$hp$-a posteriori error estimates for hybrid high-order methods applied to biharmonic problems
Zhaonan Dong, Alexandre Ern, Tanvi Wadhawan
TL;DR
This work develops hp-adaptive, residual-based a posteriori error estimators for hybrid high-order methods applied to the biharmonic equation on Lipschitz polytopal domains in 2D and 3D. A key novelty is bounding the nonconforming error through a local $C^1$ partition of unity built on Alfeld-split subcells and a stable local Helmholtz decomposition on vertex patches, avoiding dependence on domain topology. Two conforming-error estimators are derived from distinct interpolation operators: a canonical CH-based one yielding an $H^2$-elliptic projection and, separately, a Babuška–Suri-based operator; each provides hp-optimal or near hp-optimal bounds with different indicator terms. The main result combines these ingredients into hp-upper bounds that control the energy error by stabilization, residuals, and data oscillation, with numerical experiments confirming efficiency and adaptive refinement capability for handling singularities.
Abstract
We derive a residual-based $hp$-a posteriori error estimator for hybrid high-order (HHO) methods on simplicial meshes applied to the biharmonic problem posed on two- and three-dimensional polytopal Lipschitz domains. The a posteriori error estimator hinges on an error decomposition into conforming and nonconforming components. To bound the nonconforming error, we use a $C^1$-partition of unity constructed via Alfeld splittings, combined with local Helmholtz decompositions on vertex stars. For the conforming error, we design two residual-based estimators, each associated with a specific interpolation operator. In the first setting, the upper bound for the conforming error involves only the stabilization term and the data oscillation. In the second setting, the bound additionally incorporates bulk residuals, normal flux jumps, and tangential jumps. Numerical experiments confirm the theoretical findings and demonstrate the efficiency of the proposed estimators.
