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1.
Ewa Zadrzyńska Wojciech M. Zajączkowski 《Mathematical Methods in the Applied Sciences》2014,37(3):360-383
We examine the solvability in Besov spaces of an initial–boundary value problem for the nonstationary Stokes system with the slip boundary conditions. We prove the existence and uniqueness of solutions to the problem in a bounded domain . The existence is shown by localizing the system to interior and boundary subdomains of Ω. The localized Stokes system is transformed by the Helmholtz–Weyl decomposition to the heat and the Poisson equations, which are solved in the Besov spaces. Next, by the properties of the partition of unity and a perturbation argument, the existence is proved in domain Ω. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
2.
Chérif Amrouche Huy Hoang Nguyen 《Mathematical Methods in the Applied Sciences》2008,31(18):2147-2171
This paper is devoted to some mathematical questions related to the three‐dimensional stationary Navier–Stokes equations. Our approach is based on a combination of properties of Oseen problems in ?3. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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The boundedness of the finite Hilbert transform operator on certain weighted Lp spaces is well known. We extend this result to give the boundedness of that operator on certain weighted Sobolev spaces. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
4.
Dirk Pauly 《Mathematical Methods in the Applied Sciences》2008,31(13):1509-1543
We study in detail Hodge–Helmholtz decompositions in nonsmooth exterior domains Ω??N filled with inhomogeneous and anisotropic media. We show decompositions of alternating differential forms of rank q belonging to the weighted L2‐space Ls2, q(Ω), s∈?, into irrotational and solenoidal q‐forms. These decompositions are essential tools, for example, in electro‐magnetic theory for exterior domains. To the best of our knowledge, these decompositions in exterior domains with nonsmooth boundaries and inhomogeneous and anisotropic media are fully new results. In the Appendix, we translate our results to the classical framework of vector analysis N=3 and q=1, 2. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
5.
Megan M. Kerr 《Annals of Global Analysis and Geometry》1997,15(5):437-445
In this paper we examine homogeneous Einstein–Weyl structures and classify them on compact irreducible symmetric spaces. We find that the invariant Einstein–Weyl equation is very restrictive: Einstein–Weyl structures occur only on those spaces for which the isotropy representation has a trivial component, for example, the total space of a circle bundle. 相似文献
6.
Miloslav Feistauer Anna‐Margarete Sändig 《Numerical Methods for Partial Differential Equations》2012,28(4):1124-1151
Error estimates for DGFE solutions are well investigated if one assumes that the exact solution is sufficiently regular. In this article, we consider a Dirichlet and a mixed boundary value problem for a linear elliptic equation in a polygon. It is well known that the first derivatives of the solutions develop singularities near reentrant corner points or points where the boundary conditions change. On the basis of the regularity results formulated in Sobolev–Slobodetskii spaces and weighted spaces of Kondratiev type, we prove error estimates of higher order for DGFE solutions using a suitable graded mesh refinement near boundary singular points. The main tools are as follows: regularity investigation for the exact solution relying on general results for elliptic boundary value problems, error analysis for the interpolation in Sobolev–Slobodetskii spaces, and error estimates for DGFE solutions on special graded refined meshes combined with estimates in weighted Sobolev spaces. Our main result is that there exist a local grading of the mesh and a piecewise interpolation by polynoms of higher degree such that we will get the same order O (hα) of approximation as in the smooth case. © 2011 Wiley Periodicals, Inc. Numer Mehods Partial Differential Eq, 2012 相似文献
7.
Vivette Girault Jizhou Li Beatrice M. Rivière 《Numerical Methods for Partial Differential Equations》2017,33(2):489-513
Strong convergence of the numerical solution to a weak solution is proved for a nonlinear coupled flow and transport problem arising in porous media. The method combines a mixed finite element method for the pressure and velocity with an interior penalty discontinuous Galerkin method in space for the concentration. Using functional tools specific to broken Sobolev spaces, the convergence of the broken gradient of the numerical concentration to the weak solution is obtained in the L2 norm. © 2016 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 33: 489–513, 2017 相似文献
8.
