一类含广义p-Laplace算子的积分微分方程的单调方法(英文)

利用极大单调算子和伪单调算子值域的结论,研究一类与广义p-Laplace算子相关的、具混合边值条件的积分微分方程.证明了这个方程解的存在唯一性.本文所研究的问题及所用方法是对以往一些研究工作的推广和补充.     

Potential bounds in problems on quasilinear elliptic equations

We study quasilinear elliptic equations with strong nonlinear terms and systems of such equations. The methods developed by the authors in [1], [2] are used to prove the existence of solutions for boundary—value problems using some information on behavior of potential bounds for nonlinearities; the L–characteristics of elliptic operators and their fractional powers play an important role. New conditions are suggested for the existence of classical solutions of quasilinear second order elliptic equations.     

Dirichlet Problem for Degenerate Quasilinear Elliptic Equations Suggested by the Anisotropic Permeation

By Browder's pseudo-monotone operator theory and the techniques belonging to J. Leray and J. Lions, the existence theorem of the generalized solution of the Dirichlet problem for a strongly degenerate quasilincar elliptic equation has been proved in the anisotropic Sobolev space.     

Note on the existence theory for evolution equations with pseudo-monotone operators

In this note we present a framework which allows to prove an abstract existence result for evolution equations with pseudo-monotone operators. The assumptions on the spaces and the operators can be easily verified in concrete examples.     

A comparison principle for quasilinear operators in unbounded domains

We establish a comparison principle for quasilinear elliptic operators in unbounded cylindrical domains by combining the traditional test function method with nonlinear capacity techniques. Some applications to monotonicity and symmetry of solutions to nonlinear elliptic problems are given.     

Transmission problems for Maxwell's equations with weakly Lipschitz interfaces

We prove sufficient conditions on material constants, frequency and Lipschitz regularity of interface for well posedness of a generalized Maxwell transmission problem in finite energy norms. This is done by embedding Maxwell's equations in an elliptic Dirac equation, by constructing the natural trace space for the transmission problem and using Hodge decompositions for operators d and δ on weakly Lipschitz domains to prove stability. We also obtain results for boundary value problems and transmission problems for the Hodge–Dirac equation and prove spectral estimates for boundary singular integral operators related to double layer potentials. Copyright © 2005 John Wiley & Sons, Ltd.     

Existence of solutions to nonlinear Neumann boundary value problems with <Emphasis Type="Italic">p</Emphasis>-Laplacian operator and iterative construction

By using some results of pseudo-monotone operator, we discuss the existence and uniqueness of the solution of one kind nonlinear Neumann boundary value problems involving the p-Laplacian operator. We also construct an iterative scheme converging strongly to this solution.     

Study of the initial value problems appearing in a method of factorization of second-order elliptic boundary value problems

In [J. Henry, A.M. Ramos, Factorization of second order elliptic boundary value problems by dynamic programming, Nonlinear Analysis. Theory, Methods & Applications 59 (2004) 629–647] we presented a method for factorizing a second-order boundary value problem into a system of uncoupled first-order initial value problems, together with a nonlinear Riccati type equation for functional operators. A weak sense was given to that system but we did not perform a direct study of those equations. This factorization utilizes either the Neumann to Dirichlet (NtD) operator or the Dirichlet to Neumann (DtN) operator, which satisfy a Riccati equation. Here we consider the framework of Hilbert–Schmidt operators, which provides tools for a direct study of this Riccati type equation. Once we have solved the system of Cauchy problems, we show that its solution solves the original second-order boundary value problem. Finally, we indicate how this techniques can be used to find suitable transparent conditions.     

偏微分方程的调和分析方法简介

本文致力于阐述调和分析与现代偏微分方程研究的关系,特别是奇异积分算子、拟微分算子、Fourier限制性估计、Fourier频率分解方法在椭圆边值问题、非线性发展方程研究中的重要作用.对于偏微分方程研究的各种方法进行了比较与分析,指出了偏微分方程的调和分析方法的优点与局限性.与此同时,还给出了偏微分方程的调和分析方法这一领域的最新研究进展.     

