Oscillatory radial solutions for subcritical biharmonic equations

It is well known that the biharmonic equation Δ2u=uup−1 with p (1,∞) has positive solutions on if and only if the growth of the nonlinearity is critical or supercritical. We close a gap in the existing literature by proving the existence and uniqueness, up to scaling and symmetry, of oscillatory radial solutions on in the subcritical case. Analyzing the nodal properties of these solutions, we also obtain precise information about sign-changing large radial solutions and radial solutions of the Dirichlet problem on a ball.