An Adaptive Least-Squares Mixed Finite Element Method for Fourth- Order Elliptic Equations

A least-squares mixed finite element (LSMFE) method for the numerical solution of fourth-order elliptic equations is analyzed and developed in this paper. The a posteriori error estimator which is needed in the adaptive refinement algorithm is proposed. The local evaluation of the least-squares functional serves as a posteriori error estimator. The posteriori errors are effectively estimated.