共查询到20条相似文献,搜索用时 31 毫秒
1.
Pu Zhang 《数学学报(英文版)》2008,24(8):1387-1400
Let μ be the n-dimensional Marcinkiewicz integral and μb the multilinear commutator of μ. In this paper, the following weighted inequalities are proved for ω ∈ A∞ and 0 〈 p 〈 ∞,
||μ(f)||LP(ω)≤C|Mf|LP(ω) and ||μb(f)||LP(ω)≤C||ML(log L)^1/r f||LP(ω).
The weighted weak L(log L)^1/r -type estimate is also established when p=1 and ω∈A1. 相似文献
||μ(f)||LP(ω)≤C|Mf|LP(ω) and ||μb(f)||LP(ω)≤C||ML(log L)^1/r f||LP(ω).
The weighted weak L(log L)^1/r -type estimate is also established when p=1 and ω∈A1. 相似文献
2.
K-functional, weighted moduli of smoothness, and best weighted polynomial approximation on a simplex
Song Li 《数学学报(英文版)》1999,15(3):395-406
An inverse theorem for the best weighted polynomial approximation of a function in
(S) is established. We also investigate Besov spaces generated by Freud weight and their connection with algebraic polynomial
approximation in
, wherew
α is a Jacobi-type weight onS, 0<p ≤ ∞,S is a simplex andW
λ is a Freud weight. For Ditzian-TotikK-functionals onL
p(S), 1 ≤p ≤ ∞, we obtain a new equivalence expression. 相似文献
3.
The asymptotic expansions are studied for the vorticity
to 2D incompressible Euler equations with-initial vorticity
, where ϕ0(x) satisfies |d ϕ0(x)|≠0 on the support of
and
is sufficiently smooth and with compact support in ℝ2 (resp. ℝ2×T) The limit,v(t,x), of the corresponding velocity fields {v
ɛ(t,x)} is obtained, which is the unique solution of (E) with initial vorticity ω0(x). Moreover,
(ℤ2)) for all 1≽p∞, where
and ϕ(t,x) satisfy some modulation equation and eikonal equation, respectively. 相似文献
4.
Yu. V. Sadovnichii 《Journal of Mathematical Sciences》2006,136(5):4156-4165
The main result of this paper consists of two theorems. One of them asserts that the functor U
τ takes the 0-soft mappings between spaces of weight ≤ω
1 and Polish spaces to soft mappings. The other theorem, which is a corollary of the first one, asserts that the functor U
τ takes the AE(0)-spaces of weight ≤ω
1 to AE-spaces. These theorems are proved under Martin’s axiom MA(ω
1). The results cannot be extended to spaces of weight ≥ω
2. For spaces of weight ω
1, these results cannot be obtained without additional set-theoretic assumptions. Thus, the question as to whether the space
is an absolute extensor cannot be answered in ZFC. The main result cannot be transferred to the functor U
R
of the unit ball of Radon measures. Indeed, the space
is not real-compact and, therefore,
.
__________
Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 9, No. 4, pp. 41–54, 2003. 相似文献
5.
Wang Yuan 《数学学报(英文版)》1993,9(4):382-389
Let
be a quadratic form with integer coefficients and letp denote a prime. Cochrane[1] proved that ifn≥4 then
has a solution
satisfying
, where
. The aim of the present paper is to generalize the above result to finite fields. 相似文献
6.
WangJianli ZhouSongping 《分析论及其应用》2003,19(3):280-288
The present paper deals with best onesided approximation rate in Lp spaces ^~En(f)Lp of f∈C2π.Although it is clear that the estimate ^~E(f)Lp≤C‖f‖Lp cannot be correct for all f∈L^p2π in case p<∞, the question whether ~En(f)Lp≤Cω(f,n^-l)Lp or ^~En(f)Lp≤CEn(f)Lp holds for f∈ C2π remains totally untouched.Therefore it forms a basic problem to justify onesided approximation. The present paper will provide an answer to settle down the basis. 相似文献
7.
Zhu Yaochen 《数学学报(英文版)》1988,4(4):364-371
Let
be a finitely generated extension field of ℚ, andα
i,βj(1⩽i⩽m,1⩽j⩽n) be some complex numbers. Let
(k=1,2,3) be fields obtained by adjoining to
the numbers {α
i,βj exp(αiβj)}, {αi, exp(αiβj)}, and {exp(αiβj)}, respectively. In the present note the relation between the transcendental degree of
over
and the transcendence type of
over ℚ is given.
