English

Dao numbers and the asymptotic behaviour of fullness

Commutative Algebra 2025-08-05 v4 Combinatorics

Abstract

In the present paper, we study the Dao numbers d1(I),d2(I)\mathfrak{d}_1(I),\mathfrak{d}_2(I) and d3(I)\mathfrak{d}_3(I) of an ideal II of a Noetherian local ring (R,m,K)(R,\mathfrak{m},K) or a standard graded Noetherian KK-algebra. They are defined as the smallest 0\ell\ge0 such that ImkI\mathfrak{m}^k is m\mathfrak{m}-full, full, weakly m\mathfrak{m}-full, respectively, for all kk\ge\ell. We provide general bounds for the Dao numbers in terms of the Castelnuovo-Mumford regularity of certain modules over the Rees algebra R(m)\mathcal{R}(\mathfrak{m}). If RR is a Koszul algebra, we prove that the Dao numbers are less or equal to reggrm(R)grm(I)\text{reg}_{\text{gr}_\mathfrak{m}(R)}\text{gr}_\mathfrak{m}(I), where grm(I)\text{gr}_\mathfrak{m}(I) is the associated graded module of II. Finally, for monomial ideals, we combinatorially bound the Dao numbers in terms of asymptotic linear quotients and bounding multidegrees.

Keywords

Cite

@article{arxiv.2402.05555,
  title  = {Dao numbers and the asymptotic behaviour of fullness},
  author = {Antonino Ficarra},
  journal= {arXiv preprint arXiv:2402.05555},
  year   = {2025}
}

Comments

This is the final version of the paper, accepted for publication in Journal of Algebra and its Applications, https://doi.org/10.1142/S021949882650132X