Estimates for the $L^q$-mixed problem in $C^{1,1}$-domains

Abstract

We consider the $L^q$-mixed problem in domains in ${\bf R}^n$ with $C^ {1,1}$-boundary. We assume that the boundary between the sets where we specify Neumann and Dirichlet data is Lipschitz. With these assumptions, we show that we may solve the $L^q$-mixed problem for $q$ in the range $1<q < n/(n-1)$.