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1.
有限重位移     
It is shown in this paper that a weighted unilateral Shift T of multiplicity k (0n}0 converge, is unitarily equialent to a Toeplitz operator if and only if (1-|an|2)=(1-|a0|2) (1-|an-k|2)(n>k) and |a0|= |a1|=…|ak-1| where we assume ‖T‖=1.  相似文献   

2.
In this note, we prove that ap,q,a(0-1) is a self-con jugate spacl, so ap ( =ap,q,a) is self-conjugate, in other words, we prove that the conjecture of S. Axler istrue.  相似文献   

3.
二值回归模型中自变量误差的处理   总被引:1,自引:0,他引:1  
In this paper the binary regression model, in which the response Y is binary, i.e. Y takes the value 0 or 1 only, is considered. The conditional probability P{Y=1|X=x} is assumed to be of the form G(a0+a1x), where x is the measurement of the factor, a= (a0,a1)′ is the vector of the unknown parameter being estimated and G(a) = (1+ea)-1. The measurement x is assu-med to be contaminated when the value of x is out of certain limit. M-estimation is employed to estimate the unknown a of the model. In this paper, the consistent M-estimation is proved to be asymptotically normal and the optimal M-equation is obtained. Finally, a computation method is introduced to solve the M-equation and to get the optimal solution.  相似文献   

4.
In this paper, the author partly proves a supercongruence conjectured by Z.-W.Sun in 2013. Let p be an odd prime and let a ∈ Z+. Then, if p ≡ 1 (mod 3),k=0 6pa 2k k/16k ≡ 3/pa(modp2) is obtained, where is the Jacobi symbol.  相似文献   

5.
李忠 《中国科学A辑》1992,35(5):463-470
设f(z)=a0+a1z+…是单位圆内不取0与1的全纯函数.著名的Landau定理断言:存在一个与f无关的常数C使得|a1|≤2|a0|{|log|a0||+C}.曾有许多数学家致力于估计此常数C.最后在1980年前后,由赖万才、Hempel及Jenkins独立地给出C的精确值:C=Γ4(1/4)/4π2.本文的主要目的是要建立一种新形式的上界估计式以表明上述结果仍可改进.本文证明了: |a1|≤2|a0|{|log|a0||+C-M|a0n+1|2},其中M是一个与f无关的正的常数,而n取值为-1或1,依照|a0|>1或≤1而定.  相似文献   

6.
In this paper,we consider Schrodinger forms (operators) with singular magnetic vectorpotentials ─(▽—ia)2+Ⅴ. We prove that when the negative part V_ of electric potentialV satisfies(?) in dependentof V and a=(a1,a2,…,aN)∈Lloc2(RN)N, ─(▽—ia)2+Ⅴ has essential self-adjointextension F and it is the only self-adjoint realization of ─(▽—ia)2+Ⅴ. Moreover,We consider the continuity of (a,V) respect to a and V in the sense of strong resolvent.  相似文献   

7.
Let K be a field, K* be the multiplicative group of nonzero elements of K and S be a subgroup of K*. In this paper we show that S is a group of units of a valuation ring of K if and only if S satisfies the following conditions:1.a∈S implies -a∈S;2. for any a∈K*\S either a+S?S or a-1+S?S. Additional properties cf such groups are included.  相似文献   

8.
本文讨论了以第二类多项式Ua(x)的零点为插值节点的Hermite-Fejér插值算子Ha(f,x)及若干非一致收敛的Hermite-Fejér型插值算子在区间[-1,1]上关于权函数(1-x2)1/2的平均收敛问题.我们主要证得:当0[-1,1]都有(?),并给出了收敛阶.此外也指明,当p=3时,该式对某些连续函数未必成立.  相似文献   

9.
钱涛 《中国科学A辑》1984,27(11):987-995
记Hl={w∈C(Rk\{0}):w是l次齐次函数),R(-a)(m)是Taylor级数余项算子的n重叠合:m=(m1,…,mn)∈Zn,Z记非负整数的集,α∈(Rk)n,定义 其中a=(a1,…,an),ai,f∈(Rk), 主要结果如下: 1.证明了几个介于算子TR(-a)(m)w(ξ)),(a,f)的类与多线性奇异积分算子的类之间的对等定理; 2.作为应用,算子及 的某些有界性结果被给出,其中Ω∈H0,|β|≤|m|,且,mi≥1。  相似文献   

