Regularity of weak solutions to obstacle problems for nondiagonal quasilinear degenerate elliptic systems

Abstract

Let X = {X 1 ,. .. , X m } be a system of smooth real vector fields satisfying Hörmander's rank condition. We consider the interior regularity of weak solutions to an obstacle problem associated with the nonhomogeneous nondiagonal quasilinear degenerate elliptic system X * α (A αβ