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Related papers: Nearly Gorenstein rings arising from finite graphs

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Let $J_G$ be the binomial edge ideal of a graph $G$. We characterize all graphs whose binomial edge ideals, as well as their initial ideals, have regularity $3$. Consequently we characterize all graphs $G$ such that $J_G$ is extremal…

Commutative Algebra · Mathematics 2017-06-29 Sara Saeedi Madani , Dariush Kiani

One of the main results of this paper is the characterization of the rings over which all modules are strongly Gorenstein projective. We show that these kinds of rings are very particular cases of the well-known quasi-Frobenius rings. We…

Commutative Algebra · Mathematics 2008-04-13 D. Bennis , N. Mahdou , K. Ouarghi

The non-Gorenstein locus of stable set rings of finite simple perfect graphs is studied. We describe combinatorially those perfect graphs whose stable set rings are Gorenstein on the punctured spectrum. In addition, we show that, in…

Commutative Algebra · Mathematics 2021-11-30 Takayuki Hibi , Dumitru I. Stamate

We extend the notion of type sequence to rings that are not necessarily residually rational. Using this invariant we characterize different types of rings as almost Gorenstein rings and rings of maximal length.

Commutative Algebra · Mathematics 2016-08-14 Valentina Barucci , Ioana Cristina Şerban

In this paper, we give a criterion of the Gorenstein property of the Ehrhart ring of the stable set polytope of an h-perfect graph: the Ehrhart ring of the stable set polytope of an h-perfect graph $G$ is Gorenstein if and only if (1) sizes…

Combinatorics · Mathematics 2020-08-18 Mitsuhiro Miyazaki

A $k$-regular graph of girth $g$ is called edge-girth-regular graph, shortly egr-graph, if each of its edges is contained in exactly $\lambda$ distinct $g-$cycles. An egr-graph is called extremal for the triple $(k, g, \lambda)$ if has the…

Combinatorics · Mathematics 2024-01-30 Gabriela Araujo-Pardo , György Kiss , István Porupsánszki

We classify the finite connected simple graphs whose edge rings are strongly Koszul. From the classification, it follows that if the edge ring is strongly Koszul, then its toric ideal possesses a quadratic Gr\"obner basis.

Commutative Algebra · Mathematics 2016-02-02 Takayuki Hibi , Kazunori Matsuda , Hidefumi Ohsugi

Let $A$ be an excellent two-dimensional normal local ring containing an algebraically closed field. Then $A$ is called an elliptic singularity if $p_f(A)=1$, where $p_f$ denotes the fundamental genus. On the other hand, the concept of…

Commutative Algebra · Mathematics 2024-11-01 Tomohiro Okuma , Kei-ichi Watanabe , Ken-ichi Yoshida

Semi-standard graded rings are a generalized notion of standard graded rings. In this paper, we compare generalized notions of the Gorenstein property in semi-standard graded rings. We discuss the commonalities between standard graded rings…

Commutative Algebra · Mathematics 2023-10-06 Sora Miyashita

Due to their elegant and simple nature, unitary Cayley graphs have been an active research topic in the literature. These graphs are naturally connected to several branches of mathematics, including number theory, finite algebra,…

Combinatorics · Mathematics 2024-09-04 Ján Mináč , Tung T. Nguyen , Nguyen Duy Tân

This paper considers graded near-rings over a monoid G as a generalizations of the graded rings over groups, introduce certain innovative graded weakly prime ideals and graded almost prime ideals as a generalizations of graded prime ideals…

General Mathematics · Mathematics 2022-04-26 Malik Bataineh , Tamem Al-shorman , Eman Al-Kilany

A near-factor of a finite simple graph $G$ is a matching that saturates all vertices except one. A graph $G$ is said to be near-factor-critical if the deletion of any vertex from $G$ results in a subgraph that has a near-factor. We prove…

Combinatorics · Mathematics 2014-05-19 Kuo-Ching Huang , Ko-Wei Lih

Let $(R,\mathfrak{m})$ be a two-dimensional regular local ring with infinite residue class field. Then the Rees algebra $\mathcal{R} (I)= \bigoplus_{n \ge 0}I^n$ of $I$ is an almost Gorenstein graded ring in the sense of…

Commutative Algebra · Mathematics 2015-06-23 Shiro Goto , Naoyuki Matsuoka , Naoki Taniguchi , Ken-ichi Yoshida

A countable, bounded degree graph is almost finite if it has a tiling with isomorphic copies of finitely many F\o lner sets, and we call it strongly almost finite, if the tiling can be randomized so that the probability that a vertex is on…

Group Theory · Mathematics 2025-09-22 Gábor Elek , Ádám Timár

We investigate the nearly Gorenstein property among $d$-dimensional cyclic quotient singularities $\Bbbk[[x_1,\dots,x_d]]^G$, where $\Bbbk$ is an algebraically closed field and $G\subseteq{\rm GL}(d,\Bbbk)$ is a finite small cyclic group…

Commutative Algebra · Mathematics 2020-07-22 Alessio Caminata , Francesco Strazzanti

We study the graphs formed from instances of the stable matching problem by connecting pairs of elements with an edge when there exists a stable matching in which they are matched. Our results include the NP-completeness of recognizing…

Discrete Mathematics · Computer Science 2020-10-20 David Eppstein

Several polytopes arise from finite graphs. For edge and symmetric edge polytopes, in particular, exhaustive computation of the Ehrhart polynomials not merely supports the conjecture of Beck {\it et al.}\ that all roots $\alpha$ of Ehrhart…

Combinatorics · Mathematics 2015-03-13 Tetsushi Matsui , Akihiro Higashitani , Yuuki Nagazawa , Hidefumi Ohsugi , Takayuki Hibi

This article provides structural characterization of simple graphs whose edge-set can be partitioned into maximum matchings. We use Vizing's classification of simple graphs based on edge chromatic index.

Combinatorics · Mathematics 2012-10-19 Niraj Khare

We characterize the Gorensteinness of endomorphism rings of a fractional ideal on a curve singularity by stability of the ideal and a condition on its value semigroup ideal. Moreover, the Gorenstein algebroid curves with only Gorenstein…

Commutative Algebra · Mathematics 2023-04-26 Philipp Korell

In this paper, we prove that if Cohen-Macaulay local/graded rings $R_1$, $R_2$ and $R$ satisfy certain conditions regarding multiplicity and Cohen-Macaulay type, then almost Gorenstein property of $R$ implies Gorenstein properties for all…

Commutative Algebra · Mathematics 2023-12-29 Koji Matsushita , Sora Miyashita