L-smooth factorization for Noetherian F-finite rings
We show that any homomorphism between Noetherian $F$-finite rings can be factored into a regular morphism between Noetherian $F$-finite rings followed by a surjection. This result establishes an analog of the 'smooth-by-surjective' factorization for finite type maps. As part of our analysis, we observe that for maps of Noetherian $F$-finite rings, regularity and formal smoothness are both equivalent to $L$-smoothness, meaning that the cotangent complex, as in the smooth case, is a locally free module of finite rank concentrated in degree zero. Our findings may also be viewed as a relative version of Gabber's final remark in \citep{Gab04}, which states that any Noetherian $F$-finite ring is a quotient of a regular Noetherian $F$-finite ring.
Authors
- Manuel Blickle (ORCID: https://orcid.org/0009-0005-1209-503X)
- Daniel Fink (ORCID: https://orcid.org/0000-0003-2953-7971)
Publication Details
- Journal
- Advances in Mathematics
- Published
- 2026-06-16
- DOI
- https://doi.org/10.1016/j.aim.2026.111105
- Primary Topic
- Rings, Modules, and Algebras
- Type
- preprint
- Field-Weighted Citation Impact
- 0.00
Funders
- Deutsche Forschungsgemeinschaft