Sous-solutions d'equations elliptiques dans L~1

摘要

We study subsolutions for semilinear elliptic boundary value problems in L~1. We consider as well nonlinear as linear boundary conditions. The nonlinear functions may be multivalued. We characterize in terms of p.d.e. the subsolutions defined by a nonlinear functional analysis argument. Application are given to obtain existence results for semilinear elliptic boundary value problems and comparison and estimates for nonlinear parabolic boundary value problems.