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Related papers: Binomial Edge Ideals of Generalized block graphs

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Let $G$ be a finite simple graph on the vertex set $[n] = \{ 1, \ldots, n \}$ and $K[X, Y] = K[x_1, \ldots, x_n, y_1, \ldots, y_n]$ the polynomial ring in $2n$ variables over a field $K$ with each $\mathrm{deg} x_i = \mathrm{deg} y_j = 1$.…

Commutative Algebra · Mathematics 2020-08-27 Takayuki Hibi , Kazunori Matsuda

Write ${\cal I}(G)$ for the set of independent sets of a graph $G$ and $i(G)$ for $|{\cal I}(G)|$. It has been conjectured (by Alon and Kahn) that for an $N$-vertex, $d$-regular graph $G$, $$ i(G) \leq \left(2^{d+1}-1\right)^{N/2d}. $$ If…

Combinatorics · Mathematics 2010-07-29 David Galvin

We prove the regularity conjecture, namely Eisenbud-Goto conjecture, for a normal surface with rational, Gorenstein elliptic and log canonical singularities. Along the way, we bound the regularity for a dimension zero scheme by its Loewy…

Algebraic Geometry · Mathematics 2015-08-11 Wenbo Niu

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

We prove that, for the edge ideal of a graph whose cycles are pairwise vertex-disjoint, the arithmetical rank is bounded above by the sum of the number of cycles and the maximum height of its associated primes.

Commutative Algebra · Mathematics 2015-11-24 Margherita Barile , Antonio Macchia

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

We study some algebraic invariants of $t$-spread ideals, $t\ge 1$, such as the projective dimension and the Castelnuovo-Mumford regularity, by means of well-known graded resolutions. We state upper bounds for these invariants and,…

Commutative Algebra · Mathematics 2024-03-28 Luca Amata , Marilena Crupi , Antonino Ficarra

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

The regular graph of ideals of the commutative ring $R$, denoted by $\Gamma_{reg}(R)$, is a graph whose vertex set is the set of all non-trivial ideals of $R$ and two distinct vertices $I$ and $J$ are adjacent if and only if either $I$…

Combinatorics · Mathematics 2015-01-05 Farzad Shaveisi

Let $I(G)$ be a topological index of a graph. If $I(G+e)<I(G)$ (or $I(G+e)>I(G)$, respectively) for each edge $e\not\in G$, then $I(G)$ is monotonically decreasing (or increasing, respectively) with the addition of edges. In this article,…

Combinatorics · Mathematics 2017-04-19 Hanlin Chen , Renfang Wu , Hanyuan Deng

The random intersection graph model $\mathcal G(n,m,p)$ is considered. Due to substantial edge dependencies, studying even fundamental statistics such as the subgraph count is significantly more challenging than in the classical binomial…

Combinatorics · Mathematics 2025-04-01 Katarzyna Rybarczyk , Grzegorz Serafin

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 identify several classes of monomial ideals that possess minimal generalized Barile-Macchia resolutions. These classes of ideals include generic monomial ideals, monomial ideals with linear quotients, and edge ideals of hypertrees. We…

Commutative Algebra · Mathematics 2026-05-11 Trung Chau , Huy Tai Ha , Aryaman Maithani

We study the depth of classes of binomial edge ideals and classify all closed graphs whose binomial edge ideal is Cohen--Macaulay.

Commutative Algebra · Mathematics 2011-07-08 Viviana Ene , Juergen Herzog , Takayuki Hibi

We present new combinatorial insights into the calculation of (Castelnuovo-Mumford) regularity of graphs.

Combinatorics · Mathematics 2015-03-23 Turker Biyikoglu , Yusuf Civan

We compute the multigraded Betti numbers of edge ideals for weighted oriented crown graphs using a novel approach. This approach, which we still call the \emph{induced subgraph approach}, originates from our prior work on computing Betti…

Commutative Algebra · Mathematics 2025-05-13 Zexin Wang , Dancheng Lu

We give lower bounds on the size and total size of clique partitions of a graph in terms of its spectral radius and minimum degree, and derive a spectral upper bound for the maximum number of edge-disjoint $t$-cliques. The extremal graphs…

Combinatorics · Mathematics 2021-11-05 Jiang Zhou , Edwin R. van Dam

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

In this paper, we compare the $\mathrm{v}$-numbers and the degree of the $h$-polynomials associated with edge ideals of connected graphs. We prove that the $\mathrm{v}$-number can be arbitrarily larger or smaller than the degree of the…

Commutative Algebra · Mathematics 2025-07-21 Kamalesh Saha , Adam Van Tuyl

This paper exhibits some new examples of the behavior of the Castelnuovo-Mumford regularity of homogeneous ideals in polynomial rings. More precisely, we present new examples of homogenous ideals with large regularity compared to the…

Commutative Algebra · Mathematics 2015-08-18 Keivan Borna , Abolfazl Mohajer
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