An Optimal Embedded Discontinuous Galerkin Method for Second-Order Elliptic Problems
For researchers in numerical analysis, this work provides an optimal EDG method on general polygonal meshes, extending prior work limited to simplex meshes.
This paper proposes a new embedded discontinuous Galerkin method for second-order elliptic problems on polygonal/polyhedral meshes, achieving optimal convergence rates for both potential and flux approximations using piecewise polynomials of degrees k+1, k+1, and k.
The embedded discontinuous Galerkin (EDG) method by Cockburn et al. [SIAM J. Numer. Anal., 2009, 47(4), 2686-2707] is obtained from the hybridizable discontinuous Galerkin method by changing the space of the Lagrangian multiplier from discontinuous functions to continuous ones, and adopts piecewise polynomials of equal degrees on simplex meshes for all variables. In this paper, we analyze a new EDG method for second order elliptic problems on polygonal/polyhedral meshes. By using piecewise polynomials of degrees $k+1$, $k+1$, $k$ ($k\geq 0$) to approximate the potential, numerical trace and flux, respectively, the new method is shown to yield optimal convergence rates for both the potential and flux approximations. Numerical experiments are provided to confirm the theoretical results.