Sequential and continuum bifurcations in degenerate elliptic equations

We examine the bifurcations to positive and sign-changing solutions of degenerate elliptic equations. In the problems we study, which do not represent Fredholm operators, we show that there is a critical parameter value at which an infinity of bifurcations occur from the trivial solution. Moreover, a bifurcation occurs at each point in some unbounded interval in parameter space. We apply our results to non-monotone eigenvalue problems, degenerate semi-linear elliptic equations, boundary value differential-algebraic equations and fully non-linear elliptic equations.

     

Lp Estimates for a Class of Integral Operators

With the aid of the nonhomogeneous Calderon-Zygmund decomposition the present paper studies the L^p estimates for a class of integral operators related to the boundary value problems of degenerate elliptic equations. The method used here is also applicable to general evolution equations of elliptic type.     

Harnack inequalities for fuchsian type weighted elliptic equations

Harnack type inequalities for nonnegative (weak) solutions of degenerate elliptic equations, in divergence form, are established. The asymptotic behavior of solutions of Fuchsian type weighted elliptic operators is also investigated.     

A-priori bounds and asymptotics on the eigenvalues in bifurcation problems for perturbed self-adjoint operators

We prove upper and lower bounds on the eigenvalues and discuss their asymptotic behaviour (as the norm of the eigenvector tends to zero) in bifurcation problems from the line of trivial solutions, considering perturbations of linear self-adjoint operators in a Hilbert space. The proofs are based on the Lyapounov-Schmidt reduction. The results are applied to a class of semilinear elliptic operators in bounded domains of RN and in particular to Sturm-Liouville operators.     

Multi-valued boundary value problems involving Leray-Lions operators and discontinuous nonlinearities

We prove an existence result for a class of Dirichlet boundary value problems with discontinuous nonlinearity and involving a Leray-Lions operator. The proof combines monotonicity methods for elliptic problems, variational inequality techniques and basic tools related to monotone operators. Our work generalizes a result obtained in Carl [4].     

Wave Factorization of Elliptic Symbols

We introduce a definition of the wave factorization of symbols of elliptic pseudodifferential operators and demonstrate applications of the wave factorization to the analysis of pseudodifferential equations in cones.     

STEKLOV－POINCARE算子与自然积分算子及GREEN函数间的关系

ＳＴＥＫＬＯＶ－ＰＯＩＮＣＡＲＥ算子与自然积分算子及ＧＲＥＥＮ函数间的关系余德浩（中国科学院计算数学与科学工程计算研究所）ＯＮＲＥＬＡＴＩＯＮＳＨＩＰＢＥＴＷＥＥＮＳＴＥＫＬＯＶ－ＰＯＩＮＣＡＲＥＯＰＥＲＡＴＯＲＳＡＮＤＮＡＴＵＲＡＬＩＮＴＥＧＲＡＬ...     

Starshapedness of level sets of solutions to elliptic PDEs

We investigate how some geometric properties of the domain are inherited by level sets of solutions of elliptic equations. In particular we prove that, under suitable assumptions, solutions of elliptic Dirichlet problems in starshaped rings have starshaped level sets. Our results are applicable to a large class of operators, including fully-nonlinear ones.     

Mesh independent superlinear convergence estimates of the conjugate gradient method for some equivalent self-adjoint operators

A mesh independent bound is given for the superlinear convergence of the CGM for preconditioned self-adjoint linear elliptic problems using suitable equivalent operators. The results rely on K-condition numbers and related estimates for compact Hilbert-Schmidt operators in Hilbert space.This research was supported by the Hungarian National Research Fund OTKA under grant No. T043765.     

一致椭圆型算子边值问题变号解的存在性

利用Banach空间锥理论、算子的指数理论、上下解理论研究了含有一致椭圆型算子的椭圆边值问题变号解的存在性,同时分别得到了一个正解和一个负解.特别当非线性项是奇函数时,该边值问题至少存在一个正解,一个负解和两个变号解.     

Combined perturbation effects for a class of nonlinear fourth-order Navier problems

We study a class of nonlinear elliptic problems with Navier boundary condition and involving the Laplace and the biharmonic operators. The main result of this paper establishes a sufficient condition for the existence of nontrivial weak solutions, in relationship with the values of a certain real parameter with respect to the principal eigenvalue of the Laplace operator.