Lehmer序列中的平方数与平方类

设Vn(R,Q)表示参数为R和Q的Lehmer伴随序列.如果R和Q为互素奇数且D=R-4Q>0,我们找出了满足Qn(R,Q)或n1Qn(R,Q)是平方数的所有奇数n.这里,从而改进了文[15]的工作.     

Pascal矩阵与Vandermonde矩阵的关系

EI-Mikkawy M证明了对称Pascal矩阵Q_n和Vlandermonde矩阵V_n之间满足矩阵方程Q_n=T_nV_n,这里T_n是一个随机矩阵。本文证明了随机矩阵T_n能够分解成第一类Stirling矩阵和对角矩阵的乘积,得到了矩阵T_n的元素之间的递推关系,从而回答了EI-Mikkawy M的一个公开问题。同时得到了一些与Stirling数相关的组合恒等式。     

《数学年刊》第8卷B辑第1期1987——目录和提要

正鞅和随机测度Kahane Jean-pierre对以 t 为指标的正鞅 Q_n(t)(n=0,1,…),(t∈T,T 为紧度量空间)和测度:σ∈M~ (G),随机测度Qσ定义为 Q_nσ的极限.一般来说,EQσ≤σ.本文给出的条件保证了 EQσ=0(退化)或者 EQσ=σ(完全作用),当 Q_n(t)为独立权函数的乘积这一特殊情况下,σ能分解成两个互相奇异的测度之和σ=σ′ σ″,使得 Q 在σ′,上为完全作用,而在σ″上是退化的,EQ 是一个射影算子.本文还给出了一些例子和应用(例如随机覆盖,B.Mandelbrot 鞅以及乘法浑沌).     

二面体群的增广商群

记整群环ZG的增广理想△(G)的n次幂为△~n(G).描述了二面体群G=D_2t_r(t≥2,r为奇数)的n-次增广商群Q_n(G)=△n(G)/△~(n+1)(G)的结构,并得到Q_n(D_2t_r)≌Z_2~((s(n))),其中,如果1≤n≤t,那么s(n)=2n;如果n≥t+1,那么s(n)=2t+1.     

最佳L_∞逼近的存在性

令V_n=span{_1,_2,…,_n},设函数f∈L_p[E,μ],1≤p<∞,在点p 处定义一个最佳L_p 逼近算子τ∫(p)。记N_f(p)=∥f-τ∫(p)∥_p=inf/Q∈V_n∥f-Q∥_(po)本文证明了N_f(p)/[μ(E)]l/p 是p 的单调增加且有界的函数。如果f∈L_∞[E,μ],则存在τ∫(∞)∈V_n,使得∥f-τ∫(∞)∥_∞=inf/Q∈V_n∥f-Q∥∞,并且给出了最佳逼近值。     

二次函数域理想类数问题的一个注记

应用F_q[t]上的Pell方程这一初等方法重新证明一个已知的结果:实二次函数域F_q(t)(D~(1/2))理想类数为1时,D只能为P或QR,其中P,Q,R是F_q[t]中的首一不可约多项式且Q,R次数为奇数.     

二次域Q(7~(1/2))的单位给出的Pronic数及相关的不定方程问题

研究了二次域Q(7~(1/2))中单位V_n+U_n7~(1/2)=(8+3 7~(1/2))~n所给出的两个递归数列{V_n},{U_n}中的Pronic数问题,找到了{V_n},{U_n}中的所有的Pronic数.作为应用,给出了与其相关的两个不定方程的整数解.     

具有“积分小”系数的奇数阶中立型方程的振动性

考虑中立型微分方程dndtn[x( t) -P( t) x( t-τ) ]+Q( t) x( t-σ) =0 ,　 t≥ t0 ,( * )其中 n≥ 1 ,n为奇数 ,P( t) ,Q( t)∈ C( [t0 ,+∞ ) ,R+ ) τ>0 ,σ>0 .本文在不需要通常假设 ∫∞t0Q( s) ds=∞的条件下 ,获得了保证 ( * )的所有解振动的几个充分条件 ,并推广了文 [1 ]、[3]的相应结论 .     

