Fast Spectral Solvers for PDEs on Triangulated Surfaces

This paper addresses the limitations of existing high-order spectral methods for solving PDEs on surfaces, specifically those relying on quadrilateral meshes. It introduces and validates two new high-order strategies for triangulated geometries, extending the applicability of the hierarchical Poincaré-Steklov (HPS) framework. This is significant because it allows for more flexible mesh generation and the ability to handle complex geometries, which is crucial for applications like deforming surfaces and surface evolution problems. The paper's contribution lies in providing efficient and accurate solvers for a broader class of surface geometries.