activity
20242026
collaborators

6 papers

math.NA2026

Local Multilevel Preconditioned Jacobi-Davidson Method for Elliptic Eigenvalue Problems on Adaptive Meshes

Jianing Guo, Qigang Liang, Xuejun Xu

In this work, we propose an efficient adaptive multilevel preconditioned Jacobi-Davidson (PJD) method for eigenvalue problems with singularity. Our multilevel method utilizes a loc…

math.NA2026

A Two-Level Additive Schwarz Method for Computing Interior Multiple and Clustered Eigenvalues of Symmetric Elliptic Operators

Qigang Liang, Xuejun Xu

In this paper, we propose an efficient two-level additive Schwarz method for solving large-scale eigenvalue problems arising from the finite element discretization of symmetric ell…

math.NA2026

Adaptive Multilevel Methods for the Maxwell Eigenvalue Problem

Qigang Liang, Xuejun Xu, Qingquan Zhang

In this paper, we propose an adaptive multilevel preconditioned Helmholtz-Jacobi-Davidson (PHJD) method for the Maxwell eigenvalue problem with singularities. The key idea in this…

math.NA2025

Pointwise A Posteriori Error Estimators for Multiple and Clustered Eigenvalue Computations

Zhenglei Li, Qigang Liang, Xuejun Xu

In this work, we propose an a pointwise a posteriori error estimator for conforming finite element approximations of eigenfunctions corresponding to multiple and clustered eigenval…

math.NA2025

Pointwise A Posteriori Error Estimators for Elliptic Eigenvalue Problems

Zhenglei Li, Qigang Liang, Xuejun Xu

In this work, we propose and analyze a pointwise a posteriori error estimator for simple eigenvalues of elliptic eigenvalue problems with adaptive finite element methods (AFEMs). W…

math.NA2024

Computing Both Upper and Lower Eigenvalue Bounds by HDG Methods

Qigang Liang, Xuejun Xu, Liuyao Yuan

In this paper, we observe an interesting phenomenon for a hybridizable discontinuous Galerkin (HDG) method for eigenvalue problems. Specifically, using the same finite element meth…