English

Linkage classes of grade 3 perfect ideals

Commutative Algebra 2019-06-05 v2

Abstract

While every grade 2 perfect ideal in a regular local ring is linked to a complete intersection ideal, it is known not to be the case for ideals of grade 3. We soften the blow by proving that every grade 3 perfect ideal in a regular local ring is linked to a complete intersection or a Golod ideal. Our proof is indebted to a homological classification of Cohen-Macaulay local rings of codimension 3. That debt is swiftly repaid, as we use linkage to reveal some of the finer structures of this classification.

Keywords

Cite

@article{arxiv.1812.11552,
  title  = {Linkage classes of grade 3 perfect ideals},
  author = {Lars Winther Christensen and Oana Veliche and Jerzy Weyman},
  journal= {arXiv preprint arXiv:1812.11552},
  year   = {2019}
}

Comments

Added proofs of 4.1 and 4.4; strengthened 5.3. Final version, to appear in J. Pure Appl. Algebra; 29 pp

R2 v1 2026-06-23T06:59:11.496Z