A numerical domain decomposition method for solving elliptic equations on manifolds
Shuhao Cao, Lizhen Qin
TL;DR
The paper develops a flexible numerical framework for elliptic PDEs on compact manifolds that avoids global triangulations by using overlapping domain decomposition with local coordinate charts. Building on Lions' Schwarz-type method, it couples subdomain solves through coordinate transitions and interpolation on nonmatching grids, and discretizes each chart with tensor-product finite elements on $d$-rectangles. The approach is validated on four-dimensional manifolds ($S^{4}$, $\mathbb{CP}^{2}$, $S^{2}\times S^{2}$), showing geometric convergence in the continuous setting and robust, convergent behavior in the discrete scheme, with iteration counts decreasing as overlap increases. This method extends DDM techniques to general high-dimensional manifolds, enabling scalable solutions without requiring a global mesh.
Abstract
A new numerical domain decomposition method is proposed for solving elliptic equations on compact Riemannian manifolds. The advantage of this method is to avoid global triangulations or grids on manifolds. Our method is numerically tested on some $4$-dimensional manifolds such as the unit sphere $S^{4}$, the complex projective space $\mathbb{CP}^{2}$ and the product manifold $S^{2} \times S^{2}$.
