A Primal-dual weak Galerkin finite element method for linear convection equations in non-divergence form

Abstract: A new primal-dual weak Galerkin (PD-WG) finite element method was developed and analyzed in this article for first-order linear convection equations in non-divergence form. The PD-WG method results in a symmetric discrete system involving not only the original equation for the primal variable, but also the dual/adjoint equation for the dual variable (also known as Lagrangian multiplier). Optimal order of error estimates in various discrete Sobolev norms are derived for the numerical solutions arising from the PD-WG scheme. Numerical results are produced and reported to illustrate the accuracy and effectiveness of the new PD-WG method.