Abstract

Let D be a bounded domain in n(n2). We consider the following nonlinear elliptic problem: Δu=f(,u) in D (in the sense of distributions), u|D=ϕ, where ϕ is a nonnegative continuous function on D and f is a nonnegative function satisfying some appropriate conditions related to some Kato class of functions K(D). Our aim is to prove that the above problem has a continuous positive solution bounded below by a fixed harmonic function, which is continuous on D¯. Next, we will be interested in the Dirichlet problem Δu=ρ(,u) in D (in the sense of distributions), u|D=0, where ρ is a nonnegative function satisfying some assumptions detailed below. Our approach is based on the Schauder fixed-point theorem.