共查询到20条相似文献,搜索用时 31 毫秒
1.
Frank Blume 《Israel Journal of Mathematics》1998,108(1):1-12
If (X,T) is a completely ergodic system, then there exists a positive monotone increasing sequence {a
n
}
n
1/∞
with lim
n
→∞a
n
=∞ and a positive concave functiong defined on [1, ∞) for whichg(x)/x
2 isnot integrable such that
for all nontrivial partitions α ofX into two sets. 相似文献
2.
A general result on precise asymptotics for linear processes of positively associated sequences 总被引:2,自引:0,他引:2
Let {εt; t ∈ Z^+} be a strictly stationary sequence of associated random variables with mean zeros, let 0〈Eε1^2〈∞ and σ^2=Eε1^2+1∑j=2^∞ Eε1εj with 0〈σ^2〈∞.{aj;j∈Z^+} is a sequence of real numbers satisfying ∑j=0^∞|aj|〈∞.Define a linear process Xt=∑j=0^∞ ajεt-j,t≥1,and Sn=∑t=1^n Xt,n≥1.Assume that E|ε1|^2+δ′〈 for some δ′〉0 and μ(n)=O(n^-ρ) for some ρ〉0.This paper achieves a general law of precise asymptotics for {Sn}. 相似文献
3.
Wlodzimier Greblicki Miroslaw Pawlak 《Annals of the Institute of Statistical Mathematics》1985,37(1):443-454
Summary In the paper we estimate a regressionm(x)=E {Y|X=x} from a sequence of independent observations (X
1,Y
1),…, (X
n, Yn) of a pair (X, Y) of random variables. We examine an estimate of a type
, whereN depends onn andϕ
N is Dirichlet kernel and the kernel associated with the hermite series. Assuming, that E|Y|<∞ and |Y|≦γ≦∞, we give condition for
to converge tom(x) at almost allx, provided thatX has a density. if the regression hass derivatives, then
converges tom(x) as rapidly asO(nC−(2s−1)/4s) in probability andO(n
−(2s−1)/4s logn) almost completely. 相似文献
4.
Saharon Shelah 《Israel Journal of Mathematics》2008,166(1):61-96
We show that, consistently, there is an ultrafilter on ω such that if N
nℓ = (P
nℓ ∪ Q
nℓ, P
nℓ, Q
nℓ, R
nℓ) (for ℓ = 1, 2, n < ω), P
nℓ ∪ Q
nℓ ⊆ ω, and are models of the canonical theory t
ind of the strong independence property, then every isomorphism from onto is a product isomorphism.
The first version of this work done in 93; First typed: May 1993.
This research was partially supported by the United States-Israel Binational Science Foundation. Publication 509 相似文献
5.
Shan-tao Liao 《Frontiers of Mathematics in China》2006,1(1):1-52
Let M
n
be an n-dimensional compact C
∞-differentiable manifold, n ≥ 2, and let S be a C
1-differential system on M
n
. The system induces a one-parameter C
1 transformation group φ
t
(−∞ < t < ∞) over M
n
and, thus, naturally induces a one-parameter transformation group of the tangent bundle of M
n
. The aim of this paper, in essence, is to study certain ergodic properties of this latter transformation group.
Among various results established in the paper, we mention here only the following, which might describe quite well the nature
of our study.
(A) Let M be the set of regular points in M
n
of the differential system S. With respect to a given C
∞ Riemannian metric of M
n
, we consider the bundle
of all (n−2) spheres Q
x
n−2, x∈M, where Q
x
n−2 for each x consists of all unit tangent vectors of M
n
orthogonal to the trajectory through x. Then, the differential system S gives rise naturally to a one-parameter transformation group ψ
t
#
(−∞<t<∞) of
. For an l-frame α = (u
1, u
2,⋯, u
l
) of M
n
at a point x in M, 1 ≥ l ≥ n−1, each u
i
being in
, we shall denote the volume of the parallelotope in the tangent space of M
n
at x with edges u
1, u
2,⋯, u
l
by υ(α), and let
. This is a continuous real function of t. Let
α is said to be positively linearly independent of the mean if I
+
*(α) > 0. Similarly, α is said to be negatively linearly independent of the mean if I
−
*(α) > 0.
