Enveloping Classes over Commutative Rings
Abstract
Given a -tilting cotorsion pair over a commutative ring, we characterise the rings over which the -tilting class is an enveloping class. To do so, we consider the faithful finitely generated Gabriel topology associated to the -tilting class over a commutative ring as illustrated by Hrbek. We prove that a -tilting class is enveloping if and only if is a perfect Gabriel topology (that is, it arises from a perfect localisation) and is a perfect ring for each , or equivalently is a perfect Gabriel topology and the discrete quotient rings of the topological ring End are perfect rings where denotes the ring of quotients with respect to . Moreover, if the above equivalent conditions hold it follows that pdim and arises from a flat ring epimorphism.
Cite
@article{arxiv.1901.07921,
title = {Enveloping Classes over Commutative Rings},
author = {Silvana Bazzoni and Giovanna Le Gros},
journal= {arXiv preprint arXiv:1901.07921},
year = {2020}
}
Comments
Updated version includes improvement of main theorem due to recent results, generalisation of techniques which were moved to Section 4 from Section 5, updates and additions to references and a change of abstract