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1.
V. A. Solonnikov 《Journal of Mathematical Sciences》1998,92(6):4364-4385
The main result is an asymptotic formula for a solution to the conjugation problem for the Navier-Stokes equations describing
the slow motion of two immiscible liquids such that one of them occupies a bounded domain Ω1 ⊂ ℝ3, whereas the other occupies the exterior domain Ω2=ℝ4∖Ω. Such a formula was obtained for a solution to the exterior problem with sticking conditions on the boundary in the works
of Fischer, Hsiao, and Wendland. The result obtained is applied to the proof of the solvability of a free-boundary problem
describing a uniform drop in an infinite liquid. Bibliography: 10 titles.
Translated fromProblemy Matematicheskogo Analiza, No. 16. 1997, pp. 208–238. 相似文献
2.
Area,coarea, and approximation in <Emphasis Type="Italic">W</Emphasis><Superscript>1,1</Superscript>
David Swanson 《Arkiv f?r Matematik》2007,45(2):381-399
Let Ω⊂ℝ
n
be an arbitrary open set. We characterize the space W
1,1
loc(Ω) using variants of the classical area and coarea formulas. We use these characterizations to obtain a norm approximation
and trace theorems for functions in the space W
1,1(ℝ
n
). 相似文献
3.
Martin Fuchs 《manuscripta mathematica》1991,72(1):131-140
Given a smooth domain Ω in ℝ
m+1 with compact closure and a smooth integrable functionh: ℝ
m+1→ℝ satisfyingh(x)≥H
∂Ω
(x) on ∂Ω whereH
∂ω denotes the mean curvature of ∂Ω calculated w.r.t. the interior unit normal we show that there is a setA⊂ℝ
m+1 with the properties
andH
∂A=h on ∂A. 相似文献
4.
Andreas Fr?hlich 《Annali dell'Universita di Ferrara》2000,46(1):11-19
We consider weights of Muckenhoupt classA
q, 1<q<∞. For a bounded Lipschitz domain Ω⊂ℝn we prove a compact embedding and a Poincaré inequality in weighted Sobolev spaces. These technical tools allow us to solve
the weak Neumann problem for the Laplace equation in weighted spaces on ℝn, ℝn
+, on bounded and on exterior domains Ω with boundary of classC
1, which will yield the Helmholtz decomposition ofL
ω
q(Ω)n for general ω∈A
q. This is done by transferring the method of Simader and Sohr [4] to the weighted case. Our result generalizes a result of
Farwig and Sohr [2] where the Helmholtz decomposition ofL
ω
p(Ω)n is proved for an exterior domain and weights of Muckenhoupt class without singularities or degeneracies in a neighbourhood
of ϖΩ.
Sunto In questo lavoro consideriamo dei pesi della classe di MuckenhouptA q, 1<q<∞. Per un dominio limitato lipschitziano Ω⊂ℝn, dimostriamo una immersione compatta ed una disuguaglianza di Poincaré in spazi di Sobolev con peso. Questa tecnica ci consente di risolvere il problema debole di Neumann per l’equazione di Laplace in spazi pesati in ℝn, ℝn + in domini limitati ed in domini esterni con frontiera di classeC 1, che conduce alla decomposizione di Helmholtz diL ω q(Ω)n per un qualsiasi ω∈A q. Il risultato è ottenuto trasferendo il metodo di Simader e Sohr [4] al caso pesato. Quello qui presente estende un risultato di Farwig e Sohr [2] dove la decomposizione di Helmholtz diL ω q(Ω)n è dimostrata per domini esterni e pesi della classe di Muckenhoupt privi di singolarità in un intorno di ϖΩ.相似文献
5.
A. A. Kovalevskii 《Ukrainian Mathematical Journal》1996,48(9):1402-1422
By using special local characteristics of domains Ω
s
⊂Ω,s=12,..., we establish necessary and sufficient conditions for the γ-convergence of sequences of integral functionalsI
λs
:W
k,m
(Ω
s
)→ℝ, λ⊂Ω to interal functionals defined on W
k,m
(Ω).
Institute of Applied Mathematics and Mechanics, Ukrainian Academy of Sciences, Donetsk. Translated from Ukrainskii Matematicheskii
Zhurnal, Vol. 48, No. 9, pp. 1236–1254, September, 1996. 相似文献
6.
