Coupling of Mixed Finite Elements and Boundary Elements

The symmetric coupling of mixed nite element and boundary element methods is analysed for a model interface problem with the Laplacian. The coupling involves a further continuous ansatz function on the interface to link the discontinuous displacement eld to the necessarily continuous boundary ansatz function. Quasi-optimal a priori error estimates and sharp a posteriori error estimates are established which justify adaptive mesh-reening algorithms. Numerical experiments prove the adaptive coupling as an eecient tool for the numerical treatment of transmission problems.