This paper is a continuation of work of the author and joint work with Winfried Sickel. Here we shall investigate the asymptotic behaviour of Weyl and Bernstein numbers of embeddings of Sobolev spaces with dominating mixed smoothness into Lebesgue spaces. 相似文献
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In this paper, we use a weighted version of Poincaré's inequality to study density and extension properties of weighted Sobolev spaces over some open set . Additionally, we study the specific case of monomial weights , showing the validity of a weighted Poincaré inequality together with some embedding properties of the associated weighed Sobolev spaces. 相似文献
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Alois Kufner 《Acta Appl Math》2001,65(1-3):273-281
We define the critical exponent of (compact and noncompact) imbeddings of certain special weighted Sobolev spaces into weighted Lebesgue spaces. 相似文献
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Wojciech M. Zaja̧czkowski 《Mathematical Methods in the Applied Sciences》2015,38(12):2466-2478
The nonstationary Stokes system with slip boundary conditions is considered in a bounded domain . We prove the existence and uniqueness of solutions to the problem in anisotropic Sobolev spaces . Thanks to the slip boundary conditions, the Stokes problem is transformed to the Poisson and the heat equation. In this way, difficult calculations that must be performed in considerations of boundary value problems for the Stokes system are avoided. This approach does not work for the Dirichlet and the Neumann boundary conditions. Because solvability of the Poisson and the heat equation is carried out by the regularizer technique, we have that σ > 3,α > 0. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
15.
This paper examines the estimation of an indirect signal embedded in white noise on vector bundles. It is found that the sharp asymptotic minimax bound is determined by the degree to which the indirect signal is embedded in the linear operator. Thus when the linear operator has polynomial decay, recovery of the signal is polynomial where the exact minimax constant and rate are determined. Adaptive sharp estimation is carried out using a blockwise shrinkage estimator. Application to the spherical deconvolution problem for the polynomially bounded case is made. 相似文献
16.
Hela Louati Mohamed Meslameni Ulrich Razafison 《Mathematical Methods in the Applied Sciences》2016,39(8):1990-2010
In the present paper, we study the vector potential problem in exterior domains of . Our approach is based on the use of weighted spaces in order to describe the behavior of functions at infinity. As a first step of the investigation, we prove important results on the Laplace equation in exterior domains with Dirichlet or Neumann boundary conditions. As a consequence of the obtained results on the vector potential problem, we establish useful results on weighted Sobolev inequalities and Helmholtz decompositions of weighted spaces. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
17.
NourElHouda Bourguiba Ahmed Souabni 《Mathematical Methods in the Applied Sciences》2021,44(1):634-649
In this work, we first give some mathematical preliminaries concerning the generalized prolate spheroidal wave function (GPSWF). This set of special functions have been defined as the infinite and countable set of the eigenfunctions of a weighted finite Fourier transform operator. Then, we show that the set of the singular values of this operator has a super‐exponential decay rate. We also give some local estimates and bounds of these GPSWFs. As an application of the spectral properties of the GPSWFs and their associated eigenvalues, we give their quality of approximation in a weighted Sobolev space. Finally, we provide the reader with some numerical examples that illustrate the different results of this work. 相似文献
18.
In the first part of the paper we study the minimal and maximal extension of a class of weighted pseudodifferential operators in the Fréchet space . In the second one non homogeneous microlocal properties are introduced and propagation of Sobolev singularities for solutions to (pseudo)differential equations is given. For both the arguments actual examples are provided. 相似文献
19.
本文结合仿微分算子理论研究了一类锥Sobolev空间上的Littlewood—Paley分解,讨论了该分解在非线性偏微分方程上的应用. 相似文献
20.
Hoai-Minh Nguyen 《Journal of Functional Analysis》2006,237(2):689-720
In this paper, we present some new characterizations of Sobolev spaces. Here is a typical result. Let g∈Lp(RN), 1<p<+∞; we prove that g∈W1,p(RN) if and only if