English
Related papers

Related papers: Monomial ideals of weighted oriented graphs

200 papers

We introduce a class of ideals generated by a set of 2-minors of $m\times n$-matrix of indeterminates indexed by a pair of graphs. This class of ideals is a natural common generalization of binomial edge ideals and ideals generated by…

Commutative Algebra · Mathematics 2015-01-14 Viviana Ene , Jürgen Herzog , Takayuki Hibi , Ayesha Asloob Qureshi

We introduce binomial edge ideals attached to a simple graph $G$ and study their algebraic properties. We characterize those graphs for which the quadratic generators form a Gr\"obner basis in a lexicographic order induced by a vertex…

Commutative Algebra · Mathematics 2009-10-16 Juergen Herzog , Takayuki Hibi , Freyja Hreinsdottir , Thomas Kahle , Johannes Rauh

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

Inspired by the notion of K\"onig graphs we introduce graded ideals of K\"onig type with respect to a monomial order $<$. It is shown that if $I$ is of K\"onig type, then the Cohen--Macaulay property of $\ini_<(I)$ does not depend on the…

Commutative Algebra · Mathematics 2021-03-16 Jürgen Herzog , Takayuki Hibi , Somayeh Moradi

For a graph $G$, Bolognini et al. have shown $J_{G}$ is strongly unmixed $\Rightarrow$ $J_{G}$ is Cohen-Macaulay $\Rightarrow$ $G$ is accessible, where $J_{G}$ denotes the binomial edge ideals of $G$. Accessible and strongly unmixed…

Commutative Algebra · Mathematics 2022-03-10 Kamalesh Saha , Indranath Sengupta

Independent sets play a key role into the study of graphs and important problems arising in graph theory reduce to them. We define the monomial ideal of independent sets associated to a finite simple graph and describe its homological and…

Commutative Algebra · Mathematics 2013-07-12 Oana Olteanu

Let $S=K[x_1,\dots,x_n]$ be the polynomial ring over a field $K$ and $I\subset S$ be a squarefree monomial ideal generated in degree $n-2$. Motivated by the remarkable behavior of the powers of $I$ when $I$ admits a linear resolution, as…

Commutative Algebra · Mathematics 2025-08-28 Antonino Ficarra , Somayeh Moradi

We study the depth of classes of binomial edge ideals and classify all closed graphs whose binomial edge ideal is Cohen--Macaulay.

Commutative Algebra · Mathematics 2011-07-08 Viviana Ene , Juergen Herzog , Takayuki Hibi

In this paper we provide a full combinatorial characterization of sequentially Cohen-Macaulay binomial edge ideals of closed graphs. In addition, we show that a binomial edge ideal of a closed graph is approximately Cohen-Macaulay if and…

Commutative Algebra · Mathematics 2022-07-12 Viviana Ene , Giancarlo Rinaldo , Naoki Terai

Let G be a bipartite graph with edge ideal I(G) whose quotient ring R/I(G) is sequentially Cohen-Macaulay. We prove: (1) the independence complex of G must be vertex decomposable, and (2) the Castelnuovo-Mumford regularity of R/I(G) can be…

Commutative Algebra · Mathematics 2009-06-02 Adam Van Tuyl

Given a vertex-weighted oriented graph, we can associate to it a set of monomials. We consider the toric ideal whose defining map is given by these monomials. We find a generating set for the toric ideal for certain classes of graphs which…

Commutative Algebra · Mathematics 2021-07-12 Jennifer Biermann , Selvi Kara , Kuei-Nuan Lin , Augustine O'Keefe

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

Let $D$ be a weighted oriented graph and $I(D)$ be its edge ideal. We provide one method to find all the minimal generators of $ I_{\subseteq C} $, where $ C $ is a maximal strong vertex cover of $D$ and $ I_{\subseteq C} $ is the…

Commutative Algebra · Mathematics 2023-06-16 Mousumi Mandal , Dipak Kumar Pradhan

Let $D$ be a weighted oriented graph with the underlying graph $G$ and $I(D), I(G) $ be the edge ideals corresponding to $D$ and $G$ respectively. We show that the regularity of edge ideal of a certain class of weighted oriented graph…

Combinatorics · Mathematics 2022-04-12 Mousumi Mandal , Dipak Kumar Pradhan

B. Sturmfels and S. Sullivant associated to any graph a toric ideal, called the cut ideal. We consider monomial cut ideals and we show that their algebraic properties such as the minimal primary decomposition, the property of having a…

Commutative Algebra · Mathematics 2011-05-19 Anda Olteanu

We apply some basic notions from combinatorial topology to establish various algebraic properties of edge ideals of graphs and more general Stanley-Reisner rings. In this way we provide new short proofs of some theorems from the literature…

Combinatorics · Mathematics 2008-10-23 Anton Dochtermann , Alexander Engstrom

Let G be a simple undirected graph on n vertices, and let I(G) \subseteq R = k[x_1,...,x_n] denote its associated edge ideal. We show that all chordal graphs G are sequentially Cohen-Macaulay; our proof depends upon showing that the…

Commutative Algebra · Mathematics 2007-06-13 Christopher A. Francisco , Adam Van Tuyl

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

For the edge ideal I of an arbitrary simple graph G we describe the monomials of the saturation of a power of I in terms of (vertex) weighted graphs associated with the monomials. This description allows us to characterize the embedded…

Commutative Algebra · Mathematics 2014-12-01 Ha Thi Thu Hien , Ha Minh Lam , Ngo Viet Trung

Let $\mathcal{D}$ be a weighted oriented graph and $I(\mathcal{D})$ be its edge ideal. In this paper, we investigate the Betti numbers of $I(\mathcal{D})$ via upper-Koszul simplicial complexes, Betti splittings and the mapping cone…

Commutative Algebra · Mathematics 2020-09-24 Beata Casiday , Selvi Kara