Back to Search Start Over

The Ohm-Rush content function III: Completion, globalization, and power-content algebras

Authors :
Epstein, Neil
Shapiro, Jay
Publication Year :
2020

Abstract

One says that a ring homomorphism $R \rightarrow S$ is Ohm-Rush if extension commutes with arbitrary intersection of ideals, or equivalently if for any element $f\in S$, there is a unique smallest ideal of $R$ whose extension to $S$ contains $f$, called the content of $f$. 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.<br />Little changes made throughout. 14 pages. Comments welcome!

Details

Language :
English
Database :
OpenAIRE
Accession number :
edsair.doi.dedup.....a060a7150c7cf1d301aa3abf582052af