V. A. Solonnikov 《Journal of Mathematical Sciences》1995,77(3):3250-3255
A new method of estimating the solutions of the Navier-Stokes equations for a viscous compressible barotropic fluid in a bounded
domain Ω⊂ℝ3 is suggested, which makes it possible to investigate the problem for the whole scale of anisotropic spaces W
2
l+2,l/2+1
(QT), QT=Ω×(0,T), for arbitrary l>1/2. Bibliography: 10 titles.
To dear Olga Alexandrovna Ladyzenskaya on her jubilee
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 200, 1992, pp. 177–186.
Translated by V. A. Solonnikov. 相似文献
7.
V. V. Makeev 《Journal of Mathematical Sciences》2007,140(4):529-534
A convex figure K ⊂ ℝ2 is a compact convex set with nonempty interior, and αK is a homothetic image of K with coefficient α ∈ ℝ. It is proved that
for any two convex figures K1, K2 ⊂ ℝ2 there is an affine transformation T of the plane such that K1 ⊂ T(K2) ⊂ 2.7K1. Bibliography: 2 titles.
__________
Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 329, 2005, pp. 58–66. 相似文献
8.
A. P. Oskolkov 《Journal of Mathematical Sciences》1997,83(2):320-326
In this paper, we study some nonlocal problems for the Kelvin-Voight equations (1) and the penalized Kelvin-Voight equations
(2): the first and second initial boundary-value problems and the first and second time periodic boundary problems. We prove
that these problems have global smooth solutions of the classW
∞
1
(ℝ+;W
2
2+k
(Ω)),k=1,2,...;Ω⊂ℝ3. Bibliography: 25 titles.
Dedicated to N. N. Uraltseva on her jubilee
Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 221, 1995, pp. 185–207.
Translated by N. A. Karazeeva. 相似文献
9.
M. Langenbruch 《manuscripta mathematica》2000,103(2):241-263
Let P(D) be a partial differential operator with constant coefficients which is surjective on the space A(Ω) of real analytic functions on a covex open set Ω⊂ℝ
n
. Let L(P
m
) denote the localizations at ∞ (in the sense of H?rmander) of the principal part P
m
. Then Q(x+iτN)≠ 0 for (x,τ)∈ℝ
n
×(ℝ\{ 0}) for any Q∈L(P
m
) if N is a normal to δΩ which is noncharacteristic for Q. Under additional assumptions this implies that P
m
must be locally hyperbolic.
Received: 24 January 2000 相似文献
10.
Zeng Jian LOU Shou Zhi YANG Dao Jin SONG 《数学学报(英文版)》2005,21(4):949-954
We give a decomposition of the Hardy space Hz^1(Ω) into "div-curl" quantities for Lipschitz domains in R^n. We also prove a decomposition of Hz^1(Ω) into Jacobians det Du, u ∈ W0^1,2 (Ω,R^2) for Ω in R^2. This partially answers a well-known open problem. 相似文献
11.
For an arbitrary domain Ω ⊂ ℝn, n=2,3, Ω ≠ ℝn, we prove the existence of weak periodic solutions to the Navier-Stokes equations and of regular solutions if the data are
small or satisfy certain symmetry conditions. We also show that the periodic regular solutions are stable. Bibliography: 38
titles.
Published inZapiski Nauchnykh Seminarov POMI, Vol. 233, 1996, pp. 142–182. 相似文献
12.
Let Ω be a bounded Lipschitz domain. Define B
0,1
1,
r
(Ω) = {f∈L
1 (Ω): there is an F∈B
0,1
1 (ℝ
n
) such that F|Ω = f} and B
0,1
1
z
(Ω) = {f∈B
0,1
1 (ℝ
n
) : f = 0 on ℝ
n
\}. In this paper, the authors establish the atomic decompositions of these spaces. As by-products, the authors obtained the
regularity on these spaces of the solutions to the Dirichlet problem and the Neumann problem of the Laplace equation of ℝ
n
+.
Received June 8, 2000, Accepted October 24, 2000 相似文献
13.
We consider the zero-velocity stationary problem of the Navier–Stokes equations of compressible isentropic flow describing
the distribution of the density ϱ of a fluid in a spatial domain Ω⊂ℝ
N
driven by a time-independent potential external force b=∇F. A sharp condition in terms of F is given for the problem to possess a unique nonnegative solution ϱ having a prescribed mass m > 0.
Received: 20 October 1997 相似文献
14.
