Campanato estimates for the generalized Stokes System

We study interior regularity of solutions of a generalized stationary Stokes problem in the plane. The main, elliptic part of the problem is given in the form div(A(Du)), where D is the symmetric part of the gradient. The model case is A(Du)=(kappa+|Du|)^{p-2}Du. We show optimal BMO and Campanato estimates for A(Du). Some corollaries for the generalized stationary Navier-Stokes system and for its evolutionary variant are also mentioned.