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

Abstract

A least-squares mixed finite element method for the numerical solution of second order elliptic equations is analyzed and developed in this paper.The quadratic nonconforming and Raviart-Thomas finite element spaces are used to approximate.The aposteriori 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.