The classification of dp-minimal integral domains
Christian d'Elbée, Yatir Halevi, Will Johnson
TL;DR
This work provides a complete classification of dp-minimal integral domains, showing they are either dp-minimal fields, dp-minimal valuation rings, or arise from a dp-minimal valuation overring via a finite quotient, with the overring and quotient data definable in the domain. The authors develop a two-pronged proof: first verify the constructive direction where the preimage construction yields dp-minimal domains; then, for nontrivial cases, reduce to a dp-minimal field K=Frac(R) and analyze K under ACVF-like, pCF-like, or RCVF-like trichotomy, eliminating rogue phenomena through m^{00}-dichotomy and external definability arguments. The paper introduces and leverages tools such as external definability of valuation rings, 00-connectedness of prime ideals, and the logic topology on R^{00}-quotients, to tightly constrain the structure and ensure the reduction to the preimage construction. Additional results include the dp-minimal extension to more general rings, a trichotomy for dp-minimal fields, and a decomposition principle for dp-minimal rings into a henselian local component and a finite component, clarifying the landscape of dp-minimal algebraic structures with potential implications for model-theoretic algebra and valued-field theory.
Abstract
We classify dp-minimal integral domains, building off the existing classification of dp-minimal fields and dp-minimal valuation rings. We show that if R is a dp-minimal integral domain, then R is a field or a valuation ring or arises from the following construction: there is a dp-minimal valuation overring O extending R, a proper ideal I in O, and a finite subring S in O/I such that R is the preimage of S in O.
