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1.
The inverse spectral problem for the Dirac operators defined on the interval[0, π] with self-adjoint separated boundary conditions is considered. Some uniqueness results are obtained, which imply that the pair of potentials(p(x), r(x)) and a boundary condition are uniquely determined even if only partial information is given on(p(x), r(x))together with partial information on the spectral data, consisting of either one full spectrum and a subset of norming constants, or a subset of pairs of eigenvalues and the corresponding norming constants. Moreover, the authors are also concerned with the situation where both p(x) and r(x) are C n-smoothness at some given point.  相似文献   

2.
To each Dirac type operator there is assigned a formally exact elliptic complex of length 2. We study the Neumann problem for this complex in a bounded domain with smooth boundary in Rn, as it was formulated by Spencer in 1957.  相似文献   

3.
A uniqueness theorem is established for the elastodynamic problemof direct scattering of harmonic small-amplitude waves by anobstacle embedded in an isotropic medium with spatially varyingparameters. Uniqueness theorems are then developed for the inverseproblem of boundary determination of the obstacle associatedwith this direct scattering problem. In particular, it is shownfor nondegenerate elastodynamic problems that knowledge of boththe lamellar and the solenoidal far-field patterns is necessaryto reconstruct the obstacle's boundary.  相似文献   

4.
We consider inverse boundary value problems for elliptic equations of second order of determining coefficients by Dirichlet-to-Neumann map on subboundaries, that is, the mapping from Dirichlet data supported on subboundary ${\partial \Omega \setminus \Gamma_{-}}$ to Neumann data on subboundary ${\partial \Omega \setminus \Gamma_{+}}$ . First we prove uniqueness results in three dimensions under some conditions such as ${\overline{\Gamma_{+}\cup\Gamma_{-}}= \partial\Omega}$ Next we survey uniqueness results in two dimensions for various elliptic systems for arbitrarily given ${\Gamma_{-} = \Gamma_{+}}$ Our proof is based on complex geometric optics solutions which are constructed by a Carleman estimate.  相似文献   

5.
An inverse nodal problem lies in constructing operators from the given zeros of their eigenfunctions. In this work, we deal with an inverse nodal problem of reconstructing the Dirac system with the spectral parameter in the boundary conditions. We prove that a set of nodal points of one of the components of the eigenfunctions uniquely determines all the parameters of the boundary conditions and the coefficients of the Dirac equations. We also provide a constructive procedure for solving this inverse nodal problem.  相似文献   

6.

We consider a nonlinear initial boundary value problem in a two-dimensional rectangle. We derive variational formulation of the problem which is in the form of an evolutionary variational inequality in a product Hilbert space. Then, we establish the existence of a unique weak solution to the problem and prove the continuous dependence of the solution with respect to some parameters. Finally, we consider a second variational formulation of the problem, the so-called dual variational formulation, which is in a form of a history-dependent inequality associated with a time-dependent convex set. We study the link between the two variational formulations and establish existence, uniqueness, and equivalence results.

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7.
本文利用上下解的构造研究了三阶奇摄动边值问题 ,建立了解的唯一性定理 .  相似文献   

8.
Russian Mathematics - We consider the inverse boundary value problem of aerohydrodynamics in which it is required to find a form of the airfoil circulated by a potential stream of incompressible...  相似文献   

9.
We prove a uniqueness theorem for an inverse boundary value problem for the Maxwell system with boundary data assumed known only in part of the boundary. We assume that the inaccessible part of the boundary is either part of a plane, or part of a sphere. This work generalizes the results obtained by Isakov [4 Isakov , V. ( 2007 ). On uniqueness in the inverse conductivity problem with local data . Inverse Probl. Imaging 1 : 95105 .[Crossref], [Web of Science ®] [Google Scholar]] for the Schrödinger equation to Maxwell equations.  相似文献   

10.
There is given the formulation and the solution of the inverse boundary value problem of the plane theory of elasticity in this paper. The solution is reduced to finding the Taylor coefficients for the function which maps the unit dick onto the unknown domain.  相似文献   

11.
研究了一类含参数的非线性三阶边值问题,利用不动点指数理论并结合Green函数估计,在适当条件下证明了其正解的存在性与唯一性.  相似文献   

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We study overdetermined boundary conditions for positive solutions to the p Laplacian in a bounded domain D. We show these conditions imply uniqueness in certain free boundary problems.  相似文献   

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Strong solvability in Sobolev spaces is proved for a unilateral boundary value problem for nonlinear parabolic operators. The operator is assumed to be of Carathéodory type and to satisfy a suitable ellipticity condition; only measurability with respect to the independent variable X is required. The main tools of the proof are an estimate for the second derivatives of functions which satisfy the unilateral boundary conditions and the monotonicity of the operator − u t with respect to Δu for the same functions.  相似文献   

18.
《Quaestiones Mathematicae》2013,36(1-3):221-228
Abstract

This note contains an order-theoretical approach to the theory of stochastic operators. Our main result is a necessary condition for the existence of n-th roots of an ergodic and conservative operator, which generalizes known results for measure-preserving operators and operators on L p-type spaces.  相似文献   

19.
利用解的先验估计和极值原理,研究了一类具有Riemann-Stieltjes积分边值问题正解的存在唯一性.  相似文献   

20.
研究了一类上半平面中双周期函数的Hilbert边值逆问题.利用函数的对称扩张,将其转化为无穷直线上双周期Riemann边值问题,得到了问题的一般解及可解性定理.  相似文献   

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