M. V. Korobkov 《Siberian Mathematical Journal》2009,50(5):874-886
We find necessary and sufficient conditions for a curve in ℝ
m×n
to be the gradient range of a C
1-smooth function υ: Ω ⊂ ℝ
n
→ ℝ
m
. We show that this curve has tangents in a weak sense; these tangents are rank 1 matrices and their directions constitute
a function of bounded variation. We prove also that in this case v satisfies an analog of Sard’s theorem, while the level
sets of the gradient mapping ▿υ: Ω → ℝ
m×n
are hyperplanes. 相似文献
15.
We define and study a class of summable processes, called additive summable processes, that is larger than the class used
by Dinculeanu and Brooks [D-B].
We relax the definition of a summable processesX:Ω×ℝ+→E⊂L(F, G) by asking for the associated measureI
X to have just an additive extension to the predictableσ-algebra ℘, such that each of the measures (I
X)
z
, forz∈(L
G
p
)*, beingσ-additive, rather than having aσ-additive extension. We define a stochastic integral with respect to such a process and we prove several properties of the
integral. After that we show that this class of summable processes contains all processesX:Ω×ℝ+→E⊂L(F, G) with integrable semivariation ifc
0 ∋G. 相似文献
16.
LetV ⊂ ℙℝ
n
be an algebraic variety, such that its complexificationV
ℂ ⊂ ℙ
n
is irreducible of codimensionm ≥ 1. We use a sufficient condition on a linear spaceL ⊂ ℙℝ
n
of dimensionm + 2r to have a nonempty intersection withV, to show that any six dimensional subspace of 5 × 5 real symmetric matrices contains a nonzero matrix of rank at most 3. 相似文献
17.
V. I. Burenkov M. Lanza de Cristoforis 《Proceedings of the Steklov Institute of Mathematics》2008,260(1):68-89
We consider the Robin Laplacian in two bounded regions Ω1 and Ω2 of ℝ
N
with Lipschitz boundaries and such that Ω2 ⊂ Ω1, and we obtain two-sided estimates for the eigenvalues λ
n,2 of the Robin Laplacian in Ω2 via the eigenvalues λ
n, 1 of the Robin Laplacian in Ω1. Our estimates depend on the measure of the set difference Ω\Ω2 and on suitably defined characteristics of vicinity of the boundaries ∂Ω1 and ∂Ω2, and of the functions defined on ∂Ω1 and on ∂Ω2 that enter the Robin boundary conditions. 相似文献
18.
A set N ⊂ ℝ
d
is called a weak
ɛ-net (with respect to convex sets) for a finite X ⊂ ℝ
d
if N intersects every convex set C with |X ∩ C| ≥ ɛ|X|. For every fixed d ≥ 2 and every r ≥ 1 we construct sets X ⊂ ℝ
d
for which every weak 1/r -net has at least Ω(r log
d−1
r) points; this is the first superlinear lower bound for weak ɛ-nets in a fixed dimension. 相似文献
19.
Roger Moser 《Journal of Geometric Analysis》2011,21(3):588-598
For maps from a domain Ω⊂ℝ
m
into a Riemannian manifold N, a functional coming from the norm of a fractional Sobolev space has recently been studied by Da Lio and Rivière. An intrinsically
defined functional with a similar behavior also exists, and its first variation can be identified with a Dirichlet-to-Neumann
map belonging to the harmonic map problem. The critical points have regularity properties analogous to harmonic maps. 相似文献
20.
A. N. Starkov 《Mathematical Notes》1995,58(1):744-751
Ergodic one-parameter flows (G/Γ,g
ℝ) induced by the left action of a subgroupg
ℝ ⊂G on homogeneous spaces of finite volume are considered. Letℳ ⊂ ℝ+ be the set of allt>0 such that the cascade (G/Γ,g
t
ℤ) is metrically isomorphic to the cascade (G/Γ,g
ℤ). We prove that eitherℳ is at most countable or the subgroupg
ℝ is horocyclic andℳ=ℝ+. We prove that a metric isomorphism of ergodic quasi-unipotent cascades (or flows) is affine on almost all fibers of a certain
natural bundle. The result generalizes Witte's theorem on the affinity of such isomorphisms of cascades with the mixing property;
this is applied to the study of the structure of the setℳ ⊂ ℝ+. The proof is based on the fundamental Ratner theorem stating that the ergodic measures of unipotent cascades are algebraic.
Translated fromMatematicheskie Zametki, Vol. 58, No. 1, pp. 98–110, July, 1995.
This research was partially supported by the Russian Foundation for Basic Research under grant No. 94-01-00082a and by the
International Science Foundation. 相似文献