On complete space-like hypersurfaces with constant mean curvature in a Lorentz space form of dimension 4, we study the case that the scalar curvature is constant and that the Ricci curvature is bounded from above.
In this paper first we establish the existence of solutions for a large class of nonlinear, nonconvex evolution inclusions and then we show that the solution multifunction has a continuous selector. Then we use that selector result to establish the existence of periodic trajectories and we show how this result can be used in nonlinear closed loop (feedback) control systems.