Hom and Ext, Revisited
Commutative Algebra
2017-11-06 v4
Abstract
Let be a commutative Noetherian local ring and be finitely generated -modules. We prove a number of results of the form: if has some nice properties and for some , then (and sometimes ) must be be close to free. Our methods are quite elementary, yet they suffice to give a unified treatment, simplify, and sometimes extend a number of results in the literature.
Cite
@article{arxiv.1710.05123,
title = {Hom and Ext, Revisited},
author = {Hailong Dao and Mohammad Eghbali and Justin Lyle},
journal= {arXiv preprint arXiv:1710.05123},
year = {2017}
}
Comments
Some typos fixed. Remark 2.1 and Lemma 3.1 were expanded to cover semi-dualizing modules. Remark 3.17 was added