“…Numerous numerical approaches also exists, for example using Lagrange multipliers [12], finite cell methods [13,14,15], immersed interface methods [16], the s-version of the finite element method [17,18] and XFEM [19,20,21] to name a few. Discontinuous Galerkin methods have also successfully been used [22,23,24,25], as well as variants using local enrichments [26,27,28]. There are also substantial and important works in domain decomposition methods see for example [29,30] or [31,32] and the references therein.…”