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Related papers: Nearly Gorenstein rings arising from finite graphs

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A partial complement of the graph $G$ is a graph obtained from $G$ by complementing all the edges in one of its induced subgraphs. We study the following algorithmic question: for a given graph $G$ and graph class $\mathcal{G}$, is there a…

Computational Complexity · Computer Science 2020-06-11 Fedor V. Fomin , Petr A. Golovach , Torstein J. F. Strømme , Dimitrios M. Thilikos

For each infinite word over a given finite alphabet, we define an increasing sequence of rooted finite graphs, that can be thought as approximations of the famous Sierpinski carpet. These sequences naturally converge to an infinite rooted…

Combinatorics · Mathematics 2018-02-28 Daniele D'Angeli , Alfredo Donno

A classification is given for factorizations of almost simple groups with at least one factor solvable, and it is then applied to characterize $s$-arc-transitive Cayley graphs of solvable groups, leading to a striking corollary: Except the…

Group Theory · Mathematics 2016-02-29 Cai Heng Li , Binzhou Xia

A dominating set in a graph $G$ is a set $S$ of vertices such that every vertex of $G$ is either in $S$ or is adjacent to a vertex in $S$. Nordhaus-Gaddum inequailties relate a graph $G$ to its complement $\bar{G}$. In this spirit Wagner…

Combinatorics · Mathematics 2019-10-30 Lauren Keough , David Shane

The question of when the Rees algebra ${\mathcal R} (I)= \bigoplus_{n \ge 0}I^n$ of $I$ is an almost Gorenstein graded ring is explored, where $R$ is a two-dimensional regular local ring and $I$ a contracted ideal of $R$. It is known that…

Commutative Algebra · Mathematics 2019-12-19 Shiro Goto , Naoyuki Matsuoka , Naoki Taniguchi , Ken-ichi Yoshida

T.C. Burness and S.D. Scott \cite{3} classified finite groups $G$ such that the number of prime order subgroups of $G$ is greater than $|G|/2-1$. In this note, we study finite groups $G$ whose subgroup graph contains a vertex of degree…

Group Theory · Mathematics 2025-02-05 Marius Tărnăuceanu

A totally silver coloring of a graph G is a k--coloring of G such that for every vertex v \in V(G), each color appears exactly once on N[v], the closed neighborhood of v. A totally silver graph is a graph which admits a totally silver…

Combinatorics · Mathematics 2013-02-14 M. Ghebleh , E. S. Mahmoodian

In this paper we study generalized Gorenstein Arf rings; a class of one-dimensional Cohen-Macaulay local Arf rings that is strictly contained in the class of Gorenstein rings. We obtain new characterizations and examples of Arf rings, and…

Commutative Algebra · Mathematics 2020-08-11 Ela Celikbas , Olgur Celikbas , Shiro Goto , Naoki Taniguchi

We classify the far-flung Gorenstein numerical semigroup rings of type 4.

Commutative Algebra · Mathematics 2025-12-23 Teodor I. Grigorescu

It is known that complete graphs and complete multipartite graphs have modularity zero. We show that the least number of edges we may delete from the complete graph $K_n$ to obtain a graph with non-zero modularity is $\lfloor n/2\rfloor…

Combinatorics · Mathematics 2023-12-21 Colin McDiarmid , Fiona Skerman

Relations between Gorenstein derived categories, Gorenstein defect categories and Gorenstein stable categories are established. Using these, the Gorensteinness of an algebra $A$ and invariants with respect to recollements of the bounded…

Representation Theory · Mathematics 2014-02-14 Nan Gao

We prove that two-sided tilting complexes, and dualizing complexes, over simple Goldie rings (with some technical conditions) are always shifts of invertible bimodules. This allows us to describe the derived Picard groups of such rings, and…

Rings and Algebras · Mathematics 2007-05-23 Amnon Yekutieli , James J. Zhang

In this paper we study prime graphs of finite groups. The prime graph of a finite group $G$, also known as the Gruenberg-Kegel graph, is the graph with vertex set {primes dividing $|G|$} and an edge $p$-$q$ if and only if there exists an…

Group Theory · Mathematics 2022-01-04 Chris Florez , Jonathan Higgins , Kyle Huang , Thomas Michael Keller , Dawei Shen , Yong Yang

We study how many comparability subgraphs are needed to partition the edge set of a perfect graph. We show that many classes of perfect graphs can be partitioned into (at most) two comparability subgraphs and this holds for almost all…

Combinatorics · Mathematics 2026-03-10 András Gyárfás , Márton Marits , Géza Tóth

We study the class of 1-perfectly orientable graphs, that is, graphs having an orientation in which every out-neighborhood induces a tournament. 1-perfectly orientable graphs form a common generalization of chordal graphs and circular arc…

Combinatorics · Mathematics 2016-03-08 Tatiana Romina Hartinger , Martin Milanič

Recently, nearly complete intersection ideals were defined by Boocher and Seiner to establish lower bounds on Betti numbers for monomial ideals (arXiv:1706.09866). Stone and Miller then characterized nearly complete intersections using the…

Commutative Algebra · Mathematics 2024-10-15 Chiara Bondi , Courtney R. Gibbons , Yuye Ke , Spencer Martin , Shrunal Pothagoni , Andrew Stelzer

Motivated by pseudo-Gorenstein rings in commutative algebra, introduced by Herzog et al., we define pseudo-Gorenstein$^{*}$ graphs and classify them in several natural graph families using independence polynomials.

Commutative Algebra · Mathematics 2026-03-10 Takayuki Hibi , Selvi Kara , Dalena Vien

As part of stratification of Cohen-Macaulay rings, we introduce and develop the theory of Goto rings, generalizing the notion of almost Gorenstein rings originally defined by V. Barucci and R. Fr\"oberg in 1997. What has dominated the…

Commutative Algebra · Mathematics 2023-12-25 Naoki Endo

Let $\alpha=\alpha(G)$ be the independence number of a simple graph $G$ with $n$ vertices and $I(G)$ be its edge ideal in $S=K[x_1,\ldots, x_n]$. If $S/I(G)$ is Gorenstein, the graph $G$ is called Gorenstein over $K$ and if $G$ is…

Combinatorics · Mathematics 2020-12-10 Mohammad Reza Oboudi , Ashkan Nikseresht

The nearly complete bipartite graph $G(m,n,k)$ is obtained by removing $k$ independent edges from the complete bipartite graph $K_{m,n}$. In this paper, we prove that for any nearly complete bipartite graph $G(m,n,k)$ with $m, n\geq 3$, and…

Combinatorics · Mathematics 2026-01-13 Shengxiang Lv