Auto-Stabilized Weak Galerkin Finite Element Methods on Polytopal Meshes without Convexity Constraints
Chunmei Wang
TL;DR
This work develops an auto-stabilized weak Galerkin method for the Poisson equation on general polytopal meshes, including non-convex elements, and in arbitrary dimension. Leveraging bubble functions as a core analytical tool, the approach yields a simple, symmetric, and positive definite discretization with built-in stabilization, while preserving sparsity. The authors prove existence and uniqueness, derive an error equation, and establish optimal-order convergence in the discrete $H^1$-norm and $L^2$-norm under standard regularity assumptions. The resulting framework broadens applicability of WG methods beyond stabilizer-free schemes, enables flexible polynomial degrees, and provides a solid theoretical foundation for practical finite element computations on complex polyhedral grids.
Abstract
This paper introduces an auto-stabilized weak Galerkin (WG) finite element method with a built-in stabilizer for Poisson equations. By utilizing bubble functions as a key analytical tool, our method extends to both convex and non-convex elements in finite element partitions, marking a significant advancement over existing stabilizer-free WG methods. It overcomes the restrictive conditions of previous approaches and is applicable in any dimension $d$, offering substantial advantages. The proposed method maintains a simple, symmetric, and positive definite structure. These benefits are evidenced by optimal order error estimates in both discrete $H^1$ and $L^2$ norms, highlighting the effectiveness and accuracy of our WG method for practical applications.