This work was completed in Dpt. Math., Univ. of Southern Mississippi, Hattiesburg, USA. 相似文献
8.
By employing the generalized Riccati transformation technique, we will establish some new oscillation criteria and study the
asymptotic behavior of the nonoscillatory solutions of the second-order nonlinear neutral delay dynamic equation
, on a time scale . The results improve some oscillation results for neutral delay dynamic equations and in the special case when = ℝ our results cover and improve the oscillation results for second-order neutral delay differential equations established
by Li and Liu [Canad. J. Math., 48 (1996), 871–886]. When = ℕ, our results cover and improve the oscillation results for second order neutral delay difference equations established
by Li and Yeh [Comp. Math. Appl., 36 (1998), 123–132]. When =hℕ, = {t: t = q
k
, k ∈ ℕ, q > 1}, = ℕ2 = {t
2: t ∈ ℕ}, = = {t
n
= Σ
k=1
n
, n ∈ ℕ0}, ={t
2: t ∈ ℕ}, = {√n: n ∈ ℕ0} and ={: n ∈ ℕ0} our results are essentially new. Some examples illustrating our main results are given.
相似文献
9.
Consider the parameter space Θ which is an open subset of ℝ
k
,k≧1, and for each θ∈Θ, let the r.v.′sY
n
,n=0, 1, ... be defined on the probability space (X,A,P
θ) and take values in a Borel setS of a Euclidean space. It is assumed that the process {Y
n
},n≧0, is Markovian satisfying certain suitable regularity conditions. For eachn≧1, let υ
n
be a stopping time defined on this process and have some desirable properties. For 0 < τ
n
→ ∞ asn→∞, set
h
n
→h ∈R
k
, and consider the log-likelihood function
of the probability measure
with respect to the probability measure
. Here
is the restriction ofP
θ to the σ-field induced by the r.v.′sY
0,Y
1, ...,
. The main purpose of this paper is to obtain an asymptotic expansion of
in the probability sense. The asymptotic distribution of
, as well as that of another r.v. closely related to it, is obtained under both
and
.
This research was supported by the National Science Foundation, Grant MCS77-09574.
Research supported by the National Science Foundation, Grant MCS76-11620. 相似文献
10.
Chen Hua 《数学学报(英文版)》1997,13(1):81-89
In this paper, we study the asymptotic behaviour of the scattering phases(λ) of the Dirichlet Laplacian associated with obstacle
, where Ω is a bounded open subset of ℝ
n
(n≥2) with non-smooth boundary ∂Ω and connected complement Ω
e
=ℝ
n
. We can prove that if Ω satisfies a certain geometrical condition, then
where
,d
n>0 depending only onn, and |·|
j
(j = n - l, n) is aj- dimensional Lebesgue measure.
Research partially supported by the Natural Science Foundation of China and the Grant of Chinese State Education Committee 相似文献
11.
E. Odell 《Israel Journal of Mathematics》1976,23(3-4):353-367
It is shown that ifX is a complemented subspace of (Σ
(1<p<∞), thenX is isomorphic to eitherl
2,l
p,l
2⊗l
p or (Σ
. IfX is a complemented subspace ofC
p(1<p<∞) which does not contain an isomorph of (Σ which does not contain an isomorph of thenX is isomorphic to a complemented subspace of (Σ
⊗l
2.
This research was partially supported by NSF MPS 72-04634-A03. 相似文献
12.
E. M. E. ZAYED 《数学学报(英文版)》2005,21(4):733-752
The trace of the wave kernel μ(t) =∑ω=1^∞ exp(-itEω^1/2), where {Eω}ω^∞=1 are the eigenvalues of the negative Laplacian -△↓2 = -∑k^3=1 (δ/δxk)^2 in the (x^1, x^2, x^3)-space, is studied for a variety of bounded domains, where -∞ 〈 t 〈 ∞ and i= √-1. The dependence of μ (t) on the connectivity of bounded domains and the Dirichlet, Neumann and Robin boundary conditions are analyzed. Particular attention is given for a multi-connected vibrating membrane Ω in Ra surrounded by simply connected bounded domains Ω j with smooth bounding surfaces S j (j = 1,……, n), where a finite number of piecewise smooth Dirichlet, Neumann and Robin boundary conditions on the piecewise smooth components Si^* (i = 1 + kj-1,……, kj) of the bounding surfaces S j are considered, such that S j = Ui-1+kj-1^kj Si^*, where k0=0. The basic problem is to extract information on the geometry Ω by using the wave equation approach from a complete knowledge of its eigenvalues. Some geometrical quantities of Ω (e.g. the volume, the surface area, the mean curvuture and the Gaussian curvature) are determined from the asymptotic expansion ofexpansion of μ(t) for small │t│. 相似文献
13.
