Felix Dangel Bálint Mucsányi Tobias Weber Runa Eschenhagen Kronecker-factored Approximate Curvature (KFAC) From Scratch. 2025 July abs/2507.05127 CoRR https://doi.org/10.48550/arXiv.2507.05127 db/journals/corr/corr2507.html#abs-2507-05127 streams/journals/corr