Comparisons between ordinary and symbolic powers of edge ideals with respect to regularity and depth
Abstract
In this paper, we investigate the difference between ordinary and symbolic powers of edge ideals on the Castelnuovo-Mumford regularity and the depth. As a main theorem, we prove that the regularities of ordinary and symbolic powers coincide for edge ideals of simplicial graphs, as a partial result of Minh's conjecture. For the depth, we first show that, for each k≥2, the inequality depth S/I(k)≥depth S/Ik does not hold for squarefree monomial ideals in general. On the other hand, we prove that it holds for edge ideals when k=2,3. We also study the symbolic-ordinary discrepancy module I(G)(k)/I(G)k of the edge ideal I(G) of a graph G and give a graph-theoretic formula for its Krull dimension in terms of induced odd cycles of G, thereby answering a question and a problem posed by Ha and Minh.
Related
- Regularity of symbolic powers of complementary edge ideals
- Regularity of Symbolic Powers of Polymatroidal Ideals and Supermodular Prime Intersections
- Regularity, depth and Serre depth of symbolic powers of complementary edge ideals
- v-numbers of symbolic-ordinary discrepancy modules
- Uniform bounds on symbolic powers in regular rings
BibTeX
@misc{muta2026comparisons,
title = {{Comparisons between ordinary and symbolic powers of edge ideals with respect to regularity and depth}},
author = {Yuji Muta},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.05945},
eprint = {2609.05945},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.05945},
}
RIS
TY - UNPB
TI - Comparisons between ordinary and symbolic powers of edge ideals with respect to regularity and depth
AU - Yuji Muta
PY - 2026
DA - 2026/09/05
PB - arXiv
DO - 10.48550/arxiv.2609.05945
UR - https://arxiv.org/abs/2609.05945
AB - In this paper, we investigate the difference between ordinary and symbolic powers of edge ideals on the Castelnuovo-Mumford regularity and the depth. As a main theorem, we prove that the regularities of ordinary and symbolic powers coincide for edge ideals of simplicial graphs, as a partial result of Minh's conjecture. For the depth, we first show that, for each k≥2, the inequality depth S/I^(k)≥depth S/I^k does not hold for squarefree monomial ideals in general. On the other hand, we prove that it holds for edge ideals when k=2,3. We also study the symbolic-ordinary discrepancy module I(G)^(k)/I(G)^k of the edge ideal I(G) of a graph G and give a graph-theoretic formula for its Krull dimension in terms of induced odd cycles of G, thereby answering a question and a problem posed by Ha and Minh.
ER -