xxSUPERCONVERGENCE OF MIXED FINITE ELEMENTAPPROXIMATIONS OVER QUADRILATERALSRICHARD
نویسندگان
چکیده
A superconvergence is established in this article for approximate solutions of second order elliptic equations by mixed nite element methods over quadrilaterals. The superconvergence indicates an accuracy of O(h k+2) for the mixed nite element approximation if the Raviart-Thomas or Brezzi-Douglas-Fortin-Marini elements of order k are employed with optimal error estimate of O(h k+1). Numerical experiments are presented to illustrate the theoretical result.
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