Bootstrap multigrid finite element method for eigenvalue
problems of Laplace-Beltrami operator on closed surfaces
Shuhao Cao
Penn State University
Abstract:
This talk introduces a two-grid and a bootstrap multigrid
finite element approximations to the Laplace-Beltrami eigenvalue
problem on closed surfaces. The latter can be viewed as a special case
of the BAMG (Bootstrap Algebraic Multi-Grid) framework applying on
surface finite element method. Nonlinear eigenvalue problems are solved
in the enriched finite element space on coarse mesh, while on the fine
mesh only linear problems are approximated. Several interesting
phenomena for approximating eigenvalues with high multiplicity are
shown comparing conventional two-grid/multigrid ideas with the new
bootstrap multigrid methods. Then some a posteriori error estimation
technique for the multigrid iterate will be discussed which considers
how accurate the linear problems need to be approximated to guarantee
the overall optimal rate of convergence.