Saharon Shelah 《Israel Journal of Mathematics》1980,35(4):257-285
We prove some theorems on uncountable abelian groups, and consistency results promised in the first part, and also that a
variant of
called ♣ (club), is consistent with 2ℵ
0<ℵ1.
The author would like to thank the United States-Israel Binational Science Foundation for Grant 1110 and the NSF for Grant
MCS-08479. 相似文献
14.
In this paper, we consider some classes of 2π-periodic convolution functions Bp, and Kp with kernels having certain oscillation properties, which include the classical Sobolev class as special case. With the help of the spectral of nonlinear integral equations, we determine the exact values of Bernstein n-width of the classes Bp, Kp in the space Lp for 1 〈 p 〈 ∞. 相似文献
15.
R. E. Maiboroda 《Ukrainian Mathematical Journal》1998,50(7):1067-1079
For a process X(t)=Σ
j=1
M
g
j
(t)ξ
j
(), where gj(t) are nonrandom given functions, is a stationary vector-valued Gaussian process, Eξk(t) = 0, and Eξk(0) Eξl(τ) = r
kl(τ), we construct an estimate for the functions r
kl(τ) on the basis of observations X(t), t ∈ [0, T]. We establish conditions for the asymptotic normality of as T → ∞. We consider the problem of the optimal choice of parameters of the estimate depending on observations.
Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 50, No. 7, pp. 937–947, July, 1998. 相似文献
16.
Gerd Herzog 《Periodica Mathematica Hungarica》1995,30(3):205-210
Given a sequence (
n
)
n
in
with
there are functions
such that
, is a dense subset of
, and the set of functions with this property is residual in
. We will show that in
and some related Banach spaceX there are functionsf with
is dense in
, and we will give a sufficient condition when the set of such functions is residual inX. 相似文献
17.
In this paper we mainly study the derivations for even part of the finite-dimensional odd Hamiltonian superalgebra HO over a field of prime characteristic. We first give the generating set of the even part g of HO. Then we compute the derivations from g into the even part m of the generalized Witt superalgebra. Finally, we determine the derivation algebra and outer derivation algebra of and the dimension formulas. In particular, the first cohomology groups H^1(g;m) and H^1(g;g) are determined. 相似文献
18.
Herz-type Triebel-Lizorkin Spaces, Ⅰ 总被引:1,自引:0,他引:1
Jing Shi XU Da Chun YANG 《数学学报(英文版)》2005,21(3):643-654
Let s ∈R,0〈β≤∞, 0〈 q, p〈 ∞ and-n/q〈α. In this paper the authors introduce the Herz-type Triebel-Lizorkin spaces,Kq^α,pFβ^s(R^n)andKq^α,pFβ^s(R^n)which are the generalizations of the well-known Herz-type spaces and the inhomogeneous Triebel-Lizorkin spaces, Some properties on these Herz-type Triebel Lizorkin spaces are also given. 相似文献
19.
Saharon Shelah 《Israel Journal of Mathematics》1975,20(2):127-148
We investigate the categoricity and number of non-isomorphic models in ℵ1 of sentences in
. AssumingV=L we prove that no sentence in
has exactly one uncountable model. Thus partially answering problem 24 of a problem list by Friedman. 相似文献
20.
Let
be a unit sphere of the d–dimensional Euclidean space ℝ
d
and let
(0 < p ≤ 1) denote the real Hardy space on
For 0 < p ≤ 1 and
let
E
j
(f,H
p
) (j = 0, 1, ...) be the best approximation of f by spherical polynomials of degree less than or
equal to j, in the space
Given a distribution f on
its Cesàro mean of order δ > –1 is
denoted by
For 0 < p ≤ 1, it is known that
is the critical index for the uniform
summability of
in the metric H
p
. In this paper, the following result is proved:
Theorem
Let
0<p<1 and
Then for
where
A
N
(f)≈B
N
(f) means that there’s a positive constant C, independent of N and f, such that
In the case
d = 2, this result was proved by Belinskii in 1996.
The authors are partially supported by NNSF of China under the grant # 10071007 相似文献