English
Related papers

Related papers: Bounding Betti numbers of bipartite graph ideals

200 papers

Let I(G) be the edge ideal associated to a simple graph G. We study the graded Betti numbers that appear in the linear strand of the minimal free resolution of I(G).

Commutative Algebra · Mathematics 2007-05-23 Mike Roth , Adam Van Tuyl

Let $\operatorname{pd}(I(G))$ and $\operatorname{reg}(I(G))$ respectively denote the projective dimension and the regularity of the edge ideal $I(G)$ of a graph $G$. For any positive integer $n$, we determine all pairs…

Commutative Algebra · Mathematics 2022-12-13 Nursel Erey , Takayuki Hibi

Let $G$ be a finite simple graph and $I(G)$ denote the corresponding edge ideal. For all $s \geq 1$, we obtain upper bounds for reg$(I(G)^s)$ for bipartite graphs. We then compare the properties of $G$ and $G'$, where $G'$ is the graph…

Commutative Algebra · Mathematics 2016-09-07 A V Jayanthan , N Narayanan , S Selvaraja

We classify generalized block graphs whose binomial edge ideals admit a unique extremal Betti number. We prove that the Castelnuovo-Mumford regularity of binomial edge ideals of generalized block graphs is bounded below by $m(G)+1$, where…

Commutative Algebra · Mathematics 2021-12-07 Arvind Kumar

The Ferrers bound conjecture is a natural graph-theoretic extension of the enumeration of spanning trees for Ferrers graphs. We document the current status of the conjecture and provide a further conjecture which implies it.

Combinatorics · Mathematics 2022-10-07 MLE Slone

Let $I(G)$ be a topological index of a graph. If $I(G+e)<I(G)$ (or $I(G+e)>I(G)$, respectively) for each edge $e\not\in G$, then $I(G)$ is monotonically decreasing (or increasing, respectively) with the addition of edges. In this article,…

Combinatorics · Mathematics 2017-04-19 Hanlin Chen , Renfang Wu , Hanyuan Deng

We provide the regularity and the Cohen-Macaulay type of binomial edge ideals of Cohen-Macaulay cones, and we show the extremal Betti numbers of some classes of Cohen-Macaulay binomial edge ideals: Cohen-Macaulay bipartite and fan graphs.…

Commutative Algebra · Mathematics 2018-09-11 Carla Mascia , Giancarlo Rinaldo

We compute the multigraded Betti numbers of edge ideals for weighted oriented crown graphs using a novel approach. This approach, which we still call the \emph{induced subgraph approach}, originates from our prior work on computing Betti…

Commutative Algebra · Mathematics 2025-05-13 Zexin Wang , Dancheng Lu

We compute the graded Betti numbers for the toric ideal of a family of graphs constructed by adjoining a cycle to a complete bipartite graph. The key observation is that this family admits an initial ideal which has linear quotients. As a…

We prove the multiplicity bounds conjectured by Herzog-Huneke-Srinivasan and Herzog-Srinivasan in the following cases: the strong conjecture for edge ideals of bipartite graphs, and the weaker Taylor bound conjecture for all quadratic…

Commutative Algebra · Mathematics 2007-10-16 Manoj Kummini

We provide some new conditions under which the graded Betti numbers of a monomial ideal can be computed in terms of the graded Betti numbers of smaller ideals, thus complementing Eliahou and Kervaire's splitting approach. As applications,…

Commutative Algebra · Mathematics 2009-02-14 Christopher A. Francisco , Huy Tai Ha , Adam Van Tuyl

We prove two recent conjectures on some upper bounds for the Castelnuovo-Mumford regularity of the binomial edge ideals of some different classes of graphs. We prove the conjecture of Matsuda and Murai for graphs which has a cut edge or a…

Commutative Algebra · Mathematics 2013-11-19 Dariush Kiani , Sara Saeedi Madani

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

The present work is concerned with characterizing some algebraic invariants of edge ideals of hypergraphs. To this aim, firstly, we introduce some kinds of combinatorial invariants similar to matching numbers for hypergraphs. Then we…

Commutative Algebra · Mathematics 2025-06-10 Somayeh Moradi , Fahimeh Khosh-Ahang Ghasr

We study minimal free resolutions of edge ideals of bipartite graphs. We associate a directed graph to a bipartite graph whose edge ideal is unmixed, and give expressions for the regularity and the depth of the edge ideal in terms of…

Commutative Algebra · Mathematics 2012-12-04 Manoj Kummini

We provide a closed formula for the graded Betti numbers in the linear strands of all powers of binomial edge ideals $J_G$ arising from closed graphs $G$ that do not have the complete graph $K_4$ as an induced subgraph. We show that these…

Commutative Algebra · Mathematics 2026-01-19 Abbas Dohadwala , Bryan Flores-Silva , Alicia Orozco-Moya , Zoe Siegelnickel

A bihole in a bipartite graph $G$ with partite sets $A$ and $B$ is an independent set $I$ in $G$ with $|I\cap A|=|I\cap B|$. We prove lower bounds on the largest order of biholes in balanced bipartite graphs subject to conditions involving…

Combinatorics · Mathematics 2020-04-13 Stefan Ehard , Elena Mohr , Dieter Rautenbach

For a bipartite graph $G$ with parts $X$ and $Y$, an $X$-interval coloring is a proper edge coloring of $G$ by integers such that the colors on the edges incident to any vertex in $X$ form an interval. Denote by $\chi'_{int}(G,X)$ the…

Combinatorics · Mathematics 2021-06-29 Carl Johan Casselgren

Cut ideals, introduced by Sturmfels and Sullivant, are used in phylogenetics and algebraic statistics. We study the minimal free resolutions of cut ideals of tree graphs. By employing basic methods from topological combinatorics, we obtain…

Commutative Algebra · Mathematics 2013-10-29 Samu Potka , Camilo Sarmiento

Let $G$ be a finite simple graph on $n$ non-isolated vertices, and let $J_G$ be its binomial edge ideal. We determine almost all pairs $(\text{projdim}(J_G),\text{reg}(J_G))$, where $G$ ranges over all finite simple graphs on $n$…

Commutative Algebra · Mathematics 2025-01-15 Antonino Ficarra , Emanuele Sgroi