A point x of M is said to possess positive generic index κ = κ
+
*(x) if, at x, there is a κ-frame
,
, of M
n
having the property of being positively linearly independent in the mean, but at x, every l-frame
, of M
n
with l >
κ does not have the same property. Similarly, we define the negative generic index κ
−
*(x) of x. For a nonempty closed subset F of M
n
consisting of regular points of S, invariant under φ
t
(−∞ < t < ∞), let the (positive and negative) generic indices of F be defined by
Theorem
κ
+
*(F)=κ
−
*(F).
(B) We consider a nonempty compact metric space x and a one-parameter transformation group ϕ
t
(−∞ < t < ∞) over X. For a given positive integer l ≥ 2, we assume that, to each x∈X, there are associated l-positive real continuous functions
of −∞ < t < ∞. Assume further that these functions possess the following properties, namely, for each of k = 1, 2,⋯, l,
for each x∈X, each −∞ < s < ∞, and each −∞ < t < ∞.
Theorem
With X, etc., given above, let μ
be a normal measure of X that is ergodic and invariant under ϕ
t
(−∞
< t < ∞). Then, for a certain permutation k→p(k) of k= 1, 2,⋯, l, the set W of points x of X such that all the inequalities
(I
k
)
(II
k
)
(k=2, 3,⋯, l) hold is invariant under ϕ
t
(−∞
< t < ∞) and is μ-measurable with μ-measure1.
In practice, the functions h
xk
(t) will be taken as length functions of certain tangent vectors of M
n
. This theory, established such as in this paper, is expected to be used in the study of structurally stable differential
systems on M
n
.
Translated from Qualitative Theory of Differentiable Dynamical Systems, Beijing, China: Science Press, 1996, by Dr. SUN Wen-xiang, School of Mathematical Sciences, Peking University, Beijing 100871,
China. The Chinese version of this paper was published in Acta Scientiarum Naturalium Universitatis Pekinensis, 1963, 9: 241–265, 309–326 相似文献
(i*) | h k (x, t) = h xk (t) is a continuous function of the Cartesian product X×(−∞, ∞). |
(ii*) |
6.
In this paper, the boundedness of Toeplitz operator T
b(f) related to strongly singular Calderón-Zygmund operators and Lipschitz function b ε
(ℝn) is discussed from L
p(ℝn) to L
q(ℝn),
, and from L
p(ℝn) to Triebel-Lizorkin space
. We also obtain the boundedness of generalized Toeplitz operator Θ
α0
b
from L
p(ℝn) to L
q(ℝn),
. All the above results include the corresponding boundedness of commutators. Moreover, the boundedness of Toeplitz operator
T
b(f) related to strongly singular Calderón-Zygmund operators and BMO function b is discussed on L
p(ℝn), 1 < p < ∞. 相似文献
7.
Piotr Niemiec 《Rendiconti del Circolo Matematico di Palermo》2008,57(3):391-399
The aim of the paper is to prove that every f ∈ L
1([0,1]) is of the form f = , where j
n,k
is the characteristic function of the interval [k- 1 / 2
n
, k / 2
n
) and Σ
n=0∞Σ
k=12n
|a
n,k
| is arbitrarily close to ||f|| (Theorem 2). It is also shown that if μ is any probabilistic Borel measure on [0,1], then for any ɛ > 0 there exists a sequence (b
n,k
)
n≧0
k=1,...,2n
of real numbers such that and for each Lipschitz function g: [0,1] → ℝ (Theorem 3).
相似文献
8.
