A THREE-LEVEL BDDC ALGORITHM FOR MORTAR DISCRETIZATIONS

In this talk, three-level BDDC algorithms will be presented for the solutions of large sparse linear algebraic systems arising from the mortar discretization of elliptic boundary value prob-lems. The mortar discretization is considered on geometrically non-conforming subdomain par-titions. In the algorithms, the large coarse problems from two-level BDDC algorithms are solved approximately while a good rate of convergence is maintained. This is an extension of previ-ous work for the three-level BDDC algorithms with standard finite element discretization by Tu [12,13]. Estimates of the condition numbers are provided for the three-level BDDC methods and numerical experiments are also discussed