Fully automatic hp-adaptivity for Maxwell's equations

I report on the development of a fully automatic hp-adaptive strategy for the solution of time-harmonic Maxwell equations. The strategy produces a sequence of grids that deliver exponential convergence for both regular and singular solutions. Given a (coarse) mesh, we refine it first globally in both h and p, and solve the problem on the resulting fine mesh. We consider then the projection-based interpolants of the fine mesh solution with respect to both current and next (to be determined) coarse grid, and introduce the interpolation error decrease rate equal to the difference of the old and new (coarse) mesh interpolation errors vs. number of degrees-of-freedom added. The optimal hp-refinements leading to the next coarse grid are then determined by maximizing the interpolation error decrease rate.