A note on the reflection principle for the biharmonic equation and the Stokes system (Q1341885)

The reflection principle for the biharmonic equation \(\Delta^ 2 u=0\) and for the Stokes system \(-v \delta u+\nabla p=0\), \(\text{div } u=0\), in the half-space \(\mathbb{R}^ n_ +\) is studied for different types of boundary conditions. The results are applied to problems of uniqueness of weak solutions in weighted \(L^ q\)-spaces.