Existence results for dirichlet problems in L1via minty's lemma
Lucio Boccardo, Luigi Orsina · Applicable Analysis · 2000
In some recent papers, existence and qualitative properties of solutions for nonlinear elliptic equations with right hand side measures have been proved (see the references). This paper is concerned with the existence of solutions of elliptic problems as where A(u) = −div(a(x,u, Δu)) is a Leray Lions operator defined from W1,p 0(ω) into its dual, ω is a bounded domain of RN, N≥2,fεL1(ω) and |F|εLp'(ω). We will give an existence result for the so called entropy solutions, using as main tool an L1 version of Minty's Lemma. This approach allows both to extend the known existence results (see [1]) to the case of operators defined by a function a which is not strictly monotone with respect to the gradient, and to avoid the technical result of almost everywhere convergence for gradients of suitable approximating solutions (see [2], [4], [5] and [11]) which was needed in order to prove existence.