An existence and localization theorem for the solutions of a Dirichlet problem
We establish an existence theorem for a Dirichlet problem with homogeneous boundary conditions by using a general variational principle of Ricceri.
An existence result for a semipositone problem with a sign changing weight.
An existence result for nonlinear elliptic problems involving critical Sobolev exponent
An explicit potential theory for the stokes resolvent boundary value problems in three dimensions.
An extension of a multiplicity theorem by Ricceri with an application to a class of quasilinear equations
A recent multiplicity result by Ricceri, stated for equations in Hilbert spaces, is extended to a wider class of Banach spaces. Applications to nonlinear boundary value problems involving the p-Laplacian are presented.
An Extrerior Mixed Boundary Value Problem for the Helmholtz Equation
An Hadamard maximum principle for the biplacian on hyperbolic manifolds
We prove the existence of a maximum principle for operators of the type , for weights with subharmonic. It is associated with certain simply connected subdomains that are produced by a Hele-Shaw flow emanating from a given point in the domain. For constant weight, these are the circular disks in the domain. The principle is equivalent to the following statement. THEOREM. Suppose is logarithmically subharmonic on the unit disk, and that the weight times area measure is a reproducing measure...
An integral equation technique for solving mixed boundary value problems
An iterative method of alternating type for systems with special block matrices
An iterative procedure for systems with matrices originalting from the domain decomposition technique is proposed. The procedure introduces one iteration parameter. The convergence and optimization of the method with respect to the parameter is investigated. The method is intended not as a preconditioner for the CG method but for the independent use.
An Orlicz-Sobolev space setting for quasilinear elliptic problems.
An overdetermined elliptic problem in a domain with countably rectifiable boundary
We examine an elliptic equation in a domain Ω whose boundary ∂Ω is countably (m-1)-rectifiable. We also assume that ∂Ω satisfies a geometrical condition. We are interested in an overdetermined boundary value problem (examined by Serrin [Arch. Ration. Mech. Anal. 43 (1971)] for classical solutions on domains with smooth boundary). We show that existence of a solution of this problem implies that Ω is an m-dimensional Euclidean ball.
An upper bound for positive solutions of the equation .
An upwind finite element method for singularly perturbed elliptic problems and local estimates in the -norm
Analyse limite d'équations variationnelles dans un domaine contenant une grille
Analysis of a non-standard mixed finite element method with applications to superconvergence
We show that a non-standard mixed finite element method proposed by Barrios and Gatica in 2007, is a higher order perturbation of the least-squares mixed finite element method. Therefore, it is also superconvergent whenever the least-squares mixed finite element method is superconvergent. Superconvergence of the latter was earlier investigated by Brandts, Chen and Yang between 2004 and 2006. Since the new method leads to a non-symmetric system matrix, its application seems however more expensive...
Analysis of Compatible Discrete Operator schemes for elliptic problems on polyhedral meshes
Compatible schemes localize degrees of freedom according to the physical nature of the underlying fields and operate a clear distinction between topological laws and closure relations. For elliptic problems, the cornerstone in the scheme design is the discrete Hodge operator linking gradients to fluxes by means of a dual mesh, while a structure-preserving discretization is employed for the gradient and divergence operators. The discrete Hodge operator is sparse, symmetric positive definite and is...
Analysis of Finite Element Methods for Second Order Boundary Value Problems Using Mesh Dependent Norms.
Analysis of finite element methods on Bakhvalov-type meshes for linear convection-diffusion problems in 2D
So far optimal error estimates on Bakhvalov-type meshes are only known for finite difference and finite element methods solving linear convection-diffusion problems in the one-dimensional case. We prove (almost) optimal error estimates for problems with exponential boundary layers in two dimensions.
Analysis of mixed finite element methods on locally refined grids.
Analysis of mixed methods using conforming and nonconforming finite element methods