p-Multigrid for Fekete spectral element method

Spectral element approximations based on triangular elements and on the so-called Fekete points of the triangle have been recently developed. p-multigrid methods offer an interesting way to resolve efficiently the resulting ill-conditioned algebraic systems. For elliptic problems, it is shown that a well chosen restriction operator and a good set up of the coarse grid matrices may lead to valuable results, even with a standard Gauss-Seidel smoother.