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Related papers: Koszul Binomial Edge Ideals

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We show that the minimal resolution of the quotient of the polynomial algebra over a field by a cointerval edge ideal can be given the structure of a DG-algebra.

Commutative Algebra · Mathematics 2016-09-26 Emil Sköldberg

We show that attaching a whisker (or a pendant) at the vertices of a cycle cover of a graph results in a new graph with the following property: all symbolic powers of its cover ideal are Koszul or, equivalently, componentwise linear. This…

Commutative Algebra · Mathematics 2021-09-08 Yan Gu , Huy Tài Hà , Joseph W. Skelton

We consider the edge ideals of large classes of graphs with whiskers and for these ideals we prove that the arithmetical rank is equal to the big height. Then we extend these results to other classes of squarefree monomial ideals, generated…

Commutative Algebra · Mathematics 2013-07-08 Antonio Macchia

Fr\"oberg's classical theorem about edge ideals with $2$-linear resolution can be regarded as a classification of graphs whose edge ideals have linearity defect zero. Extending his theorem, we classify all graphs whose edge ideals have…

Commutative Algebra · Mathematics 2016-01-19 Hop D. Nguyen , Thanh Vu

Let $G$ be a simple graph on $n$ vertices. Let $L_G \text{ and } \mathcal{I}_G \: $ denote the Lov\'asz-Saks-Schrijver(LSS) ideal and parity binomial edge ideal of $G$ in the polynomial ring $S = \mathbb{K}[x_1,\ldots, x_n, y_1, \ldots,…

Commutative Algebra · Mathematics 2021-12-07 Arvind Kumar

Edge ideals of finite simple graphs $G$ on $n$ vertices are the ideals $I(G)$ of the polynomial ring $S$ in $n$ variables generated by the quadratic monomials associated with the edges of $G$. In this paper, we consider the possible pairs…

Commutative Algebra · Mathematics 2023-01-18 Akihiro Higashitani , Akane Kanno , Ryota Ueji

The v-number of a graded ideal is an invariant recently introduced in the context of coding theory, particularly in the study of Reed--Muller-type codes. In this work, we study the localized v-numbers of a binomial edge ideal $J_G$…

Commutative Algebra · Mathematics 2025-07-04 Emiliano Liwski

In a directed graph, a kernel is a subset of vertices that is both stable and absorbing. Not all digraphs have a kernel, but a theorem due to Boros and Gurvich guarantees the existence of a kernel in every clique-acyclic orientation of a…

Discrete Mathematics · Computer Science 2018-01-09 Adèle Pass-Lanneau , Ayumi Igarashi , Frédéric Meunier

We use the correspondence between hypergraphs and their associated edge ideals to study the minimal graded free resolution of squarefree monomial ideals. The theme of this paper is to understand how the combinatorial structure of a…

Commutative Algebra · Mathematics 2007-06-13 Huy Tai Ha , Adam Van Tuyl

For a set of graphs $\mathcal{H}$, the \textsc{$\mathcal{H}$-free Edge Deletion} problem asks to find whether there exist at most $k$ edges in the input graph whose deletion results in a graph without any induced copy of $H\in\mathcal{H}$.…

Data Structures and Algorithms · Computer Science 2014-11-19 N. R. Aravind , R. B. Sandeep , Naveen Sivadasan

Let $I$ be an ideal generated by quadrics in a standard graded polynomial ring $S$ over a field. A question of Avramov, Conca, and Iyengar asks whether the Betti numbers of $R = S/I$ over $S$ can be bounded above by binomial coefficients on…

Commutative Algebra · Mathematics 2020-06-09 Paolo Mantero , Matthew Mastroeni

We prove a theorem unifying three results from combinatorial homological and commutative algebra, characterizing the Koszul property for incidence algebras of posets and affine semigroup rings, and characterizing linear resolutions of…

Commutative Algebra · Mathematics 2016-06-22 Victor Reiner , Dumitru I. Stamate

We study absolutely Koszul algebras, Koszul algebras with the Backelin-Roos property and their behavior under standard algebraic operations. In particular, we identify some Veronese subrings of polynomial rings that have the Backelin-Roos…

Commutative Algebra · Mathematics 2014-12-01 Aldo Conca , Srikanth B. Iyengar , Hop D. Nguyen , Tim Römer

Let $G$ be a finite connected simple graph, and let $\mathcal{J}_{K_m,G}$ denote its generalized binomial edge ideal. By investigating the colon ideals of $\mathcal{J}_{K_m,G}$, we derive a formula for the local $\mathrm{v}$-number of…

Commutative Algebra · Mathematics 2026-04-08 Yi-Huang Shen , Guangjun Zhu

In this article we prove that every toric ideal associated with a gap-free graph $G$ has a squarefree lexicographic initial ideal. Moreover, in the particular case when the complementary graph of $G$ is chordal (i.e. when the edge ideal of…

Commutative Algebra · Mathematics 2020-06-17 Alessio D'Alì

The independence gap of a graph was introduced by Ekim et al. (2018) as a measure of how far a graph is from being well-covered. It is defined as the difference between the maximum and minimum size of a maximal independent set. We…

Combinatorics · Mathematics 2018-12-14 Tınaz Ekim , Didem Gözüpek , Ademir Hujdurović , Martin Milanič

In this article, we compute the regularity of Rees algebra of binomial edge ideals of closed graphs. We obtain a lower bound for the regularity of Rees algebra of binomial edge ideals. We also study some algebraic properties of the Rees…

Commutative Algebra · Mathematics 2021-12-07 Arvind Kumar

We consider homogeneous binomial ideals $I=(f_1,\ldots,f_n)$ in $K[x_1, \ldots, x_n]$, where $f_i = a_i x_i^{d_i} - b_i m_i$ and $a_i \neq 0$. When such an ideal is a complete intersection, we show that the monomials which are not divisible…

Commutative Algebra · Mathematics 2024-08-09 Filip Jonsson Kling , Samuel Lundqvist , Lisa Nicklasson

We construct a Koszul complex in the category of left skew polynomial rings associated to a flat endomorphism that provides a finite free resolution of an ideal generated by a Koszul regular sequence.

Commutative Algebra · Mathematics 2017-12-22 Josep Àlvarez Montaner , Alberto F. Boix , Santiago Zarzuela

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