Multiplicity of nodal solutions for a critical quasilinear equation with symmetry

We consider the quasilinear problem div(|∇u|p-2∇u)+λ|u|q-2u+|u|p*-2u=0 in Ω, u=0 on ∂Ω, where Ω⊂RN is a bounded smooth domain, N⩾p2, λ>0 and p