共查询到20条相似文献,搜索用时 779 毫秒
1.
Friedrich Roesler 《Archiv der Mathematik》1999,73(3):193-198
Abstract. For natural numbers n we inspect all factorizations n = ab of n with a £ ba \le b in \Bbb N\Bbb N and denote by n=an bnn=a_n b_n the most quadratic one, i.e. such that bn - anb_n - a_n is minimal. Then the quotient k(n) : = an/bn\kappa (n) := a_n/b_n is a measure for the quadraticity of n. The best general estimate for k(n)\kappa (n) is of course very poor: 1/n £ k(n) £ 11/n \le \kappa (n)\le 1. But a Theorem of Hall and Tenenbaum [1, p. 29], implies(logn)-d-e £ k(n) £ (logn)-d(\log n)^{-\delta -\varepsilon } \le \kappa (n) \le (\log n)^{-\delta } on average, with d = 1 - (1+log2 2)/log2=0,08607 ?\delta = 1 - (1+\log _2 \,2)/\log 2=0,08607 \ldots and for every e > 0\varepsilon >0. Hence the natural numbers are fairly quadratic.¶k(n)\kappa (n) characterizes a specific optimal factorization of n. A quadraticity measure, which is more global with respect to the prime factorization of n, is k*(n): = ?1 £ a £ b, ab=n a/b\kappa ^*(n):= \textstyle\sum\limits \limits _{1\le a \le b, ab=n} a/b. We show k*(n) ~ \frac 12\kappa ^*(n) \sim \frac {1}{2} on average, and k*(n)=W(2\frac 12(1-e) log n/log 2n)\kappa ^*(n)=\Omega (2^{\frac {1}{2}(1-\varepsilon ) {\log}\, n/{\log} _2n})for every e > 0\varepsilon>0. 相似文献
2.
Li Xin Zhang 《数学学报(英文版)》2008,24(4):631-646
Let X, X1, X2,... be i.i.d, random variables with mean zero and positive, finite variance σ^2, and set Sn = X1 +... + Xn, n≥1. The author proves that, if EX^2I{|X|≥t} = 0((log log t)^-1) as t→∞, then for any a〉-1 and b〉 -1,lim ε↑1/√1+a(1/√1+a-ε)b+1 ∑n=1^∞(logn)^a(loglogn)^b/nP{max κ≤n|Sκ|≤√σ^2π^2n/8loglogn(ε+an)}=4/π(1/2(1+a)^3/2)^b+1 Г(b+1),whenever an = o(1/log log n). The author obtains the sufficient and necessary conditions for this kind of results to hold. 相似文献
3.
H. Crauel 《Archiv der Mathematik》2000,75(6):472-480
Let x1,..., xn be points in the d-dimensional Euclidean space Ed with || xi-xj|| £ 1\| x_{i}-x_{j}\| \le 1 for all 1 \leqq i,j \leqq n1 \leqq i,j \leqq n, where || .||\| .\| denotes the Euclidean norm. We ask for the maximum M(d,n) of \mathop?i, j=1n|| xi-xj|| 2\textstyle\mathop\sum\limits _{i,\,j=1}^{n}\| x_{i}-x_{j}\| ^{2} (see [4]). This paper deals with the case d = 2. We calculate M(2, n) and show that the value M(2, n) is attained if and only if the points are distributed as evenly as possible among the vertices of a regular triangle of edge-length 1. Moreover we give an upper bound for the value \mathop?i, j=1n|| xi-xj|| \textstyle\mathop\sum\limits _{i,\,j=1}^{n}\| x_{i}-x_{j}\| , where the points x1,...,xn are chosen under the same constraints as above. 相似文献
4.
The composition operators on weighted Bloch space 总被引:9,自引:0,他引:9
R. Yoneda 《Archiv der Mathematik》2002,78(4):310-317
We will characterize the boundedness and compactness of the composition operators on weighted Bloch space B log = { f ? H(D): supz ? D (1-| z|2) ( log\frac21-| z|2 )| f¢(z)| B_{ \log }= \{ f \in H(D): \sup_{z \in D } (1-\left| z\right|^2) \left( \log \frac{2}{1-\left| z\right|^2} \right)\left| f'(z)\right| < +¥} +\infty \} , where H(D) be the class of all analytic functions on D. 相似文献
5.
