English

Infinite free resolutions over numerical semigroup algebras via specialization

Commutative Algebra 2024-05-06 v1

Abstract

Each numerical semigroup SS with smallest positive element mm corresponds to an integer point in a polyhedral cone CmC_m, known as the Kunz cone. The faces of CmC_m form a stratification of numerical semigroups that has been shown to respect a number of algebraic properties of SS, including the combinatorial structure of the minimal free resolution of the defining toric ideal ISI_S. In this work, we prove that the structure of the infinite free resolution of the ground field k\Bbbk over the semigroup algebra k[S]\Bbbk[S] also respects this stratification, yielding a new combinatorial approach to classifying homological properties like Golodness and rationality of the poincare series in this setting. Additionally, we give a complete classification of such resolutions in the special case m=4m = 4, and demonstrate that the associated graded algebras do not generally respect the same stratification.

Keywords

Cite

@article{arxiv.2405.01700,
  title  = {Infinite free resolutions over numerical semigroup algebras via specialization},
  author = {Tara Gomes and Christopher O'Neill and Aleksandra Sobieska and Eduardo Torres Dávila},
  journal= {arXiv preprint arXiv:2405.01700},
  year   = {2024}
}
R2 v1 2026-06-28T16:14:50.792Z