共查询到20条相似文献,搜索用时 15 毫秒
1.
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
2.
K. I. Beidar M. Bre@scaron;ar M. A. Chebotar 《Journal of Mathematical Sciences》2000,102(6):4557-4565
Let
, be the algebra of upper triangular r×r matrices over field aF. We describe multilinear maps
, where n≤r, such that [f(A,...,A), A]=0 for all
, provided that |F| >n + 1. As an application of the results obtained, we describe linear automorphisms θ of
such that [θ(A2), θ(A)]=0 for all
.
Translated from Itogi Nauki i Tekhniki, Seriya Sovremennaya Matematika i Ee Prilozheniya. Tematicheskie Obzory. Vol. 74, Algebra-15,
2000. 相似文献
3.
4.
B. S. Pavlov 《Journal of Mathematical Sciences》1995,77(3):3232-3235
A method of deducing an expansion theorem in resonance states for the two-dimensional Friedrichs model
is suggested. The construction is based on detailed Lax-Phillips analogs of the corresponding unitary Friedrichs model
, perturbed by the projector Pϕ, generated by an element ϕ possessing special analytic properties. Bibliography: 11 titles.
To Olga A. Ladyzhenskaya on the occasion of the jubilee
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 200, 1992, pp. 149–155.
Translated by V. I. Ochkur. 相似文献
5.
Small into-isomorphism from L∞(A,μ) into L∞(B,υ) 总被引:1,自引:0,他引:1
DING Guanggui 《中国科学A辑(英文版)》2001,44(3):273-279
In this paper we shall assert that if T is an isomorphism of L∞(Ω1, A, μ) into L∞(Ω2, B, υ) satisfying the condition ‖T‖·‖T
−1‖⩽1+ɛ for ɛ∈
, then
is close to an isometry with an error less than 6ε in some conditions. 相似文献
6.
M. F. Gamal' 《Journal of Mathematical Sciences》1997,85(2):1779-1789
A general scheme which enables us to consider convolution operators with measures acting in a wide class of spaces of distributions
on the interval [0, a), 0<a<∞, is represented. It is proved that if a measure μ is a weak generator of the algebra of measures
on [0, a), then Cμ (the convolution operator with μ) is unicellular. We give a condition for a measure μ under which the unicellularity of Cμ implies that μ is a weak generator of the algebra of measures. The following statement is also proved. Let
, Kθ=H2⊖θH2, and let Pθ be the orthogonal projector from H2 onto Kθ; in addition, let μ be a weak generator of the algebra of measures on [0, a) and
, z ∈
(here
is the unit disk and F-1 is the inverse Fourier transformation). Let ψ∈H∞ and let p be a polynomial such that p o(ψ−φ)∈θH∞. Then the operator x→Pθψx, acting in Kθ, is unicellular. Bibliography: 13 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 217, 1994, pp. 36–53. 相似文献
7.
The set of increments of the Wiener process
, where aT∈(0,T) and LT=(2[log(T/aT)+loglogT])1/2 is considered. Under the assumptionlog(T/aT)/loglogT→c, the set VT oscillates between b
, and
, where b=[c/(c+1)]1/2 and
is the Strassen ball. Bibliography: 9 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 216, 1994, pp. 33–41. 相似文献
8.
I. N. Kostin 《Journal of Mathematical Sciences》1995,77(3):3195-3198
In this paper the problem of the numerical approximation of the minimal global B-attractor
for a semiflow generated by the Navier-Stokes equations in a two-dimensional bounded domain Ω is considered. The method suggested
here is based on the formula
, where GN is a sequence of compact subsets of L2(Ω),
. The procedure of constructing GN is finite and includes the numerical solution of the Navier-Stokes equations by means of the Galerkin method, together with
an explicit finite-difference discretization in time. Bibliography: 5 titles.
To dear teacher Olga A. Ladyzhenskaya on the occasion of the jubilee
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 200, 1992, pp. 91–97.
Translated by V. I. Ochkur. 相似文献
9.
Summary Let
a plane angle of opening α∈(π, 2π). LetP
D andP
N the Dirichlet and Neumann problems associated to the Poisson equation in
. ForP
D andP
N it is proved non existence of solution in L
p
(
) whenp=2/(1±π/α). In other words, the ranges of elliptic operators naturally associated toP
D andP
N are not-closed in L
p
(
) forp=2/(1±π/α).
Sunto Sia } un angolo piano di apertura α∈(π, 2π). SianoP D eP N i problemi di Dirichlet e di Neumann associati all'equazione di Poisson in . PerP D eP N si prova non esistenza di soluzioni in L p ( ) quandop=2/(1±π/α). Vale a dire i ranges degli operatori ellittici naturalmente associati aP D eP N sono non-chiusi in π--AgBrα K L p ( ) perp=2/(1±π/α).相似文献
10.
A. M. Arkhipov 《Journal of Mathematical Sciences》2006,139(6):7013-7024
In this paper, we consider the Kuramoto-Sivashinskii equation on the multidimensional torus with a Riemannian metric:
where
. For this equation the theorem on energy transfer holds. It is formulated in the following way. Let
be the Fourier expansion of the function u. Denote by P
N
and P
N
⊥
the operators of rejection of the “leading” and, respectively, “lowest” terms of the Fourier expansion (harmonics), i.e.,
.
For any ρ > 0,N ∈ ℕ, s ≥ n/2+5, and λ ∈ (0, 1), there exists R such that for any function. ϕ ∈
lying outside the ball
in the ball
, there exists an instant of time t ∈ (0, 1) such that g
KS
t
ϕ=ψ and
. Here, R is a constant depending on the metric (g), n
s
is the sth Sobolev norm, and
is the C
1-norm.
