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Related papers: Regularity of Powers of Unicyclic Graphs

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We study the Castelnuovo-Mumford regularity of powers of edge ideals. We prove that if G is a bipartite graph, then reg(I(G)^s) \leq 2s + reg I(G) - 2 for all s \geq 2, which is the best possible upper bound for any s. Suspension plays a…

Commutative Algebra · Mathematics 2019-09-06 Arindam Banerjee , Eran Nevo

A Cameron-Walker graph is a graph for which the matching number and the induced matching number are the same. Assume that $G$ is a Cameron-Walker graph with edge ideal $I(G)$, and let $\ind-match(G)$ be the induced matching number of $G$.…

Commutative Algebra · Mathematics 2019-07-08 S. A. Seyed Fakhari

We give a necessary and sufficient graph-theoretic characterization of toric ideals of graphs that are unimodular. As a direct consequence, we provide the structure of unimodular graphs by proving that the incidence matrix of a graph $G$ is…

Commutative Algebra · Mathematics 2025-10-15 Christos Tatakis

Let $G$ be a simple graph. We demonstrate a method for using $t$-admissible subgraphs of $G$ to determine the regularity of the $t$-th symbolic power of the cover ideal of $G$. As an application, we compute the regularity of powers of cover…

Commutative Algebra · Mathematics 2026-05-21 Nguyen Thu Hang , Thanh Vu

Let $G$ be a finite simple graph and let $I(G)$ denote its edge ideal. For $q \ge 1$, the $q$-th squarefree power $I(G)^{[q]}$ is generated by squarefree monomials corresponding to matchings of size $q$ in $G$. We denote by…

Commutative Algebra · Mathematics 2026-04-21 Sanjoy Das , Arka Ghosh , S Selvaraja

The cyclic matching sequenceability of a simple graph $G$, denoted $\mathrm{cms}(G)$, is the largest integer $s$ for which there exists a cyclic ordering of the edges of $G$ so that every set of $s$ consecutive edges forms a matching. In…

Combinatorics · Mathematics 2021-06-23 Daniel Horsley , Adam Mammoliti

The regularity of an edge ideal of a finite simple graph $G$ is at least the induced matching number of $G$ and is at most the minimum matching number of $G$. If $G$ possesses a dominating inuduced matching, i.e., an induced matching which…

Combinatorics · Mathematics 2015-08-27 Takayuki Hibi , Akihiro Higashitani , Kyouko Kimura , Akiyoshi Tsuchiya

For an $n \times n$ matrix $A$, let $q(A)$ be the number of distinct eigenvalues of $A$. If $G$ is a connected graph on $n$ vertices, let $\mathcal{S}(G)$ be the set of all real symmetric $n \times n$ matrices $A=[a_{ij}]$ such that for…

Combinatorics · Mathematics 2023-05-19 Wayne Barrett , Shaun Fallat , Veronika Furst , Shahla Nasserasr , Brendan Rooney , Michael Tait

We study the regularity of small symbolic powers and integral closure of small powers of edge ideals. We also prove that the regularity of integral closure of powers of edge ideals of graphs with at most two odd cycles is the same as the…

Commutative Algebra · Mathematics 2022-10-12 Arvind Kumar , Rajiv Kumar

Let $G$ be a simple graph on $n$ vertices and $\mathcal{I}_G$ denotes parity binomial edge ideal of $G$ in the polynomial ring $S = \mathbb{K}[x_1,\ldots, x_n, y_1, \ldots, y_n].$ We obtain a lower bound for the regularity of parity…

Commutative Algebra · Mathematics 2021-08-20 Arvind Kumar

Let $D$ be a weighted oriented graph and $I(D)$ be its edge ideal. If $D$ contains an induced odd cycle of length $2n+1$, under certain condition we show that $ {I(D)}^{(n+1)} \neq {I(D)}^{n+1}$. We give necessary and sufficient condition…

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

Let $G$ be a simple undirected graph. The regular number of $G$ is defined to be the minimum number of subsets into which the edge set of $G$ can be partitioned so that the subgraph induced by each subset is regular. In this work, we obtain…

Discrete Mathematics · Computer Science 2015-12-11 Ashwin Ganesan , Radha R. Iyer

Let $K[G]$ denote the edge ring of a finite connected simple graph $G$ on $[d]$ and $\mat(G)$ the matching number of $G$. It is shown that $\reg(K[G]) \leq \mat(G)$ if $G$ is non-bipartite and $K[G]$ is normal, and that $\reg(K[G]) \leq…

Commutative Algebra · Mathematics 2019-11-25 Jürgen Herzog , Takayuki Hibi

Assume that $G$ is a graph with edge ideal $I(G)$ and matching number ${\rm match}(G)$. For every integer $s\geq 1$, we denote the $s$-th squarefree power of $I(G)$ by $I(G)^{[s]}$. It is shown that for every positive integer $s\leq {\rm…

Commutative Algebra · Mathematics 2022-07-19 S. A. Seyed Fakhari

We classify all unicycle graphs whose edge-binomials form a $d$-sequence, particularly linear type binomial edge ideals. We also classify unicycle graphs whose parity edge-binomials form a $d$-sequence. We study the regularity of powers of…

Commutative Algebra · Mathematics 2024-03-19 Marie Amalore Nambi , Neeraj Kumar

We give a formula for the v-number of a graded ideal that can be used to compute this number. Then we show that for the edge ideal $I(G)$ of a graph $G$ the induced matching number of $G$ is an upper bound for the v-number of $I(G)$ when…

Commutative Algebra · Mathematics 2021-10-15 Gonzalo Grisalde , Enrique Reyes , Rafael H. Villarreal

In this article, we obtain an upper bound for the Castelnuovo-Mumford regularity of powers of an ideal generated by a homogeneous quadratic sequence in a polynomial ring in terms of the regularity of its related ideals and degrees of its…

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

We prove that the regularity of edge ideals of powers of forests is weakly decreasing. We then compute the regularity of edge ideals of powers of cycles.

Commutative Algebra · Mathematics 2025-02-10 My Hanh Pham , Thanh Vu

Let $G$ be a graph and $I=I(G)$ be its edge ideal. When $G$ is the clique sum of two different length odd cycles joined at single vertex then we give an explicit description of the symbolic powers of $I$ and compute the Waldschmidt…

Commutative Algebra · Mathematics 2019-08-27 Bidwan Chakraborty , Mousumi Mandal

The regular number of a graph G denoted by reg(G) is the minimum number of subsets into which the edge set of G can be partitioned so that the subgraph induced by each subset is regular. In this work we answer to the problem posed as an…

Combinatorics · Mathematics 2014-06-09 Ali Dehghan , Mohammad-Reza Sadeghi , Arash Ahadi