Looking for the best constant in a Sobolev inequality: a numerical approach

Author: Caboussat Alexandre  

Publisher: Springer Publishing Company

ISSN: 0008-0624

Source: CALCOLO, Vol.47, Iss.4, 2010-12, pp. : 211-238

Disclaimer: Any content in publications that violate the sovereignty, the constitution or regulations of the PRC is not accepted or approved by CNPIEC.

Previous Menu Next

Abstract

A numerical method for the computation of the best constant in a Sobolev inequality involving the spaces H 2(Ω) and $C^{0}(overline{Omega})$ is presented. Green's functions corresponding to the solution of Poisson problems are used to express the solution. This (kind of) non-smooth eigenvalue problem is then formulated as a constrained optimization problem and solved with two different strategies: an augmented Lagrangian method, together with finite element approximations, and a Green's functions based approach. Numerical experiments show the ability of the methods in computing this best constant for various two-dimensional domains, and the remarkable convergence properties of the augmented Lagrangian based iterative method.