Narcisse Randrianantoanina 《Israel Journal of Mathematics》2004,140(1):333-365
We prove a non-commutative version of the weak-type (1,1) boundedness of square functions of martingales. More precisely,
we prove that there is an absolute constantK with the following property: ifM is a semifinite von Neumann algebra with a faithful normal traceτ and (M
n
)
n=1
∞
is an increasing filtration of von Neumann subalgebras of (M then for any martingalex=
n=1
∞
inL
1(M,τ), adapted to (M
n
)
n=1
∞
, there is a decomposition into two sequences (x
n
)
n=1
∞
and (z
n
)
n=1
∞
withx
n=y
n+z
nfor everyn≥1 and such that
. This generalizes a result of Burkholder from classical martingale theory to non-commutative martingales. We also include
some applications to martingale Hardy spaces.
Supported in part by NSF grant DMS-0096696. 相似文献
9.
We consider the weighted Hardy integral operatorT:L
2(a, b) →L
2(a, b), −∞≤a<b≤∞, defined by
. In [EEH1] and [EEH2], under certain conditions onu andv, upper and lower estimates and asymptotic results were obtained for the approximation numbersa
n(T) ofT. In this paper, we show that under suitable conditions onu andv,
where ∥w∥p=(∫
a
b
|w(t)|p
dt)1/p.
Research supported by NSERC, grant A4021.
Research supported by grant No. 201/98/P017 of the Grant Agency of the Czech Republic. 相似文献
10.
Keiji Izuchi 《Journal d'Analyse Mathématique》1998,75(1):135-154
Letb be a Blaschke product with zeros {z
n
} in the open unit disk Δ. Let
be the set of sequences of non-negative integersp=(p
1,p
2,…) such that ∑
n=1
∞
p
n
(1 − |z
n
|) < ∞ andp
n
→∞ asn→∞. We study the class of weak infinite powers ofb,
Properties of these classes depend on the setS(b) of the cluster points in ∂Δ of {z
n
}. It is proved thatS(b)=∂Δ if and only if
, the Douglas algebra generated by
. Also, it is proved thatdθ(S(b))=0 if and only if there exists an interpolating Blaschke productB such that
. 相似文献
11.
Multilinear Singular Integrals with Rough Kernel 总被引:9,自引:0,他引:9
ShanZhenLU HuoXiongWU PuZHANG 《数学学报(英文版)》2003,19(1):51-62
For a class of multilinear singular integral operators T
A
,
where R
m
(A; x, y) denotes the m-th Taylor series remainder of A at x expanded about y, A has derivatives of order m − 1 in
is homogeneous of degree zero, the authors prove that T
A
is bounded from L
p
(ℝ
n
) to
and from L
1(ℝ
n
) to L
n/(n−β),∞(ℝ
n
) with the bound
And if Ω has vanishing moments of order m − 1 and satisfies some kinds of Dini regularity otherwise, then T
A
is also bounded from L
p
(ℝ
n
) to
with the bound
Supported by the National 973 Project (G1990751) and SEDF of China (20010027002) 相似文献
12.
Suppose that (F
n
)
n=1
∞
is a sequence of regular families of finite subsets of ℝ and (θ
n
)
n=1
∞
is a nonincreasing null sequence in (0,1). The mixed Tsirelson spaceT[(θ
n
,F
n
)
n=1
∞
] is the completion ofc
00 with respect to the implicitly defined norm
, where the last supremum is taken over all sequences (E
i
)
i=1
k
in [ℕ]<∞ such that maxE
i<minE
i
+1 and
. Necessary and sufficient conditions are obtained for the existence of higher order ℓ1-spreading models in every subspace generated by a subsequence of the unit vector basis ofT[(θ
n
,F
n
)
n=1
∞
]. 相似文献
13.
K. F. Cheng 《Annals of the Institute of Statistical Mathematics》1982,34(1):479-489
Summary Letf
n
(p)
be a recursive kernel estimate off
(p) thepth order derivative of the probability density functionf, based on a random sample of sizen. In this paper, we provide bounds for the moments of
and show that the rate of almost sure convergence of
to zero isO(n
−α), α<(r−p)/(2r+1), iff
(r),r>p≧0, is a continuousL
2(−∞, ∞) function. Similar rate-factor is also obtained for the almost sure convergence of
to zero under different conditions onf.
