A conforming discontinuous Galerkin finite element method on rectangular partitions (Q2030415)

This paper presents a new conforming discontinuous Galerkin (DG) scheme for second order elliptic equations on rectangular partitions. The new method is based on DG finite element space and uses a weak gradient arising from local Raviart-Thomas space for gradient approximations. By using the weak gradient and enforcing inter-element continuity strongly, the scheme maintains the simple formulation of conforming finite element method while have the flexibility of using discontinuous approximations. Hence, the programming complexity of this new conforming DG scheme is reduced compared to other existing DG methods. Error estimates of optimal order are established for the corresponding conforming DG approximations in energy norm and \(L^2\)-norm. Numerical results are presented to confirm the theoretical rates of convergence.