Smooth bifurcation for variational inequalities and reaction-diffusion systems

Bifurcation of stationary solutions to a reaction-diffusion system with simple non-local unilateral boundary conditions described by variational inequalities is studied with diffusion coefficients as a two-dimensional parameter. Using former results about a destabilizing effect of unilateral conditions, the existence of bifurcation points is obtained in the domain of parameters where a bifurcation for the corresponding classical boundary conditions is excluded. Our new results concerning smooth bifurcation branches for variational inequalities are applied to these bifurcation points.