English

Modules of infinite regularity over commutative graded rings

Commutative Algebra 2018-09-28 v2

Abstract

In this work, we prove that if a graded, commutative algebra RR over a field kk is not Koszul then, denoting by m\mathfrak{m} the maximal homogeneous ideal of RR and by MM a finitely generated graded RR-module, the nonzero modules of the form mM\mathfrak{m} M have infinite Castelnuovo-Mumford regularity. We also prove that over complete intersections which are not Koszul, a nonzero direct summand of a syzygy of kk has infinite regularity. Finally, we relate the vanishing of the graded deviations of RR to having a nonzero direct summand of a syzygy of kk of finite regularity.

Keywords

Cite

@article{arxiv.1801.08207,
  title  = {Modules of infinite regularity over commutative graded rings},
  author = {Luigi Ferraro},
  journal= {arXiv preprint arXiv:1801.08207},
  year   = {2018}
}
R2 v1 2026-06-22T23:55:08.721Z