2019/10/21 by Dorin Popescu, Popescu, Dorin
Mathematics · #Rings, Modules, and Algebras #Advanced Topology and Set Theory
paper · pdf · doi:10.48550/arxiv.1910.09123
Zariski's local uniformization, a weak form of resolution of singularities, implies that every valuation ring containing \bf Q is a filtered direct limit of smooth \bf Q-algebras. Given an immediate extension of valuation rings V⊂ V' containing \bf Q we show that V' is a filtered direct limit of smooth V-algebras. This corrects a paper of us \citePo1 where we thought that we may reduce to the case when the value groups are finitely generated. For this correction we use an infinite tower of ultrapowers construction that rests on results from model theory. .