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Let $G$ be a graph with $n$ vertices and let $S=\mathbb{K}[x_1,\dots,x_n]$ be the polynomial ring in $n$ variables over a field $\mathbb{K}$. Assume that $I(G)$ and $J(G)$ denote the edge ideal and the cover ideal of $G$, respectively. We…

Commutative Algebra · Mathematics 2023-08-22 Seyed Amin Seyed Fakhari , Siamak Yassemi

Let $S$ be a positively graded polynomial ring over a field of characteristic 0, and $I\subset S$ a proper graded ideal. In this note it is shown that $S/I$ is Golod if $\partial(I)^2\subset I$. Here $\partial(I)$ denotes the ideal…

Commutative Algebra · Mathematics 2013-01-01 Jürgen Herzog , Craig Huneke

To a graph $G$ one associates the binomial edge ideal $J_G$ generated by a collection of binomials corresponding to the edges of $G$. In this paper, we study the asymptotic behavior of symbolic powers of $J_G$, its lexicographic initial…

Commutative Algebra · Mathematics 2025-10-17 Dennis Belotserkovskiy , Mariana Landín , Charlie Ruppe , Lizzy Teryoshin

We compute the regularity of powers and symbolic powers of edge ideals of all cubic circulant graphs. In particular, we establish Conjecture of Minh for cubic circulant graphs.

Commutative Algebra · Mathematics 2024-10-01 Nguyen Thu Hang , My Hanh Pham , Thanh Vu

In this article, we prove that for several classes of graphs, the Castelnuovo-Mumford regularity of symbolic powers of their edge ideals coincide with that of their ordinary powers.

Commutative Algebra · Mathematics 2019-12-17 A. V. Jayanthan , Rajiv Kumar

Let $G$ be a graph with $n$ vertices and $S=\mathbb{K}[x_1,\dots,x_n]$ be the polynomial ring in $n$ variables over a field $\mathbb{K}$. Assume that $J(G)$ is the cover ideal of $G$ and $J(G)^{(k)}$ is its $k$-th symbolic power. We prove…

Commutative Algebra · Mathematics 2016-04-05 S. A. Seyed Fakhari

The power graph of a group $G$ is a graph with vertex set $G$, in which two vertices are adjacent if one is some power of the other. In the commuting graph, with $G$ as the vertex set, two vertices are joined by an edge if they commute in…

Group Theory · Mathematics 2024-06-04 Surbhi , Geetha Venkataraman

In this paper we provide some exact formulas for the projective dimension and the regularity of edge ideals of vertex-weighted oriented unicyclic graphs. These formulas are in function of the weight of the vertices, the numbers of edges. We…

Commutative Algebra · Mathematics 2023-09-20 Guangjun Zhu , Hong Wang

Let $G$ be a finite simple graph and $I(G)$ denote the corresponding edge ideal. In this paper we prove that if $G$ is a unicyclic graph then for all $s \geq 1$ the regularity of $I(G)^s$ is exactly $2s+\text{reg}(I(G))-2$. We also…

Commutative Algebra · Mathematics 2022-09-30 Ali Alilooee , Selvi Kara , S. Selvaraja

Given an oriented graph $\overrightarrow{G}$ and $D$ a distance set of $\overrightarrow{G}$, $\overrightarrow{G}$ is $D$-antimagic if there exists a bijective vertex labeling such that the sum of all labels of the $D$-out-neighbors of each…

Combinatorics · Mathematics 2025-01-10 Ahmad Muchlas Abrar , Rinovia Simanjuntak

Assume that $G$ is a graph with edge ideal $I(G)$ and star packing number $\alpha_2(G)$. We denote the $s$-th symbolic power of $I(G)$ by $I(G)^{(s)}$. It is shown that the inequality ${\rm depth} S/(I(G)^{(s)})\geq \alpha_2(G)-s+1$ is true…

Commutative Algebra · Mathematics 2020-09-30 S. A. Seyed Fakhari

In this paper, we investigate whether the symbolic and ordinary powers of a binomial edge ideal $J_{G}$ are equal. We show that the equality $J_{G}^{t}=J_{G}^{(t)}$ holds for every $t \geq 1$ when $|Ass(J_{G})|=2$. Moreover, if $G$ is a…

Commutative Algebra · Mathematics 2023-12-06 Iman Jahani , Shamila Bayati , Farhad Rahmati

In this paper, we investigate some properties of symbolic powers and symbolic Rees algebras of binomial edge ideals associated with some classes of block graphs. First, it is shown that symbolic powers of binomial edge ideals of pendant…

Commutative Algebra · Mathematics 2024-09-17 Iman Jahani , Shamila Bayati , Farhad Rahmati

In this paper we provide some precise formulas for regularity of powers of edge ideal of the disjoint union of some weighted oriented gap-free bipartite graphs. For the projective dimension of such an edge ideal, we give its exact formula.…

Commutative Algebra · Mathematics 2019-06-12 Guangjun Zhu , Li Xu , Hong Wang , Jiaqi Zhang

Let $\mathcal{D}$ be a weighted oriented graph and let $I(\mathcal{D})$ be its edge ideal. Under a natural condition that the underlying (undirected) graph of $\mathcal{D}$ contains a perfect matching consisting of leaves, we provide…

Commutative Algebra · Mathematics 2018-05-14 Huy Tài Hà , Kuei-Nuan Lin , Susan Morey , Enrique Reyes , Rafael H. Villarreal

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

For an arbitrary set of distances $D\subseteq \{0,1, \ldots, diam(G)\}$, a $D$-weight of a vertex $x$ in a graph $G$ under a vertex labeling $f:V\rightarrow \{1,2, \ldots , v\}$ is defined as $w_D(x)=\sum_{y\in N_D(x)} f(y)$, where $N_D(x)…

Combinatorics · Mathematics 2013-12-31 Rinovia Simanjuntak , Kristiana Wijaya

We show that under some conditions, if the initial ideal in$_<(I)$ of an ideal $I$ in a polynomial ring has the property that its symbolic and ordinary powers coincide, then the ideal $I$ shares the same property. We apply this result to…

Commutative Algebra · Mathematics 2020-09-08 Viviana Ene , Jürgen Herzog

Let ${\cal G}=(G,w) $ be a positive-weighted graph, that is a graph $G$ endowed with a function $w$ from the edge set of $G$ to the set of positive real numbers; for any distinct vertices $i,j $, we define $D_{i,j}({\cal G})$ to be the…

Combinatorics · Mathematics 2016-05-04 Agnese Baldisserri , Elena Rubei

In this work, we classify the circuit binomials of any weighted oriented graph $D$ and we explicitly compute the circuit binomials of $D$ in terms of the minors of the incidence matrix of $D$. We show that the circuit binomials of any…

Commutative Algebra · Mathematics 2024-10-08 Ramakrishna Nanduri , Tapas Kumar Roy