arxivcs.SE2026-07-30
Reducing Data Movement in the Galerkin Product of Block Algebraic Multigrid on GPUs
The Galerkin triple product $A_c = P^T A P$ dominates the recurring per-solve setup cost of algebraic multigrid (AMG). For AMG on systems of PDEs the product is a rectangular-block sparse matrix triple product: for 3D elasticity the fine operator has $3\times3$ blocks, the prolon…