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1.
Let {R n } n≥0 be a binary linear recurrence defined by R n+2 = A R n+1 + B R n (n ≥ 0), where A, B, R 0, R 1 are integers and Δ = A 2 + 4B > 0. We give necessary and sufficient conditions for the transcendence of the numbers
where r ≥ 2 is an integer, {a k } k ≥ 0 is a linear recurrence of algebraic numbers, and b is an algebraic number. We remove the condition assumed in the preceding work that A ≠ 0 and Δ is not a perfect square.   相似文献   

2.
3.
Let k be a field and A be a separable k-algebra. Let r ≥ 3 be an integer. Generalizing a result of Reichstein (Arch. Math. 88 (2007), 12–18), we prove that the essential dimension over k of A equals that of the r-fold trace form
Fr: (a1,?,ar)? tr(a1?ar)F_r: (a_1,\ldots,a_r)\mapsto \mbox{tr}(a_1\ldots a_r)  相似文献   

4.
On the universal A.S. central limit theorem   总被引:1,自引:0,他引:1  
Let (X k ) be a sequence of independent r.v.’s such that for some measurable functions gk : R k R a weak limit theorem of the form
holds with some distribution function G. By a general result of Berkes and Csáki (“universal ASCLT”), under mild technical conditions the strong analogue
is also valid, where (d k ) is a logarithmic weight sequence and D N = ∑ k=1 N d k . In this paper we extend the last result for a very large class of weight sequences (d k ), leading to considerably sharper results. We show that logarithmic weights, used traditionally in a.s. central limit theory, are far from optimal and the theory remains valid with averaging procedures much closer to, in some cases even identical with, ordinary averages.   相似文献   

5.
Let β 0=0.308443… denote the Littlewood-Salem-Izumi number, i.e., the unique solution of the equation
In this paper it is proved that if a 0a 1⋅⋅⋅a n >0 and , k≥1 then for all θ∈(0,π)
and furthermore, the number β 0 is best possible in the sense that for any β∈(0,β 0)
where the coefficients c k (β) are defined as
Results for the sine sums are obtained as well. These results generalize and sharpen the well known trigonometric inequalities of Vietoris. This research was supported by a grant from the Australian Research Council. The second author was also supported in part by the NSERC Canada under grant G121211001. The third author was also supported in part by the NSFC of China under grant 10471010.  相似文献   

6.
We present results on total domination in a partitioned graph G = (V, E). Let γ t (G) denote the total dominating number of G. For a partition , k ≥ 2, of V, let γ t (G; V i ) be the cardinality of a smallest subset of V such that every vertex of V i has a neighbour in it and define the following
We summarize known bounds on γ t (G) and for graphs with all degrees at least δ we derive the following bounds for f t (G; k) and g t (G; k).
(i)  For δ ≥ 2 and k ≥ 3 we prove f t (G; k) ≤ 11|V|/7 and this inequality is best possible.
(ii)  for δ ≥ 3 we prove that f t (G; 2) ≤ (5/4 − 1/372)|V|. That inequality may not be best possible, but we conjecture that f t (G; 2) ≤ 7|V|/6 is.
(iii)  for δ ≥ 3 we prove f t (G; k) ≤  3|V|/2 and this inequality is best possible.
(iv)  for δ ≥ 3 the inequality g t (G; k) ≤ 3|V|/4 holds and is best possible.
  相似文献   

7.
In this paper, we prove the following. Let be a Cohen-Macaulay local ring of dimension d ≥ 2. Suppose that either R is not regular or if R is regular assume that d ≥ 3. Let t ≥ 2 be a positive integer. If is a regular sequence contained in , then
This result gives an affirmative answer to a conjecture raised by Polini and Ulrich. The author is partially supported by N.S.C. Taiwan.  相似文献   

8.
Let G be a graph with n vertices, m edges and a vertex degree sequence (d 1, d 2,..., d n ), where d 1d 2 ≥ ... ≥ d n . The spectral radius and the largest Laplacian eigenvalue are denoted by ϱ(G) and μ(G), respectively. We determine the graphs with
and the graphs with d n ≥ 1 and
We also present some sharp lower bounds for the Laplacian eigenvalues of a connected graph. The work was supported by National Nature Science Foundation of China (10201009), Guangdong Provincial Natural Science Foundation of China (021072) and Com2MaC-KOSEF  相似文献   

9.
Letf(X) be an additive form defined by
wherea i ≠0 is integer,i=1,2…,s. In 1979, Schmidt proved that if ∈>0 then there is a large constantC(k,∈) such that fors>C(k,∈) the equationf(X)=0 has a nontrivial, integer solution in σ1, σ2, …, σ3,x 1,x 2, …,x 3 satisfying
Schmidt did not estimate this constantC(k,∈) since it would be extremely large. In this paper, we prove the following result  相似文献   

