A bulk perturbation in a grafted brush

We find the response of a grafted polymer brush in a melt state to the insertion of a small, impenetrable object in its bulk. The response is calculated by means of perturbation theory applied to Semenov's self-consistent mean-field theory of polymer brushes. We find that both the induced pressure field and the deformation of the free surface decay exponentially away from the region of insertion. The pressure field exhibits no dependence on the depth at which the object is inserted. The decay length for both quantities is of the order of the thickness of the brush, h₀. We also discuss the induced interaction between two immersed objects.