共查询到20条相似文献，搜索用时 343 毫秒
1.
A. S. Zhuk 《Journal of Mathematical Sciences》2008,150(3):2034-2044
Let M be either the space of 2π-periodic functions Lp, where 1 ≤ p < ∞, or C; let ωr(f, h) be the continuity modulus of order r of the function f, and let
, where
, be the generalized Jackson-Vallée-Poussin integral. Denote
. The paper studies the quantity Km(f − Dn,r,l(f)). The general results obtained are applicable to other approximation methods. Bibliography: 11 titles.
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Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 350, 2007, pp. 52–69. 相似文献
2.
We extend the results of Rubio de Francia and Bourgain by showing that, for arbitrary mutually disjoint intervals Δk ⊂ ℤ+, arbitrary p ∈, (0, 2], and arbitrary trigonometric polynomials f
k with supp
, we have
. The method is a development of that by Rubio de Francia. Bibliography: 9 titles.
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Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 327, 2005, pp. 98–114. 相似文献
3.
N. A. Shirokov 《Journal of Mathematical Sciences》2006,134(4):2320-2323
Let Λα be the analytic Holder class in the unit disk
. For f ∈ Λα and
, let Mf (I) = max
I |f|. Assume that I and J are arcs such that |J| = 2|I| and J and I have the same midpoint. Then
It is proved that this estimate cannot be improved. Bibliography: 1 title.
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Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 315, 2004, pp. 149–154. 相似文献
4.
O. M. Fomenko 《Journal of Mathematical Sciences》2006,133(6):1749-1755
Let f(z) be a holomorphic Hecke eigenform of weight k with respect to SL(2, ℤ) and let
denote the symmetric square L-function of f. A Voronoi type formula for
and the relation
are proved. Heuristic approaches to estimation of exponential sums arising in this connection are considered. Bibliography:
9 titles.
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Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 314, 2004, pp. 247–256. 相似文献
5.
A. K. Prykarpatsky D. L. Blackmore Ya. V. Mykytyuk 《Journal of Mathematical Sciences》2001,104(5):1411-1421
This article is a continuation of [J. Math. Sci., 99, No.5, 1541–1547 (2000)] devoted to the validity of the Lax formula (cited in the article of Crandall, Ishii, and Lions [Bull. AMS, 27, No.1, 1–67 (2000)])
for a solution to the Hamilton–Jacobi nonlinear partial differential equation
where the Cauchy data
are now a function semicontinuous from below,
is the usual norm in
,
, and
is a positive evolution parameter. We proved that the Lax formula solves the Cauchy problem (2) at all points
,
fixed save for an exceptional set of points R of the F
type, having zero Lebesgue measure. In addition, we formulate a similar Lax-type formula without proof for a solution to a new nonlinear equation of the Hamilton–Jacobi-type:
where
is a diagonal positive-definite matrix, mentioned in Part I and having interesting applications in modern mathematical physics. 相似文献
6.
In what follows, $C$ is the space of
-periodic continuous functions; P is a seminorm defined on C, shift-invariant, and majorized by the uniform norm;
is the mth modulus of continuity of a function f with step h and calculated with respect to P;
,
(
),
,
,
Theorem 1.
Let
. Then
For some values of
and seminorms related to best approximations by trigonometric polynomials and splines in the uniform and integral metrics, the inequalities are sharp. Bibliography: 6 titles. 相似文献
7.
O. M. Fomenko 《Journal of Mathematical Sciences》2006,133(6):1733-1748
Let Sk(Γ) be the space of holomorphic Γ-cusp forms f(z) of even weight k ≥ 12 for Γ = SL(2, ℤ), and let Sk(Γ)+ be the set of all Hecke eigenforms from this space with the first Fourier coefficient af(1) = 1. For f ∈ Sk(Γ)+, consider the Hecke L-function L(s, f). Let
It is proved that for large K,
where ε > 0 is arbitrary. For f ∈ Sk(Γ)+, let L(s, sym
2 f) denote the symmetric square L-function. It is proved that as k → ∞ the frequence
converges to a distribution function G(x) at every point of continuity of the latter, and for the corresponding characteristic
function an explicit expression is obtained. Bibliography: 17 titles.
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Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 314, 2004, pp. 221–246. 相似文献
8.
A power series
with radius of convergence equal 1 is called a (p,A)-lacunary one if nk ≥ Akp, A > 0, 1 < p < ∞. It is proved that if 1 < p < 2 and f(x) is a (p,A)-lacunary series that satisfies the condition
, where
, for some ε > 0, then f ≡ 0. We construct a (p,A)-lacunary series f
0 such that
with a constant C0 = C0(p,A) > 0. Bibliography: 4 titles.
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Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 327, 2003, pp. 135–149. 相似文献
9.
