TY - JOUR T1 - Unfitted Spectral Element Method for Interfacial Models AU - Gonzalez , Nicolas AU - Guo , Hailong AU - Yang , Xu JO - Communications in Computational Physics VL - 4 SP - 987 EP - 1016 PY - 2025 DA - 2025/09 SN - 38 DO - http://doi.org/10.4208/cicp.OA-2024-0056 UR - https://global-sci.org/intro/article_detail/cicp/24351.html KW - Elliptic interface problem, interface eigenvalue problem, unfitted Nitsche’s method, $hp$ estimate, ghost penalty. AB -
In this paper, we propose an unfitted spectral element method for solving elliptic interface and corresponding eigenvalue problems. The novelty of the proposed method lies in its combination of the spectral accuracy of the spectral element method and the flexibility of the unfitted Nitsche’s method. We also use tailored ghost penalty terms to enhance its robustness. We establish optimal $hp$ convergence rates for both elliptic interface problems and interface eigenvalue problems. Additionally, we demonstrate spectral accuracy for model problems in terms of polynomial degree.