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There is a natural infinite graph whose vertices are the monomial ideals in a polynomial ring. The definition involves Gr\"obner bases or the action of an algebraic torus. We present algorithms for computing the (affine schemes…

Commutative Algebra · Mathematics 2007-05-23 Klaus Altmann , Bernd Sturmfels

We classify all graphs for which the Rees algebras of their edge ideals are normal and have regularity equal to their matching numbers.

Commutative Algebra · Mathematics 2024-05-21 Cao Huy Linh , Quang Hoa Tran , Thanh Vu

In this paper, we describe primary decomposition of the edge ideal of the join of some graphs in terms of that information of the edge ideal of every weighted oriented graph. Meanwhile, we also study depth and regularity of symbolic powers…

Commutative Algebra · Mathematics 2022-09-15 Yijun Cui , Guangjun Zhu , Xiaoqi Wei

A special class of algebras which are intermediate between the symmetric and the Rees algebras of an ideal was introduced by P. Aluffi in 2004 to define characteristic cycle of a hypersurface parallel to conormal cycle in intersection…

Commutative Algebra · Mathematics 2013-03-15 Abbas Nasrollah Nejad , Rashid Zaare-Nahandi

This paper studies a class of binomial ideals associated to graphs with finite vertex sets. They generalize the binomial edge ideals, and they arise in the study of conditional independence ideals. A Gr\"obner basis can be computed by…

Commutative Algebra · Mathematics 2014-06-18 Johannes Rauh

Inspired by the Erd\H{o}s R\'enyi model, we propose a new model for freesquare random monomial ideals generated by edges and covers of a graph. This permit us to investigate the conditions of normality for which we obtain asymptotic…

Commutative Algebra · Mathematics 2026-01-13 Daniel Munoz George , Humberto Muñoz-George , Kevin Muñoz George

In [9] we proved that the space of countable torsion-free abelian groups is Borel complete. In this paper we show that our construction from [9] satisfies several additional properties of interest. We deduce from this that countable…

Logic · Mathematics 2026-01-27 Gianluca Paolini , Saharon Shelah

In this paper, we study the Hankel edge ideals of graphs. We determine the minimal prime ideals of the Hankel edge ideal of labeled Hamiltonian and semi-Hamiltonian graphs, and we investigate radicality, being a complete intersection,…

Commutative Algebra · Mathematics 2022-05-13 Dariush Kiani , Sara Saeedi Madani , Saeed Tafazolian

Following Matveev, a k-normal surface in a triangulated 3-manifold is a generalization of both normal and (octagonal) almost normal surfaces. Using spines, complexity, and Turaev-Viro invariants of 3-manifolds, we prove the following…

Geometric Topology · Mathematics 2011-05-13 Evgeny Fominykh , Bruno Martelli

Let $G$ be a simple graph and $I(G)$ be its edge ideal. In this article, we study the Castelnuovo-Mumford regularity of symbolic powers of edge ideals of join of graphs. As a consequence, we prove Minh's conjecture for wheel graphs,…

Commutative Algebra · Mathematics 2020-08-04 Arvind Kumar , Rajiv Kumar , Rajib Sarkar

Fr\"oberg's classical theorem about edge ideals with $2$-linear resolution can be regarded as a classification of graphs whose edge ideals have linearity defect zero. Extending his theorem, we classify all graphs whose edge ideals have…

Commutative Algebra · Mathematics 2016-01-19 Hop D. Nguyen , Thanh Vu

We introduce the concept of distance ideals of graphs, which can be regarded as a generalization of the Smith normal form and the spectra of the distance matrix of a graph. We obtain a classification of the graphs with at most one trivial…

Combinatorics · Mathematics 2018-04-13 Carlos A. Alfaro , Libby Taylor

Recently, nearly complete intersection ideals were defined by Boocher and Seiner to establish lower bounds on Betti numbers for monomial ideals (arXiv:1706.09866). Stone and Miller then characterized nearly complete intersections using the…

Commutative Algebra · Mathematics 2024-10-15 Chiara Bondi , Courtney R. Gibbons , Yuye Ke , Spencer Martin , Shrunal Pothagoni , Andrew Stelzer

We determine all possible triples of depth, dimension, and regularity of edge ideals of weighted oriented graphs with a fixed number of vertices. Also, we compute all the possible Betti table sizes of edge ideals of weighted oriented trees…

Commutative Algebra · Mathematics 2025-04-18 Trung Chau , Richie Sheng , Deborah Wooton

We give a complete characterization of graphs whose binomial edge ideal is licci. An important tool is a new general upper bound for the regularity of binomial edge ideals.

Commutative Algebra · Mathematics 2019-10-10 Viviana Ene , Giancarlo Rinaldo , Naoki Terai

Parity binomial edge ideals of simple undirected graphs are introduced. Unlike binomial edge ideals, they do not have square-free Gr\"obner bases and are radical if only if the graph is bipartite or the characteristic of the ground field is…

Commutative Algebra · Mathematics 2017-02-15 Thomas Kahle , Camilo Sarmiento , Tobias Windisch

We determine the maximum number of edges in a $K_4$-minor-free $n$-vertex graph of girth $g$, when $g = 5$ or $g$ is even. We argue that there are many different $n$-vertex extremal graphs, if $n$ is even and $g$ is odd.

Combinatorics · Mathematics 2021-11-11 János Barát

As a higher analogue of the edge ideal of a graph, we study the $t$-connected ideal $\operatorname{J}_{t}$. This is the monomial ideal generated by the connected subsets of size $t$. For chordal graphs, we show that $\operatorname{J}_{t}$…

Commutative Algebra · Mathematics 2025-04-02 H. Ananthnarayan , Omkar Javadekar , Aryaman Maithani

We classify the finite connected simple graphs whose edge rings are strongly Koszul. From the classification, it follows that if the edge ring is strongly Koszul, then its toric ideal possesses a quadratic Gr\"obner basis.

Commutative Algebra · Mathematics 2016-02-02 Takayuki Hibi , Kazunori Matsuda , Hidefumi Ohsugi

We characterize some asymptotic properties of edge exchangeable random graphs in terms of the measure used to generate them. In particular, we give a necessary and sufficient condition for eventual forever connectedness, a sufficient…

Probability · Mathematics 2026-05-07 Edward Eriksson