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An Elliptic Neumann Problem with Subcritical Nonlinearity

Jan Chabrowski, Kyril Tintarev (2005)

Bulletin of the Polish Academy of Sciences. Mathematics

We establish the existence of a solution to the Neumann problem in the half-space with a subcritical nonlinearity on the boundary. Solutions are obtained through the constrained minimization or minimax. The existence of solutions depends on the shape of a boundary coefficient.

An elliptic semilinear equation with source term involving boundary measures: the subcritical case.

Marie Françoise Bidaut-Véron, Laurent Vivier (2000)

Revista Matemática Iberoamericana

We study the boundary behaviour of the nonnegative solutions of the semilinear elliptic equation in a bounded regular domain Ω of RN (N ≥ 2),⎧   Δu + uq = 0,   in Ω⎨⎩   u = μ,      on ∂Ωwhere 1 < q < (N + 1)/(N - 1) and μ is a Radon measure on ∂Ω. We give a priori estimates and existence results. The lie on the study of superharmonic functions in some weighted Marcinkiewicz spaces.

An energy analysis of degenerate hyperbolic partial differential equations.

William J. Layton (1984)

Aplikace matematiky

An energy analysis is carried out for the usual semidiscrete Galerkin method for the semilinear equation in the region Ω (E) ( t u t ) t = i , j = 1 ( a i j ( x ) u x i ) x j - a 0 ( x ) u + f ( u ) , subject to the initial and boundary conditions, u = 0 on Ω and u ( x , 0 ) = u 0 . (E) is degenerate at t = 0 and thus, even in the case f 0 , time derivatives of u will blow up as t 0 . Also, in the case where f is locally Lipschitz, solutions of (E) can blow up for t > 0 in finite time. Stability and convergence of the scheme in W 2 , 1 is shown in the linear case without assuming u t t (which can blow up as t 0 is...

An entropy satisfying scheme for two-layer shallow water equations with uncoupled treatment

François Bouchut, Tomás Morales de Luna (2008)

ESAIM: Mathematical Modelling and Numerical Analysis

We consider the system of partial differential equations governing the one-dimensional flow of two superposed immiscible layers of shallow water. The difficulty in this system comes from the coupling terms involving some derivatives of the unknowns that make the system nonconservative, and eventually nonhyperbolic. Due to these terms, a numerical scheme obtained by performing an arbitrary scheme to each layer, and using time-splitting or other similar techniques leads to instabilities in...

An equilibrated residual method with a computable error approximation for a singularly perturbed reaction-diffusion problem on anisotropic finite element meshes

Sergey Grosman (2006)

ESAIM: Mathematical Modelling and Numerical Analysis

Singularly perturbed reaction-diffusion problems exhibit in general solutions with anisotropic features, e.g. strong boundary and/or interior layers. This anisotropy is reflected in a discretization by using meshes with anisotropic elements. The quality of the numerical solution rests on the robustness of the a posteriori error estimator with respect to both, the perturbation parameters of the problem and the anisotropy of the mesh. The equilibrated residual method has been shown to provide one...

An error analysis of the multi-configuration time-dependent Hartree method of quantum dynamics

Dajana Conte, Christian Lubich (2010)

ESAIM: Mathematical Modelling and Numerical Analysis

This paper gives an error analysis of the multi-configuration time-dependent Hartree (MCTDH) method for the approximation of multi-particle time-dependent Schrödinger equations. The MCTDH method approximates the multivariate wave function by a linear combination of products of univariate functions and replaces the high-dimensional linear Schrödinger equation by a coupled system of ordinary differential equations and low-dimensional nonlinear partial differential equations. The main result of this...

An error estimate uniform in time for spectral Galerkin approximations for the equations for the motion of a chemical active fluid.

M. A. Rojas-Medar, S. A. Lorca (1995)

Revista Matemática de la Universidad Complutense de Madrid

We study error estimates and their convergence rates for approximate solutions of spectral Galerkin type for the equations for the motion of a viscous chemical active fluid in a bounded domain. We find error estimates that are uniform in time and also optimal in the L2-norm and H1-norm. New estimates in the H(-1)-norm are given.

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