共查询到20条相似文献,搜索用时 312 毫秒
1.
Guo Xin WEI 《数学学报(英文版)》2007,23(6):1075-1082
In this paper, we give a characterization of tori S^1 ( √ nr+2-n/nr)×S^n-1(√ n-2/nr) and S^m ( √n/m ) ×S^n-m (√n-m/n). Our result extends the result due to Li (1996)on the condition that M is an n-dimensional complete hypersurface in Sn+1 with two distinct principal curvatures. Keywords principal curvature, Clifford torus, Gauss equations 相似文献
2.
Michel WEBER 《数学学报(英文版)》2006,22(2):377-382
Let D be an increasing sequence of positive integers, and consider the divisor functions:
d(n, D) =∑d|n,d∈D,d≤√n1, d2(n,D)=∑[d,δ]|n,d,δ∈D,[d,δ]≤√n1,
where [d,δ]=1.c.m.(d,δ). A probabilistic argument is introduced to evaluate the series ∑n=1^∞and(n,D) and ∑n=1^∞and2(n,D). 相似文献
3.
Isotropic bodies and Bourgain's problem 总被引:1,自引:0,他引:1
HE Binwu & LENG Gangsong Department of Mathematics Shanghai University Shanghai China 《中国科学A辑(英文版)》2005,48(5):666-679
Let K (?) Rn be a convex body of volume 1 whose barycenter is at the origin, LK be the isotropic constant of K. Finding the least upper bound of LK , being called Bourgain's problem, is a well known open problem in the local theory of Banach space. The best estimate known today is LK < cn1/4 log n, recently shown by Bourgain, for an arbitrary convex body in any finite dimension. Utilizing the method of spherical section function, it is proven that if K is a convex body with volume 1 and r1Bn2 (?) K (?) r2Bn2,(r1≥1/2, r2≤(?)/2), then (?) ≤(?) and find the conditions with equality. Further, the geometric characteristic of isotropic bodies is shown. 相似文献
4.
Precise Asymptotics in the Law of the Iterated Logarithm of Moving-Average Processes 总被引:1,自引:0,他引:1
Yun Xia LI Li Xin ZHANG 《数学学报(英文版)》2006,22(1):143-156
In this paper, we discuss the moving-average process Xk = ∑i=-∞ ^∞ ai+kεi, where {εi;-∞ 〈 i 〈 ∞} is a doubly infinite sequence of identically distributed ψ-mixing or negatively associated random variables with mean zeros and finite variances, {ai;-∞ 〈 i 〈 -∞) is an absolutely solutely summable sequence of real numbers. 相似文献
5.
Let X, X1 , X2 , . . . be i.i.d. random variables, and set Sn = X1 +···+Xn , Mn = maxk≤n |Sk|, n ≥1. Let an = o( (n)(1/2)/logn). By using the strong approximation, we prove that, if EX = 0, VarX = σ2 0 and E|X| 2+ε ∞ for some ε 0, then for any r 1, lim ε1/(r-1)(1/2) [ε-2-(r-1)]∞∑n=1 nr-2 P{Mn ≤εσ (π2n/(8log n))(1/2) + an } = 4/π . We also show that the widest a n is o( n(1/2)/logn). 相似文献
6.
Summary The members of the power divergence family of statistics
all have an asymptotically equivalent χ2 distribution (Cressie and Read [1]). An asymptotic expansion for the distribution function is derived which shows that the
speed of convergence to this asymptotic limit is dependent on λ. Known results for Pearson'sX
2 statistic and the log-likelihood ratio statistic then appear as special cases in a continuum rather than as separate (unrelated)
expansions. 相似文献
7.
In [6] it is shown that the hexagonal circle packing rigidity constants s
n
satisfy
$\lim_{n\rightarrow \infty}ns_n=\displaystyle{\frac{2\sqrt[3]{2}
\Gamma^2({1}/{3})}{3\Gamma({2}/{3})}}.$\lim_{n\rightarrow \infty}ns_n=\displaystyle{\frac{2\sqrt[3]{2}
\Gamma^2({1}/{3})}{3\Gamma({2}/{3})}}. 相似文献
8.
Yuexu Zhao 《Bulletin of the Brazilian Mathematical Society》2006,37(3):377-391
Let X1, X2, ... be i.i.d. random variables with EX1 = 0 and positive, finite variance σ2, and set Sn = X1 + ... + Xn. For any α > −1, β > −1/2 and for κn(ε) a function of ε and n such that κn(ε) log log n → λ as n ↑ ∞ and
, we prove that
9.
In the “lost notebook”, Ramanujan recorded infinite product expansions for
|