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Let $G$ be a simple graph on $n$ vertices. We introduce the notion of bipartite connectivity of $G$, denoted by $\operatorname{bc}(G)$ and prove that $$\lim_{s \to \infty} \operatorname{depth} (S/I(G)^{(s)}) \le \operatorname{bc}(G),$$…

Commutative Algebra · Mathematics 2024-06-19 Nguyen Cong Minh , Tran Nam Trung , Thanh Vu

Let $G$ be a graph and $t\ge 0$. The largest reduced neighborhood clique cover number of $G$, denoted by ${\hat\beta}_t(G)$, is the largest, overall $t$-shallow minors $H$ of $G$, of the smallest number of cliques that can cover any closed…

Combinatorics · Mathematics 2018-02-13 Farhad Shahrokhi

Let $G$ be a simple graph with binomial edge ideal $J_G$. We prove how to calculate the multidegree of $J_G$ based on combinatorial properties of $G$. In particular, we study the set $S_{\min}(G)$ defined as the collection of subsets of…

Commutative Algebra · Mathematics 2024-05-14 Jacob Cooper , Ethan Leventhal

We consider the problem of determining the maximum order of an induced vertex-disjoint union of cliques in a graph. More specifically, given some family of graphs $\mathcal{G}$ of equal order, we are interested in the parameter…

Combinatorics · Mathematics 2019-12-11 Nika Salia , Christoph Spiegel , Casey Tompkins , Oscar Zamora

Binomial edge ideals associated to a simple graph G were introduced by Herzog and collaborators and, independently, by Ohtani. They became an ``instant classic" in combinatorial commutative algebra with more than 100 papers devoted to their…

Commutative Algebra · Mathematics 2026-01-13 Aldo Conca , Emanuela De Negri , Volkmar Welker

More than forty years ago, Erd\H{o}s conjectured that for any T <= N/K, every K-uniform hypergraph on N vertices without T disjoint edges has at most max{\binom{KT-1}{K}, \binom{N}{K} - \binom{N-T+1}{K}} edges. Although this appears to be a…

Combinatorics · Mathematics 2011-09-16 Hao Huang , Po-Shen Loh , Benny Sudakov

In this article, we give a comprehensive survey of the recent progress of research on binomial edge ideal of a graph since 2018.

Commutative Algebra · Mathematics 2023-07-14 Priya Das

Let $G$ be a simple graph on $n$ vertices and $J_G$ denote the binomial edge ideal of $G$ in the polynomial ring $S = \mathbb{K}[x_1, \ldots, x_n, y_1, \ldots, y_n].$ In this article, we compute the second graded Betti numbers of $J_G$, and…

Commutative Algebra · Mathematics 2020-10-22 A. V. Jayanthan , Arvind Kumar , Rajib Sarkar

The Gamma-Theta Conjecture states that if the domination number of a graph is equal to its eternal domination number, then it is also equal to its clique covering number. This conjecture is known to be true for several graph classes, such…

Combinatorics · Mathematics 2025-07-01 Dmitrii Taletskii

We introduce the concept of minimum edge cover for an induced subgraph in a graph. Let $G$ be a unicyclic graph with a unique odd cycle and $I=I(G)$ be its edge ideal. We compute the exact values of all symbolic defects of $I$ using the…

Commutative Algebra · Mathematics 2022-04-13 Mousumi Mandal , Dipak Kumar Pradhan

Recently Cutler and Radcliffe proved that the graph on $n$ vertices with maximum degree at most $r$ having the most cliques is a disjoint union of $\lfloor n/(r+1)\rfloor$ cliques of size $r+1$ together with a clique on the remainder of the…

Combinatorics · Mathematics 2021-02-19 Rachel Kirsch , A. J. Radcliffe

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

In this paper, we first give some sufficient criteria for normality of monomial ideals. As applications, we show that closed neighborhood ideals of complete bipartite graphs are normal, and hence satisfy the (strong) persistence property.…

Commutative Algebra · Mathematics 2023-08-15 Mehrdad Nasernejad , Somayeh Bandari , Leslie G. Roberts

Given a graph $G$, the strong clique number $\omega_2'(G)$ of $G$ is the cardinality of a largest collection of edges every pair of which are incident or connected by an edge in $G$. We study the strong clique number of graphs missing some…

Combinatorics · Mathematics 2019-03-15 Wouter Cames van Batenburg , Ross J. Kang , François Pirot

We consider the binomial random graph $G(n,p)$, where $p$ is a constant, and answer the following two questions. First, given $e(k)=p{k\choose 2}+O(k)$, what is the maximum $k$ such that a.a.s.~the binomial random graph $G(n,p)$ has an…

Combinatorics · Mathematics 2021-09-23 Jozsef Balogh , Maksim Zhukovskii

Let $\alpha_{1} (G)$ denote the maximum size of an edge set that contains at most one edge from each triangle of $G$. Let $\tau_{B} (G)$ denote the minimum size of an edge set whose deletion makes $G$ bipartite. It was conjectured by Lehel…

Combinatorics · Mathematics 2016-09-20 Honghai Xu

This paper analyzes the cohomological dimension of the generalized binomial edge ideal $\calJ_{K_m,G}$ for a complete $r$-partite graph $G$. Additionally, the Krull dimension, the depth, the Castelnuovo--Mumford regularity, the Hilbert…

Commutative Algebra · Mathematics 2023-12-20 Yi-Huang Shen , Guangjun Zhu

A topological graph drawn on a cylinder whose base is horizontal is \emph{angularly monotone} if every vertical line intersects every edge at most once. Let $c(n)$ denote the maximum number $c$ such that every simple angularly monotone…

Combinatorics · Mathematics 2013-07-17 Radoslav Fulek

In this work, some combinatorial lower bound for regularity of powers of the edge ideal of a uniform hypergarph is gained. A family of hypergraphs whose regularity of edge ideal attains this bound and has a significant difference from the…

Commutative Algebra · Mathematics 2025-06-03 Fahimeh Khosh-Ahang Ghasr

Let $G$ be a simple graph on $n$ vertices and let $J_{G,m}$ be the generalized binomial edge ideal associated to $G$ in the polynomial ring $K[x_{ij}, 1\le i \le m, 1\le j \le n]$. We classify the Cohen-Macaulay generalized binomial edge…

Commutative Algebra · Mathematics 2023-07-04 Luca Amata , Marilena Crupi , Giancarlo Rinaldo