3 papers
math.NA2026
Why the Kellogg Mesh Is Radial: A Mathematical Explanation of a Classical Computational Benchmark
Shun Zhang
Kellogg's checkerboard interface problem is a classical benchmark for robust adaptive finite element methods. Its successful adaptive meshes are radial: they refine strongly toward…
math.NA2026
Mixed Finite Element Methods for a Dirac Source: Divergence-Form Splitting and L^p Error Analysis
Yueyao Wu, Shun Zhang
For a mixed finite element method, a Dirac source is first a failure of duality, not of regularity: the conservation equation is tested against a Lebesgue space, and a Dirac measur…
math.NA2026
Goal-Oriented Error Estimation for Least-Squares Finite Element Methods via Physically Meaningful Adjoint PDEs
Yueyao Wu, Shun Zhang
We develop a goal-oriented error-estimation framework for first-order system least-squares (FOSLS) finite element methods based on the physical PDE adjoint rather than the adjoint…