A comparison of computational complexities of HFEM and ABC based finite element methods

The solution of a hybrid finite element method (HFEM) problem is considered. It is shown that a suitable ordering of the FEM mesh results in a canonical HFEM matrix system. This linear system can be solved in O(N 1.5) cost when sparse direct methods are used. This cost is comparable to FEM methods using approximate boundary conditions and a similar sparse solution method.link_to_subscribed_fulltex