Least-squares mixed method for second-order elliptic problems

摘要

A theoretical analysis of a least-squares mixed finite element method for second-order elliptic problems having non-symmetric matrix of coefficients is presented. It is proved that the method is not subject to the Ladyzhenskaya–Babuska–Brezzi (LBB) condition and that the finite element approximation yields a symmetric positive definite linear system with condition number O(h−2). Optimal error estimates are developed.