Max Firmbach Malachi Phillips Christian A. Glusa Alexander Popp 0002 Christopher M. Siefert Matthias Mayr Smoothed aggregation algebraic multigrid for problems with heterogeneous and anisotropic materials. 2026 February abs/2602.05686 CoRR https://doi.org/10.48550/arXiv.2602.05686 db/journals/corr/corr2602.html#abs-2602-05686 streams/journals/corr