English

Cohen-Macaulay approximations and the $\text{SC}_r$-condition

Commutative Algebra 2026-01-16 v3

Abstract

We study the relation between MCM approximations and FID hulls of modules over a Cohen-Macaulay local ring RR with canonical module, specifically when RR is generically Gorenstein. We then generalize a result of Kato, who proved that a Gorenstein complete local ring RR satisfies the SC2\text{SC}_{2}-condition if and only if RR is a UFD. For r3r \geq 3, we prove a criterion for when an MCM RR-module MM satisfies the SCr\text{SC}_{r}-condition, assuming that its first syzygy ΩR1(M)\Omega_{R}^{1}(M) satisfies the SCr1\text{SC}_{r-1}-condition.

Keywords

Cite

@article{arxiv.2507.14424,
  title  = {Cohen-Macaulay approximations and the $\text{SC}_r$-condition},
  author = {Richard F. Bartels},
  journal= {arXiv preprint arXiv:2507.14424},
  year   = {2026}
}

Comments

23 pages. Corrected statement of Proposition 2.4 (c). Revised Propositions 2.6, 2.8, and 2.9

R2 v1 2026-07-01T04:08:53.165Z