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Related papers: Some algebraic properties of hypergraphs

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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

We describe all the trees with the property that the corresponding edge ideal of their line graph has a linear resolution. As a consequence, we give a complete characterization of those trees $T$ for which the line graph $L(T)$ is…

Commutative Algebra · Mathematics 2021-08-09 Anda Olteanu

We compute one of the distinguished extremal Betti number of the binomial edge ideal of a block graph, and classify all block graphs admitting precisely one extremal Betti number.

Commutative Algebra · Mathematics 2018-02-19 Juergen Herzog , Giancarlo Rinaldo

In this paper, we obtain a combinatorial formula for computing the Betti numbers in the linear strand of edge ideals of bipartite Kneser graphs. We deduce lower and upper bounds for regularity of powers of edge ideals of these graphs in…

Commutative Algebra · Mathematics 2021-05-14 Ajay Kumar , Pavinder Singh , Rohit Verma

We say that a $k$-uniform hypergraph $C$ is a Hamilton cycle of type $\ell$, for some $1\le \ell \le k$, if there exists a cyclic ordering of the vertices of $C$ such that every edge consists of $k$ consecutive vertices and for every pair…

Combinatorics · Mathematics 2011-02-09 Deepak Bal , Alan Frieze

We show that for an infinitely many natural numbers $k$ there are $k$-uniform hypergraphs which admit a `rescaling phenomenon' as described in [9]. More precisely, let $\mathcal{A}(k,I, n)$ denote the class of $k$-graphs on $n$ vertices in…

Combinatorics · Mathematics 2018-07-09 Tomasz Łuczak , Joanna Polcyn , Christian Reiher

Let I(G) be the edge ideal associated to a simple graph G. We study the graded Betti numbers that appear in the linear strand of the minimal free resolution of I(G).

Commutative Algebra · Mathematics 2007-05-23 Mike Roth , Adam Van Tuyl

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

We introduce a persistent commutative algebra for studying the algebraic and combinatorial evolution of edge ideals of graphs and hypergraphs under filtration. Building on the Persistent Stanley--Reisner Theory (PSRT), we develop the notion…

Commutative Algebra · Mathematics 2025-12-22 Faisal Suwayyid , Guo-Wei Wei

We associate a sequence of positive integers, termed the type sequence, with a cochordal graph. Using this type sequence, we compute all graded Betti numbers of its edge ideal. We then classify all positive integer $n$ such that the zero…

Commutative Algebra · Mathematics 2024-11-13 Le Xuan Dung , Thanh Vu

We study properties of random subcomplexes of partitions returned by (a suitable form of) the Strong Hypergraph Regularity Lemma, which we call regular slices. We argue that these subcomplexes capture many important structural properties of…

Combinatorics · Mathematics 2014-11-19 Peter Allen , Julia Böttcher , Oliver Cooley , Richard Mycroft

Let $G$ be a graph with the usual shortest-path metric. A graph is $\delta$-hyperbolic if for every geodesic triangle $T$, any side of $T$ is contained in a $\delta$-neighborhood of the union of the other two sides. A graph is chordal if…

Combinatorics · Mathematics 2015-05-22 A. Martínez-Pérez

In this paper, we introduce and generalize some combinatorial invariants of graphs such as matching number and induced matching number to hypergraphs. Then we compare them together and present some upper bounds for the regularity of…

Commutative Algebra · Mathematics 2025-06-10 Fahimeh Khosh-Ahang , Somayeh Moradi

We introduce and study the concept which we call the splitting of a graph and compare algebraic properties of the edge ideals of graphs and those of their splitting graphs.

Commutative Algebra · Mathematics 2019-08-27 Jürgen Herzog , Somayeh Moradi , Masoomeh Rahimbeigi

Fix an integer $n \geq 1$, and consider the set of all connected finite simple graphs on $n$ vertices. For each $G$ in this set, let $I(G)$ denote the edge ideal of $G$ in the polynomial ring $R = K[x_1,\ldots,x_n]$. We initiate a study of…

Combinatorics · Mathematics 2020-03-18 Takayuki Hibi , Kyouko Kimura , Kazunori Matsuda , Adam Van Tuyl

This paper deals with three graph characteristics related to graph covering named the (vertex, edge, and total, resp.) H-irregularity strength of a graph G admitting H-covering. Those are the minimum values of positive integer k such that G…

Combinatorics · Mathematics 2021-10-22 Meilin Imelda Tilukay

In the present note we study Waldschmidt constants of Stanley-Reisner ideals of a hypergraph and a graph with vertices forming a bipyramid over a planar n-gon. The case of the hypergraph has been studied by Bocci and Franci. We reprove…

Algebraic Geometry · Mathematics 2017-04-21 Tomasz Szemberg , Justyna Szpond

We give an upper bound for the Stanley depth of the edge ideal $I$ of a $k$-partite complete graph and show that Stanley's conjecture holds for $I$. Also we give an upper bound for the Stanley depth of the edge ideal of a $k$-uniform…

Commutative Algebra · Mathematics 2011-04-07 Muhammad Ishaq , Muhammad Imran Qureshi

In this paper firstly, we generalize the concept of codismantlable graphs to hypergraphs and show that some special vertex decomposable hypergraphs are codismantlable. Then we generalize the concept of bouquet in graphs to hypergraphs to…

Commutative Algebra · Mathematics 2016-01-05 Fahimeh Khosh-Ahang , Somayeh Moradi

Associated to a simple undirected graph G is a simplicial complex whose faces correspond to the independent sets of G. We call a graph G shellable if this simplicial complex is a shellable simplicial complex in the non-pure sense of…

Combinatorics · Mathematics 2007-11-06 Adam Van Tuyl , Rafael H. Villarreal