In this paper, we provide a priori and a posteriori error analyses of an augmented mixed finite element method with Lagrange multipliers applied to elliptic equations in divergence form with mixed boundary conditions. The ...

Residual type a posteriori error estimators are introduced in this paper for an advection–diffusion–reaction problem with a Dirac delta source term. The error is measured in an adequately weighted W1,pW1,p-norm. These ...

This paper deals with a posteriori error estimates for advection–reaction–diffusion equations. In particular, error estimators based on the solution of local problems are derived for a stabilized finite element method. ...