topic to study, for quadratic number ?elds F = Q(√2p) with a prime p,the exact 2-power dividing the narrow class number h (F) and the norm of the fundamentalunit ε of F.The 2-primary subgroup of the narrow class group …