# On the implementation of mixed methods as nonconforming methods for second-order elliptic problems

@article{Arbogast1995OnTI, title={On the implementation of mixed methods as nonconforming methods for second-order elliptic problems}, author={Todd Arbogast and Zhangxin Chen}, journal={Mathematics of Computation}, year={1995}, volume={64}, pages={943-972} }

In this paper we show that mixed finite element methods for a fairly general second-order elliptic problem with variable coefficients can be given a nonmixed formulation. (Lower-order terms are treated, so our results apply also to parabolic equations.) We define an approximation method by incorporating some projection operators within a standard Galerkin method, which we call a projection finite element method. It is shown that for a given mixed method, if the projection method's finite…

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