S. Wada 《Archiv der Mathematik》2001,77(5):415-422
A generalized Hlawka's inequality says that for any n (\geqq 2) (\geqq 2) complex numbers¶ x1, x2, ..., xn,¶¶ ?i=1n|xi - ?j=1nxj| \leqq ?i=1n|xi| + (n - 2)|?j=1nxj|. \sum_{i=1}^n\Bigg|x_i - \sum_{j=1}^{n}x_j\Bigg| \leqq \sum_{i=1}^{n}|x_i| + (n - 2)\Bigg|\sum_{j=1}^{n}x_j\Bigg|. ¶¶ We generalize this inequality to the trace norm and the trace of an n x n matrix A as¶¶ ||A - Tr A ||1 \leqq ||A||1 + (n - 2)| Tr A|. ||A - {\rm Tr} A ||_1\ \leqq ||A||_1 + (n - 2)| {\rm Tr} A|. ¶¶ We consider also the related inequalities for p-norms (1 \leqq p \leqq ¥) (1 \leqq p \leqq \infty) on matrices. 相似文献
6.
周泽华 《中国科学A辑(英文版)》2003,46(1):33-38
Let Un be the unit polydisc of Cn and φ= (φ1,...,φn? a holomorphic self-map of Un. Let 0≤α< 1. This paper shows that the composition operator Cφ, is bounded on the Lipschitz space Lipa(Un) if and only if there exists M > 0 such thatfor z∈Un. Moreover Cφ is compact on Lipa(Un) if and only if Cφ is bounded on Lipa(Un) and for every ε > 0, there exists a δ > 0 such that whenever dist(φ(z),σUn) <δ 相似文献
7.
Shaun Cooper 《The Ramanujan Journal》2002,6(4):469-490
Let r
k(n) denote the number of representations of an integer n as a sum of k squares. We prove that
where
Here n = 2 p
p
p
is the prime factorisation of n, n is the square-free part of n, the products are taken over the odd primes p, and (
) is the Legendre symbol.Some similar formulas for r
7(n) and r
9(n) are also proved. 相似文献
8.
Wei HUANG Ye JIANG Li Xin ZHANG 《数学学报(英文版)》2005,21(5):1057-1070
Let {X,Xn;n ≥ 1} be a strictly stationary sequence of ρ-mixing random variables with mean zeros and finite variances. Set Sn =∑k=1^n Xk, Mn=maxk≤n|Sk|,n≥1.Suppose limn→∞ESn^2/n=:σ^2〉0 and ∑n^∞=1 ρ^2/d(2^n)〈∞,where d=2 if 1≤r〈2 and d〉r if r≥2.We prove that if E|X|^r 〈∞,for 1≤p〈2 and r〉p,then limε→0ε^2(r-p)/2-p ∑∞n=1 n^r/p-2 P{Mn≥εn^1/p}=2p/r-p ∑∞k=1(-1)^k/(2k+1)^2(r-p)/(2-p)E|Z|^2(r-p)/2-p,where Z has a normal distribution with mean 0 and variance σ^2. 相似文献
9.
Precise Rates in the Law of Iterated Logarithm for the Moment of I.I.D. Random Variables 总被引:1,自引:0,他引:1
Ye JIANG Li Xin ZHANG 《数学学报(英文版)》2006,22(3):781-792
Let{X,Xn;n≥1} be a sequence of i,i.d, random variables, E X = 0, E X^2 = σ^2 〈 ∞.Set Sn=X1+X2+…+Xn,Mn=max k≤n│Sk│,n≥1.Let an=O(1/loglogn).In this paper,we prove that,for b〉-1,lim ε→0 →^2(b+1)∑n=1^∞ (loglogn)^b/nlogn n^1/2 E{Mn-σ(ε+an)√2nloglogn}+σ2^-b/(b+1)(2b+3)E│N│^2b+3∑k=0^∞ (-1)k/(2k+1)^2b+3 holds if and only if EX=0 and EX^2=σ^2〈∞. 相似文献
10.
Bodo Dittmar 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2009,95(1):565-568
For a simply connected and normalized domain D in the plane it was proven by Pólya and Schiffer in 1954 for the fixed membrane eigenvalues
?n1 \frac1lj 3 ?n1 \frac1l(0)j\sum \limits^{n}_{1} \frac{1}{{\lambda}_j} \geq \sum \limits^{n}_{1} \frac{1}{{\lambda}^{(0)}_j} 相似文献
11.
K. Petras 《Acta Mathematica Hungarica》1999,83(3):241-250
Denote by R
n
G
the remainder functional of the Gaussian quadrature formula involving n nodes. Using an elementary method, we derive the asymptotically best possible inequalities
12.
