Extrapolation for the Dirichlet Problem in Lipschitz domains
arXiv:1801.00828
Abstract
Let be a second-order linear elliptic operator with complex coefficients. We show that if the Dirichlet problem for the elliptic system in a fixed Lipschitz domain in is solvable for some , then it is solvable for all satisfying The proof is based on a real-variable argument. It only requires that local solutions of satisfy a boundary Cacciopoli inequality.