A. A. Kon'kov 《Journal of Mathematical Sciences》2006,134(3):2073-2237
The paper considers solutions of the coercive inequalities
defined on an arbitrary (possibly, unbounded) subset ℝ
n
, where n ≥ 2, L and
are elliptic operators of the form
, and F is a certain function.
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Translated from Sovremennaya Matematika. Fundamental'nye Napravleniya (Contemporary Mathematics. Fundamental Directions),
Vol. 7, Partial Differential Equations, 2004. 相似文献
10.
In the present paper, we derive the Laplace transforms of the integral functionals
and
where p and q are real numbers, {B
t
(μ)
: t ≥ 0} is a Brownian motion with drift μ > 0 (denoted BM(μ)), and {R
t
(3)
: t ≥ 0} is a 3-dimensional Bessel process (denoted BES(3)). The transforms are given in terms of Gauss' hypergeometric functions, and the results are closely related to some results
for functionals of Jacobi diffusions. This work generalizes and completes some results of Donati-Martin and Yor and Salminen
and Yor. Bibliography: 18 titles.
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Published in Zapiski Nauchnykh Seminarov POMI, Vol. 311, 2004, pp. 51–78. 相似文献
11.
Using the following notation: C is the space of continuous bounded functions f equipped with the norm
, V is the set of functions f such that
, the set E consists of fCV and possesses the following property:
is summable on each finite interval,
we establish some assertions similar to the following theorem: Let
0$$
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,
Then for fV the series
uniformly converges with respect to
and the following equality holds:
This theorem develops some results obtained by Zubov relative to the approximation of probability distributions. Bibliography: 4 titles. 相似文献
12.
V. V. Vysotsky 《Journal of Mathematical Sciences》2007,147(4):6873-6883
Let Si be a random walk with standard exponential increments. The sum ∑
i=1
k
Si is called the k-step area of the walk. The random variable
∑
i=1
k
Si plays an important role in the study of the so-called one-dimensional sticky particles model. We find the distribution of
this variable and prove that
for 0 ≤ t ≤ 1. We also show that
, where the Ui,n are order statistics of n i.i.d. random variables uniformly distributed on [0, 1]. Bibliography: 6 titles.
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Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 341, 2007, pp. 48–67. 相似文献
13.
D. E. Apushkinskaya H. Shahgholian N. N. Uraltseva 《Journal of Mathematical Sciences》2003,115(6):2720-2730
Let u and solve the problem
where is an open set in
0\} ,n \geqslant 2,H = \Delta - \partial _t \hfill \\ \hfill \\ \end{gathered} $$
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is the heat operator,
denotes the characteristic function of ,
is the unit cylinder in n+1,
, and the first equation is satisfied in the sense of distributions. We obtain the optimal regularity of the function u, i.e., we show that
. Bibliography: 6 titles. 相似文献
14.
15.
16.
V. N. Denisov 《Journal of Mathematical Sciences》2008,150(5):2344-2357
In the paper, we study the sufficient conditions for the lower-order coefficient of the parabolic equation
under which its solution satisfying the initial condition
stabilizes to zero, i.e., there exists the limit
uniform in x from every compact set K in ℝN for any function u
0(x) belonging to a certain uniqueness class of the problem considered and growing not rapidly than
with a > 0 and b < 0 at infinity.
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Translated from Fundamentalnaya i Prikladnaya Matematika, Vol. 12, No. 4, pp. 79–97, 2006. 相似文献
17.
Piotr Kot 《Czechoslovak Mathematical Journal》2007,57(1):29-47
We solve the Dirichlet problem for line integrals of holomorphic functions in the unit ball
For a function u which is lower semi-continuous on
we give necessary and sufficient conditions in order that there exists a holomorphic function f ∈
such that
. 相似文献
18.
Hoai-Minh Nguyen 《Journal d'Analyse Mathématique》2007,101(1):367-395
In this paper, we prove the estimate
, for every δ ∈ (0, ℓN), where C = C(N) is a positive constant depending only on N and
. We show that the constant ℓN in this estimate is optimal. We also present a class of maps from
into
, strictly larger than
, on which we can define the notion of degree and for which the previous inequality still holds. 相似文献
19.
S. V. Kislyakov 《Journal of Mathematical Sciences》2009,156(5):824-833
Let 1 < r < 2 and let b is a weight on ℝ such that satisfies the Muckenhoupt condition Ar′/2 (r′ is the exponent conjugate to r). If fj are functions whose Fourier transforms are supported on mutually disjoint intervals, then
for 0 < p ≤ r. Bibliography: 9 titles.
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 355, 2008, pp. 180–198. 相似文献
20.
The following classes of functions analytic in the unit disk are considered:
and
where
is the Nevanlinna characteristic and
is a properly changing positive function on (0,1]. Necessary and sufficient conditions on
are established under which the classes
and
are invariant under the operators of differentiation and integration. Bibliography: 7 titles. 相似文献