10.
强拟星函数的Fekete-Szeg?不等式   总被引:9,自引:0,他引:9  
令T(β)表示β级强拟星函数类,f(z)=z+a2z2+a3z3+…∈T(β),对任意实参数μ,本文得到了|a3-μa22|的准确上界.  相似文献   

11.
曹永罗 《中国科学A辑》1994,37(8):795-799
考虑Hnon映射Ta.b,对于正测度的参数集合,构造了Ta.b的拓扑可迁的奇怪吸引子Λa.b的一个捕捉区G,证明Λa.b=Ta.bnG,同时证明Λa.b的吸引域恰好就是那些边界包含在Wu(P)∪Ws(P)中的区域的并以及Ws(P),从而肯定地回答了Benedicks和Carleson关于奇怪吸引子的吸引域的猜测。  相似文献   

12.
In this paper we study the oscillation of the retarded differential equation x′(t)+∫abp(t,ξ)x[g(t,ξ)]dσ(ξ)=0 (b>a) (1)and the advanced differential equation x′(t)-∫abp(t,ξ)x[g(t,ξ)]dσ(ξ)=0 (b>a) (2) We improved the main results of [1-4].  相似文献   

13.
Let G be a compact, connected semisimple Lie group and f∈L1(G) . De note by GRa(f,g) the Gauss-Weierstrass type means of Fourier series of f.  相似文献   

14.
论Szegǒ的定理   总被引:1,自引:0,他引:1  
设f(z)=Z+a2z2+…∈S.Szegǒ证明:Sn(z)=z+a2z2+…+anzn(n=2,3…)在|z|<1/4内单叶。ρ0=1/4最好的,我们证明了更强的结果: 定理:若f(z)∈s.则sn(z)(n=2,3…)在|z|<1/4内关于原点成星形。 当f∈S*时为吴卓人所得。  相似文献   

15.
Let Mn+p-1 denote the class of functions f(z) = 1/zp+a0/zp-2+a1/zp-2+…+an+p-1zn+…, regular and p-valent in the annulus 0<|z|<1 and satisfying Re((Dn+p f(z))/(Dn+p-1 f(z)))-2)<-(n+p-1)/(n+p),|z|<1,n>-p where Dn+p-1 f(z)=1/zp((zn+2p-1f(z))/(n+p-1)!)(n+p-1).Mn+p?Mn+p-1 is proved. Since M0 is the subclass of p-valent meromorphically starlike functions, all functions in Mn + p-1 are p-valent meromorphically star-like functions. Further the integrals of functions in Mn+p-1, are considered.  相似文献   

16.
In this paper, we study the unilateral weighted shift which is unitarily equivalent to a Toeplitz operator and prove a similar result to that in [ 1 ] without the hypothesis that the shift must be hyponormal. As a corollary, we show that if the weight sequence {an}n=0 of the shift is convergent, then 1-an2=(1-a02)n+1 ?n≥0  相似文献   

17.
研究环Z/(2e)上本原序列的最高权位序列ae-1的0,1分布问题,给出了序列ae-1在1个周期中0,1个数的比值的上下界,并显示出当e越大时,ae-1的0,1个数的比值越接近1。  相似文献   

18.
A non-flat Riemannian space Vn is called Riemannian space with constant connection if its Christoffel symbols of the second kind are constant in some coordinate system {xi}. Following G. Vranceanu [3], a Riemannian space Vn with constant connection is said to be of genus p, if the components of the fundamental tensor in the coordinate system {xi/sup>} can be written in the form gij=cijata(a=1,…,p) where cija are constant, and p is least.In this paper we prove the following  相似文献   

19.
本文得到了多体问题中在(p,t)平面上允许区域与禁区之间的分歧曲线,其中p为“平方平均距离”(正比于惯量矩的平方根)。这说明了,例如对负能量系统在大于T/2的时间间隔内ρ不能保持小于α,其中α为广义半长轴,T为对应的周期,即T=2π(a3/μ)1/2,μ为引力常数。  相似文献   

20.
龙瑞麟 《中国科学A辑》1982,25(11):995-1005
本文证明了鞅的空间aKΦaLΦ,它们是分别由Garsia与Herz定义的空间的Φ-推广,都等价于aLΦ(一个Orlicz型的空间),这里0...  相似文献   

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