Asymptotic regularity of graded families of ideals
Fuente:
arXiv
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866916700827418624 |
|---|---|
| author | Ha, Tai Huy Nguyen, Hop D. Nguyen, Thai Thanh |
| author_facet | Ha, Tai Huy Nguyen, Hop D. Nguyen, Thai Thanh |
| contents | We show that the asymptotic regularity of a graded family $(I_n)_{n \ge 0}$ of homogeneous ideals in a reduced standard graded algebra, i.e., the limit $\lim_{n \rightarrow \infty} \text{reg } I_n/n$, exists in several cases; for example, when the family $(I_n)_{n \ge 0}$ consists of artinian ideals, or Cohen-Macaulay ideals of the same codimension over an uncountable base field of characteristic $0$, or when its Rees algebra is Noetherian. Many applications, including simplifications and generalizations of previously known results on symbolic powers and integral closures of powers of homogeneous ideals, are discussed. We provide a combinatorial interpretation of the limit $\lim_{n \rightarrow \infty} \text{reg } I_n/n$ in terms of the associated Newton--Okounkov region in various situations. We give a negative answer to the question of whether the limits $\lim_{n \rightarrow \infty} \text{reg } (I_1^n + \dots + I_p^n)/n$ and $\lim_{n \rightarrow \infty} \text{reg } (I_1^n \cap \cdots \cap I_p^n)/n$ exist, for $p \ge 2$ and homogeneous ideals $I_1, \dots, I_p$. We also examine ample evidence supporting a negative answer to the question of whether the asymptotic regularity of the family of symbolic powers of a homogeneous ideal always exists. Our work presents explicit Gröbner basis construction for ideals of the form $Q^n + (f^k)$, where $Q$ is a monomial ideal, $f$ is a polynomial in the polynomial ring in 4 variables over a field of characteristic $2$. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2501_07710 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Asymptotic regularity of graded families of ideals Ha, Tai Huy Nguyen, Hop D. Nguyen, Thai Thanh Commutative Algebra 13D45, 13P10 We show that the asymptotic regularity of a graded family $(I_n)_{n \ge 0}$ of homogeneous ideals in a reduced standard graded algebra, i.e., the limit $\lim_{n \rightarrow \infty} \text{reg } I_n/n$, exists in several cases; for example, when the family $(I_n)_{n \ge 0}$ consists of artinian ideals, or Cohen-Macaulay ideals of the same codimension over an uncountable base field of characteristic $0$, or when its Rees algebra is Noetherian. Many applications, including simplifications and generalizations of previously known results on symbolic powers and integral closures of powers of homogeneous ideals, are discussed. We provide a combinatorial interpretation of the limit $\lim_{n \rightarrow \infty} \text{reg } I_n/n$ in terms of the associated Newton--Okounkov region in various situations. We give a negative answer to the question of whether the limits $\lim_{n \rightarrow \infty} \text{reg } (I_1^n + \dots + I_p^n)/n$ and $\lim_{n \rightarrow \infty} \text{reg } (I_1^n \cap \cdots \cap I_p^n)/n$ exist, for $p \ge 2$ and homogeneous ideals $I_1, \dots, I_p$. We also examine ample evidence supporting a negative answer to the question of whether the asymptotic regularity of the family of symbolic powers of a homogeneous ideal always exists. Our work presents explicit Gröbner basis construction for ideals of the form $Q^n + (f^k)$, where $Q$ is a monomial ideal, $f$ is a polynomial in the polynomial ring in 4 variables over a field of characteristic $2$. |
| title | Asymptotic regularity of graded families of ideals |
| topic | Commutative Algebra 13D45, 13P10 |
| url | https://arxiv.org/abs/2501.07710 |