This work was supported in part by the Research Foundation of SUNY. 相似文献
14.
It is shown that in the spacesA
R
(0 <R ⩽ ∞) of all functions which are single-valued and analytic in the disk |z| < R with the topology of compact convergence,
the differential operator of infinite order with constant coefficients
is equivalent to the operator Dn (n is a fixed natural number) if and only if
and |ϕ
n
| = 1 for R < ∞ or ϕ
n
≠ 0 for R = ∞. Also the equivalence of two shift operators in the space A∞ is investigated.
Translated from Matematicheskie Zametki, Vol. 21, No. 1, pp. 33–37, January, 1977. 相似文献
15.
Let A
0, ... , A
n−1 be operators on a separable complex Hilbert space , and let α0,..., α
n−1 be positive real numbers such that 1. We prove that for every unitarily invariant norm,
for 2 ≤ p < ∞, and the reverse inequality holds for 0 < p ≤ 2. Moreover, we prove that if ω0,..., ω
n−1 are the n roots of unity with ω
j
= e
2πij/n
, 0 ≤ j ≤ n − 1, then for every unitarily invariant norm,
for 2 ≤ p < ∞, and the reverse inequalities hold for 0 < p ≤ 2. These inequalities, which involve n-tuples of operators, lead to natural generalizations and refinements of some of the classical Clarkson inequalities in the
Schatten p-norms. Extensions of these inequalities to certain convex and concave functions, including the power functions, are olso
optained.
相似文献
16.
I. I. Sharapudinov 《Mathematical Notes》1997,62(4):501-512
Suppose that 0<δ≤1,N=1/δ, and α, ga≥0, is an integer. For the classical Meixner polynomials
orthonormal on the gird {0, δ, 2δ, ...} with weight ρ(x)=(1-e
−δ)αг(Nx+α+ 1)/г(Nx+1), the following asymptotic formula is obtained:
. The remainderv
n,N
α
(z) forn≤λN satisfies the estimate
where Λ
k
α
(x) are the Laguerre orthonormal polynomials. As a consequence, a weighted estimate, for the Meixner polynomial
on the semiaxis [0, ∞) is obtained.
Translated fromMatematicheskie Zametki, Vol. 62, No. 4, pp. 603–616, October, 1997.
Translated by N. K. Kulman 相似文献
17.
We investigate the correlation between the constants K(ℝn) and
, where
is the exact constant in a Kolmogorov-type inequality, ℝ is the real straight line,
, L
l
p, p
(G
n) is the set of functions ƒ ∈ L
p
(G
n
) such that the partial derivative
belongs to L
p
(G
n
),
, 1 ≤ p ≤ ∞, l ∈ ℕn, α ∈ ℕ
0
n
= (ℕ ∪ 〈0〉)n, D
α
f is the mixed derivative of a function ƒ, 0 < μi < 1,
, and ∑
i=0
n
. If G
n
= ℝ, then μ0=1−∑
i=0
n
(α
i
/l
i
), μi = αi/l
i
,
if
, then μ0=1−∑
i=0
n
(α
i
/l
i
) − ∑
i=0
n
(λ/l
i
), μi = αi/ l
i
+ λ/l
i
,
, λ ≥ 0. We prove that, for λ = 0, the equality
is true.
__________
Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 58, No. 5, pp. 597–606, May, 2006. 相似文献
18.
Bin Heng SONG Huai Yu JIAN 《数学学报(英文版)》2005,21(5):1183-1190
We establish the existence of fundamental solutions for the anisotropic porous medium equation, ut = ∑n i=1(u^mi)xixi in R^n × (O,∞), where m1,m2,..., and mn, are positive constants satisfying min1≤i≤n{mi}≤ 1, ∑i^n=1 mi 〉 n - 2, and max1≤i≤n{mi} ≤1/n(2 + ∑i^n=1 mi). 相似文献
19.
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
20.
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