__________
Translated from Sovremennaya Matematika i Ee Prilozheniya (Contemporary Mathematics and Its Applications), Vol. 24, Dynamical
Systems and Optimization, 2005. 相似文献
11.
Xu Chaojiang 《数学学报(英文版)》1992,8(4):362-374
We prove in this paper theC
∞ regularity for a “very strict” local minimum of classC
loc
ρ
, ρ>3, of functionals with genuine degenerate quasiconvex integrand
depending on a vector-valued function u. Such a minimum satisfies the condition: for all x∈Ω, there exists a neighbourhoodK(x) ofx in Ω andC
1
(x)>0,C
2
(x)>0,1≥ε(x)>0, such that
for all real ϕ∈c
0
∞
(K).
This work is supported by the National Natural Science Foundation of China and the Fok Ying Tung Education Foundation. 相似文献
12.
V. L. Oleînik 《Journal of Mathematical Sciences》2000,101(3):3133-3138
Let {
}, where {
} is the open unit disk on the complex plane {
}. In G, we consider analytic solutions u(t, z) ({
}, {
}) of the heat equation 2ut=uzz with initial data f(z)=u(0, z) belonging to the Fock space F, i.e., to the space of entire functions square summable with
the weight e−|z|2.Conditions on a nonnegative measure μ on G are described under which for all f ∈ F we have {
} Bibliography: 17 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 247, 1997, pp. 146–155.
Translated by S. V. Kislyakov. 相似文献
13.
M. B. Zvyagina 《Journal of Mathematical Sciences》1998,89(2):1122-1126
Let Λ be an associative ring with identity and let
be the category of left unitary Λ-modules. A subcateqory
of the category
is said to be small if the pairwise nonisomorphic objects of
form a set. The main result of this paper consists of the fact that for every small full subcategory
, there exists a ring Γ such that
is dual to a small full subcategory of the category
. Some applications of this result are indicated. Bibliography: 3 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 227, 1995, pp. 66–73. 相似文献
14.
In this paper, a natural R
+
n+1
extension of singular integrals, i.e.,T
κ:f→K*φ
t
*t with K a standard C-Z kernel and ϕ usual one, is investigated. One of the main results is: Let (dμ, udx) ∈C1 and u-Mw, w∈A∞, then Tk is of type (Lp(udx), Lp(dμ)). As a related topic, a maximal operator
is proved to be of type
, where
, provided (dμ, udx) ∈C1 and u∈ A∞.
Supported by National Science Foundation of China 相似文献
15.
Let F be a subfield of a commutative field extending ℝ. Let
We say thatf :
preserves distanced ≥ 0 if for eachx,y ∈ ℝ ∣x- y∣= d implies ϕ2(f(x),f(y)) = d2
. We prove that each unit-distance preserving mappingf :
has a formI o (ρ,ρ), where
is a field homomorphism and
is an affine mapping with orthogonal linear part. 相似文献
16.
T. Levasseur 《Transformation Groups》1998,3(4):337-353
Let
u
be a compact Lie algebra and let
u
be its complexification. Let ζ−1/2 be the inverse on the set of regular elements of
u
of a square root of the discriminant of
. Generalizing a result of W. Lichtenstein in the case
u
=
(n, ℂ) or
(nℝ), we prove that ∂(q).ζ1/2 is non zero for all harmonic polynomialsq ∈S(
) \ {0}. This fact is deduced from results about equivariantD-modules supported on the nilpotent cone of
. 相似文献
17.
E. Amar 《Journal of Geometric Analysis》1991,1(4):291-305
We show that if f1, f2 are bounded holomorphic functions in the unit ball
of ℂn such that
, |f1(z)|2 + |f2(z)2|2 ≥ δ2 >; 0, then any functionh in the Hardy space
,p < +∞ can be decomposed ash = f1h1
+ f2h2 with
. The Corona theorem in
would be the same result withp = +∞ and this question is still open forn ≳-2, but the preceding result goes in this direction. 相似文献
18.
Zoé Chatzidakis 《Israel Journal of Mathematics》1986,55(2):173-183
LetK be a hilbertian field,G(K) its absolute Galois group. IfK is countable, then for a.a.
inG(K)
e
,
and there is no intermediate field
with
. Let
∈G(K)
e
. Then for a.a.
in
. 相似文献
19.
M. S. Ermakov 《Journal of Mathematical Sciences》1996,81(1):2379-2393
Given subsets Ω, ϕ of a set of probability measures, questions about the uniform in P∈ϕ convergence of the normalized large
deviations
and about the convergence of the supremum over ϕ of this value are considered for empirical distributions
. The results are used for the proof of the asymptotic minimaxity of the Kolmogorov, omega-square, and rank tests by nonparametric
sets of alternatives. A new bound for the efficiency of statistical tests is obtained. Bibliography: 19 titles.
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 207, pp. 37–59, 1993.
Translated by the author. 相似文献
20.
V. V. Bakun 《Ukrainian Mathematical Journal》2000,52(2):173-182
We prove that the functionals of a d-dimensional Brownian process are Hida distributions, i.e., generalized Wiener functionals. Here, δΓ(·) is a generalization of the δ-function constructed on a bounded closed smooth surface Γ⊂R
d
, k≥1 and acting on finite continuous functions φ(·) in R
d according to the rule where ι(·) is a surface measure on Γ. 相似文献