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Related papers: Regularity in weighted oriented graphs

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We classify all normal edge ideals of edge-weighted graphs.

Commutative Algebra · Mathematics 2024-07-24 Thanh Vu , Guangjun Zhu

We determine all possible triples of depth, dimension, and regularity of edge ideals of weighted oriented graphs with a fixed number of vertices. Also, we compute all the possible Betti table sizes of edge ideals of weighted oriented trees…

Commutative Algebra · Mathematics 2025-04-18 Trung Chau , Richie Sheng , Deborah Wooton

This paper gives exact formulas for the regularity of powers of edge ideals of an edge-weighted integrally closed cycle.

Commutative Algebra · Mathematics 2024-07-09 Guangjun Zhu , Yijun Cui , Jiaxin Li , Yi Yang

A good edge-labelling of a simple graph is a labelling of its edges with real numbers such that, for any ordered pair of vertices (u,v), there is at most one nondecreasing path from u to v. Say a graph is good if it admits a good…

Combinatorics · Mathematics 2012-11-13 Abbas Mehrabian

In this paper we provide some exact formulas for the projective dimension and the regularity of edge ideals associated to three special types of vertex-weighted oriented $m$-partite graphs. These formulas are functions of the weight and…

Commutative Algebra · Mathematics 2019-06-04 Guangjun Zhu , Hong Wang , Li Xu , Jiaqi Zhang

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

A graph is edge-distance-regular when it is distance-regular around each of its edges and it has the same intersection numbers for any edge taken as a root. In this paper we give some (combinatorial and algebraic) proofs of the fact that…

Combinatorics · Mathematics 2012-10-23 M. Cámara , C. Dalfó , C. Delorme , M. A. Fiol , H. Suzuki

Let $D$ be a weighted oriented graph with the underlying graph $G$ when vertices with non-trivial weights are sinks and $I(D), I(G) $ be the edge ideals corresponding to $D$ and $G,$ respectively. We give explicit description of the…

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

We study weighted graphs and their "edge ideals" which are ideals in polynomial rings that are defined in terms of the graphs. We provide combinatorial descriptions of m-irreducible decompositions for the edge ideal of a weighted graph in…

Commutative Algebra · Mathematics 2013-02-26 Chelsey Paulsen , Sean Sather-Wagstaff

Let $I=I(D)$ be the edge ideal of a weighted oriented graph $D$, let $G$ be the underlying graph of $D$, and let $I^{(n)}$ be the $n$-th symbolic power of $I$ defined using the minimal primes of $I$. We prove that $I^2=I^{(2)}$ if and only…

Commutative Algebra · Mathematics 2024-03-11 Gonzalo Grisalde , Jose Martinez-Bernal , Rafael H. Villarreal

Let $G$ be a graph with $n$ vertices, $S=\mathbb{K}[x_1,\dots,x_n]$ be the polynomial ring in $n$ variables over a field $\mathbb{K}$ and $I(G)$ denote the edge ideal of $G$. For every collection $\mathcal{H}$ of connected graphs with…

Commutative Algebra · Mathematics 2017-05-30 Seyed Amin Seyed Fakhari , Siamak Yassemi

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 $I(\mathcal{D})$ be its edge ideal. In this paper, we investigate the Betti numbers of $I(\mathcal{D})$ via upper-Koszul simplicial complexes, Betti splittings and the mapping cone…

Commutative Algebra · Mathematics 2020-09-24 Beata Casiday , Selvi Kara

We study the regularity of binomial edge ideals. For a closed graph $G$ we show that the regularity of the binomial edge ideal $J_G$ coincides with the regularity of $\ini_{\lex}(J_G)$ and can be expressed in terms of the combinatorial data…

Commutative Algebra · Mathematics 2013-07-09 Viviana Ene , Andrei Zarojanu

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

Let I=I(D) be the edge ideal of a weighted oriented graph D. We determine the irredundant irreducible decomposition of I. Also, we characterize the associated primes and the unmixed property of I. Furthermore, we give a combinatorial…

Commutative Algebra · Mathematics 2020-12-08 Yuriko Pitones , Enrique Reyes , Jonathan Toledo

For a finite simple graph $G$ we give an upper bound for the regularity of the powers of the edge ideal $I(G)$.

Commutative Algebra · Mathematics 2018-10-16 Jürgen Herzog , Takayuki Hibi

Let $G$ be a bipartite graph and $I=I(G)$ be its edge ideal. The aim of this note is to investigate different aspects of the Rees algebra $\mathcal{R}(I)$ of $I$. We compute its regularity and the universal Gr\"obner basis of its defining…

Commutative Algebra · Mathematics 2018-05-10 Yairon Cid-Ruiz

We find a class of block graphs whose binomial edge ideals have minimal regularity. As a consequence, we characterize the trees whose binomial edge ideals have minimal regularity. Also, we show that the binomial edge ideal of a block graph…

Commutative Algebra · Mathematics 2014-02-11 Faryal Chaudhry , Ahmet Dokuyucu , Rida Irfan

We prove an extension of the Regularity Lemma with vertex and edge weights which can be applied for a large class of graphs. The applications involve random graphs and a weighted version of the Erd\H{o}s-Stone theorem. We also provide means…

Combinatorics · Mathematics 2011-02-15 Béla Csaba , András Pluhár