On an iterative method for the solution of discretized elliptic problems with imperfect contact condition

Iterative method for the solution of discretized elliptic boundary value problem with imperfect contact condition on an internal boundary is constructed. It is proved that the method is robust with respect to the coefficient K appearing in the imperfect contact condition, i.e., its convergence rate is independent of the coefficient K. Numerical tests confirming the theoretical result are presented.