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Related papers: Koszulness of binomial edge ideals

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This work concerns commutative algebras of the form $R=Q/I$, where $Q$ is a standard graded polynomial ring and $I$ is a homogenous ideal in $Q$. It has been proposed that when $R$ is Koszul the $i$th Betti number of $R$ over $Q$ is at most…

Commutative Algebra · Mathematics 2017-05-04 Adam Boocher , S. Hamid Hassanzadeh , Srikanth B. Iyengar

In this article, we compute the regularity of Rees algebra of binomial edge ideals of closed graphs. We obtain a lower bound for the regularity of Rees algebra of binomial edge ideals. We also study some algebraic properties of the Rees…

Commutative Algebra · Mathematics 2021-12-07 Arvind Kumar

Let $G$ be a connected simple graph on the vertex set $[n]$. Banerjee-Betancourt proved that $depth(S/J_G)\leq n+1$. In this article, we prove that if $G$ is a unicyclic graph, then the depth of $S/J_G$ is bounded below by $n$. Also, we…

Commutative Algebra · Mathematics 2021-12-10 Rajib Sarkar

A graph is maximal knotless if it is edge maximal for the property of knotless embedding in $R^3$. We show that such a graph has at least $\frac74 |V|$ edges, and construct an infinite family of maximal knotless graphs with $|E| <…

Geometric Topology · Mathematics 2023-06-21 Lindsay Eakins , Thomas Fleming , Thomas W. Mattman

A graph-theoretic method, simpler than existing ones, is used to characterize the minimal set of monomial generators for the integral closure of any algebra of polynomials generated by quadratic monomials. The toric ideal of relations…

Commutative Algebra · Mathematics 2010-01-31 Peter M. Johnson

Let $R$ be a ring with unity. The cozero-divisor graph of a ring $R$ is an undirected simple graph whose vertices are the set of all non-zero and non-unit elements of $R$ and two distinct vertices $x$ and $y$ are adjacent if and only if $x…

Combinatorics · Mathematics 2023-01-31 Praveen Mathil , Barkha Baloda , Jitender Kumar

The v-number of a graded ideal is an algebraic invariant introduced by Cooper et al., and originally motivated by problems in algebraic coding theory. In this paper we study the case of binomial edge ideals and we establish a significant…

Commutative Algebra · Mathematics 2023-08-29 Delio Jaramillo-Velez , Lisa Seccia

Let $G=(V,E)$ be a simple graph. A set $I\subseteq V$ is an independent set, if no two of its members are adjacent in $G$. The $k$-independent graph of $G$, $I_k (G)$, is defined to be the graph whose vertices correspond to the independent…

Combinatorics · Mathematics 2020-01-03 Davood Fatehi , Saeid Alikhani , Abdul Jalil M. Khalaf

The symmetric edge polytope of a simple graph is a lattice polytope defined as the convex hull of a subset of the type A roots corresponding to the edges of the graph. In this article we prove a sharp lower bound for the number of edges of…

Combinatorics · Mathematics 2025-12-19 Giulia Codenotti , Roberto Riccardi , Lorenzo Venturello

Let $G$ be a simple graph of order $n\geq 2$ and let $k\in \{1,\ldots ,n-1\}$. The $k$-token graph $F_k(G)$ of $G$ is the graph whose vertices are the $k$-subsets of $V(G)$, where two vertices are adjacent in $F_k(G)$ whenever their…

Combinatorics · Mathematics 2019-09-17 J. Leaños , M. K. Christophe Ndjatchi

A graph $G$ is said to be chordal if it has no induced cycles of length four or more. In a recent preprint Culbertson, Guralnik, and Stiller give a new characterization of chordal graphs in terms of sequences of what they call…

Combinatorics · Mathematics 2021-02-25 Anton Dochtermann

Let $G$ be a simple graph on $d$ vertices. We define a monomial ideal $K$ in the Stanley-Reisner ring $A$ of the order complex of the Boolean algebra on $d$ atoms. The monomials in $K$ are in one-to-one correspondence with the proper…

Combinatorics · Mathematics 2007-05-23 Einar Steingrimsson

A simple topological graph $G$ is a graph drawn in the plane so that any pair of edges have at most one point in common, which is either an endpoint or a proper crossing. $G$ is called saturated if no further edge can be added without…

Combinatorics · Mathematics 2015-01-30 Jan Kynčl , János Pach , Radoš Radoičić , Géza Tóth

The line graph of a graph $G$ is the graph $L(G)$ whose vertex set is the edge set of $G$ and there is an edge between $e,f\in E(G)$ if $e$ and $f$ share an endpoint in $G$. A graph is called line graph if it is a line graph of some graph.…

Data Structures and Algorithms · Computer Science 2020-06-30 Eduard Eiben , William Lochet

A graph with at most two vertices of the same degree is called antiregular (Merris 2003), maximally nonregular (Zykov 1990) or quasiperfect (Behzad, Chartrand 1967). If s_{k} is the number of independent sets of cardinality k in a graph G,…

Discrete Mathematics · Computer Science 2010-07-07 Vadim E. Levit , Eugen Mandrescu

Edge ideals of finite simple graphs are well-studied over polynomial rings. In this paper, we initiate the study of edge ideals over exterior algebras, specifically focusing on the depth and singular varieties of such ideals. We prove an…

Commutative Algebra · Mathematics 2022-08-09 Matthew Mastroeni , Jason McCullough , Andrew Osborne , Joshua Rice , Cole Willis

Suppose a finite, unweighted, combinatorial graph $G = (V,E)$ is the union of several (degree-)regular graphs which are then additionally connected with a few additional edges. $G$ will then have only a small number of vertices $v \in V$…

Combinatorics · Mathematics 2023-10-25 Tony Zeng

We prove that level binomial edge ideals with regularity 2 and pseudo-Gorenstein binomial edge ideals with regularity 3 are cones, and we describe them completely. Also, we characterize level and pseudo-Gorenstein binomial edge ideals of…

Commutative Algebra · Mathematics 2023-08-11 Giancarlo Rinaldo , Rajib Sarkar

A graph is said to be well-edge-dominated if all its minimal edge dominating sets are minimum. It is known that every well-edge-dominated graph $G$ is also equimatchable, meaning that every maximal matching in $G$ is maximum. In this paper,…

Combinatorics · Mathematics 2021-10-15 Sarah E. Anderson , Kirsti Kuenzel , Douglas F. Rall

A cut ideal of a graph was introduced by Sturmfels and Sullivant. In this paper, we give a necessary and sufficient condition for toric rings associated to the cut ideal to be Strongly Koszul.

Commutative Algebra · Mathematics 2019-07-24 Kazuki Shibata