实 Clifford 分析中的一个边值问题

考虑以 e_A=e_(α1)…e_(αh)(A={α_1,α_2,…,α_h)(?){1,2,3,…,n),1≤α_1<α_2<…<α_h≤n)为基底元素的实 Clifford 代数 A_n(R),其中 e_1=1,e_k~2=-1(k=2,3,4,…,n),e_ke_m e_me_k=0(k≠m,k,m=2,3,4,…,n).并用 V_n 表示由向量组 e_1,e_2,…,e_n 所张成的 A_n(R)的子空间,V_n 中元素为 x=(?)x_ke_k,A_n(R)中的     

Weierstrass逼近定理的一个初等証明

以下将给出Weierstrass定理的一个既初等又简短的证明。该定理是说:任何一个在闭区间[0,1]上连续的函数f(x)都可以用多项式一致逼近。作为辅助工具,只要用到Bernóulli不等式: (1+h)~n≥1+nh(h>-1,n为自然数)。它容易用归纳法证得。我们考察多项式 Q_n(x)=(1-x~n)~(2~n)。当x从0变到1时,Q_n(x)的值从1单调地变到0。在0≤x≤q<1/2中,Q_n(x)当n→∞时一致收敛于1,因为 1≥Q_n(x)≥Q_n(q)= =(1-q~n)~(2~n)≥1-2~nq~n=1-(2q)~n→1。     

OSCILLATION AND ASYMPTOTIC BEHAVIOR OF HIGHER ORDER NEUTRAL EQUATIONS WITH VARIAPLE COEFFICIENTS

The authors establish sufficient conditions for the oscillation of all solution of neutral delay differential equations of even and odd order of the form $$\[\frac{{{d^n}}}{{d{t^n}}}[y(t) + p(t)y(t - \tau )] + Q(t)y(t - C) = 0,t \ge {t_0},\]$$ where $\[P,Q \in C[[{t_0},\infty ),R],\tau ,\sigma \in {R^ + }\]$ and $\[n \ge 1\]$.     

Rectangling a rectangle

We show that the following are equivalent: (i) A rectangle of eccentricityv can be tiled using rectangles of eccentricityu. (ii) There is a rational function with rational coefficients,Q(z), such thatv =Q(u) andQ maps each of the half-planes {z | Re(z) < 0} and {z | Re(z) > 0 into itself, (iii) There is an odd rational function with rational coefficients,Q(z), such thatv = Q(u) and all roots ofv = Q(z) have a positive real part. All rectangles in this article have sides parallel to the coordinate axes and all tilings are finite. We letR(x, y) denote a rectangle with basex and heighty. In 1903 Dehn [1 ] proved his famous result thatR(x, y) can be tiled by squares if and only ify/x is a rational number. Dehn actually proved the following result. (See [4] for a generalization to tilings using triangles.) The first and third authors were partially supported by NSF.     

Characterizations of P(Q(4,Q),L)

In [2] we dealt with a characterization of the generalized quadrangle Q(4,q), q odd, by introducing the concept of (0,2)-set. The aim of this paper is to give a characterization of P(Q(4,q),L), q odd and L an arbitrary regular line of Q(4,q), by constructing these (0,2)-sets and using the result of [2].     

一类连续体上连续映射的周期点

设X是个阶有限的遗传可分解可链连续体, f:X→X是X上的连续自映射, On(x,f)={fi(x):0≤i≤n)是f的一个返回轨道, inf(On(x,f))相似文献   

New series of odd non-congruent numbers Dedicated to Professor Sheng GONG on the occasion of his 75th birthday

We determine all square-free odd positive integers n such that the 2-Selmer groups Sn and Sn of the elliptic curve En: y2 = x(x -n)(x - 2n) and its dual curve En: y2 = x3 6nx2 n2x have the smallest size: Sn = {1}, Sn = {1,2,n,2n}. It is well known that for such integer n, the rank of group En(Q) of the rational points on En is zero so that n is a non-congruent number. In this way we obtain many new series of elliptic curves En with rank zero and such series of integers n are non-congruent numbers.     

素数p在数域Q(u~(1/2),v~(1/2))上的素理想分解

运用局部域理论给出了奇素数p在数域K=Q(u~(1/2),v~(1/2))上的素理想分解形式,其中l是奇素数,u,v∈z~*,且u/vQ~l.     

Translation Ovoids of Generalized Quadrangles and Hexagnos

We define the notion of a translation ovoid in the classical generalized quadrangles and hexagons of order q, and we enumerate all known examples; translation spreads are defined dually. A modification of the known ovoids in the generalized hexagon H(q), q=3^2h+1, yields new ovoids of that hexagon. Dualizing and projecting along reguli, we obtain an alternative construction of the Roman ovoids due to Thas and Payne. Also, we construct a new translation spread in H(q) for any 1 mod 3, q odd, with the property that any projection along reguli yields the classical ovoid in the generalized quadrangle Q(4,q). Finally, we prove that for q odd, the new example is the only non-Hermitian translation spread in H(q) with the property that any projection along reguli yields the classical ovoid in Q(4,q).     

General quantum antibrackets

The recently introduced quantum antibracket is further generalized such that the odd operator Q can be arbitrary. We give exact formulas for quantum antibrackets of arbitrary higher orders and for their generalized Jacobi identities. We review applications of the quantum antibrackets to the BV and BFV-BRST quantizations and include some new aspects. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 120, No. 3 pp. 358–379, September, 1999.