The Ohm-Rush content function III: Completion, globalization, and power-content algebras
Abstract
One says that a ring homomorphism is Ohm-Rush if extension commutes with arbitrary intersection of ideals, or equivalently if for any element , there is a unique smallest ideal of whose extension to contains , called the content of . For Noetherian local rings, we analyze whether the completion map is Ohm-Rush. We show that the answer is typically `yes' in dimension one, but `no' in higher dimension, and in any case it coincides with the content map having good algebraic properties. We then analyze the question of when the Ohm-Rush property globalizes in faithfully flat modules and algebras over a 1-dimensional Noetherian domain, culminating both in a positive result and a counterexample. Finally, we introduce a notion that we show is strictly between the Ohm-Rush property and the weak content algebra property.
Cite
@article{arxiv.2008.07616,
title = {The Ohm-Rush content function III: Completion, globalization, and power-content algebras},
author = {Neil Epstein and Jay Shapiro},
journal= {arXiv preprint arXiv:2008.07616},
year = {2021}
}
Comments
Little changes made throughout. 14 pages. Comments welcome!