10.
For positive integers with a r  = 2, the multiple zeta value or r-fold Euler sum is defined as [2]
. There is a celebrated sum formula [6, 10] among multiple zeta values as
, where range over all positive integers with in the summation. In this paper, we shall prove the so called restricted sum formula [4]. Namely, for all positive integers m and q with m ≥ q and a nonnegative integer p, that
. We prove the assertion by new expressions of multiple zeta values in terms of Drinfeld integrals. This work was supported by the Department of Mathematics, National Chung Cheng University and by the National Science Council of Taiwan, Republic of China.  相似文献   

11.
We determine exact values for the k-error linear complexity L k over the finite field of the Legendre sequence of period p and the Sidelnikov sequence of period p m  − 1. The results are
for 1 ≤ k ≤ (p m  − 3)/2 and for k≥ (p m  − 1)/2. In particular, we prove
  相似文献   

12.
An exact expression for the extreme values of the integer vector that maximize the function
for arbitrary integersl 1>0, ...,l k >0,k≥2, and a givenN 0=N 1+...+N k is derived. Also, statistical applications of the result are discussed. Translated fromMatematicheskie Zametki, Vol. 62, No. 2, pp. 216–222, August, 1997. Translated by G. I. Ivchenko  相似文献   

13.
We show that the essential dimension of a finite-dimensional central simple algebra coincides with the essential dimension of its r-linear trace form, for any r ≥ 3. Received: 15 March 2006  相似文献   

14.
15.
For a trigonometric series
defined on [−π, π) m , where V is a certain polyhedron in R m , we prove that
if the coefficients a k satisfy the following Sidon-Telyakovskii-type conditions:
Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 60, No. 5, pp. 579–585, May, 2008.  相似文献   

16.
We consider some classes of 2π-periodic functions defined by a class of operators having certain oscillation properties, which include the classical Sobolev class and a class of analytic functions which can not be represented as a convolution class as its special cases. Let be the largest integer not bigger than x. We prove that on these classes of functions the rectangular formula
is optimal among all quadrature formulae of the form
where the nodes 0 ≤  t 1 < ... < t n  < 2π and the coefficients (weights) are arbitrary, i = 1,...,nj = 0,1,..., ν i − 1, and (ν1,...,ν n ) is a system of positive integers satisfying the condition . In particular, the rectangular formula is optimal for these classes of functions among all quadrature formulae of the form
with free nodes 0 ≤  t 1 <  ... < t N <  2π and arbitrary weights . Moreover, we exactly determine the error estimates of the optimal quadrature formulae on these classes of functions.Project supported by the National Natural Science Foundation of China (Grant No. 10671019) and Research Fund for the Doctoral Program Higher Education (Grant No. 20050027007).  相似文献   

17.
We study the limit as n goes to +∞ of the renormalized solutions u n to the nonlinear elliptic problems
where Ω is a bounded open set of ℝ N , N≥ 2, and μ is a Radon measure with bounded variation in Ω. Under the assumption of G-convergence of the operators , defined for , to the operator , we shall prove that the sequence (u n ) admits a subsequence converging almost everywhere in Ω to a function u which is a renormalized solution to the problem
  相似文献   

18.
For a sequence of i.i.d. Banach space-valued random variables {Xn; n ≥ 1} and a sequence of positive constants {an; n ≥ 1}, the relationship between the Baum-Katz-Spitzer complete convergence theorem and the law of the iterated logarithm is investigated. Sets of conditions are provided under which (i) lim sup n→∞ ||Sn||/an〈∞ a.s.and ∞ ∑n=1(1/n)P(||Sn||/an ≥ε〈∞for all ε 〉 λ for some constant λ ∈ [0, ∞) are equivalent; (ii) For all constants λ ∈ [0, ∞), lim sup ||Sn||/an =λ a.s.and ^∞∑ n=1(1/n) P(||Sn||/an ≥ε){〈∞, if ε〉λ =∞,if ε〈λare equivalent. In general, no geometric conditions are imposed on the underlying Banach space. Corollaries are presented and new results are obtained even in the case of real-valued random variables.  相似文献   

19.
Essentially sharp bounds for small prime solutionsp j ,q i of the following two different types of equations are obtained.
  相似文献   

20.
We consider quadratic forms of the type
where Xj are i.i.d. random variables with common distribution F and finite fourth moment, denotes a symmetric matrix with eigenvalues λ1, ..., λN ordered to be non-increasing in absolute value. We prove explicit bounds in terms of sums of 4th powers of entries of the matrix A and the size of the eigenvalue λ13 for the approximation of the distribution of Q(F,A) by the distribution of Q (φ, A) where φ is standard Gaussian distribution. In typical cases this error is of optimal order Supported by the DFG-Forschergruppe FOR 399/1-1 at Bielefeld. Partially supported by INTAS N 03-51-5018. Partially supported by RFBR and RFBR–DFG, grants NN 02-01-00233, 04-01-04000  相似文献   

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