Convergence problem of linear wave equation

dolfinx
,
6

For future reference:

  1. the convergence rate with p=2 polynomials can be shown to be 3, if one refines the time step faster than the mesh size, rather than choosing Nt fixed like I did in the code above.
  2. the boundary integrals are wrong, they should be removed. We have dirichlet BC and therefore they vanish (on both equations), but this was not the reason for the convergence problem.