This talk is devoted to analyzing the structure of global attractors for reactions diffusion equations without uniqueness of solutions of the Cauchy problem.
We consider a scalar reaction-diffusion equation in a three-dimensional bounded domain in which the nonlinear term satisfy suitable growth and dissipative conditions, but there is no condition ensuring uniqueness of the Cauchy problem (like e.g. a monotonicity assumption). Such equation generates a multivalued semiflow having a global compact attractor, which is the union of all bounded complete trajectories of the semiflow. We establish that the global attractor can be characterized as the unstable manifold of the set of stationary points.