A. Erfanian 《Archiv der Mathematik》2002,78(4):257-262
The aim of this paper is to give a lower bound for h(2, An), where h(2, An) is the maximum number such that Anh(2, An) A_n^{h(2, A_n)} can be generated by 2 elements, where An is the alternating group on n symbols, and n \geqq 5 n \geqq 5 . Kantor and Lubotzky (1990) gave a lower bound¶ \fracn!8 \frac{n!}{8} for sufficiently large n by the probability of generating the symmetric group. I have improved the above lower bound to \fracn!5 \frac{n!}{5} for large n, using a different method. 相似文献
13.
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
14.
L. Losonczi 《Aequationes Mathematicae》1999,58(3):223-241
Summary. Let F, Y \Phi, \Psi be strictly monotonic continuous functions, F,G be positive functions on an interval I and let n ? \Bbb N \{1} n \in {\Bbb N} \setminus \{1\} . The functional equation¶¶F-1 ([(?i=1nF(xi)F(xi))/(?i=1n F(xi)]) Y-1 ([(?i=1nY(xi)G(xi))/(?i=1n G(xi))]) (x1,?,xn ? I) \Phi^{-1}\,\left({\sum\limits_{i=1}^{n}\Phi(x_{i})F(x_{i})\over\sum\limits_{i=1}^{n} F(x_{i}}\right) \Psi^{-1}\,\left({\sum\limits_{i=1}^{n}\Psi(x_{i})G(x_{i})\over\sum\limits_{i=1}^{n} G(x_{i})}\right)\,\,(x_{1},\ldots,x_{n} \in I) ¶was solved by Bajraktarevi' [3] for a fixed n 3 3 n\ge 3 . Assuming that the functions involved are twice differentiable he proved that the above functional equation holds if and only if¶¶Y(x) = [(aF(x) + b)/(cF(x) + d)], G(x) = kF(x)(cF(x) + d) \Psi(x) = {a\Phi(x)\,+\,b\over c\Phi(x)\,+\,d},\qquad G(x) = kF(x)(c\Phi(x) + d) ¶where a,b,c,d,k are arbitrary constants with k(c2+d2)(ad-bc) 1 0 k(c^2+d^2)(ad-bc)\ne 0 . Supposing the functional equation for all n = 2,3,... n = 2,3,\dots Aczél and Daróczy [2] obtained the same result without differentiability conditions.¶The case of fixed n = 2 is, as in many similar problems, much more difficult and allows considerably more solutions. Here we assume only that the same functional equation is satisfied for n = 2 and solve it under the supposition that the functions involved are six times differentiable. Our main tool is the deduction of a sixth order differential equation for the function j = F°Y-1 \varphi = \Phi\circ\Psi^{-1} . We get 32 new families of solutions. 相似文献
15.
Zhi-Wei Sun 《Israel Journal of Mathematics》2002,128(1):135-156
In this paper we study [
r
n
]
m
=Σ
k≡r(modm) (
k
n
) wherem>0,n≥0 andr are integers. We show that [
r
n
]
m
(m>2) can be expressed in terms of some linearly recurrent sequences with orders not exceeding ϕ(m)/2. In particular, we determine [
r
n
]
12
explicitly in terms of first order and second order recurrences. It follows that for any primep>3 we have
and
.
The research is supported by the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions
of MOE, and the National Natural Science Foundation of P. R. China. 相似文献
16.
V. A. Sadovnichii 《Mathematical Notes》1973,14(2):717-723
We investigate the question of the regularized sums of part of the eigenvalues zn (lying along a direction) of a Sturm-Liouville operator. The first regularized sum is $$\sum\nolimits_{n = 1}^\infty {(z_n - n - \frac{{c_1 }}{n} + \frac{2}{\pi } \cdot z_n arctg \frac{1}{{z_n }} - \frac{2}{\pi }) = \frac{{B_2 }}{2} - c_1 \cdot \gamma + \int_1^\infty {\left[ {R(z) - \frac{{l_0 }}{{\sqrt z }} - \frac{{l_1 }}{z} - \frac{{l_2 }}{{z\sqrt z }}} \right]} } \sqrt z dz,$$ where the zn are eigenvalues lying along the positive semi-axis, z n 2 =λn, $$l_0 = \frac{\pi }{2}, l_1 = - \frac{1}{2}, l_2 = - \frac{1}{4}\int_0^\pi {q(x) dx,} c_1 = - \frac{2}{\pi }l_2 ,$$ , B2 is a Bernoulli number, γ is Euler's constant, and \(R(z)\) is the trace of the resolvent of a Sturm-Liouville operator. 相似文献
17.
Let u = (u
n
) be a sequence of real numbers whose generator sequence is Cesàro summable to a finite number. We prove that (u
n
) is slowly oscillating if the sequence of Cesàro means of (ω
n
(m−1)(u)) is increasing and the following two conditions are hold:
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